Dissertations / Theses on the topic 'Vocalisations'

A vocalisation may be described as a historical linguistic change where a sound which is formerly consonantal within a language becomes pronounced as a vowel. Although vocalisations have occurred sporadically in many languages they are particularly prevalent in the history of Germanic languages and have affected sounds from all places of articulation. This study will address two main questions. The first is why vocalisations happen so regularly in Germanic languages in comparison with other language families. The second is what exactly happens in the vocalisation process. For the first question there will be a discussion of the concept of ‘drift’ where related languages undergo similar changes independently and this will therefore describe the features of the earliest Germanic languages which have been the basis for later changes. The second question will include a comprehensive presentation of vocalisations which have occurred in Germanic languages with a description of underlying features in each of the sounds which have vocalised. When considering phonological changes a degree of phonetic information must necessarily be included which may be irrelevant synchronically, but forms the basis of the change diachronically. A phonological representation of vocalisations must therefore address how best to display the phonological information whilst allowing for the inclusion of relevant diachronic phonetic information. Vocalisations involve a small articulatory change, but using a model which describes vowels and consonants with separate terminology would conceal the subtleness of change in a vocalisation. The model presented here has therefore been designed to unite the descriptions of consonants and vowels to better demonstrate this change whilst allowing for relevant phonetic information to be included.

Though human nonverbal vocalisations are widespread, scientific consideration of their mechanisms and communicative functions has been largely overlooked. This is despite their close alignment with the vocal communicative systems of primates and other mammals, whose primary function is to signal indexical information relevant to sexual and natural selection processes. In this thesis, I examine human nonverbal vocalisations from an evolutionary perspective, with the central hypothesis that they are functionally and structurally homologous to nonhuman mammal calls, communicating evolutionarily relevant indexical information that is perceived and utilised by listeners. In Chapter 1, I introduce the methodological framework (source-filter theory) necessary to understand the production of vocal signals in mammals, before summarising the information contained within the acoustic structure of nonhuman mammals and human speech, and the effects these cues have on both vocaliser and listener. I then examine the current evidence for functional and structural homology between human and nonhuman nonverbal vocalisations. In Chapters 2 to 5, I quantitatively analyse the acoustic structure of a number of nonverbal vocalisations, and perform playback experiments to examine their functional effects on listeners. In Chapters 2 and 3, I investigate whether aggressive roars and distress screams communicate acoustic cues to absolute and relative strength and height. In Chapter 4, I analyse the acoustic structure of pain cries of varying intensity, and conduct playback experiments to explore the acoustic and perceptual correlates of pain. In Chapter 5, I examine whether the fundamental frequency of tennis grunts produced during professional tennis matches is dependent on the sex and body posture of the vocaliser, as well as the progress and outcome of the contest, and whether listeners can infer these cues. In Chapter 6, I tie these findings together, arguing that the acoustic structure of human nonverbal vocalisations, in continuity with nonhuman mammal vocalisations, has been selected to support the functional communication of indexical and motivational information.

Infant vocalisations are uniquely salient sounds in the environment. They universally attract attention and compel the listener to respond with speed and care. They provide a wealth of information to parents about their infant’s needs and affective state. There is a scientific consensus that early parenting has a profound impact on child development. In particular, the sensitivity with which parents respond to their infant’s communicative cues has been shown to affect cognitive and socio-emotional outcomes. The mechanisms underlying such sensitivity are not well understood. In this thesis, adults’ sensitivity to infant cues will be considered in terms of two components, the ‘promptness’ and ‘appropriateness’ of responses, as originally conceptualised by Bell and Ainsworth (1972). Promptness of responses is considered in terms of adults’ ability to move with speed and effort after listening to infant vocalisations. Appropriateness, on the other hand, is considered in terms of adults’ ability to differentiate between functionally significant parameters in infant vocalisations. The effect of modifiable environmental factors on the promptness and appropriateness of responses is also investigated. Finally, a focused investigation of the brain basis of responses to infant vocalisations is presented. Overall, findings demonstrated that infant vocalisations undergo privileged, specialised processing in the adult brain. After hearing an infant cry, adults with and without depression were found to move with greater coordination and effort. Adults were also found to be attuned to subtle parameters in infant cries. This sensitivity was shown to be affected by two participant-level factors, depression and previous musical training. Furthermore, this sensitivity could be enhanced through intervention, as evidenced by findings from short-term, perceptual discrimination training. The notion of privileged processing of infant vocalisations is further supported by evidence of early discrimination of infant sounds in a survival-related subcortical brain structure. Future directions for this work include directly relating current experimental measures of adults’ responses to infant cues with parental sensitivity to infant communication during dynamic interactions. Translating current findings into applied settings would require an investigation of the effects of factors such as musical and perceptual training on sensitivity to infant cues in at-risk populations, such as mothers and fathers with depression. Lastly, an increased understanding of the brain basis of adults’ sensitivity to infant cues will provide insight into our greatest challenge: parenting our young.

Chez les espèces sociales, les vocalisations transmettent des informations qui participent au maintien et à la survie du groupe. Alors que de nombreuses études se sont intéressées aux informations stables portées par les vocalisations telles que l’identité, peu d’études se sont interrogées sur le rôle des signaux vocaux dans la transmission des informations plus labiles, telles que l’état émotionnel de l’émetteur. Le stress est un bon candidat pour l’étude de l’expression des émotions chez les animaux, puisqu’il est directement mesurable via un dosage de la concentration plasmatique en glucocorticoïdes. Le stress est connu pour modifier les paramètres acoustiques des vocalisations chez les mammifères, mais peu d’études ont traité ce processus chez les oiseaux, qui présentent pourtant des réseaux sociaux complexes. Le but de cette thèse est de déterminer de quelle manière les oiseaux expriment vocalement leur stress, et d’évaluer dans quelle mesure la corticostérone, hormone de stress principale chez l’oiseau, est impliquée dans le phénomène. Je me suis intéressée au Diamant mandarin (Taenopygia guttata), un oiseau chanteur australien au comportement grégaire qui forme des liens d’appariements à vie et prodigue des soins biparentaux à sa progéniture. En administrant de la corticostérone exogène à des oiseaux et en utilisant également des évènements sociaux stressants, nous montrons que les mâles adultes et les poussins expriment leur stress à travers l’émission de cris modifiés dans leur structure, ce qui suggère que la flexibilité des cris chez les oiseaux est plus importante que l’avaient montré des études précédentes. Par une analyse complète des paramètres temporels et spectraux des cris, nous montrons pour la première fois que le stress, par un effet direct de la corticostérone, déclenche l’émission de vocalisations présentant un spectre de fréquence déplacé vers les hautes fréquences. De plus, les receveurs du signal (respectivement les partenaires femelles et les parents) semblent capables de décoder l’information portée par ces cris de stress car ils modifient leur comportement en conséquence. Les processus physiques impliqués dans l’émission de cris modulés par le stress sont également discutés en appliquant la théorie « source-filtre » généralement utilisée chez les mammifères. Enfin, les valeurs adaptatives de ces cris sont également envisagées, en rapport avec le réseau social du Diamant mandarin et les risques de prédation encourus par l’émetteur du signal. Ce travail apporte de nouvelles preuves sur l’expression du stress chez les oiseaux, et propose une étude complète, des signaux physiologiques impliqués dans le stress aux modifications de comportement de l’émetteur, qui déclenchent une réponse adaptative des receveurs du signal
In social species, vocalisations convey information that participates in the maintenance and the survival of the group. While many studies were interested in stable information carried by vocal signals, like identity, fewer studies dealt with their potential role in informing about labile information such as the senders’ emotional state. Stress is a good candidate for the study of the expression of emotions in animals, as it is directly measurable by the plasma levels of glucocorticoïds. Stress is known to modify acoustic parameters of vocalisations in mammals, but few studies studied the process in birds, that also show complex social networks. The aim of this thesis is thus to determine how birds can vocally express their stress and to what extent corticosterone, the main stress hormone in birds, is implicated in this expression. I focused my research on the zebra finch (Taenopygia guttata), a gregarious Australian songbird that form lifelong pairbond and provides biparental care to its young. Using oral administration of exogenous corticosterone but also social stressful events, we show that both adult males and nestlings can express their stress through modulations of their calls’ structure, suggesting that flexibility in birds’ vocalisations is higher than previously expected. With a complete analysis of temporal and spectral parameters of calls, we show for the first time that stress evokes the emission of vocalisations with up-shifted frequency spectrum via a direct effect of corticosterone. Moreover, we show that females and parents are able to decode the information carried by stressed-induced calls of respectively their male partner and their young, as they exhibit modifications of behaviour in accordance with the context. The physical processes leading to the emission of stressed-induced vocalisations are discussed by applying the source-filter theory usually used in mammals. Adaptive values are also proposed, in regards with the zebra finch social network and predation risks for the caller. This work gives new evidences about the expression of stress in birds, and proposes a comprehensive study, from the physiological signals involved in stress to the resulting modifications of communication behaviour for the sender, that leads to an adaptive response from the receivers

Vocal communication underpins behavioural interactions in many species. Receivers often show flexible responses to the same or acoustically similar vocalisations, but the causes and adaptive significance of this flexibility remain poorly understood in comparison to variation in signaller behaviour. In this thesis, I explore flexibility in responses to anti-predator vocalisations depending on caller identity and context, using dwarf mongooses (Helogale parvula) as a model system. I demonstrate that foragers rely more on surveillance calls from dominant sentinels compared to subordinates; dominant individuals perform more sentinel duty and chose higher guard posts, thus may provide higher quality information (Chapter 2). I find little evidence that caller dominance status affects response to recruitment calls, but that individuals show a stronger mobbing response to recruitment calls of closely affiliated groupmates; anti-predator assistance may be a benefit of close 'friendships' (Chapter 3). In Chapter 4, I examine whether receivers balance personal and social information when deciding whether to respond to potentially false alarm calls. Individuals use alarm · calls when they provide information about risk which is novel compared to personal information, are more responsive to alarms from sentinels (whose elevated position enhances predator detection) than foragers, and are more likely to respond when supplementary fed, adjusting their responses to the relative likelihood of predation and starvation. In Chapter 5, I explore potential effects of anthropogenic noise on receiver behaviour. Traffic noise lessens the response of foragers to surveillance calls through a combination of partial acoustic masking and greater perceived risk, disrupting optimisation of the foraging-vigilance trade-off. Finally, I show the importance of having previous knowledge about signallers when assessing available social information quality; foragers treated surveillance calls from recent immigrants as less reliable than those from resident individuals, and thus dispersal may carry short-term information costs (Chapter 6).

The information encoded in cattle vocalisations remains underexplored. The objective of this thesis is to provide fundamental knowledge on the vocal behaviour of Holstein-Friesian cows exhibited during a variety of free-ranging and commercial dairy farming contexts. This thesis commenced with a literature review of previous cattle bioacoustics studies (Chapter 2) and highlighted the benefits of adopting the human-derived source-filter theory and arousal-valence dimensional framework for deciphering vocal information content. The experiment provided as Chapter 3 revealed that heifers have individually distinct voices, with different source and nonlinear parameters contributing to this distinctiveness. This work is also the first to show that heifer vocal individuality is maintained across putatively positive and negative farming contexts. Chapter 4 observed cow vocalisations during parturition and calf separation, uncovering context-related variation in the spectrographic vocal features and underlying phonatory gestures of the cows. Chapter 5 further showed that a disruption to cow and calf contact can lead to temporal modulations in the organisation of vocal, maternal and stress responses in cows. The vocal features observed in Chapters 4 and 5 varied depending on the signal receiver as well as distance over which communication occurred. These features also likely reflected emotional or motivational differences in the peri-partum cows. This thesis enhances our understanding of the static and dynamic information content of cattle vocalisations and demonstrates the feasibility of assessing certain vocal parameters in the commercial farming environment, where the soundscape is uncontrolled. It may also encourage farming practices to be shaped according to the vocal feedback of cows and highlights the opportunity to vocally assess cow welfare by visual and aural means.

