Дисертації з теми "BRAIN COMMUNICATION"

Proefschrift Rijksuniversiteit Groningen.
Auteursnaam op omslag: Freddy van der Veen. Kop titelpagina vermeldt: Rijksuniversiteit Groningen. Datum laatste controle: 02-07-1997. Met lit. opg. - Met een samenvatting in het Nederlands.

Asthma, a chronic TH2-mediated inflammatory disease of the airways, is the most common form of allergy in the Western world, affecting 300 million people worldwide. Epidemiological studies have shown that asthma is associated with mood disorders, such as anxiety and depression, and numerous experiments have reported that asthma induces functional changes in neuronal fibres of the peripheral nervous system (PNS), which innervate the brain. It is unknown, however, how allergic lung inflammation impacts on the central nervous system (CNS). The ability for peripheral inflammation to impact on the brain, altering behaviour and neuronal activity in the CNS, is a well-recognised and physiological phenomenon, known as immune to brain communication, but has, until now, only focused on how innate pro-inflammatory and TH1, but not TH2, type immune responses impact on the brain. Critically, immunomodulatory therapeutics, which involve stimulation of an innate pro-inflammatory immune response, are currently being developed for the treatment of asthma, highlighting the importance of understanding the effect of allergic lung inflammation and its treatment on the brain. Consequently, using acute and chronic localised TH2 models of inflammation, we investigated how allergic lung inflammation impacted on the CNS and subsequently determined the secondary impact of immunomodulation with the Toll-like receptor 7 (TLR7) agonist resiquimod. Acute TH2 inflammation in the peritoneum and lung was found to communicate with the brain, via a vagal route of communication. Crucially, it led to a distinct pattern of neuronal activity, with no changes in sickness behaviour or CNS inflammation, changes widely different to those known to occur following systemic TH1 inflammation. At chronic stages of lung inflammation, changes in genes associated with synaptic plasticity in the brainstem and altered expression of the GABAB receptor and brain-derived neurotrophic factor in the hippocampus were observed, firstly providing a CNS-dependent biological explanation for airway hyperresponsiveness, a critical pathological symptom of asthma, and secondly offering a biological justification for the prevalence of mood disorders in asthmatic patients. Resiquimod treatment in allergic animals was associated with attenuated central inflammatory responses, as compared to treatment in healthy animals, encouraging and reassuring in terms of patient well-being and, critically, also insinuating that safety of therapeutics differs in diseased, as opposed to healthy individuals. The results in this thesis are some of the first to identify that physiological inflammatory diseases impact on the CNS, highlighting the importance of immune to brain communication on pathological and psychopathological symptoms of a disease, and additionally demonstrating how inflammatory conditions can modify the off-target effects of a drug. Not only do these results provide a foundation for the future of immune to brain communication research, namely understanding how physiological inflammatory diseases impact on the CNS, but also have the potential to be translational and emulated in a clinical setting.

L'interleukine 1β agit sur le cerveau en provoquant la fièvre et des altérations comportementales. L'objectif de nos études était de déterminer de quelle façon l'interleukine-1β libérée par des cellules phagocytaires du système immunitaire medie son action sur le cerveau. L'approche expérimentale a consisté à injecer le lipopolysaccharide d'E. Coli dans la cavité abdominale de rats Wistars. Le lipolysaccharide induit la libération d'interleukine-1β. Sachant que le foie contient des terminaisons sensorielles du nerf vague et contient des cellules phagocytaires, nous avons cherché à investiguer si le nerf vague joue un rôle dans l'action de l'interleukine-1β sur le sustème nerveux central. Chez les animaux ayant subi une vagotomie sous-diaphragmatique, le lipopolysaccharide n'induit plus l'expression du marqueur d'activation cellulaire Fos dans l'hypothalamus ni dans les structures limbiques telles que l'amygdale. Par ailleurs, la diminution des interactions sociales, une des altérations comportementales observées après injection d'interleukine-1β, a été reportée comme étant significativement moindre chez les animaux vagotomisés. D'autre part, des cellules phagocytaires interleukine-1β immunoréactives ont été ide,tifiées dans les organes circumventriculaires du cerveau après injection de lipopolysaccharide. L'hypothèse selon laquelle la diffusion de cette interleukine-1β serait impliquée dans la communication entre système immunitaire et le cerveau a été étudiée en administrant l'antagoniste de récepteurs à l'interleukine-1 dans le ventrivule latéral. Une diminution des altérations comportementales induites par l'administration de lipopolysaccharide ainsi qu'un bloquage de l'expression de Fos dans l'amygdale ont été observés chez les animaux ayant reçu cet antagoniste. Nous avons donc montré que le nerf vague ainsi que la libération de l'interleukine-1β dans les organes circumventriculaires sont importants dans la communication entre le système immunitaire et le cerveau
Interleukin-1β acts on the brain to induce fever and behavioural changes. The aim of this thesis was to determine how interleukin-1β that is released by phagocytic cells of the immune system can act on the brain. The experimental model used consisted of injecting Wistar rats intraperitoneally with lipopolysaccharide from E. Coli. Lipopolysaccharide administration induces the release of interleukin-1β. In view of the fact that the liver is innervated by vagal sensory nerve endings and contains phagocytic cells, the role of the vagus nerve in the action of interleukin-1β on the brain was studied. In animals in which the vagus nerve was cut under the diaphragm lipopolysaccharide failed to induce the cellular activation marker Fos in the hypothalamus and amygdala. In addition, the reduction in social interaction, one of the behavioural changes observed after injection of interleukin-1β, was significantly less in vagotomized animals. Interleukin-1β immunoreactive phagocytic cells were also observed in circumventricular organs of the brain after injection of lipopolysaccharide. Their hypothesis that diffusion of thus produced interleukin-1β is implicated in the communication between the immune system and the brain was tested by administration of the interleukin-1 receptor antagonist into the lateral cerebra ventricle. A reduction in the behavioural changes induced by lipopolysaccharide as well as a blockage of Fos expression in the amygdala was observed in those animals that received this antagonist. In conclusion, it was shown that the vagus nerve and the release of interleukin-1β from circumventricular organs are important in the communication between the immune system and the brain

The purpose of this exploratory study was to determine if a single communication measure or combination of measures could discriminate employed from unemployed individuals with traumatic brain injury (TBI). Twenty adult subjects (ten employed and ten unemployed), one to four years post injury, with comparable severity of injury and type of work participated in the study. Each subject was given ten communication tests measuring: auditory processing (Filtered Words, Auditory Figure Ground, Competing Words, and Competing Sentences subtests of the SCAN-A); the effects of speaking under time pressure (FAS and Rapid Automatized Naming); production of oral language (local coherence); language ability (Aphasia Quotient portion of the Western Aphasia Battery); and functional verbal reasoning ability (Scheduling and Planning an Event subtests of the Functional Assessment of Verbal Reasoning (FAVR)). Results revealed that when a combination of three communication tests, the Scheduling subtest of the FAVR, and the Filtered Words and Competing Sentences subtests of the SCAN-A, was used, the model correctly classified 85% of employed and unemployed individuals. The findings suggest that both impairment and disability-based tasks (i.e. those measuring activities that reflect daily communication) may be more revealing than the impairment-level tasks alone that frequently appear in the TBI and work re-entry literature. Impairment and disability level communication tasks may provide functional and practical information, which can be used to assist in work re-entry.