The voice contains a wealth of information relevant for successful and meaningful social interactions. Aside from speech, the vocal signal also contains paralinguistic information such as the emotional state and identity of the speaker. The three empirical chapters reported in this thesis research the perceptual processing of paralinguistic vocal cues. The first set of studies uses unimodal adaptation to explore the mental representation of emotion in the voice. Using a series of different adaptor stimuli -human emotional vocalisations, emotive dog calls and affective instrumental bursts- it was found that aftereffects in human vocal emotion perception were largest following adaptation to human vocalisations. There was still an aftereffect present following adaptation to dog calls, however it was smaller in magnitude than that of the human vocalisation aftereffect and potentially as a result of the acoustic similarities between adaptor and test stimuli. Taken together, these studies suggest that the mental representation of emotion in the voice is not species specific but is specific to vocalisations as opposed to all affective auditory stimuli. The second empirical chapter examines the supramodal relationship between identity and emotion in face-voice adaptation. It was found that emotional faces have the ability to produce aftereffects in vocal emotion perception, irrespective of the identity of the adaptor and test stimuli being congruent. However, this effect was found to be dependent upon the adapting stimuli being dynamic as opposed to static in nature. The final experimental chapter looks at the mechanisms underlying the perception of vocal identity. A voice matching test was developed and standardised, finding large individual differences in voice matching ability. Furthermore, in an identity adaptation experiment, absolute difference in aftereffect size demonstrated a trend towards significance when correlated with voice matching ability, suggesting that there is a relationship between perceptual abilities and the degree of plasticity observed in response adaptation.

Dans la nature, les oiseaux développent très précocement une préférence marquée pour les membres de leur propre espèce. Cette préférence, qui se traduit par le rapprochement réciproque des individus, résulte du caractère attractif de certains stimulus visuels ou auditifs et la réponse d'approche, émise lors de la perception de ces stimulus, constitue un élément essentiel des interactions sociales. Le problème que nous avons voulu aborder ici est celui du développement de cette réponse d'approche et plus précisément de la relation entre celle-ci et le stimulus qui la déclenche. Dans ce travail, qui est donc destiné à analyser les mécanismes qui déterminent la valeur attractive des signaux émis lors des interactions sociales, nous nous attacherons plus particulièrement à l'étude des vocalisations. Cependant, dans la mesure où elles leur sont souvent associées, les stimulus émanant du partenaire seront également envisagés.

付記する学位プログラム名: 霊長類学・ワイルドライフサイエンス・リーディング大学院
Kyoto University (京都大学)
0048
新制・課程博士
博士(理学)
甲第22298号
理博第4612号
新制||理||1661(附属図書館)
京都大学大学院理学研究科生物科学専攻
(主査)教授 幸島 司郎, 教授 平田 聡, 教授 伊谷 原一
学位規則第4条第1項該当

This study constructed phylogenies for the Nectariniidae from up to 20 parameters derived from quantitative analyses of their vocalisations and used these to test hypotheses on whether or not the origin of sunbirds is African or Asian. In addition to standard sonographic measurements, this study is the first to use entropy values derived directly from sonograms as an objective way of separating calls from songs and simple songs from complex songs. The affinities of the genera of flowerpeckers were firmly established on vocal grounds and concurred with their traditional taxonomy. The vocal phylogeny failed to separate sunbirds from spiderhunters but showed that the Asian group of sunbirds emerged as the basal clade and therefore the most primitive clade of the sunbird lineage. This is in agreement with the phylogenetic outcome of recent DNA studies. It is therefore concluded that sunbirds may have originated on the Indian subcontinent, reached Indian Ocean islands including Madagascar and then penetrated into Africa, with the possibility that some oceanic island species were later derived from secondary invasions from Africa. The results further suggest that the clade of the Gulf of Guinea group of species may have arisen from a common ancestor from the African continent. The Indian Ocean island species also separated as a distinct group. Mean bill lengths and body sizes of different taxa were analysed in relation to the vocalisations. The results indicated significant relationships between bill length and body size and song complexity, with the latter higher in the more advanced genera.

Vocal production: Guinea pigs (GP) are gregarious animals with a well-characterised repertoire of 11 vocalisations. These are context dependent, communicating information about danger, identity and emotional state. Vocalisations have previously been produced by electrical stimulation of three areas in the GP brain: anterior cingulate, hypothalamus and periaqueductal grey. These vocalisations were reported as natural-sounding, but with little or no spectral analysis to support this assertion. I elicited calls from urethane-anaesthetised GP by stimulating all the above areas, and from the amygdala and several thalamic nuclei. The spectrotemporal properties of these vocalisations were analysed and eight distinct vocal patterns were identified. For comparison, recordings of spontaneous calls from the same colony (Grimsley et al., 2012) were analysed in the same way, then used to name the electrically elicited calls. For six call types the matches between electrically elicited and spontaneous calls were unambiguous. The remaining two elicited calls were identified as being slightly unnatural versions of one spontaneous call. Five calls were produced during the (1.6 s) electrical stimulation and three were produced after the stimulation, lasting up to 30 s. Concurrent bilateral stimulation of loci producing post-stimulus calls always had an additive effect, whereas stimulation of two loci giving during-stimulus calls was more complex. Auditory representation of vocalisations: To date, eight functional areas of GP auditory cortex have been identified using electrophysiology, and their responses to vocalisations has been investigated previously. I have discovered a new area, ventral to those currently described, which was named deep ventrorostral belt (dVRB). It is unresponsive to a broad range of puretone auditory stimuli, yet is highly selective to conspecific vocalisations. Single neuron recordings were taken from dVRB and the primary auditory region (AI) during the audio-vocal study. Audio-vocal interactions: The vocal production system communicates the expected sensory consequences of its action. This allows the auditory system to discriminate between self-produced and external sounds. These sensorimotor connections originate in premotor areas of the midbrain as well as motor planning areas of neo- and paleocortex. The basal amygdala (BA) – an emotion-mediating structure – yields vocalisations in GP when stimulated, and is involved in the affective prosody of human speech. It was hypothesised, therefore, that BA would also have an audio-vocal role. A protocol was developed to combine electrical stimulation in BA with auditory presentation of a range of GP vocalisations, whilst recording neural activity in AI and dVRB. In both cortical areas, single-neuron responses demonstrated a complex interaction of electrical and auditory stimuli; showing both enhanced or suppressed responses, depending on call type.

North American red squirrels are a solitary, territorial species that confront various predators. Previous research proposed that squirrels produce predator-specific, referential ‘seet’ and ‘bark’ alarm calls to aerial and ground predators, respectively. To test this hypothesis, I examined alarm call production during natural encounters with predators, conspecific intruders and in a series of predator simulation experiments. Call production patterns were consistent across all types of disturbance and involved protracted bouts where both call types were inter-mixed. Hence, the call types were not predator-specific but rather their patterning reflected the persistence of disturbances of any type. Tests of alternative call functions further indicated that calls were not actually directed at conspecifics, but rather at predators and intruders and might function to deter or repel them directly. These outcomes are consistent with life-history details of red squirrels and contradict the proposal that this species produces predator-specific, referential alarm calls.
xi, 153 leaves : ill. ; 29 cm

This thesis aims to determine the function of howl vocalisations performed by the black and gold howler monkey, Alouatta caraya, and to examine the connections between howling, welfare and breeding in captivity. Comparisons of the behaviours performed during natural howling bouts and during howling bouts in response to experimental playbacks provide evidence for a range of howl functions including regular advertisement of the caller’s occupancy and mate defence and attraction. Detailed analyses of howl call acoustics provide the first evidence of both individuality and context-specificity in the calls of A. caraya males. These findings further support the functions of intergroup spacing, mate defence and attraction and suggest that howling may act as an honest signal of male quality. Experimental playbacks of conspecific calls stimulated howling by captive male A. caraya and affected other behaviour patterns suggesting that playbacks are an effective form of environmental enrichment to enhance captive welfare. However, the efficacy of conspecific call playbacks as a form of enrichment were not reflected in the opinions of A. caraya keepers surveyed: responses to the use of this type of enrichment were unenthusiastic, and the routine use of auditory enrichment for captive primates was limited. Analysis of the European studbook found that individuals housed in a family group rather than a pair, and those which are regularly exposed to the calls of conspecific males had higher reproductive success. Also, males who performed higher rates of howling had higher reproductive success providing the first evidence of a link between howling and breeding rates. These findings contribute to the knowledge of howl vocalisations in Alouatta species and the influence of captivity on a highly vocal primate species. From thesis results it is recommended that captive A. caraya be housed in social groups containing more than one male and one female and that the playback of conspecific male howl calls be introduced into the husbandry of groups to provide a more naturalistic auditory environment.

Un défaut ou déficit d'attention conjointe est présent et souvent décrit dans l'autisme (e.g. Vivanti et al., 2017) qui correspond à un trouble précoce, global et sévère du développement (APA, 2013). L'objectif de cette thèse est d'étudier en quoi l'utilisation de différents indices comportementaux (regard, pointage, verbalisation, etc.) influence les capacités d'attention conjointe d'enfants présentant un trouble du spectre de l'autisme (TSA), et ce, selon la présence ou non du référent dans son champ visuel. Notre étude porte sur 50 enfants TSA d'âge préscolaire et scolaire qui sont appariés à deux groupes d'enfants typiques, soit sur leur âge chronologique soit sur leur âge de développement socio-communicatif. Nous avons étudié l'attention visuelle des enfants dans un contexte expérimental grâce à la technique d'eye-tracking (3 études) ainsi que dans une situation écologique où nous avons étudié la dynamique interactive entre l'enfant et l'adulte lors de la passation de l'ECSP (Guidetti & Tourette, 2009). Deux études ont ainsi pu être menées ; l'une compare les stratégies des enfants autistes et témoins, l'autre implique un suivi longitudinal d'enfants scolarisés en UEM. L'analyse des résultats a permis de mettre en évidence que le pointage (associé ou non à des verbalisations) permet aux enfants TSA de répondre à une proposition d'attention conjointe envers un référent présent ou absent de leur champ visuel alors que le regard seul n'est pas suffisamment saillant. De plus, nous avons pu montrer qu'une prise en charge précoce et intensive a un impact positif sur la dynamique interactive (augmentation des initiations, du maintien et des réponses à l'attention conjointe, des regards mutuels, de l'attention partagée, de l'utilisation du pointage et des vocalisations)
This thesis aims to study different kind of deictic bids used to refer to present or absent targets in the visual field of autism spectrum disorder (ASD) children. Joint attention is impaired (e.g. Vivanti et al., 2017) in this early, global and severe developmental disorder (APA, 2013). This research work is based, on one hand, on an experimental context and on the other hand, on an ecological situation. Fifty preschool and school children with ASD took part in the study. They were matched into two groups of typical children by chronological age and by socio-communicative developmental age. We studied visual attention impairments from 4 studies using eye-tracking. Moreover, we studied interaction between a child and an adult during ECSP (Guidetti & Tourette, 2009). The first study compares children with ASD to controls, the second compares the developmental evolution of children that were included in a special kindergarden school (UEM). The results'analysis highlight that ASD children need a combination of cues to follow someone's gaze. Pointing gesture (associated or not with verbalizations) allows them to respond to joint attention bids when the target is present or absent. Finally, we have shown that an early and intensive intervention has a positive impact on interaction (increased initiations, maintenance and responses to joint attention, mutual gaze, shared attention, use of pointing and vocalizations)

Recent studies have shown that there is a visual influence early in speech processing - visual speech enhances the ability to detect auditory speech in noise. However, identifying exactly how visual speech interacts with auditory processing at such an early stage has been challenging, because this so-called AV speech detection advantage is both highly related to a specific lower-order, signal-based, optic-acoustic relationship between the second formant amplitude and the area of the mouth (F2/Mouth-area), and mediated by higher-order, information-based factors. Previous investigations either have maximised or minimised information-based factors, or have minimised signal-based factors, in order to try to tease out the relative importance of these sources of the advantage, but they have not yet been successful in this endeavour. Maximising signal-based factors has not previously been explored. This avenue was explored in this thesis by manipulating speaking style, hyperarticulated speech was used to maximise signal-based factors, and hypoarticulated speech to minimise signal-based factors - to examine whether the AV speech detection advantage is modified by these means, and to provide a clearer idea of the primary source of visual influence in the AV detection advantage. Two sets of six studies were conducted. In the first set, three recorded speech styles, hyperarticulated, normal, and hypoarticulated, were extensively analysed in physical (optic and acoustic) and perceptual (visual and auditory) dimensions ahead of stimulus selection for the second set of studies. The analyses indicated that the three styles comprise distinctive categories on the Hyper-Hypo continuum of articulatory effort (Lindblom, 1990). Most relevantly, both optically and visually hyperarticulated speech was more informative, and hypoarticulated less informative, than normal speech with regard to signal-based movement factors. However, the F2/Mouth-area correlation was similarly strong for all speaking styles, thus allowing examination of signal-based, visual informativeness on AV speech detection with optic-acoustic association controlled. In the second set of studies, six Detection Experiments incorporating the three speaking styles were designed to examine whether, and if so why, more visually-informative (hyperarticulated) speech augmented, and less visually informative (hypoarticulated) speech attenuated, the AV detection advantage relative to normal speech, and to examine visual influence when auditory speech was absent. Detection Experiment 1 used a two-interval, two-alternative (first or second interval, 2I2AFC) detection task, and indicated that hyperarticulation provided an AV detection advantage greater than for normal and hypoarticulated speech, with less of an advantage for hypoarticulated than for normal speech. Detection Experiment 2 used a single-interval, yes-no detection task to assess responses in signal-absent independent of signal-present conditions as a means of addressing participants’ reports that speech was heard when it was not presented in the 2I2AFC task. Hyperarticulation resulted in an AV detection advantage, and for all speaking styles there was a consistent response bias to indicate speech was present in signal-absent conditions. To examine whether the AV detection advantage for hyperarticulation was due to visual, auditory or auditory-visual factors, Detection Experiments 3 and 4 used mismatching AV speaking style combinations (AnormVhyper, AnormVhypo, AhyperVnorm, AhypoVnorm) that were onset-matched or time-aligned, respectively. The results indicated that higher rates of mouth movement can be sufficient for the detection advantage with weak optic-acoustic associations, but, in circumstances where these associations are low, even high rates of movement have little impact on augmenting detection in noise. Furthermore, in Detection Experiment 5, in which visual stimuli consisted only of the mouth movements extracted from the three styles, there was no AV detection advantage, and it seems that this is so because extra-oral information is required, perhaps to provide a frame of reference that improves the availability of mouth movement to the perceiver. Detection Experiment 6 used a new 2I-4AFC task and the measures of false detections and response bias to identify whether visual influence in signal absent conditions is due to response bias or an illusion of hearing speech in noise (termed here the Speech in Noise, SiN, Illusion). In the event, the SiN illusion occurred for both the hyperarticulated and the normal styles – styles with reasonable amounts of movement change. For normal speech, the responses in signal-absent conditions were due only to the illusion of hearing speech in noise, whereas for hypoarticulated speech such responses were due only to response bias. For hyperarticulated speech there is evidence for the presence of both types of visual influence in signal-absent conditions. It seems to be the case that there is more doubt with regard to the presence of auditory speech for non-normal speech styles. An explanation of past and present results is offered within a new framework -the Dynamic Bimodal Accumulation Theory (DBAT). This is developed in this thesis to address the limitations of, and conflicts between, previous theoretical positions. DBAT suggests a bottom-up influence of visual speech on the processing of auditory speech; specifically, it is proposed that the rate of change of visual movements guides auditory attention rhythms ‘on-line’ at corresponding rates, which allows selected samples of the auditory stream to be given prominence. Any patterns contained within these samples then emerge from the course of auditory integration processes. By this account, there are three important elements of visual speech necessary for enhanced detection of speech in noise. First and foremost, when speech is present, visual movement information must be available (as opposed to hypoarticulated and synthetic speech) Then the rate of change, and opticacoustic relatedness also have an impact (as in Detection Experiments 3 and 4). When speech is absent, visual information has an influence; and the SiN illusion (Detection Experiment 6) can be explained as a perceptual modulation of a noise stimulus by visually-driven rhythmic attention. In sum, hyperarticulation augments the AV speech detection advantage, and, whenever speech is perceived in noisy conditions, there is either response bias to perceive speech or a SiN illusion, or both. DBAT provides a detailed description of these results, with wider-ranging explanatory power than previous theoretical accounts. Predictions are put forward for examination of the predictive power of DBAT in future studies.

Thesis (Ph.D.)--University of Western Sydney, 2007.
A thesis submitted to the University of Western Sydney, College of Arts, in fulfilment of the requirements for the degree of Doctor of Philosophy. Includes bibliography.

The loud songs of gibbons (Hylobatidae) usually consist of a duet by the mated pair delivered each morning. These songs can transmit over a kilometre through dense forest habitat and therefore presumably play a role in long-distance communication. There is some evidence to suggest that gibbons use song in contexts other than their daily duets, such as predation, but these songs have not been well studied. Close- range communication is also relevant for gibbons, but these quieter calls have completely escaped any detailed observation. The responses of wild white-handed gibbons (Hylobates lar) to simulated visual and acoustic predators (tiger, clouded leopard, reticulated python and crested serpent eagle) were studied in Khao Yai National Park, Thailand to address the lack of empirical data about these important events. Little is known about gibbons’ anti- predatory behaviour in general, and simulated predator encounters provided an opportunity to investigate these responses as well. Results showed that gibbons used song as part of their anti-predator strategy and that subtle combinatorial changes were meaningful to conspecifics. They also showed marked behavioural changes in the short-term, and some evidence of longer-term changes as well. Quiet calls were also part of the gibbons’ response repertoire with the hoo call being particularly relevant. Hoos were used as a prelude to singing both normal duets and predator songs, but there were consistent differences between each context. Hoos were also delivered independently in a number of other contexts outside predation. When analysed, these hoos showed consistent contextual differences in a number of spectral parameters. Within the duet context, important contextual subtleties were evident also revealing a remarkable vocal plasticity. In addition, gibbons voluntarily attended to specific vocal elements of other gibbon duets, indicating that certain sequences are more pertinent than others. Results suggest both gibbon song and gibbon hoos are powerful communication tools that reliably reference external objects and events; this ability is also a critical feature of human language.

Les perturbateurs endocriniens (PE) sont des polluants environnementaux naturels ou fabriqués par l'Homme capables d'interférer avec les systèmes hormonaux endogènes. Parmi ces molécules, le di(2-éthylhexyl) phtalate (DEHP) et le nonylphénol (NP) sont très répandus dans les produits du quotidien et figurent sur la liste des Substances Prioritaires de l'eau. Cependant, peu d'études s'intéressent au contrôle central de la reproduction suite à l'exposition adulte et à de faibles doses de ces PE. L'exposition chronique de souris mâles adultes à ces PE seuls ou combinés montre des altérations à des doses proches de l'exposition environnementale humaine et de la dose journalière tolérable. Nous avons constaté une diminution de l'émission des vocalisations ultrasonores (USV) et de l'attraction des femelles par les mâles exposés au DEHP. Ceci a pu être relié à une diminution de l'expression du récepteur des androgènes dans l'aire préoptique médiane, région clé dans l'expression du comportement sexuel mâle. Ces effets ont été inversés lors de l'arrêt de l'exposition au DEHP. L'exposition au NP augmente l'émission des USV et les nombres de montées, d'intromissions et de poussées pelviennes avant d'atteindre l'éjaculation. Par ailleurs, l'exposition au mélange provoque des altérations comportementales différentes de celles observées pour les molécules isolées. Ces résultats ont permis de mettre en évidence une vulnérabilité du circuit neural régulant l'expression du comportement sexuel à l'exposition à ces PE. Des cibles moléculaires ont également pu être identifiées, particulièrement pour le DEHP, aidant ainsi à la compréhension de leur mode d'action dans le système nerveux central
Endocrine disruptors are natural or man-made environmental pollutants capable of interfering with endogenous hormonal systems. Among these molecules, phthalates and particularly di(2-éthylhexyl) phtalate (DEHP) and nonylphenol are widely present in everyday products and classified as priority substances in the Water Framework Directive. These two molecules are highly studied but few publications address the neural control of reproductive behaviors following adult exposure to low doses of these molecules.Chronic exposure of adult male mice to these two molecules, alone or in combination, showed behavioral alterations at doses close to human environmental exposure and tolerable daily intake. We observed a decreased emission of ultrasonic vocalisations and attraction of receptive females by males exposed to DEHP. These behavioral alterations were related to down-regulation of the androgen receptor in the medial preoptic area, the key region involved in the expression of male sexual behavior. These behavioral and molecular effects were reversed by DEHP exposure arrest. Adult exposure to NP increased the emission of ultrasonic vocalisations and number of mounts, intromissions and pelvic thrusts, without any amelioration of sexual behavior. Interestingly, exposure to both molecules caused behavioral alterations, which are are different from those observed for each molecule alone.Altogether, these results highlight the vulnerability of the neural circuitry underlying sexual behavior to exposure to these molecules. Furthermore, molecular targets have been identified, particularly for DEHP, thereby helping to understand their mode of action in the central nervous system

Cette présente thèse a permis d'acquérir un corpus de données importantes qui valident un nouveau modèle animal d'étude du déclin cognitif lié à l'âge, le marmouset commun (Callithrix jacchus). Un ensemble de tâches comportementales ont été effectuées par nos animaux sur écran tactile dans un contexte semi-naturel. Les résultats permettent de comprendre et caractériser les divers déficits présents chez les sujets âgés et de découvrir, via une méthode d'analyse algorithmique, les périodes d'âge clés où ceux-ci apparaissent. La présence de déficits précoces souligne l'intérêt du modèle dans l'optique des pathologies dégénératives du cerveau. De plus, les analyses des données morphométriques obtenues par IRM structurale ont révélé certaines anomalies anatomiques pouvant apparaitre chez les individus âgés. Également, l'analyse des enregistrements audio que nous avons obtenus pendant les sessions comportementales a montré l'existence d'une influence de l'environnement sonore et particulièrement de certaines vocalisations sur les performances cognitives. Ce résultat souligne l'importance de mener les expérimentations dans un contexte semi-naturel tel que le nôtre. Il met également l'accent sur l'importance de mener ce genre d'approche et de l'adapter pour une meilleure compréhension du rôle du vieillissement dans la cognition sociale. L'ensemble de notre travail permet ainsi paver le chemin à de nouvelles voies de recherche fondamentale et clinique intéressantes et prometteuses
This thesis allowed the acquisition of a corpus of important data validating a new animal model for the study of cognitive decline related to age, the common marmoset (Callithrix jacchus). A set of behavioral tasks were performed by our animals on touchscreen in a semi-natural context. The results enabled us to understand and characterize the various deficits present in elderly subjects and to discover, through an algorithmic analysis method, the key periods in which they appear. The presence of early deficits underlines the interest of the model considering degenerative brain pathologies. In addition, the analysis of the morphometric data obtained by structural MRI revealed some anatomical abnormalities that may appear in the elderly. Likewise, the analysis of the audio recordings that we obtained during the behavioral sessions showed an influence of the sound environment and particularly of some vocalizations on cognitive performances. This result highlights the importance of conducting experiments in a semi-natural context as ours. It also emphasizes the importance of conducting this kind of approach and adapting it for a better understanding of the role of aging in social cognition. Thus, all of our work paves the way for a new interesting and promising issues for fundamental and clinical research

Chez les oiseaux chanteurs, la perception et la production du chant sont contrôlées par des structures cérébrales spécialisées, les noyaux du chant. Le HVC est un de ces noyaux et ses neurones présentent des réponses auditives sélectives en faveur du propre chant de l'oiseau (BOS). Ils répondent plus à la diffusion du BOS qu’au chant d’un autre oiseau de la même espèce. Nous avons étudié cette sélectivité neuronale chez un oiseau qui produit des chants variés, le canari domestique. Après avoir mis en évidence que les neurones du HVC, chez le canari anesthésié, répondent sélectivement au BOS, nous avons recherché les caractéristiques du chant sur lesquelles repose la sélectivité. Pour cela nous avons déterminé les paramètres clés qui distinguent les chants d’un individu de ceux d'un autre. Après avoir montré que l’ordre des phrases dans les chants diffère entre les canaris, nous avons mis en évidence que la sélectivité neuronale dépend de cet ordre, car l’activité des neurones est diminuée si on diffuse un BOS dont l’ordre des phrases a été modifié. Les réponses des neurones du HVC révèlent donc une int

Passive acoustic recordings collected in Australian temperate waters were used to provide the first summary of southern right whale (Eubalaena australis) vocalisations in Australia, and to document the characteristics, and temporal and spatial patterns of an as yet unattributed whale sound, referred to as the “spot” call, which is suggested to be produced by the southern right whale.