Amyotrophic Lateral Sclerosis (ALS) is a fatal neurodegenerative disease characterized by progressive paralysis of limbs and bulbar musculature. This severe physical impairment makes cognitive evaluation a big challenge, thus there is a great need for an assessment that does not require overt motor responses. Moreover, we need of augmentative communication strategies because the disease generally leads to complete paralysis and, therefore, patients are unable to communicate with the external world by any means. For this purpose, Brain Computer Interfaces (BCIs) seem a promising approach to facilitate communication with these patients. The aim of this thesis is twofold. First, assessing cognitive processing in ALS by means of a novel evaluation tool. Second, allowing brain communication in completely paralyzed ALS patients who had lost their vision in order to eliminate the unbearable loss of communication in paralysis (“unlocking the locked-in”). The first study introduces a novel approach for assessing cognitive functions in ALS. This approach uses neuropsychological tests that require minimal overt motor or verbal responses; together with vibro-tactile P300s. Results indicate mild cognitive impairment in oral language comprehension tasks and reduced vibro-tactile P300 amplitudes in patients compared to healthy controls. Importantly, correlations between the vibro-tactile P300 latency and psychometric test results suggest that the former measure could serve as a neurophysiological marker of cognitive decline in ALS patients. The second study introduces a distraction paradigm based in auditory event-related potentials (ERPs) to evaluate the ability of change detection, focusing, and re-orientation of attention in ALS. The results revealed a modification of the amplitude and the latency of the N200, the P300 and the re-orienting negativity (RON) components. This could suggest an alteration of the endogenous mechanism that controls the detection of change, thus resulting in a reduction of the allocation and the re-orientation of attentional resources. The third study aimed at testing the feasibility of a Near Infrared Spectroscopy (NIRS) -based BCI communication approach for patients in the Completely Locked-in Stage (CLIS) due to ALS. For this purpose two CLIS patients were trained to control their cerebral-cortex´s functional-activations in response to auditory processing of correct or incorrect statements assessed with NIRS. The results of the study are very promising, showing that both CLIS patients communicated with fronto-cortical oxygenation based BCI at an average correct response rate of 70% over a period of several weeks. We conclude that this novel approach of brain-communication is safe and, reliable, representing, so far, the best communication possible for patients in completely locked-in state. In conclusion we propose a) the novel combination of vibro-tactile or acoustic ERPs and motor-independent neuropsychological tests as an alternative and easily implementable way for assessing cognitive functions in ALS and b) we confirm the usefulness and effectiveness of above mentioned electrophysiological approaches in the late stage of ALS either to assess cognitive processing or to establish communication with a BCI system.
Amyotrophic Lateral Sclerosis (ALS) is a fatal neurodegenerative disease characterized by progressive paralysis of limbs and bulbar musculature. This severe physical impairment makes cognitive evaluation a big challenge, thus there is a great need for an assessment that does not require overt motor responses. Moreover, we need of augmentative communication strategies because the disease generally leads to complete paralysis and, therefore, patients are unable to communicate with the external world by any means. For this purpose, Brain Computer Interfaces (BCIs) seem a promising approach to facilitate communication with these patients. The aim of this thesis is twofold. First, assessing cognitive processing in ALS by means of a novel evaluation tool. Second, allowing brain communication in completely paralyzed ALS patients who had lost their vision in order to eliminate the unbearable loss of communication in paralysis (“unlocking the locked-in”). The first study introduces a novel approach for assessing cognitive functions in ALS. This approach uses neuropsychological tests that require minimal overt motor or verbal responses; together with vibro-tactile P300s. Results indicate mild cognitive impairment in oral language comprehension tasks and reduced vibro-tactile P300 amplitudes in patients compared to healthy controls. Importantly, correlations between the vibro-tactile P300 latency and psychometric test results suggest that the former measure could serve as a neurophysiological marker of cognitive decline in ALS patients. The second study introduces a distraction paradigm based in auditory event-related potentials (ERPs) to evaluate the ability of change detection, focusing, and re-orientation of attention in ALS. The results revealed a modification of the amplitude and the latency of the N200, the P300 and the re-orienting negativity (RON) components. This could suggest an alteration of the endogenous mechanism that controls the detection of change, thus resulting in a reduction of the allocation and the re-orientation of attentional resources. The third study aimed at testing the feasibility of a Near Infrared Spectroscopy (NIRS) -based BCI communication approach for patients in the Completely Locked-in Stage (CLIS) due to ALS. For this purpose two CLIS patients were trained to control their cerebral-cortex´s functional-activations in response to auditory processing of correct or incorrect statements assessed with NIRS. The results of the study are very promising, showing that both CLIS patients communicated with fronto-cortical oxygenation based BCI at an average correct response rate of 70% over a period of several weeks. We conclude that this novel approach of brain-communication is safe and, reliable, representing, so far, the best communication possible for patients in completely locked-in state. In conclusion we propose a) the novel combination of vibro-tactile or acoustic ERPs and motor-independent neuropsychological tests as an alternative and easily implementable way for assessing cognitive functions in ALS and b) we confirm the usefulness and effectiveness of above mentioned electrophysiological approaches in the late stage of ALS either to assess cognitive processing or to establish communication with a BCI system.

Traumatic brain injury (TBI) is a common cause of disability, which frequently causes impairments in communication skills. These impairments affect successful participation in conversations and have a long-term impact on relationships, employment, and social life. Training communication partners to use a positive and supportive approach to communication when having conversations with people with TBI has been demonstrated to be effective in improving outcomes. However, it is challenging for communication partners of people with TBI to access this training due to competing time demands and distance from rehabilitation services. Using telehealth to provide communication skills training could offer a potential solution. This thesis investigated the potential for using telehealth to provide communication skills training to people with TBI and their communication partners through: (1) a systematic review of the literature focussed on telehealth-based interventions involving family caregivers of people with TBI, (2) a reliability study comparing videoconferencing-based assessment with in-person assessment of the communication of people with TBI, (3) a single case experimental design study of telehealth-based communication skills training involving two people with severe TBI and their communication partners, and (4) a clinical trial of communication skills training for people with moderate-severe TBI and their communication partners involving 51 participants with comparison across telehealth delivery, in-person delivery, and a historical control group. Each of these studies provided evidence supporting the use of telehealth for assessment and training of social communication skills after TBI. The positive findings from this research will influence policies relating to brain injury rehabilitation services and potentially support increased provision of services via telehealth in the future.

Patients who suffer from traumatic brain injury often face communication deficits during their hospital stay. This thesis intended to examine approaches the nurse can use to facilitate communication in collaboration with the speech-language pathologist. A review of literature was conducted to examine current research on the most effective devices used to facilitate communication in this patient population. Research revealed that low-technology devices were the most effective means of communicating in the hospital setting. Barriers to effective communication were identified as lack of time, education and access to the devices. Recommendations for future research include developing a documentation component that emphasizes nursing assessment and intervention through collaboration with the SLP. Additional recommendations for research include the examination of impact of AAC use on patient satisfaction and outcomes. Communication using AAC is necessary in order to improve patient outcomes for traumatic brain injured individuals. This can be achieved through increased collaboration with the SLP, and increased nursing knowledge of the available devices and their implementation.
B.S.N.
Bachelors
Nursing
Nursing

Objective: To investigate the nature of 1) perceived communication ability, 2) communication-related metacognitive knowledge and 3) associations between communication-related metacognitive knowledge and injury and demographic variables in adults with severe traumatic brain injury (TBI) and their close others over time Participants: 27 participants with severe TBI and their close others Design: Longitudinal, repeated measures design Measure: The La Trobe Communication Questionnaire was administered at six, 12 and 24 months post injury Analysis: One-way repeated measures analysis of variance and Friedman tests were applied to measure changes in perceived communication ability. Changes in communication-related metacognitive knowledge were analysed using inferential and descriptive statistics. Spearman’s correlation coefficient was utilised to determine associations between communication-related metacognitive knowledge and injury and demographic variables over time. Results: TBI participants with a mild communication disability perceived more frequent communication problems over time, especially from 12 months. Problems perceived to occur more frequently over time were related to initiation/conversational flow. Close others did not perceive significant changes in their relatives’ communication over time. People with a mild communication disability had better communication-related metacognitive knowledge over time. They perceived more frequent problems than their close others perceived them to have, whereas participants with a moderate/severe communication disability displayed the reverse pattern. Communication-related metacognitive knowledge was better for observable communication problems. No clear associations were found between injury and demographic variables and communication-related metacognitive knowledge at each time point.