In recent years, worldwide obesity rates have risen dramatically, putting major strain on public health systems and the economy. Obesity is a multifaceted disease and its development can be influenced by a variety of factors including genetic, psychological and environmental influences. One area of current focus in obesity research is that of early life programming. It has been well-established that certain early life factors can impact the physiology and behaviour of the offspring. Because of this, early life programming has become increasingly well studied in order to develop a deeper understanding of how early life can influence obesity development. Another area of interest lies in positive mood. While there has been much research into the effects of negative states such as stress and anxiety on feeding behaviour, there is still very little known about how positive states can influence food choice. Using rat models of prenatal stress, neonatal overnutrition and positive affect, this thesis aimed to investigate the effects of early life and mood factors on feeding behaviour and food choice. Prenatal stress has been extensively studied and is characterised by an enhanced stress response in the offspring. Using two rat models of prenatal stress- social and restraint stress, the effects of prenatal stress on feeding behaviour and food choice in the offspring were examined. In both models, no effects of prenatal stress on either food intake or food choice were observed. However, in both cases the expected alterations to the offspring's stress responses when exposed to an acute stressor were not replicated. This may suggest that models of prenatal stress are not as robust as often cited in the literature. As well as the prenatal environment, the early postnatal environment is also able to influence physiology and behaviour. In terms of obesity, a well-studied model is that of small litter size. Rats from small litters are over-nourished as neonates and because of this illustrate an increased body weight that persists throughout life. While this increase in weight gain has been well-established, there is no evidence examining the impact of neonatal overnutrition on long-term food choice. Therefore, food intake and food choice were measured in small and control litter rats over a 10-week period. When placed on an ad lib diet of bland chow, sucrose and lard, small litter rats consumed significantly more chow than control litter rats, whilst maintaining similar consumption of lard and sucrose. However, when offered a high-fat high-sugar (HFHS) pellet for two hours a day alongside ad lib chow, small litter rats illustrated increased consumption of the HFHS pellet compared to controls. This suggests that small litter rats may be programmed to adjust their food choices to enable them to maintain their increased body weight in comparison to controls. To examine the effects of positive affect on feeding behaviour, ultrasonic vocalisations (USVs, specifically those at 50 kHz) were used as a measure of positive affect in rats. In order to examine whether access to a food reward could induce a positive affect (as measured by an increase in 50 kHz USVs), rats were schedule-fed sweetened condensed milk and USVs measured before, during and after consumption. No differences in 50 kHz USVs were observed suggesting that a palatable food, whilst rewarding, does not alter affective state in the rat. Using heterospecific social contact (a tickling interaction simulating rough and tumble play) to induce positive affect, rats were presented with an hour-long sucrose preference test following social contact in order to examine the impact of positive affect on food choice. While no differences in sucrose consumption were found, a reduced sucrose preference was observed in rats receiving social contact compared to controls, suggesting that positive affect may play a role in mediating food choice. Finally, the effects of fasting (a negative stimulus thought to reduce 50 kHz USVs) and a food reward on motivation for social contact were examined. Both fasting and access to a food reward resulted in no differences in conditioned place preference to receive social interaction. Overall, the results obtained in this thesis implicate both neonatal overnutrition and, for the first time, positive affect as possible mediators of food choice, although further studies are required to fully establish these effects. Importantly, these results also raise questions regarding the reproducibility of some early life models, such as prenatal stress, and highlights the importance of sharing precise experimental protocols across laboratories. Through further investigation of the effects of early life and affective states on food consumption and choice, and the mechanisms behind these, this may enable the development of therapeutic interventions and preventative measures that can help slow, or even reverse, the global obesity epidemic.

La prise de décision est un processus indispensable et vital pour les mammifères. Elle permet à l'individu de s'adapter aux changements qui s'opèrent dans son environnement et résulte de l'intégration d'informations sensorielles, émotionnelles, motivationnelles et exécutives (qui peuvent être internes ou externes à l'individu). Des études, à la fois chez le sujet humain (sujet sain, patients cérébrolésés ou atteints de pathologies psychiatriques), et sur les modèles animaux singe, rats ou souris, ont permis d'identifier le cortex préfrontal comme acteur crucial dans ces processus exécutifs complexes. La mise en place au sein de notre laboratoire d'un test d'interaction sociale permettant de générer des prises de décision rapides et adaptées en présence d'un congénère nouveau, nous a permis d'étudier les bases neurobiologiques et comportementales sous-jacentes à la prise de décision et à la flexibilité comportementale. Il est connu que les rongeurs émettent des USVs dont le rôle et les mécanismes motivationnels et/ou émotionnels restent largement inconnus à ce jour. Mon travail de thèse repose principalement sur l'identification des acteurs cérébraux de cette interaction sociale, et sur le rôle putatif des USVs. D'autre part, je me suis employé à comprendre comment les motivations naturelles (telles que la nourriture, l'exploration d'objet ou de l'environnement, et l'interaction avec un congénère) sont intégrées au canevas de prise de décision et comment elles l'influencent.Dans un premier temps, en utilisant des procédures d'imagerie cellulaire basée sur l'expression de gènes précoces (c-fos), et ce, à la fois chez des animaux contrôles et chez des animaux présentant des troubles des comportements sociaux (β2KO), nous avons pu mettre en évidence l'implication différentielle de sous-parties du cortex préfrontal chez la souris. Par la suite, la mise en place d'un logiciel spécifique d'analyse, ainsi que la modulation de l'état de motivation de l'animal lors de la tâche d'interaction sociale, nous a permis de mieux comprendre l'établissement de comportements adaptés lors de l'interaction sociale. Pour finir, en variant les contextes comportementaux, nous avons montré qu'il existe une relation étroite entre état émotionnel et motivationnel de l'animal et émission d'USVs. Notamment, les USVs semblent porter une information spécifique lors de l'interaction sociale qui reste encore largement à déterminer.

La peur est ce qui permet de réagir à un stimulus aversif par une réponse de défense adaptée à la situation. Elle peut être générée par un ensemble de stimuli naturellement aversifs ou par des stimuli ayant acquis une valeur aversive par apprentissage associatif. Cette thèse a pour but d'étudier les caractéristiques et modifications de la réponse de peur à ces deux types de stimuli au cours de l'ontogenèse. Les études présentées ici utilisent un conditionnement de peur à l'odeur chez le rat qui associe une odeur à un stimulus aversif et permet d'induire très rapidement et durablement des mémoires de peur à l'odeur. La réponse de défense peut alors être étudiée à la fois envers l'odeur apprise et envers le stimulus naturellement aversif. Nous montrons en particulier que la réponse de peur à l'odeur apprise présente un décours temporel corrélé à la durée de l'intervalle de temps entre l'odeur et le stimulus aversif, permettant d'affirmer que les animaux mémorisent et estiment le temps, et ce dès les premiers âges étudiés, avant la maturation des structures cérébrales classiquement impliquées dans cette mémoire temporelle. Par ailleurs, nous nous sommes intéressés aux vocalisations ultrasonores émises en réponse au stimulus aversif et à leur modification au cours de l'ontogenèse. Nous avons mis en évidence deux types de vocalisations chez le raton, dont les caractéristiques et critères d'induction laissent présager un rôle différentiel qui reste à explorer. L'ensemble de ces travaux soulignent que, même si les réponses de défense du rat changent au cours du développement, la capacité à produire ces réponses de manière temporellement adaptée est observée dès le plus jeune âge
Fear allows individuals to react to an aversive stimulus by a defense response adapted to the situation. It can be triggered by naturally aversive stimuli or in response to stimuli that acquired an aversive valence through associative learning. This thesis investigated the characteristics and modifications of fear responses to these two types of stimuli throughout ontogeny. The studies presented here used olfactory fear conditioning in rat, in which an odor is paired with an aversive event and allows to rapidly induce long lasting odor fear memories. Defense responses can then be studied both to the learned odor and to the naturally aversive stimulus. We showed in particular that fear response to the learned odor presents a temporal pattern correlated with the duration of the time interval between the odor and the aversive event, showing that rats can learn about time and they do so at the youngest ages studied here, before the maturation of the brain structures classically involved in interval timing. We also studied the ultrasonic vocalizations emitted in response to the aversive stimulus and their changes throughout ontogeny. We described two types of vocalizations in pups that differ in their characteristics and emission context, suggesting they could have different functions, which needs further exploration. These thesis findings highlight that although the rat’s defense responses changes through ontogeny, the ability to produce temporally adapted responses occurs from the youngest age

Des mutations du gène Foxp2 constituent le premier exemple connu de cause monogénique de troubles de la parole et du langage. Les individus atteints souffrent de difficultés d’articulation (dyspraxie verbale) mais aussi de perturbations du langage parlé et écrit, ce qui indique la présence d’un trouble cognitif. La séquence et la distribution d’expression de ce gène sont remarquablement conservées parmi les vertébrés.Cette thèse visait principalement à identifier les fonctions du facteur de transcription Foxp2 dans le cortex en caractérisant un modèle murin conditionnel dans lequel ce gène a été spécifiquement inactivé dans les neurones corticaux. Ce modèle murin permet ainsi d’étudier certains aspects des pathologies liées à Foxp2, notamment les aspects de communication et les comportements sociaux. En parallèle, j’ai entrepris, sur un autre modèle murin, des études moléculaires afin d’identifier les gènes perturbés par la réduction de l’expression de Foxp2 dans le cortex. L‘ensemble des résultats présentés suggère que l’inactivation de Foxp2 dans le cortex conduit à des défauts subtils des comportements sociaux sans modification majeure de la morphologie du cortex ou des neurones. Je montre en particulier que les souris mutées présentent des changements de vocalisation ultrasonique lors d’interactions entre mâles et femelles. Par ailleurs, en utilisant un modèle de souris hétérozygote pour une mutation dans Foxp2, j’ai identifié parmi les gènes dérégulés le gène Mint2 déjà impliqué chez l’homme dans l’autisme.En conclusion, ces résultats permettront de mieux comprendre le rôle de Foxp2 au niveau cortical chez les souris pour décrypter les mécanismes moléculaires qui ont été sélectionnés chez l’homme pendant l'évolution de la parole et du langage
Genetic disruptions of the forkhead box transcription factor FOXP2 in humans cause a severe autosomal-dominant speech and language disorder. FOXP2 expression pattern and genomic structure are highly conserved in distant vertebrates. We hypothesized that this conservation may allow the use of animal models to identify Foxp2 dependent neuronal circuits and molecular networks involved in social behaviors. Therefore I began characterizing Foxp2 functions in the mouse cortex in conventional heterozygous (Foxp2+/-) and conditional (cortex specific) Foxp2 homozygous mutant mice (Nex-Cre; Foxp2lox/lox). Initial characterization of Nex-Cre; Foxp2lox/lox mice revealed no gross alterations in morphological architecture, postnatal development and basic adult behaviors. However, behavioral profiling of Nex-Cre; Foxp2lox/lox mice demonstrated deficiency in specific social behaviors such as approach behavior towards conspecifics and responses of WT interaction partners. Furthermore, Nex-Cre; Foxp2lox/lox mice showed alterations in specific acoustical parameters of ultrasonic vocalizations (USV), and the type of modulation differed in function of social context. Gene expression profiling of Foxp2-positive cortical pyramidal neurons in Foxp2+/- mice revealed the dysregulation of Mint2, a gene involved in approach behavior in mice and autism spectrum disorder in humans. This result was further validated in cortex-specific Foxp2 mutant mice The results deliver first insights into cortical Foxp2 dependent functions in mouse social behaviors. This provides a rational basis for further mechanistic studies of the ancestral functions of cortical Foxp2 that may have been recruited during speech and language evolution