Cognitive processing requires to flexibly combine information from functionally specialized neural processes that are widely distributed throughout the brain. Neuroimaging studies have consistently reported that functional network configurations are governed by two fundamental principles of brain organization: functional segregation and integration. Yet, the mechanisms underlying the dynamic network reorganization are not well understood. In this work, we present evidence for two mechanisms through which the dynamic system-level integration is modulated. On the one hand, the large-scale brain organization is mediated by transient changes in phase-synchronization, facilitating global information flow between distant cortical areas as proposed by the "Communication Through Coherence" (CTC) theory. And in the other, it is mediated by the ascending neuromodulatory system. Neuromodulators constrain local processes by selectively changing the balance of the excitation and inhibition of individual brain regions.
El procesamiento cognitivo requiere combinar de manera flexible la información de procesos neuronales funcionalmente especializados que están ampliamente distribuidos por todo el cerebro. Los estudios de neuroimagen han informado consistentemente que las configuraciones de red funcional se rigen por dos principios fundamentales de la organización del cerebro: segregación funcional e integración. Sin embargo, los mecanismos subyacentes a la reorganización dinámica de la red aún no son bien comprendidos. En este trabajo, presentamos evidencia en soporte de dos mecanismos a través de los cuales se modula la integración dinámica a nivel de sistema. Por un lado, la organización del cerebro a gran escala está mediada por cambios transitorios en la sincronización de fases, lo que facilita el flujo de información global entre áreas corticales distantes como lo propone la teoría de "comunicación a través de la coherencia" (CTC). Y por otro, está mediada por el sistema neuromodulador ascendente. Los neuromoduladores restringen los procesos locales al cambiar selectivamente el equilibrio de la excitación e inhibición de las regiones cerebrales individuales.

This study examines facilitated communication as it was experienced by three people who were affected by acquired brain injury. Facilitated communication is a type of augmentative communication purported to allow persons with a severe communication impairments to communicate. The assumption is made that people with global apraxia can communicate if given physical support. The technique usually involves a facilitator providing physical support to the arm, hand or elbow of the person with the severe communication impairment to assist them to point to objects, pictures, printed letters and words or to a keyboard. Facilitated communication is a controversial method because it is difficult to establish the existence, or extent of the facilitator's influence in the communication of the person with a disability. Although much of the research on facilitated communication has been conducted with people with intellectual or developmental disabilities, research on the use of the technique with people with brain injury offers several advantages. Firstly, most people with brain injury were known to be competent communicators prior to the brain injury. Secondly, many recover sufficiently to allow a retrospective examination of the issues that faced them when they were using the technique. Thirdly, there can be a large amount of data available about the person's diagnosis, their prognosis and the course of their history following the event. Consequently, the current study uses a case study methodology to explore the application of facilitated communication with people with brain injury and draws on personal recollections of people with brain injury, interviews with families and medical and therapist reports. The three people interviewed in the study displayed varying language and memory abilities. They indicated a preference for independent communication techniques and they reported frustrations with using facilitated communication. They quickly rejected the method when speech began to appear even though their speech was inadequate for communication purposes, for two of them, for an extended period. One of the interviewees reported that facilitator influence was overwhelming at times but not always present. Two of the interviewees felt that facilitated communication gave them a start in their recovery process. Two of the interviewees reported that meaningful exchanges with others occurred only with speech. In addition to these findings the study, although not experimental, was able to shed light on some of the contentious issues surrounding facilitated communication. The method is reported to be designed to overcome the motor difficulties of the disabled communicator by providing physical assistance to individuals with poor fine motor control thus breaking the perseveration cycle that can be present . However the task of coping with facilitator influence may actually require some motor skills. Also, the physical effort involved in using facilitated communication for some individuals may have been underestimated by its supporters. However the study has shown that some individuals with severe communication impairments felt that facilitated communication had some merit but saw their ability to communicate independently as the significant achievement in their recovery.

All brain functions, from seeing and moving to thinking, rely on the interaction of multiple, functionally distinct brain areas. We know, however, very little about how different areas interact at the level of networks of neurons, or what mechanisms are used to control the routing of information through the brain. Only very recently has technology evolved to the point where we can simultaneously monitor multiple neurons in various brain areas. While such experiments enable a host of new and exciting questions about inter-area interaction, they also pose significant analysis and interpretation challenges. Here, we approach the problem of studying population-level interactions across brain areas using dimensionality reduction methods. In short, dimensionality reductions methods extract a small set of latent variables that summarize a given aspect of the data. Traditionally, these methods have been used to extract low-dimensional summaries of the population activity structure within a brain area. We propose to instead extract a set of latent variables that summarize the interaction between brain areas, i.e., instead of capturing the dominant features of the activity within an area, they capture the features that are relevant to its downstream targets. We used this approach to characterize both the population-level structure and the dynamics of the interactions between populations of neurons in two cortical areas, visual areas V1 and V2. We found that V1-V2 interactions occur through a communication subspace: V2 fluctuations are related to a small subset of V1 population activity patterns, distinct from the largest fluctuations shared among neurons within V1. We propose that the communication subspace may be a general, population-level mechanism by which activity can be selectively routed across brain areas. Furthermore, we found these interactions to be dynamic and flexible, changing rapidly under different stimulus contexts. This work thus provides a foundation for studying how multiple populations of neurons interact and how this interaction supports brain function.

Thesis (Ed. D.)--West Virginia University, 2000.
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Primary objective: To compare the everyday communication of individuals with mild and moderate dysarthria and concomitant cognitive-communication impairments following traumatic brain injury (TBI) Methods and procedures: Five participants with mild dysarthria and five with moderate dysarthria following TBI were recorded during telephone service enquiries with bus timetable call centre operators. Transcripts were analysed using exchange structure analysis derived from systemic functional linguistics. Listener comfort ratings were collected using a novel equal appearing interval scale to measure how comfortable people would feel interacting with the participants. Main outcomes and results: Participants with moderate dysarthria were not necessarily penalised for having poorer intelligibility during bus timetable service encounters. While participants with moderate dysarthria were given poorer listener comfort ratings, this did not affect the way information was exchanged with bus timetable call centre operators. These findings were attributed to the powerful interactional role of TBI participants as customers, the amount of disability awareness training and experience held by call centre operators and the highly structured nature of bus timetable service enquiries. Listener comfort ratings could be predicted with moderate accuracy from intelligibility scores. Conclusions: Service encounters where individuals with TBI are placed in a powerful interactional role of customer may be functional generalization tasks. Training and education of service providers may also impact on the communicative effectiveness of individuals with TBI.