Un des objectifs des neurosciences computationelles consiste à élucider le code neuronal utilisé dans le système nerveux central pour représenter l’information et élaborer des réponses adaptées à ces stimuli. Tandis que le taux de décharge des neurones reste très utilisé dans les travaux explorant les relations entre activité neuronale et fonctions cognitives, de plus en plus de recherches montrent que les aspects temporels des décharges neuronales pourraient constituer un code rapide et efficace de l’information. J’ai étudié des enregistrements électrophysiologiques collectés dans une structure du cerveau de canaris impliquée dans la perception et la production des chants. Alors qu’une minorité de ces neurones sont sélectifs pour le propre chant de l’oiseau en terme de taux de décharge, les réponses d’une majorité d’entre eux portent l’information nécessaire à la discrimination entre le propre chant et son inverse, cette information étant majoritairement portée par les aspects temporels des décharges. Nous avons ensuite analysé des enregistrements obtenus dans le système thalamocortical de cobayes lors de la présentation de vocalisations conspécifiques. Alors que ces stimuli déclenchent des réponses similaires du point de vue du nombre de PA, la quantité d’information transmise par l’organisation temporelle des PA est importante. Tant dans le système thalamocortical que dans un noyau sensorimoteur, les neurones semblent donc émettre des séquences de PA dont l’organisation temporelle est bien mieux corrélée avec les stimuli que le nombre de PA. Cette propriété dynamique de l’activité neuronale pourrait donc être impliquée dans la perception de stimuli naturels
A major goal in computational neuroscience is to understand the neural code used to represent perceptual information and elaborate appropriate motor responses. Whereas most of the researches about relationships between neural activity and cognitives functions still focus on the discharge rate, a growing number of studies show that spike timing could constitute a rapid and efficient neural code. We studied spike trains recorded in the HVC nucleus, brain’s structure involved in the perception and the production of songs in songbirds. Whereas a minority of neurons were selective in terms of spike rate, it appeared that spike timing carried the information required to disriminate between the bird’s own song and its reverse. We then studied auditory thalamocortical spike trains recorded during the presentation of conspecific vocalizations. In that case also, spike timing conveys information allowing the discrimination between vocalizations and their time-reversed versions whereas spike rate was similar for both stimuli. An analysis of the first 100ms of the spike trains revealed that first spike latency conveyed twice more information that spike count for a discrimination between vocalizations in their natural version. Therefore, in the thalamocortical auditory system as well as in a sensorimotor nucleus, neurons seem to emit temporal patterns of spikes that better correlate with sensory stimuli than spike count does. This dynamic property of neural activity may thus be involved in the perception of naturalistic stimuli

Communication is a fundamental process that allows animals to effectively transfer information between groups or individuals. Recognition plays an essential role in permitting animals to distinguish individuals based upon both communicatory and non-communicatory signals allowing animals to direct suitable behaviours towards them. Several modes of recognition exist and in colonial breeding animals which congregate in large numbers, acoustic signalling is thought to be the most effective as it suffers less from environmental degradation. Otariid seals (fur seals and sea lions) are generally colonial breeding species which congregate at high densities on offshore islands. In contrast to the other Arctocephaline species, the Australian fur seal, Arctocephalus pusillus doriferus, along with its conspecific, the Cape fur seal, A. p. pusillus, display many of the behavioural traits of sea lions. This may have important consequences in terms of its social structure and evolution. The acoustic communication of Australian fur seals was studied on Kanowna Island, Bass Strait, Australia. Analysing the acoustic structure of vocalisations and their use facilitates our understanding of the social function of calls in animal communication. The vocal repertoires of males, females, pups and yearlings were characterised and their behavioural context examined. Call structural variations in males were evident with changes in behavioural context, indicating parallel changes in the emotive state of sender. For a call to be used in vocal recognition it must display stereotypy within callers and variation between them. In Australian fur seal females and pups, individuals were found to have unique calls. Mutual mother-pup recognition has been suggested for otariids and this study supports the potential for this process to occur through the use of vocalisations. Call structural changes in pup vocalisations were also investigated over the progression of the year, from birth to weaning. Vocalisations produced by pups increased in duration, lowered in both the number of parts per call and the harmonic band containing the maximum frequency as they became older, suggesting calls are changing constantly as pups grow toward maturity. It has been suggested through descriptive reports, that the bark call produced by males is important to vocal recognition. The present study quantified this through the analysis of vocalisations produced by male Australian fur seals. Results support descriptive evidence suggesting that male barks can be used to discriminate callers. Traditional playback studies further confirmed that territorial male Australian fur seals respond significantly more to the calls of strangers than to those of neighbours, supporting male vocal recognition. This study modified call features of the bark to determine the importance to vocal recognition. The results indicate that the whole frequency spectrum was important to recognition. There was also an increase in response from males when they heard more bark units, indicating the importance of repetition by a caller. Recognition occurred when males heard between 25-75% of each bark unit, indicating that the whole duration of each bark unit is not necessary for recognition to occur. This may have particular advantages for communication in acoustically complex breeding environments, where parts of calls may be degraded by the environment. The present study examined the life history characteristics of otariids to determine the factors likely to influence and shape its vocal behaviour. Preliminary results indicate that female density, body size and the breeding environment all influence the vocal behaviour of otariids, while duration of lactation and the degree of polygyny do not appear to be influential. Understanding these interactions may help elucidate how vocal recognition and communication have evolved in different pinniped species.

Doctor of Philosophy(PhD)
Communication is a fundamental process that allows animals to effectively transfer information between groups or individuals. Recognition plays an essential role in permitting animals to distinguish individuals based upon both communicatory and non-communicatory signals allowing animals to direct suitable behaviours towards them. Several modes of recognition exist and in colonial breeding animals which congregate in large numbers, acoustic signalling is thought to be the most effective as it suffers less from environmental degradation. Otariid seals (fur seals and sea lions) are generally colonial breeding species which congregate at high densities on offshore islands. In contrast to the other Arctocephaline species, the Australian fur seal, Arctocephalus pusillus doriferus, along with its conspecific, the Cape fur seal, A. p. pusillus, display many of the behavioural traits of sea lions. This may have important consequences in terms of its social structure and evolution. The acoustic communication of Australian fur seals was studied on Kanowna Island, Bass Strait, Australia. Analysing the acoustic structure of vocalisations and their use facilitates our understanding of the social function of calls in animal communication. The vocal repertoires of males, females, pups and yearlings were characterised and their behavioural context examined. Call structural variations in males were evident with changes in behavioural context, indicating parallel changes in the emotive state of sender. For a call to be used in vocal recognition it must display stereotypy within callers and variation between them. In Australian fur seal females and pups, individuals were found to have unique calls. Mutual mother-pup recognition has been suggested for otariids and this study supports the potential for this process to occur through the use of vocalisations. Call structural changes in pup vocalisations were also investigated over the progression of the year, from birth to weaning. Vocalisations produced by pups increased in duration, lowered in both the number of parts per call and the harmonic band containing the maximum frequency as they became older, suggesting calls are changing constantly as pups grow toward maturity. It has been suggested through descriptive reports, that the bark call produced by males is important to vocal recognition. The present study quantified this through the analysis of vocalisations produced by male Australian fur seals. Results support descriptive evidence suggesting that male barks can be used to discriminate callers. Traditional playback studies further confirmed that territorial male Australian fur seals respond significantly more to the calls of strangers than to those of neighbours, supporting male vocal recognition. This study modified call features of the bark to determine the importance to vocal recognition. The results indicate that the whole frequency spectrum was important to recognition. There was also an increase in response from males when they heard more bark units, indicating the importance of repetition by a caller. Recognition occurred when males heard between 25-75% of each bark unit, indicating that the whole duration of each bark unit is not necessary for recognition to occur. This may have particular advantages for communication in acoustically complex breeding environments, where parts of calls may be degraded by the environment. The present study examined the life history characteristics of otariids to determine the factors likely to influence and shape its vocal behaviour. Preliminary results indicate that female density, body size and the breeding environment all influence the vocal behaviour of otariids, while duration of lactation and the degree of polygyny do not appear to be influential. Understanding these interactions may help elucidate how vocal recognition and communication have evolved in different pinniped species.

Le sujet de cette thèse était d'étudier les circuits de la mémoire émotionnelle olfactive en utilisant comme modèle le conditionnement de peur à l'odeur chez le rat. L'apprentissage consiste à présenter à l'animal une odeur neutre, qui se co-termine par un léger choc électrique aux pattes. Après quelques associations de ce type, l'odeur présentée seule induit une réponse de peur conditionnée. Grâce à une technique de microdialyse intracerebrale à haute résolution temporelle, nous avons étudié la dynamique fine de libération de Glutamate et de Gaba dans l'amygdale (AMY) et le cortex olfactif (CO) pendant la séance d'acquisition. Nous avons observé une augmentation transitoire précoce dans l'AMY, suivie d'augmentations plus tardives et répétées dans le CO. Nous avons ensuite montré que les augmentations dans le CO pouvaient être induites par celle observée dans l'AMY et que le rôle de l'AMY dans l'apprentissage serait surtout lié à la première association. Nous proposons que l'AMY fonctionne comme un détecteur de nouveauté et est impliquée dans la mise en place de l'association. L'information serait ensuite transférée au CO, qui permettrait le stockage progressif des attributs fins de l'odeur apprise. Nos données suggèrent également que le CO pourrait être impliqué dans le traitement de la durée des intervalles de temps entre l'odeur et le choc. Cela nous a amenés à mettre au point un dispositif expérimental permettant d'enregistrer la respiration et les vocalisations ultrasoniques, dans le but d'affiner la mesure de la réponse de peur et de détecter des réponses anticipatrices qui permettraient de conclure que les animaux sont capables d'encoder les durées à un stade très précoce de l'apprentissage
The aim of this thesis work was to investigate the circuits involved in olfactory emotional memory, using odor fear conditioning as a model in rats. During learning, the animal receives a neutral odor, which co-terminates with a mild footshock. After a few odor-shock associations, the odor presented alone induces a conditioned fear response. Using high temporal resolution intracerebral microdialysis, we studied the dynamics of glutamate and GABA release in the amygdala (AMY) and the olfactory cortex (OC) during the acquisition session. We observed an early transient increase in the AMY, followed by delayed and repeated increases in the OC. We then showed that the increases in the OC could be induced by the increase observed in the AMY, and that the involvement of the AMY in the learning was mainly linked to the first association. We suggest that the AMY operates as a novelty detector and is involved in the formation of the association. The information would then be transferred to the OC, which would progressively store of the different attributes of the learned odor. Our data also suggest that the OC may be involved in the processing of odorshock time interval duration. This led us to develop an experimental device to monitor respiration and ultrasonic vocalizations in order to refine the measure of fear response and detect anticipatory responses, indicating that the animals are able to encode durations at very early stages of the learning