By the year 2030, it is projected that over 240 million individuals will be affected by Traumatic Brain Injury (TBI). Communicating with a person who has a TBI-related cognitive-communication disorder has been described as uninteresting, effortful and unrewarding. There is currently limited evidence around cognitive-communication recovery and prognosis. Consequently, there is a lack of guidance around timing, planning and prioritisation of Speech-Pathology resources with this population. The aim of this project was to explore the nature of cognitive-communication recovery following TBI. A systematic review of cognitive-communication recovery revealed a limited body of evidence across the first few years following TBI. To address this research gap, this study used an inception cohort, comprising of 57 participants who were assessed at 3, 6, 9 and 12 months following their injury. Improvements in discourse skills were observed across the entire first year. However, the TBI group remained significantly below the control group at all time points. The time period between 9-12 months was particularly critical for recovery. A further study revealed the predictive value of the discourse measure in relation to psychosocial outcomes, which may support prioritisation of rehabilitation goals. Aphasia was identified as a key factor of recovery and was further explored from a clinical perspective. This project advocates for active Speech Pathology services up to and possibly beyond the first year following injury. Implementing this renewed understanding of communication recovery following TBI is likely to promote improved timing, planning and prioritization of Speech-Pathology services during the first important year of rehabilitation. Further research into understanding communication recovery is required to support longer-term outcomes along the continuum of care.

The focus of this research is the investigation, during the first year of life and in particular in 6 and 12 months old infants, of the development of the brain structures which are implicated in the social abilities. These abilities are fundamental for the people’s communication and they are essential for an appropriate human’s adaptation in its own social environment. Brothers in 1990 proposed to call this set of brain regions, which are dedicated to the social cognition as the “social brain”. It is well known in the literature that the development of the “social brain” includes the development of the abilities which are fundamental to communicate each other and to manipulate socially relevant information. Many studies have focus on several brain structures that play a key role in guiding social since the human being is characterized by the capacity to extract and interpret from simple cues (i.e. eye gaze) complex social state. There are a lot of studies that have investigated the development of the social brain during the life course (in newborn, infants and adults) and in these studies one of the most relevant aspects of the social cognition development studied/ which is studied is the perception of others as intentional agents. Some researchers have suggested that infants’ ability to reason about goals is developed as a result of direct experience with human agents and is then gradually extended to other agents (e.g. inanimate objects). This view predicts that young infants should attribute goals to humans, but not to other inanimate objects (Woodward 1998). Other researchers have proposed that goal attribution is rooted in a specialized system of reasoning which is activated whenever infants encounter entities with appropriate features (e.g., self-propulsion, equifinal variations, action-effect) and that young infants should attribute goals to both human and nonhuman agents (Bíró and Leslie 2007; Bíró, Csibra and Gergely, 2007). In addition to the humans or inanimate aspect’s agent, the role of the biological/social vs non-biological/mechanical motion is a further cue in order to identifying entities and behaviours as goal-directed (Lloyd, Blasi, Volein, Everdell, Elwell and Johnson, 2009). In particular, it is possible to suppose that since a motion could be biological (like the motion of a human be) or mechanical (not fluid, not harmonic, rigid), its association with different features could have modified the interpretation of the goal-directed actions. To investigate the role of the biological and non-biological movement in the comprehension of the intentionality of an action in 6 months old infants it was run five experiments. The results showed that the comprehension of goal-direct actions depends on different agents’ features and on communicative cues can modify the interpretation of goal directed actions. In particular the self-propelledness seem to be a fundamental characteristics for identifying goal-directed actions. The presence of self-propelledness was proposed by some (Premack, 1990; Baron-Cohen, 1994) as a precondition for setting up a goal-directed interpretation: only when an object’s motion is self-propelled infants will consider other cues relevant for identifying the goal of the action. According to this view, previous evidences claimed that infants can understand an intentional action not only when the agent is a biological actor, like an hand, but also when the agent is an inanimate object and seems to move in an independent way (Luo and Baillargeon, 2005). Others however, demonstrated that for 12-month old infants self-propulsion is not a necessary prerequisite for goal attribution and its absence does not necessarily inhibit the interpretation of behaviours in terms of goals (Bíró, Csibra and Gergely, 2007). With the second study we suggest the hypothesis that when the self-propelldness is not presence is absolutely necessary the presence of a communicative characteristic in the agent to permit infants to understand the intentionality of the action. This findings is supported also by the third neuro-imaging studies (NIRS study) showing that brain regions in the Superior Temporal Sulcus (a region included in the regions of the “social brain”) are involved in social interaction in response of dynamic social stimuli from the first months of life. In conclusion our findings seem to suggest that an interaction between the experience and the natural predispositions of the brain structural is at the basis of the social development. It seems that the human functional brain development is not just a passive maturational sequence, but is an activity processes mediate by experience and guides by initial predispositions, as neurocostruttivism view propos (Karmiloff-Smith, 2009)
L’obiettivo di questo lavoro è di investigare, durante il primo anno di vita ed in particolare in bambini di 0, 6 e 12 mesi, lo sviluppo delle aree cerebrali che controllano le abilità sociali che intervengono nella comunicazione tra gli individui e che costituiscono le abilità indispensabili per un adeguato adattamento dell’uomo nel proprio ambiente sociale. Brothers nel 1990 propose di chiamare queste regioni cerebrali, dedicate alla cognizione sociale, “Social Brain”. È noto in letteratura che lo sviluppo del “Social Brain” include lo sviluppo di abilità che sono fondamentali per comunicare con gli altri e manipolare informazioni sociali rilevanti per la vita quotidiana. Molti studi si sono focalizzati sull’investigazione delle strutture cerebrali che giocano un ruolo fondamentale nel guidare i comportamenti sociali poichè gli esseri umani sono caratterizzati dalla capacità di estrarre ed interpretare da semplici indizi (come per esempio la direzione dello sguardo) complesse situazioni sociali. Tra i numerosi lavori che hanno investigato lo sviluppo del “Social Brain” durante il corso della vita (nei neonati, nei bambini e negli adulti), un aspetto dello sviluppo della cognizione sociale che ha trovato una forte rilevanza è la percezione e l’elaborazione degli altri come agenti intenzionali. Alcuni ricercatori suggeriscono che le abilità dei bambini di riconoscere gli scopi delle azioni si sviluppano grazie alla diretta esperienza con gli agenti umani e solo successivamente, nel corso della vita, si estende gradualmente agli altri tipi di agenti (i.e. oggetti inanimati). Secondo questa prospettiva i bambini possono attribuire degli scopi ad agenti umani ma non agli altri oggetti inanimati (Woodward, 1998). Altri ricercatori propongono, invece, che l’attribuzione di intenzionalità agli agenti sia legata alla presenza di determinate caratteristiche fisiche (come l’autopropulsione descritta come la capacità di muoversi da soli, la direzione del movimento, la variazione equifinale del movimento intesa come la capacità di raggiungere lo stesso obiettivo con modalità e percorsi differenti, e l’efficacia dell’azione), per questo propongono che i bambini piccoli possano attribuire gli scopi delle azioni sia agli agenti animati che agli agenti inanimati (Bíró e Leslie 2007; Bíró, Csibra e Gergely, 2007). Oltre all’aspetto umano o inanimato dell’agente, anche il ruolo del movimento biologico/sociale versus non biologico/meccanico rappresenta un altro indizio utilizzato per identificare entità e comportamenti come diretti ad uno scopo (Lloyd, Blasi, Volein, Everdell, Elwell and Johnson, 2009). In particolare, è possibile ipotizzare che quando il movimento è biologico (come il movimento di un essere umano) oppure meccanico (non fluido, non armonico, rigido), la sua associazione con differenti caratteristiche fisiche possa modificare l’interpretazione dell’azione diretta ad uno scopo. Per indagare il ruolo del movimento biologico e non biologico nella comprensione dell’intenzionalità di un azione in bambini di 6 mesi ho eseguito cinque esperimenti. I risultati raggiunti dimostrano che la comprensione delle azioni diretta ad uno scopo dipende dalle differenti caratteristiche fisiche dell’agente e dalla presenza o meno di una componente comunicativa. In particolare la capacità degli agenti di muoversi in modo autonomo sembra essere fondamentale per identificare le azioni dirette ad uno scopo. La presenza di questa capacità viene proposta da alcuni studiosi come una precondizione per la costruzione di un riconoscimento di azione finalizzata: solo quando il movimento di un oggetto viene percepito autonomo, il bambino potrà considerare altri indizi rilevanti per identificare lo scopo dell’azione (Premack, 1990; Baron-Cohen, 1994). In accordo con questa prospettiva precedenti evidenze dimostrano che i bambini possono comprendere un azione intenzionale non solo quando l’agente è biologico e quindi umano, come per esempio una mano, ma anche quando l’agente è un oggetto inanimato purché sembri muoversi in modo indipendente (Luo e Baillargeon, 2005). Altre evidenze, però, dimostrano che, almeno in bambini di 12 mesi, la possibilità che un agente si muova in modo autonomo non è necessaria al fine di attribuire uno scopo all’azione e la sua assenza non necessariamente inibisce l’interpretazione dei comportamenti come diretti ad uno scopo (Bíró, Csibra e Gergely, 2007). I risultati ottenuti in un secondo studio da me svolto tuttavia dimostrano che quando il movimento dell’agente non è autonomo è assolutamente necessaria la presenza della componente comunicativa nell’agente per permettere al bambino di comprendere l’intenzionalità dell’azione. Questi risultati sono supportati anche dall’ultimo studio di neuro immagine (nel quale viene utilizzata una tecnica di neuro immagine non invasiva: NIRS) che dimostra che le regioni cerebrali del solco temporale superiore (regioni incluse nella aree del facenti parte del “Social Brain”) sono coinvolte nell’elaborazione di stimoli dinamici sociali fin dai primi mesi di vita. In conclusione questi studi sembrano suggerire che alla base dello sviluppo sociale vi sia una forte interazione tra l’esperienza e la naturale predisposizione delle strutture cerebrali. Sembra che lo sviluppo delle funzioni cerebrali nell’uomo non sia dovuto ad una passiva sequenza maturazionale, ma sia dovuto ad un processo attivo mediato dall’esperienza e guidato da predisposizioni innate come suggerito dall’ipotesi neuro costruttivista (Karmiloff-Smith, 2009)

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Brain and Cognitive Sciences, 2009.
"June 2009." Cataloged from PDF version of thesis.
Includes bibliographical references.
Unlike the human brain, which produces few neurons in adulthood, the brains of songbirds continue to produce new neurons throughout life. The function of these new neurons is not know, although it has been suggested that they endow the avian brain with a remarkable regenerative capacity that does not exist in mammals. It has also been proposed that the addition of new neurons in adulthood underlies behavioral plasticity, such as song learning. A better understanding of the cellular mechanisms that control the addition of new neurons to the postnatal brain may help clarify its biological function. This thesis is an investigation of the cell biology of postnatal neurogenesis in the songbird forebrain, with special emphasis on the High Vocal Center. Neuronal progenitors in the juvenile zebra finch brain were identified by fate mapping using engineered retroviruses. Multiple populations of neural progenitors appear to exist in the juvenile zebra finch brain, and each produces different types of neurons. At least three cell types appear to be added to the postnatal finch brain. Homology between neurogenesis in the postnatal finch and embryonic mammalian forebrain was also assessed. To characterize the mechanism of cell addition, videos were made, documenting the migration and integration of new neurons into the High Vocal Center. Neural progenitors were labeled using retroviruses, carrying the gene for the green fluorescent protein, allowing new neurons to be observed in the intact brain, with a powerful infrared laser. By replacing a small hole in the skull with a piece of optical glass, one could observe labeled neurons periodically over many days as they were born until they wired up to the existing circuitry. New neurons engaged in a previously undescribed form of migration. Further study of this form of neuron migration as well as other aspects of postnatal neurogenesis may lead to the development of strategies for replacing neurons in the human brain lost to death or disease.
by Benjamin Barnett Scott.
Ph.D.

Communication impairments are common following traumatic brain injury (TBI) and affect the ability of a person with TBI to have successful conversations. Ylvisaker, Sellers and Edelman (1998) argue that training to improve the communication skills of an everyday support person would impact on the functioning of a person with TBI. Paid caregivers are often involved to support people with TBI, however, little attention has been focused directly on improving their interaction skills. Therefore, this thesis describes a study conducted to investigate the effect of a communication training program on improving the conversational interactions between paid caregivers and people with TBI. Participants were 10 paid caregivers randomly selected and allocated to either a control or training group. Treatment comprised a 17 hour program (across 6 weeks) that combined collaboration and elaboration conversational strategies (Ylvisaker et al., 1998) with discourse activities (Togher, McDonald, Code, & Grant, 2004). Two conversational interactions (i.e. structured and casual conversations) were videotaped pretraining, posttraining and at 6 months follow-up. The conversations were rated by two independent judges. In addition, focused interviews were conducted pre and posttraining to explore the experiences of trained paid caregivers. Training for paid caregivers improved their structured conversational interactions with people with TBI. Independent raters perceived these interactions to be more appropriate, more rewarding and more interesting compared to a control group. Trained paid caregivers made greater improvements in their ability to acknowledge and reveal the competence of a person with TBI. Improvements were maintained for six months. No significant changes were found for the casual conversational interactions. Findings from the focused interviews revealed that trained paid caregivers reported improvements in their knowledge of effective communicative strategies. This perceived improvement led to interactions reported as more enjoyable and successful and less frustrating. Trained paid caregivers also perceived increased confidence and ability to self-regulate their use of strategies when communicating with people with TBI. Aspects of the training program that were felt to promote or hinder learning were also identified. The findings from this study highlight the importance of training and educating paid caregivers to improve their communication skills. Training can have a significant impact on interactions that involve both paid caregivers and a person with TBI.

The current study evaluates the effectiveness of a Brain-Computer Interface (BCI) system that operates by detecting a P300 elicited by one of four randomly presented stimuli (i.e., YES, NO, PASS, END). Two groups of participants were tested. The first group included three ALS patients that varied in degree of disability, but all retained the ability to communicate; the second group included three Non-ALS controls. Each participant participated in ten experimental sessions during a period of approximately 6 weeks. Sessions were conducted either at the participant's home or in the lab. During each run the participant's task was to attend to one stimulus and disregard the other three. Stimuli were presented auditorily, visually, or in both modes. Additionally, on each run, the experimenter would either tell the participant which stimulus to focus on, or ask the participant a question and the participant would focus on the correct "YES/NO" answer to the question. Overall, for each participant, the ERPs elicited by the target stimuli could be discriminated from the non-target stimuli; however, less variability was observed in the Non-ALS group. Comparing across sessions, the within session variability was lower than across session variability. In addition, waveform morphology varied as a function of the presentation mode, but not in a similar pattern for each participant. Offline and simulated online classification algorithms conducted using step-wise discriminant analysis produced results suggesting the potential for online classification performance at levels acceptable for communication. Future investigations will begin to focus on testing online classification performance with real-time feedback, and continuing to examine stimulus properties to determine how to maximize P300 amplitude for individual users.