Chez les baleines à bosse (Megaptera novaeangliae), le maintien des liens sociaux entre les femelles et leurs nouveau-nés implique différentes modalités sensorielles telles que l'ouïe, le toucher et la vision. Si la communication acoustique chez les mâles chanteurs de cette espèce a été largement étudiée, les sons sociaux, en particulier ceux produits par les femelles et leurs nouveau-nés, ont été peu reportés. Cette étude décrit les sons sociaux présents dans les enregistrements acoustiques axés sur les groupes mère-baleineau et discute des vocalisations produites par les femelles et les baleineaux dans les interactions mère-jeune. En considérant les sons les plus fréquents de ce répertoire vocal, une analyse centrée sur la détermination de la source des sons de bass fréquence produits par la mère a été effectuée et des analyses ont été réalisées pour mettre en évidence l'individualité de certaines vocalisations appartenant à la mère et à son petit. Une description du contexte comportemental de leur production vocale a été réalisée et parallèlement, les profils de plongée des mères et de leurs nouveau-nés ont été décrits. En outre, les femelles et leurs petits passent beaucoup de temps à la surface de l'eau. Les mères sont souvent statiques à la surface tandis que les baleineaux évoluent autour d'elles. Cette étude est également consacrée à la compréhension de leurs comportements de surface, en tenant compte des comportements initiés par les baleineaux. Des séries d’analyses ont été réalisées pour déterminer si les baleineaux présentaient des comportements de latéralisation par rapport à leur mère. Enfin, en utilisant la méthode de photogrammétrie, les tailles des femelles et des nouveau-nés ont été mesurées, ainsi que l'espace utilisée par les baleineaux autour de leur mère
In humpback whales (Megaptera novaeangliae), maintaining social bonds between females and their newborns involves different sensory modalities such as hearing, touching and vision. While acoustic communication in male singers of this species has been extensively studied, social sounds, especially those produced by the females and their newborns have been poorly documented. This study describes the social sounds present in acoustic recordings focused on mother-calf groups and discusses the vocalizations used by females and calves in mother-offspring interactions. By considering the most frequent sounds from their vocal repertoire, an analysis focused on the determination of the source of the low-frequency sounds produced by the mother have been carried out and analyses were performed to investigate the individuality of some vocalizations belonging to the mothers and the calves. A description of the behavioural context of their vocal production was performed and the diving profiles of mother-calf pairs were described. Moreover, females with their calves spend a lot of time on the water surface. Mothers are often static at the surface while calves move around them. This study is also dedicated to the understanding of their surface behaviours, considering the behaviours initiated by calves. A series of analyses were carried out to determine whether calves exhibited lateralization behaviours in relation to their mothers. Finally, by using photogrammetry method, mother-calf lengths were measured, and calves spatial range around their mothers was investigated

I use morphological, vocal, molecular, behavioural, ecological and distributional data to re-evaluate the systematics of three passerine bird groups, the Mirafraassamica complex (bush-larks), the genus Seicercus ("spectacled-warblers"; with emphasis on the the S. burkii complex) and the genus Motacilla (wagtails). Two new species are described: Seicercus soror and Motacilla samveasnae. I propose that the polytypic species M. assamica should be treated as four separate species: M. assamica, M. affinis, M. microptera and M. marionae (it is also remarked that the proper name of the latter is M. erythrocephala). That is primarily supported by vocalisations and mitochondrial DNA. The latter data set also suggests that M. assamica sensu lato is paraphyletic, since M. erythroptera, which is always treated as a separate species, is nested within the M. assamica complex. I propose that the polytypic species S. burkii comprises six sibling species. Some of these are found to breed sympatrically, although mainly or entirely segregated altitudinally. Mitochondrial DNA suggests that the S. burkii complex is non-monophyletic, and also that the divergence of the different taxa is much older than indicated by morphological and vocal data. According to the molecular phylogeny, both the genera Seicercus and its assumed sister genus Phylloscopus are paraphyletic. That is corroborated by independent data. The phylogenetic study of the genus Motacilla reveals incongruence between mitochondrial DNA, nuclear DNA and non-molecular data. I conclude that the nuclear gene tree reflects the organismal phylogeny more faithfully than the mitochondrial gene tree. The latter is likely to have been affected by introgressive hybridisation, possibly also stochastic lineage sorting. The most remarkable result that is strongly supported by both mitochondrial and nuclear DNA is that M. flava is non-monophyletic.

The human voice presents a rich and powerful medium for expressing sonic ideas such as musical sounds. This capability extends beyond the sounds used in speech, evidenced for example in the art form of beatboxing, and recent studies highlighting the utility of vocal imitation for communicating sonic concepts. Meanwhile, the advance of digital audio has resulted in huge libraries of sounds at the disposal of music producers and sound designers. This presents a compelling search problem: with larger search spaces, the task of navigating sound libraries has become increasingly difficult. The versatility and expressive nature of the voice provides a seemingly ideal medium for querying sound libraries, raising the question of how well humans are able to vocally imitate musical sounds, and how we might use the voice as a tool for search. In this thesis we address these questions by investigating the ability of musicians to vocalise synthesised and percussive sounds, and evaluate the suitability of different audio features for predicting the perceptual similarity between vocal imitations and imitated sounds. In the fi rst experiment, musicians were tasked with imitating synthesised sounds with one or two time{varying feature envelopes applied. The results show that participants were able to imitate pitch, loudness, and spectral centroid features accurately, and that imitation accuracy was generally preserved when the imitated stimuli combined two, non-necessarily congruent features. This demonstrates the viability of using the voice as a natural means of expressing time series of two features simultaneously. The second experiment consisted of two parts. In a vocal production task, musicians were asked to imitate drum sounds. Listeners were then asked to rate the similarity between the imitations and sounds from the same category (e.g. kick, snare etc.). The results show that drum sounds received the highest similarity ratings when rated against their imitations (as opposed to imitations of another sound), and overall more than half the imitated sounds were correctly identi ed with above chance accuracy from the imitations, although this varied considerably between drum categories. The fi ndings from the vocal imitation experiments highlight the capacity of musicians to vocally imitate musical sounds, and some limitations of non- verbal vocal expression. Finally, we investigated the performance of different audio features as predictors of perceptual similarity between the imitations and imitated sounds from the second experiment. We show that features learned using convolutional auto-encoders outperform a number of popular heuristic features for this task, and that preservation of temporal information is more important than spectral resolution for differentiating between the vocal imitations and same-category drum sounds.

Le Quetzal Resplendissant Pharomachrus mocinno est une espèce d’oiseau tropical considérée fortement menacée par la perte de son habitat due aux activités humaines. Le Quetzal Resplendissant joue un rôle important de disperseur de graines et constitue le centre de la culture maya passée et présente. Les recherches sur cette espèce couvrent plusieurs aspects de son histoire naturelle et de sa biologie. Néanmoins, à ce jour, il n’y a aucune description détaillée du comportement et de l’écologie acoustiques de cette espèce, condition préalable à une conservation efficace de l'espèce. L’objectif de cette thèse a été d’étudier tout particulièrement le comportement et l’écologie acoustique de P. mocino dans la forêt nuageuse du Guatemala. Une analyse détaillée des vocalisations de P. mocinno, incluant des expériences de propagation de ses vocalisations dans son habitat, a permis d’identifier deux types de vocalisations destinés à la communication à longue distance et deux autres types de vocalisations destinés à la communication à courte distance. La quantification des différences dans les vocalisations territoriales des deux sous-espèces de Quetzals Resplendissants, P. m. mocinno (partie nord de l’Amérique centrale et sud du Mexique) et P. m. costaricensis (sud de l'Amérique centrale) a révélé de nettes différences entre les sous-espèces, ce qui conforterait l'hypothèse d’espèces distinctes. L'observation de l'espèce dans la canopée dense est difficile et la manipulation des individus est controversée en raison de sa grande importance culturelle. De fait, un système acoustique automatique a été mis au point pour suivre l’espèce de manière non invasive. Le système s'est avéré efficace et a produit des résultats révélant des profils de suivis acoustiques en partie dépendants de variables environnementales. Enfin, la communauté acoustique des oiseaux à laquelle P. mocinno appartient a été analysée afin d’évaluer les interactions interspécifiques de compétition. Les recherches développées ici devraient aider aux décisions de conservation futures concernant le Quetzal Resplendissant et son habitat, la forêt nuageuse. Cette recherche montre également que l'écoacoustique peut constituer une stratégie utile pour aborder les problèmes d'écologie et de conservation dans les zones tropicales
The Resplendent Quetzal Pharomachrus mocinno is a tropical bird considered in a high risk of danger. Degradation of its habitat caused by human activities is the principal menace. The Resplendent Quetzal is important as seed disperser and is the centre of the past and present Mayan culture. The available studies about the species have covered aspects of the natural history and biology. Nevertheless, the description of the acoustic behaviour and ecology, a prerequisite for the conservation of the species, was not available. The general aim of this PhD thesis was to investigate the acoustic behaviour and ecology of P. mocinno in the cloud forest of Guatemala. A detailed analysis of P. mocinno vocalizations, including propagation experiments of these vocalizations in its habitat, led to identify two vocalizations intended for long range, and two for short range communication. Quantification of acoustic parameters in territorial vocalizations of the two subspecies of the Resplendent Quetzal, P. m. mocinno (north part of Central America and Chiapas) and P. m. costaricensis (south part of Central America), revealed clear differences between the subspecies, that could support a species separation hypothesis. . The observation of the species in the dense canopy is difficult and manipulation of individuals is controversial due to its high cultural importance. Then, an automatic acoustic system was developed as a method to study the species in a non-invasive way. The system proved to be efficient and returned results that revealed acoustic patterns linked to environmental variables. Finally, the acoustic community of other bird species P. mocinno belongs to was analysed so that interspecific competition interactions could be assessed. The research here developed should help in future conservation decisions about the Resplendent Quetzal and its habitat, the cloud forest. This research also illustrates that ecoacoustics can be a valuable strategy to tackle ecology and conservation questions in tropical areas

La fragmentation de sommeil consiste en l’interruption répétée du cycle de sommeil. Il existe peu de littérature sur la fragmentation de sommeil pure. Cette thèse se compose d’une étude in vivo où ont été développés des courbes de poids, des tests de mémoire et des enregistrements de vocalisations (sur un étude pilote de 8 rats âgés) ; et une étude in vitro dans laquelle nous nous sommes intéressés à la glie, à la perméabilité de la BHE avec l’expression de la claudine-5 et l’occludine, à l’inflammation avec des cytokines pro-inflammatoires, l’IL-6, l’IL-1β et l’IL-17, l’aquaporine-4 pour les mouvements d’eau au niveau cérébral, et les protéines précurseurs de amyloïdes, marqueur d’une neuro-inflammation ; sur rat jeune et âgé. Notre protocole de fragmentation de sommeil de 1 mois a eu très peu de conséquences au niveau comportemental. Nous avons observé une augmentation significative de la concentration cérébrale en IL-17, occludine et auqaporine-4 chez le groupe de rats âgés comparé aux rats jeunes. D’autres marqueurs ont été moins sensible à l’âge et au protocole comme l’IL-6, l’IL-1β et la claudine-5. Cependant la concentration en APP était significativement moins importante chez les rats jeunes SF que chez les contrôles. De plus, chez les rats âgés, la quantité d’APP était significativement plus importante. Nous avons observé un impact de notre protocole de fragmentation sur l’activation de la microglie et des astrocytes. L’ensemble de ces travaux de thèse permet d’émettre l’hypothèse que la glie et l’accumulation d’APP seraient deux conséquences précoces des changements au niveau cérébral lors d’une fragmentation de sommeil sévère
Sleep fragmentation is the repeated interruption of the sleep cycle. There is little literature on pure sleep fragmentation. This thesis consists of an in vivo study where weight curves, memory tests and vocalization recordings were developed (on a pilot study of 8 aged rats); and an in vitro study in which we were interested in glia, BBB permeability with the expression of claudin-5 and occludin, inflammation with pro-inflammatory cytokines, IL-6, IL-1β and IL-17, aquaporin-4 for water movement at the brain level, and amyloid precursor proteins, a marker of neuro-inflammation; on young and old rats. Our 1-month sleep fragmentation protocol had very few behavioral consequences. We observed a significant increase in the brain concentration of IL-17, occludin and auqaporin-4 in the group of aged rats compared to young rats. Other markers were less sensitive to age and protocol such as IL-6, IL-1β and claudin-5. However, APP concentration was significantly lower in young SF rats than in controls. In addition, in aged rats, the amount of APP was significantly higher. We observed an impact of our fragmentation protocol on the activation of microglia and astrocytes. Taken together, this thesis work suggests that glia and APP accumulation are two early consequences of brain changes during severe sleep fragmentation

Titi monkeys have long been known for their complex vocal behaviour with numerous high- and low-pitched calls, which can be uttered singly or combined in more complex structures. However, up to date very little is known concerning the function, meaning and context-specific use of these vocal utterances, and virtually nothing is known about their vocalisations in the predation context. This thesis presents a detailed description of the form and function of the anti-predator behaviour of one species of titi monkeys, the black-fronted titi monkey (Callicebus nigrifrons), with a specific focus on their alarm call behaviour. A second aim was to determine the exact mechanisms of alarm calling behaviour, with an emphasis on production and comprehension. Data were collected from several habituated groups in the Caraça Reserve, Minas Gerais, Brazil. Results showed that, when detecting predator species, C nigrifrons produce sequences that initially contain two types of brief, high-pitched calls with distinct frequency contours. Further evidence suggested that some of these sequences are meaningful to conspecific receivers, by indicating the general predator class and location of threat. There were also indications that, within the terrestrial threats, additional information may be encoded by acoustic and compositional differences. Analyses of call order and number of calls per sequence suggested that callers may be able to convey information on both predator type and location. The black-fronted titi monkeys’ vocal system thus provides a further example of zoo-syntax, in which acoustically fixed units of a vocal repertoire are combined into higher order sequences that are meaningful to recipients. According to current definitions, this type of calling behaviour qualifies as functionally referential, by indicating general predator class, terrestrial predator type and location. As such, this is the first empirical demonstration of a sequence-based alarm call system that conveys information on both predator category and location.

Depuis quelques années, l’étude du code neuronal impliqué dans la perception des signaux de communication acoustique est devenue un domaine de recherche considérable. La littérature récente de ce domaine suggère que la discrimination entre ces signaux reposerait plutôt sur une organisation des décharges neuronales en motifs temporels que sur des variations globales de taux de décharge. Ma thèse a eu pour objectif de déterminer dans quelle mesure une régulation des inhibitions corticales peut (i) changer les motifs temporels déclenchés par des vocalisations conspécifiques et hétérospécifiques et (ii) modifier l’information portée par ces motifs sur l’identité des vocalisations. Nous avons enregistré l’activité neuronale dans le cortex auditif de cobayes anesthésiés en 16 sites corticaux lors de la présentation d’un jeu de vocalisations, et avons partiellement bloqué les inhibitions corticales par des applications de Gabazine (4minutes, 10µm). Dans ces conditions, les réponses évoquées sont plus fortes et les motifs temporels plus marqués. L’information mutuelle quantifiée au niveau de chaque site cortical est augmentée mais l’information populationnelle au niveau de l’ensemble des 16 sites enregistrés n’est pas modifiée, un effet qui peut s’expliquer par le fait que la redondance entre les sites corticaux est augmentée. Nous avons ensuite évalué dans quelle mesure une modulation noradrénergique était susceptible de mimer les effets d’un blocage partiel des inhibitions. Bien que les agonistes utilisés (α1, α2 et ) aient tous induit des modifications des réponses évoquées et de la reproductibilité des motifs temporels, aucun d’entre eux n’a induit de changements importants de l’information portée par les réponses neuronales aux vocalisations. En revanche, les effets induits par la phenylephrine, un agoniste α1, sont vraisemblablement sous-tendus par une action sur les inhibitions intra-corticales, ce qui rend plausible l’hypothèse d’une modulation noradrénergique des inhibitions corticales. Il est donc envisageable que l’action coordonnée de plusieurs systèmes neuromodulateurs puisse moduler les inhibitions corticales et ainsi changer la quantité d’information portée par les neurones corticaux sur l’identité des stimuli à discriminer
Over the last 10 years, the neural code involved in the perception of acoustic communication signals has become a large area of researches. The recent literature suggests that the discrimination between these signals relies more on the temporal organization of neuronal discharges rather than on global changes of firing rate. My PhD thesis aimed at determining to what extent the regulation of cortical inhibition may (i) change the temporal patterns triggered by conspecific and heterospecific vocalizations and (ii) modify the information carried by these patterns on the vocalization identity. Neuronal activity was recorded in the auditory cortex of anesthetized guinea pigs in 16 cortical sites during presentation of a set of vocalizations, and a partial blockage of intra-cortical inhibition was performed by Gabazine application (4 minutes, 10μm). Under these conditions, evoked responses were stronger and the temporal patterns were reinforced. Mutual information quantified at each cortical site was increased but the information computed at the populationnal level did not change, an effect that could be explained by the fact that the redundancy between cortical sites was increased. We then assessed to which extent the noradrenergic modulation can mimic the effects of a partial blockage of inhibitions. Although all the tested drugs modulated both the evoked responses and the spike-timing reliability, none of the noradrenergic agonists used here (α1, α2 and ) induced significant changes in the information carried by neuronal responses. However, the effects induced by phenylephrine, an α1 agonist, seemed to involve an action on the intra-cortical inhibition, which suggests that a noradrenergic modulation of cortical inhibition can operate in the auditory cortex. It is therefore possible to envision that the coordinated action of several neuromodulatory systems modulates cortical inhibition and thus changes the information carried by cortical neurons on the stimuli identity

In the shallow coastal waters of New Zealand, sounds of biological origin dominate the lower frequency spectrum of the underwater soundscape. While the sounds of urchin and snapping shrimp have been well described, those of fish are poorly understood. Utilising sound recordings taken from a reef in the Cape Rodney to Okakari Point Marine Reserve, the present study described the vocalisations of two dominant fish vocalisations, the croak and the purr. These sounds dominated the soundscape at frequencies below 500 Hz and regularly formed choruses that lasted up to 3 hours after sunset during the new moon, indicating the presence of soniferous fishes in New Zealand coastal waters. To help with the identification of soniferous fish species in field recordings, two local sound producing fish were studied in detail using 24 h sound recordings in captivity, the bigeye (Pempheris adspersa) and the bluefin gurnard (Chelidonichthys kumu). The bigeye produced a previously undescribed „pop‟ vocalisation with a source level of 116 dB re 1 μPa @ 1m. The active space of their calls was estimated (radius of 0.6 – 31.6 m) which suggests that their call may serve a group cohesion function during nocturnal foraging. The bluefin gurnard was acoustically prolific (19 sounds fish-1 h-1) and had a larger acoustic repertoire than had been previously reported. In addition to the two types of grunt vocalisations, a distinctive nocturnal vocalisation consisting of two new types of growls was described. This indicates that bluefin gurnards could be a major contributor to the ambient sound of their off-shore soft bottom habitat and that field recordings in these areas may be a useful means of investigating gurnard biology and monitoring populations. The present study has also described for the first time the bioacoustic environment of a fish aggregation device (FAD). Using a Malaysian FAD as a model, the present study showed that sounds in frequency bands typically dominated by various biological sources (500 Hz – 2000 Hz octave bands) could propagate up to 400 m during the day and to more than 1 km at dusk. Thus, suggesting FADs could be acting as a long range acoustic cue for fish. The results of this study have greatly enhanced our understanding of fish vocalisations and its significance in the underwater soundscape of New Zealand coastal waters. In addition, it has contributed to our general understanding of the contribution of the underwater soundscape to fish behaviour and orientation.

An automatic analysis of bird vocalisations for the identification of bird species, the study of their behaviour and their means of communication is important for a better understanding of the environment in which we are living and in the context of environmental protection. The high variability of vocalisations within different individuals makes species’ identification challenging for bird surveyors. Hence, the availability of a reliable automatic bird identification system through their vocalisations, would be of great interest to professionals and amateurs alike. A part of this thesis provides a biological survey on the scientific theories of the study of bird vocalisation and corresponding singing behaviours. Another section of this thesis aims to discover a set of element patterns produced by each bird species in a large corpus of the natural field recordings. Also this thesis aims to develop an automatic system for the identification of bird species from recordings. Two HMM based recognition systems are presented in this research. Evaluations have been demonstrated where the proposed element based HMM system obtained a recognition accuracy of over 93% by using 3 seconds of detected signal and over 39% recognition error rate reduction, compared to the baseline HMM system of the same complexity.

Dogs and humans have through domestication and co-evolution established a close relationship and can communicate and understand each other. The objective of the present study was to deepen the understanding of the communication between dogs and humans, with focus on the vocalized communication. The study was based on video and audio recordings of dog-human communications from a total of 36 dogs in their home environment. The mean gap size in the communication ranged from 0.651.16 seconds and the overlap in communication had a percentage range of 14-50 %. These results are within the frame of other species communication with turn-taking. With these considerations, it clearly indicates that turn-taking occurs in interspecies communication between dogs and humans. The present study suggests that dogs intentionally communicate through vocalisation with their owners to gain the attention of the owner. In addition, age and sex of the dog influence their communication with their owners.

Le conditionnement de peur est l’une des tâches les plus utilisées pour étudier la formation des mémoires émotionnelles. Dans cette thèse, nous nous sommes intéressées au conditionnement de peur à l’odeur dans lequel l’arrivée d’une odeur est suivie après un intervalle de temps fixe d’un stimulus aversif. L’animal apprend très rapidement que l’odeur prédit l’arrivée du stimulus aversif et développe une réponse de peur à l’odeur caractérisée par différents comportements tels que l’immobilité de peur, l’émission de vocalisations ultrasonores, ou des variations du rythme respiratoire. Le premier objectif de la thèse a été de caractériser l’impact de l’émission des vocalisations ultrasonores sur les activités cérébrales chez le rat. Dans cet apprentissage, l’animal apprend également la durée de l’intervalle qui sépare l’arrivée de l’odeur du stimulus aversif. Les circuits sous-tendant l’encodage des durées dans cet apprentissage ont été très peu étudiés. Or l’encodage du temps est impliqué dans de nombreux comportements, et serait à la base des apprentissages associatifs. Le deuxième objectif de la thèse a donc été de caractériser le décours temporel des réponses de peur pendant l’intervalle odeur-stimulus aversif, ainsi que celui des activités cérébrales. Pour ces deux objectifs, nous avons utilisé une approche comportementale fine couplée à l’enregistrement électrophysiologique des activités oscillatoires dans un réseau de structures incluant le cortex préfrontal, l’amygdale, le striatum dorsal et le cortex olfactif. Nous avons montré qu’au sein de ce réseau, les activités oscillatoires sont modulées par la durée de l’intervalle, en lien avec les réponses comportementales
Fear conditioning is one of the most commonly used tasks to study the formation of emotional memories. In this thesis, we were interested in odor fear conditioning in which the arrival of an odor is followed after a fixed time interval by an aversive stimulus. The animal learns very quickly that the odor predicts the arrival of the aversive stimulus and develops a fear response to the odor characterized by different behaviors such as immobility of fear (freezing), the emission of ultrasonic vocalizations, or variations in respiratory rate. The first objective of this thesis was to characterize the impact of ultrasonic vocalization emission on the rat's brain activities. In this learning, the animal also learns the duration of the interval between the arrival of the odor and the aversive stimulus. The circuits underlying the encoding of durations in this learning have been very little studied. However, time encoding is involved in many behaviors, and would be a fundamental component of associative learning. The second objective of the thesis was thus to characterize the temporal course of fear responses during the odor- aversive stimulus interval, as well as that of brain activities. For these two objectives, we used a fine-grain behavioural approach coupled with electrophysiological recording of oscillatory activities in a network of structures including the prefrontal cortex, amygdala, dorsal striatum and olfactory cortex. We have shown that within this network, oscillatory activities are modulated by the duration of the interval, in relation to behavioural responses