Deciphering the rules governing synaptic communication among neurons is believed to provide the key to understanding how the brain works. Accumulating evidence supports, however, the novel view that the brain should not be regarded simply as a circuit of actively interacting neurons but rather as a network of neurons and astrocytes that intesively cooperate to perform computational feats. Astrocytes respond to the synaptic release of neurotransmitters with intracellular Ca2+ elevations mediated mainly by G-protein coupled receptors, and with the release of neuroactive molecules, collectively termed gliotransmitters, that contribute to the modulation of synaptic transmission and plasticity. The role of neuron-astrocyte interactions has been, however, intensively studied in relation to glutamatergic synaptic transmission, but little has been revealed about the role of astrocytes in GABAergic inhibitory transmission. Indeed, whether the different GABAergic interneurons specifically signal to astrocytes and what impact on the activity of local neuronal circuits this signalling pathway may are fundamental questions that have been poorly addressed. In my thesis I started to investigate the signaling between different interneurons and astrocytes, focusing on Parvalbumin (PV)- and Somatostatin (SOM)-expressing interneuron subpopulations that compose up to 70 % of the total number of GABAergic interneurons in the brain. To this aim, I developed a complex approach that combines single and two-photon laser-scanning microscopy for Ca2+ imaging, both in somatosensory cortex (SSCx) slices and in vivo, patch-clamp recording and optogenetic techniques. I found that in somatosensory and temporal cortex slices loaded with the Ca2+ indicator Fluo-4 AM and the astrocytic marker SR101, about 60 % of layer V astrocytes showed large amplitude somatic Ca2+ increases in response to GABA or baclofen (Bac, a GABAB receptor agonist) in both young and adult mice. These Ca2+ responses were abolished in mice lacking the inositol-1,4,5-trisphosphate (IP3) receptor type 2 in astrocytes, while blocking Gi/o proteins with pertussis toxin prevented Bac-mediated Ca2+ transients. These results reveal an involvement of the Gq/IP3 cascade and suggest possible Gi/o-Gq protein interactions in the astrocyte response to GABA signals. In a mouse model in which astrocytes selectively express the genetically encoded Ca2+ indicator GCaMP3, I also found that local GABA or Bac applications induced long-lasting Ca2+ oscillations at fine processes that occasionally spread to the entire astrocytic soma and other processes. I then validated the responsiveness of astrocytes to GABAergic signals in in vivo experiments from P30-60 anesthetized GCaMP3 animals where Bac locally applied to primary SSCx layers I/II evoked Ca2+ elevations in 45.46 % ± 8.07 % of the total astrocytes observed. Optogenetic stimulation of ChR2-expressing PV or SOM interneurons also evoked astrocytes Ca2+ events (the average of Ca2+ peaks per minute significantly increase from 0.15 ± 0.06 to 0.30 ± 0.05 for PV interneurons stimulation and from 0.19 ± 0.04 to 1.16 ± 0.13 for SOM interneurons stimulation). Current pulse depolarization of a single PV or SOM interneuron increased Ca2+ peaks in nearby astrocytes from 0.41 ± 0.04 to 0.65 ± 0.08 (p<0.05) and event frequency per minute from 0.10 ± 0.31 to 1.09 ± 0.16 (p<0.01), respectively. Patch-clamp recordings in the presence of TTX showed that GABAB activation triggered glutamate release in astrocytes and NMDAR-mediated slow inward currents (SICs) in nearby neurons. The frequency of SICs was strongly increased both in PV interneurons (from 0.15 ± 0.06 to 0.46 ± 0.04 event/min) and pyramidal neurons (from 0.30 ± 0.07 to 0.79 ± 0.17 event/min). The increase in SICs frequency lasted for about two minutes on average, outlasting the time of GABA agonist applications. As revealed in experiments from IP3R2 KO mice, GABA-induced SICs were also dependent on IP3R mediated intracellular Ca2+ transients in astrocytes. These data suggest that astrocytes activated by GABAergic interneurons convert a transient inhibition into a delayed excitation in local circuits. I conclude that cortical astrocytes can be activated by two of the major GABAergic interneuron classes in the brain (PV and SOM). The consequent gliotransmitter release provides a new form of homeostatic control of local network excitability.
Gli astrociti hanno un ruolo centrale nella regolazione dell’attività e della plasticità dei circuiti neuronali. I processi astrocitari avvolgono le sinapsi e rispondono al rilascio neuronale di glutammato con significativi aumenti di Ca2+ intracellulare. Tali variazioni Ca2+, principalmente mediate da recettori metabotropici, regolano il rilascio di gliotrasmettitori che modulano sia la trasmissione eccitatoria che quella inibitoria. Tuttavia, mentre l’interazione tra astrociti e neuroni eccitatori è largamente studiata, la cooperazione tra neuroni inibitori ed astrociti rimane ancora inesplorata. L'inibizione sinaptica dipende da una varietà di interneuroni GABAergici che orchestrano l’attività spontanea e le risposte a stimoli sensoriali dei neuroni eccitatori, regolando anche lo sviluppo corticale e l’insorgenza, la propagazione e la cessazione dell’attività epilettica. L’interazione tra interneuroni ed astrociti rappresenta dunque un ulteriore livello di complessità computazionale nell’elaborazione dell’informazione nervosa ed un potenziale meccanismo alla base delle crisi epilettiche. L’obiettivo della mia tesi è di studiare la comunicazione tra astrociti ed interneuroni, valutando se gli astrociti siano in grado di rispondere al neurotrasmettitore GABA e come la loro risposta possa eventualmente influenzare l’attività neuronale. Per caratterizzare questa interazione, ho effettuato esperimenti di imaging del Ca2+ in fettine corticali caricate con l’indicatore del calcio FLUO-4 AM e per marcare selettivamente gli astrociti Sulforodamina-101. Il 60 % degli astrociti monitorati ha mostrato aumenti di Ca2+ somatico in seguito a somministrazione di GABA o baclofen (Bac), un’agonista specifico dei recettori GABAB. Tale risposta Ca2+ è abolita in topi KO per il recettore astrocitario dell’inositol-1,4,5-trifosfato (IP3). D’altra parte anche il blocco delle proteine Gi/q aboliva la risposta calcio mediata dal Bac. Questi risultati rivelano un coinvolgimento della cascata Gq/IP3 e suggeriscono una possibile interazione tra Gi/Gq nel segnale di risposta al GABA da parte degli astrociti. In un modello di animale transgenico in cui gli astrociti esprimono geneticamente il sensore del Ca2+ GCaMP3, applicazioni locali di GABA o Bac hanno indotto nei processi degli astrociti oscillazioni durature e sostenute del segnale Ca2+. Tale attività Ca2+ occasionalmente poteva propagarsi e coinvolgere l’intero astrocita. La responsività degli astrociti al signalling GABAergico è stata inoltre validata in esperimenti in vivo in animali adulti P30-60 esprimenti GCaMP3, dove applicazioni locali di Bac in SSCx LI/II, hanno evocato aumenti Ca2+ nel 45.46 % ± 8.07 % del totale degli astrociti monitorati. Ho confermato la selettività di questa risposta in esperimenti di optogenetica, esprimendo negli interneuroni GABAergici Parvalbumina-positivi (PV) o Somatostatina-positivi (SOM) il canale foto-attivabile channelrhodopsin-2. La foto-stimolazione simultanea e selettiva dei PV o dei SOM ha dimostrato che gli astrociti rispondono al rilascio sinaptico di GABA con aumenti di Ca2+ mediati dal recettore GABAB. Inoltre la scarica di potenziali di azione indotta in un singolo PV o in un SOM tramite una pipetta da patch recording, produce lo stesso effetto su scala locale. Ho inoltre studiato se gli astrociti, una volta attivati da GABA, siano in grado di rilasciare glutammato evocando lente correnti depolarizzanti (SICs, slow inward currents) nei neuroni. L’imaging del Ca2+ accoppiato a registrazioni da neuroni piramidali hanno rivelato che l’attività Ca2+, indotta dal GABA negli astrociti, provocava SICs. Infatti, esperimenti di controllo in topi IP3R2-KO non hanno rivelato un significativo aumento nel numero di SICs. Questi dati sono stati confermati anche tramite stimolazione di PV o SOM esprimenti ChR2 in cui, in seguito all’attivazione selettiva delle due classi di interneuroni, si è osservato un aumento significativo nella frequenza delle SICs. Questi dati dimostrano che gli astrociti, attivati dal GABA, sono in grado di convertire un episodio inibitorio transiente, ma intenso, in un lento aumento di eccitabilità nei circuiti locali. In conclusione, gli astrociti corticali sono attivati da due classi di interneuroni GABAergici e il conseguente rilascio di gliotrasmettitori rivela una nuova forma di controllo omeostatico dell’eccitabilità di network.

1. Introduction The multidisciplinary approach of using brain signals for directly controlling external devices, like computers or prosthesis, is named brain-computer interface (BCI). Farwell and Donchin (1988) showed that it is possible for humans to communicate using a BCI, by means of their event-related potentials (ERPs; e.g., P300), without the involvement of their voluntary muscle activity. The use of brain-wave-guided BCIs offered new perspectives regarding communication and control of devices for patients suffering from severe motor impairment or for patients who completely paralyzed, such as the patients affected by amyotrophic lateral sclerosis (ALS), in the latest stages of the illness. In the last two decades an important scientific and clinical challenge has been the development of efficient BCIs for ALS patients. Most of the progress in the field has been mainly concerned with algorithm improvement for better signal classification. In contrast, only few studies have addressed, to date, the role of cognitive mechanisms underlying the elicitation of brain-signals in BCIs. In the present study we investigated the possibility to modulate the brain signal and, by doing so, the performance of an ERP-guided BCI system, by designing and implementing three new interfaces in which participants were required to perform covert visuospatial attention orienting (Posner, 1980), in order to control the movement of a cursor on a monitor. 2. Experiment 1 The effects of covert visuospatial attention orienting within an ERP-guided BCI were tested on healthy participants. We compared the effectiveness of three visual interfaces, each of whom elicited different modalities of covert visuospatial attention orienting (exogenous vs. endogenous). Twelve adult participants performed 20 sessions, using the abovementioned ERP-guided BCI interfaces to control the movement of a cursor. Brain waves were recorded on each trial and were subsequently classified online, by means of an ad-hoc algorithm. Each time the target ERPs were correctly classified, the cursor moved towards the target position. The “endogenous” interface was associated with significantly higher performance than the other two interfaces during the testing sessions, but not in the follow-up sessions. Endogenous visuospatial attention orienting can be effectively implemented to increase the performance of ERP-guided BCIs. 3. Experiment 2 To investigate whether the findings reported in Experiment 1 depended on the used classification system, we performed an offline reclassification of the data of Experiment 1. The online analysis of the epochs was made via Independent Component Analysis (ICA), which, in turn, was followed by fixed features extraction and support vector machine (SVM) classification. The offline epochs analysis was performed by means of a genetic algorithm (GA), which permitted us to retrieve the relevant features of the signal to be classified, and then to categorise them with a logistic classifier. The offline analysis confirmed the advantages derived from the use of the “endogenous” interface. The performance-related findings were in line with those obtained in the neurophysiological data analysis. Nonetheless, epoch categorization was performed better with the GA algorithm than with the ICA: the higher mean and the smaller standard deviation of the classification performed with the GA seem to promise a possible improvement of the ERP-guided BCI also on online tests. 4. Experiment 3 On the basis of the results of Experiments 1 and 2, we tested the efficacy of two visual interfaces, each of whom elicited different modalities of covert visuospatial attention orienting (exogenous vs. endogenous), in ALS patients. Ten ALS patients performed 16 online sessions with each interface. Although the ALS patients had a performance of about 70% with both the interfaces, the endogenous interface elicited a larger difference on ERP potentials between target and non-target trials. These results supported the hypothesis that the use of the endogenous interface may offer a more efficient channel of communication for ALS patients with respect to the use of the exogenous interface. 5. Conclusions Neurological diseases that affect the motor system may impair communication abilities of patients, as in the case of amyotrophic lateral sclerosis. This pathology might evolve in the locked-in syndrome (LIS), a condition in which patients remain conscious but cannot move any of their muscles. For instance, they may become unable to express their opinions and decisions on important questions regarding their clinical treatment or their living and biological wills. The BCIs represent a potential solution to the communication problems of ALS-LIS patients. Despite the fact that more than 20 years have passed since the first published article on a P300-guided BCI, the effects of cognitive mechanisms (i.e., executive functions, attention, memory, etc.) involved in brain signal elicitation have not been investigated extensively. In the abovementioned experiments, we tested the effect of covert visuospatial attention orienting on an ERP-guided BCI, by comparing a number of visual interfaces, each of whom elicited a different modality of covert visuospatial attention orienting. Taken together, the results supported our main hypothesis: It is possible to modulate the performance of an ERP-guided BCI, by using endogenous or exogenous visuospatial attention orienting. Of particular relevance is the fact that our ALS patients were able to use endogenous visuospatial attention orienting and, by doing so, they could increase their performance in an ERP-guided BCI. We suggest that the study of covert visuospatial attention orienting is essential for developing efficient visual BCIs for patients who cannot control their eye movements. Implementing principles taken from cognitive psychology, may improve BCIs efficiency. This, in turn, can increase the benefits for patients with severe motor and communication disabilities. Finally, an efficient cognitive-based BCI may have the considerable ethical implication of “giving a voice” to CLIS-ALS patients
1. Introduzione Farwell e Donchin (1988) per primi hanno dimostrato la possibilità che l’uomo ha di comunicare usando i potenziali evento correlati (ERP; e.g., P300), senza bisogno di usare alcun muscolo per tale fine. Questa scoperta ha offerto nuove prospettive per la comunicazione ed il controllo di periferiche in pazienti affetti da gravi disabilità motorie o completamente paralizzati, come nel caso dei pazienti affetti da sclerosi laterale amiotrofica (SLA), negli stadi più avanzati di malattia. L’approccio multidisciplinare che consente di tradurre segnali cerebrali direttamente in comandi per controllare computer o protesi meccaniche è chiamato brain-computer interface (BCI). Negli ultimi vent’anni un’importante sfida scientifica è stata quella di sviluppare una BCI efficace, affinché potesse essere usata nella pratica clinica con i pazienti. I progressi più rilevanti fatti finora riguardano principalmente la registrazione e l’elaborazione dei segnali cerebrali, grazie ad algoritmi sempre più potenti ed efficaci nella categorizzazione dei biosegnali. Minore attenzione è stata posta, invece, nell’investigare il ruolo dei meccanismi cognitivi che sottendono l’uso di una BCI. Nel presente studio è stata indagata la potenzialità dei partecipanti di modulare specifiche onde cerebrali e, di conseguenza, l’efficacia di un sistema BCI guidato dagli ERP, attraverso l’uso di diversi processi di orientamento implicito dell’attenzione visuospaziale (Posner, 1980). A tale scopo sono state progettate e testate tre nuove interfacce visive per controllare il movimento di un cursore su un monitor. 