Techniques of single- and multi-beam active acoustics and the passive recording of fish vocalisations were employed to evaluate the benefits and limitations of each technique as a method for assessing and monitoring fish aggregations. Five species, Samson fish (Seriola hippos), mulloway (Argyrosomus japonicus), West Australian dhufish (Glaucosoma hebraicum), Bight redfish (Centroberyx gerrardi) and pink snapper (Pagrus auratus) were investigated on the basis of their abundance, ecological importance and differing behaviour. The primary focus was on S. hippos, a large nonvocal schooling fish, and A. japonicus, a large vocal fish, with each species forming aggregations for spawning purposes.Simrad EQ60 single-beam echosounder assessments of mid-water, S. hippos aggregations at seven sites west of Rottnest Island illustrated the relative biomass increase, stabilisation and decrease between the months of October and March each year from October 2004 to March 2007. Surveys highlighted the preferred sites for spawning, spatial extents of each aggregation, as well as a decline in aggregation stability at full moon and end of season periods. Regular Department of Fisheries surveys displayed the relative ease with which single-beam techniques could be deployed, used and data analysed to monitor large, comparatively stable, deep (>50 m) aggregations of large swimbladdered fish. Acquired acoustic data illustrated the limitations of single-beam surveys conducted on a mobile school of fish.RESON 8125 and 7125 multi-beam sonar (MBS) surveys of S. hippos at Rottnest Island locations, some conducted simultaneously with the Simrad EQ60 single-beam, illustrated the improved spatial resolution of midwater targets achievable with MBS systems. The identification of individual S. hippos targets in MBS data facilitated the confirmation of S. hippos undetected by single-beam transects, due to relative sampling volumes. The MBS surveys showed evidence of possible fishing effects on S. hippos aggregations with school structure varying after a two hour period of fishing and video tows. Relative decline in aggregation stability towards the end of the season and possible avoidance behaviour from approaching vessels was observed as successive MBS transects, over a short space of time, recorded school movement around the wreck above which S. hippos aggregations sit.P. auratus spawning in the Cockburn Sound, Fremantle illustrated the limitations of single-beam acoustics to monitor aggregations of mobile fish in shallow water, due to vessel avoidance behaviour. Similar sampling issues were observed in MBS surveys despite the inherent geometric advantages of the wide acoustic swath and increased sample volume. It was anticipated that adjusting the MBS mounting position, such that nadir beams were orientated laterally athwartships (rather then vertically downwards), increased the lateral distance at which the fish could be observed, thus reducing vessel avoidance implications. However, due to time constraints and equipment availability, remounting the MBS was not possible at the time of survey and the effects of MBS orientation could not be verified.Single-beam and passive acoustic surveys of G. hebraicum illustrated the complexity of acoustic investigation of comparatively sedentary, demersal fish which often spawn in small groups. Discrimination of individuals using single-beam techniques was often restricted by the fish proximity to the seafloor and the footprint of the single-beam. Single-beam species identification of small groups of fish is impractical without simultaneous visual confirmation, due to the stochastic nature of fish reflectance. However, single-beam acoustics could provide information on G. hebraicum spawning related essential fish habitat using seafloor classification. While biological assessment of G. hebraicum otoliths, swimbladder and related muscular structure imply a soniferous species, as yet no vocal behaviour of any of the Glaucosomatidae has been reported, despite attempts here to detect vocalisations. Thus the characteristics of this species presented the greatest limitations for study using active or passive acoustic techniques.Passive acoustic techniques were shown to be ideally suited for monitoring the low density, benthic aggregations of A. japonicus in the Swan River. Spawning related vocalisations of A. japonicus were recorded in situ and in aquaria (Mosman Bay, Swan River and TAFE, Fremantle aquaculture centre respectively) each spawning season between October and May for four spawning seasons. A. japonicus calls, produced by the contraction of bi-lateral paired sonic muscles around the posterior two thirds of a heavily damped swimbladder, were classified into three categories relating to differing spawning functions. Category 1 calls (‘Bup’) of 2-4 swimbladder pulses were believed to function to gather males together in temporary broadcasting territories and to announce readiness to spawn. Category 2 calls comprised 11-32 pulses in a single audible tone (‘Baarp’), which could also be broken into two or more parts (‘Ba-Baarp’) with a believed function as a call of attraction, predominantly from males to females. The third Category comprised calls produced in quick succession at increasing call rate to a point of cessation. Series of Category 3 calls (‘Thup’) were recorded only at times associated with spawning, in fewer numbers than other call categories and consisted of between 1 and 4 pulses.Pulse repetition and spectral peak frequencies of Category 3 calls were notably higher than those of Category 1 and 2, both in situ and in aquaria, despite the similar number of pulses. For example, in situ pulse repetition frequencies of up to 114 Hz for Category 3 calls compared with approximately 59 Hz for other categories. It is suggested that the increased pulse repetition frequencies of Category 3 calls require greater, unsustainable levels of energy (corroborated by the decreasing pulse rate as these calls progress) and such calls are therefore reserved for specific, uncommon events, possibly episodes of courtship. Ground truth in aquaria calls exhibited similar call structure to those recorded in situ, however, pulse repetition rates and occurrence were significantly lower (respective pulse repetition frequencies of 41.74 and 58.68 Hz for captive and in situ Category 2 calls).Season-long monitoring of sound production in Mosman Bay determined spawning commencement was correlated with a daytime water temperature threshold at, or above 18.5 °C, occurring between October and November. Generalized Additive Models showed sound pressure levels (SPLs) and, by proxy spawning throughout the season, were correlated with temperature, salinity, sunset and tidal effects with decreasing order of effect. Increases in short-term sound production were observed on a semi-lunar basis, occurring at the new and full moons. Local chorus level maxima were found to occur on a 3.97 day basis (s.d. = 1.8), similar to that found from egg collection in aquaria and previous in situ SPLs in local studies of A. japonicus. Comparisons between Mosman Bay tidal related afternoon/evening activity and nocturnal behaviour of alternative populations in captivity suggest that A. japonicus exhibits adaptive vocal behaviour, and by proxy spawning activities, dependent on environmental variables.Individual A. japonicus were localised during spawning within and close to an array of hydrophones by using vocalisation arrival-time differences, surface reflection and comparative energy level techniques to analyse vocalisations. Several individual A. japonicus were followed for periods ranging from seconds to several minutes as they called repetitively. Monitoring individual movement and separation distances between calling fish confirmed low mobility over long periods, indicative of lekking behaviour. The determination of call source levels employed calls of known range using data from the localisation study. Mean squared pressure source levels and 95 % confidence limits of the three call categories were measured as: 163 (147.7, 178.6), 172 (168.4, 176.0) and 157 (154.0, 160.3) dB re 1μPa for Categories 1, 2 and 3, respectively.During periods of low density calling in the 2006-7 spawning season, techniques of call counting produced absolute abundance estimates for A. japonicus present within the hydrophone detection range of approximately 500 m, observing a maximum of 15 calling individuals. Assuming a 1.3:1 sex ratio this implies a detectable spawning population of 26 fish within approximately 100, 000 m[superscript]2 (range restricted across stream by depth) equivalent to approximately 3, 850 m[superscript]2 per fish (assuming a random distribution of callers and recipients). However, during high density ‘continuous chorus’ calling the maximum number of callers able to be discerned using call counting techniques was exceeded. The application of call counting techniques and call contributions to overall SPLs to estimate biomass during ‘chorus’ calling, where calls merge together, requires further investigation. Recorded chorus levels were not a simple function of animals calling within the receiver proximity, but were strongly influenced by source-receiver range. A preliminary model to estimate minimum numbers of callers within derived range boundaries has been laid out.Recording of A. japonicus vocalisations illustrated the developing capabilities of passive acoustics to monitor soniferous fish species. A suggested set of protocols has been laid out to standardise the reporting of fish calls together with supplementary data relating environmental variables to their subsequent effects on the acoustic characteristics of the call. Standardisation of reporting will facilitate future spatial and temporal comparison of inter- and intra-species sound production.This study has illustrated that the features of each acoustic technique endear them to particular species-specific characteristics. For example, although S. hippos did not vocalise they formed midwater aggregations of large fish (107 cm mean fork length) and were thus amenable to active acoustic monitoring. In contrast, A. japonicus form low density, benthic aggregations and hence are not suited to study by active acoustics, but vocalised profusely rendering them suitable for passive acoustic monitoring. In many cases a combination of techniques both acoustic and non-acoustic is required to monitor the particular species, in order to ground truth the data.

Abstract The preverbal vocalisation up to the first word, feeding skills as well as motor development until the first steps of ELBW preterm infants without disability were compared in this descriptive study to those of healthy full-term infants. In addition, preverbal and feeding skills were studied in relation to gross motor movement patterns. The preverbal development of preterm infants proceeded according to the same temporal schedule as that of full-term infants, however, preterm infants failed to produce several vocalisation skills that full-term infants presented. The preterm infants increased their vocalisation slower than the full-term infants in the beginning of each of the developmental stages. The difference between the preterm and the full-term infants grew when approaching syllables, syllable combinations, and words. The preterm infants reached the first word approximately two months later than the full-term infants. The suckling of preterm infants was either disorganised or dysfunctional, while normal or disorganised in the case of full-term infants. The preterm infants reached the spoon-feeding skills approximately at the same (corrected) ages as the full-term infants, but the transitions to new stages were difficult. Half of the preterm infants suffered from feeding problems while only two of the full-term infants had feeding problems. Both the preterm and full-term infants reached vocalisation and feeding skills in relation to gross motor movement patterns earlier than assumed according to the predominant clinical knowledge. The vocalisation and feeding skills did not seem to be dependent upon the gross motor development
Tiivistelmä Tässä kuvailevassa tutkimuksessa tarkasteltiin tiiviissä seurannassa erittäin ennenaikaisina ja pienipainoisina syntyneiden lasten esileksikaalista ääntelyä ensisanaan asti sekä syömistaitojen ja motoriikan kehitystä ensiaskeliin asti. Tuloksia verrattiin terveiden, täysiaikaisina syntyneiden lasten vastaaviin taitoihin. Lisäksi ääntelyn ja syömisen kehitystä tarkasteltiin suhteessa karkeamotoristen taitojen kehitysaikatauluun. Ennenaikaisesti syntyneiden lasten ääntely kehittyi saman aikataulun mukaan kuin täysiaikaisten lasten ääntely. Ennenaikaisesti syntyneet lapset jättivät kuitenkin väliin taitoja, jotka täysiaikaisina syntyneet lapset saavuttivat. Siirryttäessä uusille ääntelyn ja kielen kehitystasoille ennenaikaisina syntyneiden lasten ääntelyn määrä lisääntyi hitaammin kuin täysiaikaisina syntyneiden lasten ääntelyn määrä. Ero ennenaikaisina ja täysiaikaisina syntyneiden lasten kehityksessä kasvoi lähestyttäessä tavuja, tavuyhdistelmiä ja sanoja. Ennenaikaisesti syntyneet lapset saavuttivat ensisanavaiheen kaksi kuukautta täysiaikaisia lapsia myöhemmin. Ennenaikaisina syntyneiden lasten syömisen taidoissa havaittiin, että varhainen imeminen oli joko jäsentymätöntä tai poikkeavaa, kun täysiaikaisina syntyneillä se oli puolestaan normaalia tai jäsentymätöntä. Ennenaikaisina syntyneet lapset oppivat käsittelemään soseita ja kiinteitä ruokia samassa (korjatussa) iässä kuin täysiaikaisina syntyneet lapset, mutta siirtyminen kehitysvaiheesta toiseen tuotti vaikeutta. Puolet ennenaikaisista lapsista kärsi syömisvaikeuksista. Sen sijaan täysiaikaisina syntyneistä lapsista kahdella todettiin syömisen vaikeutta. Sekä ennenaikaisina että täysiaikaisina syntyneet lapset oppivat ääntelyn ja syömisen taitoja ennen tiettyjä karkeamotorisia liikemalleja, joiden on vallitsevan kuntoutuskäsityksen mukaisesti oletettu edeltävän näiden taitojen saavuttamista. Ääntelyn ja syömisen taidot eivät siis näyttäneet olevan riippuvaisia karkeamotoriikan kehityksestä