2. Esperimento 1 Nel primo esperimento è stato testato l’effetto dell’orientamento implicito dell’attenzione visuospaziale in partecipanti sani, il cui scopo era di controllare il movimento di un cursore con una BCI guidata da ERP, per raggiungere specifici bersagli. È stato confrontato l’uso di tre interfacce, ciascuna delle quali prevedeva l’utilizzo di una specifica modalità dell’orientamento implicito dell’attenzione visuospaziale (esogeno vs. endogeno). Dodici partecipanti adulti hanno eseguito 20 sessioni, con ciascuna delle tre interfacce. Simultaneamente, gli ERP associati a ciascun trial di ogni interfaccia erano registrati e classificati da un algoritmo ad hoc. Ogni volta che gli ERP associati alla direzione della posizione bersaglio erano correttamente classificati, il cursore era mosso di un passo verso la posizione bersaglio. I partecipanti hanno ottenuto un’accuratezza migliore nel controllo del cursore con l’interfaccia che prevedeva l’orientamento endogeno dell’attenzione visuospaziale rispetto alle due interfacce che prevedevano l’orientamento esogeno. 3. Esperimento 2 Nel secondo studio è stata eseguita una classificazione offline degli ERP registrati nell’Esperimento 1, con lo scopo di verificare se gli effetti ottenuti nell’Esperimento 1 fossero indipendenti dal tipo di algoritmo di classificazione utilizzato. La classificazione online dei segnali cerebrali avveniva attraverso l’analisi delle componenti indipendenti (ICA), un’estrazione di 78 caratteristiche stabilite a priori del segnale, e la loro categorizzazione attraverso un algoritmo matematico di tipo lineare (support vector macchine: SVM). La riclassificazione offline è stata eseguita per mezzo di un algoritmo genetico (genetic algorithm: GA), che rilevava ad personam le caratteristiche significative del segnale, le quali, infine, venivano categorizzate attraverso un classificatore logistico. Il metodo di classificazione offline nell’Esperimento 2 ha confermato l’effetto ottenuto nell’Esperimento 1. Questi risultati sono stati confermati anche dalle analisi statistiche eseguite sui dati neurofisiologici. Inoltre, le medie di accuratezza più alte e la minore variabilità associate al sistema di classificazione offline sembrano offrire potenziali miglioramenti dell’efficacia dell’uso in tempo reale della nostra BCI. 4. Esperimento 3 Alla luce dei risultati riportati negli Esperimenti 1 e 2, è stata testata l’efficacia di un’interfaccia che prevedeva l’uso dell’orientamento esogeno dell’attenzione visuospaziale e di un’altra che prevedeva l’uso dell’orientamento endogeno, con pazienti affetti da SLA. Dieci pazienti con SLA hanno eseguito 16 sessioni con ciascuna delle due interfacce. Anche se i pazienti hanno ottenuto un’accuratezza di circa 70% con entrambe le interfacce, è stata registrata una maggior differenza tra gli ERP target e quelli non-target con l’uso dell’interfaccia “endogena”. Questi risultati supportano l’ipotesi che l’interfaccia che usa l’orientamento endogeno dell’attenzione visuospaziale consenta un miglior controllo del sistema BCI, con conseguenti vantaggi comunicativi per i pazienti affetti da SLA. 5. Conclusioni Le patologie neurologiche che colpiscono il sistema motorio possono intaccare i normali canali di comunicazione, come nel caso di pazienti affetti dal SLA. Questa malattia può sfociare nello stato denominato sindrome locked-in (LIS), una condizione clinica in cui i pazienti sono completamente paralizzati ma mantengono intatta la loro consapevolezza. Nella condizione di LIS, un paziente non può comunicare, non potendo così esprimere la propria opinione riguardo alle scelte etico-giuridiche legate alla sua condizione clinica. Le BCI rappresentano una potenziale soluzione ai problemi comunicativi dei pazienti nella LIS. Negli ultimi vent’anni di ricerca scientifica sulle BCI è stata rivolta grande attenzione alle componenti tecnologiche implicate nella registrazione del segnale cerebrale e nella sua classificazione in comandi per controllare specifiche periferiche. Viceversa, minor attenzione è stata posta alle caratteristiche dell’utente nell’utilizzo delle BCI, in particolar modo riguardo alle componenti cognitive coinvolte. Negli esperimenti riportati nella presente tesi, abbiamo testato l’efficacia di diverse interfacce, ciascuna delle quali utilizzava una specifica modalità dell’orientamento implicito dell’attenzione visuospaziale (endogena o esogena). I risultati di questi esperimenti supportano l’ipotesi che è possibile modulare l’efficacia di una BCI guidata da ERP attraverso l’implementazione di interfacce visive che utilizzano diversi principi dell’orientamento implicito dell’attenzione visuospaziale. Tale risultato è di particolare rilevanza dal punto di vista clinico per i pazienti affetti da SLA, negli stadi terminali di malattia, cioè quando entrano nella condizione clinica di LIS. In particolare nell’Esperimento 3 è riportato come l’ampiezza degli ERP sia diversamente modulata nelle due interfacce testate e questo fatto può giocare un ruolo rilevante nello sviluppo di un efficace sistema BCI che permetta la comunicazione a pazienti affetti da SLA nella condizione di completa LIS. I nostri risultati portano evidenze di come l’implementazione dei principi della psicologia cognitiva nello sviluppo di una BCI ne possano modulare l’efficacia, e questo a vantaggio dei pazienti affetti da gravi disabilità motorie. In conclusione, un’efficace applicazione dei principi cognitivi nello sviluppo delle BCI può avere l’effetto rilevante di “dare una voce” a pazienti in stato di completa LIS

Thesis (Ph. D.)--University of California, San Diego, 2006.
Title from first page of PDF file (viewed September 19, 2006). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references.

ABSTRACT This thesis investigates a range of everyday interactions of traumatic brain injury (TBI) subjects when compared with control subjects to examine whether there are differences in the overall structure of interactions, in the way information is exchanged and in the wording which is used. Analyses from systemic functional linguistics including generic structure potential analysis, exchange structure analysis and analysis of politeness markers were used to examine the interactional impairments reported to follow TBI. Results indicated that TBI subjects differed from controls in their use of interpersonal language resources. These differences were exaggerated when subjects were interacting with someone in authority. When placed in a more powerful role, TBI subjects were able to utilise language resources to a similar extent to controls across the three levels of analysis. This thesis has important implications for the assessment and management of interactional communication impairments which may follow TBI, including suggestions for therapy with the person with TBI and for communication partners of people with TBI including therapists, family members and the community.

Thesis: Ph. D., Massachusetts Institute of Technology, Department of Brain and Cognitive Sciences, 2015.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 112-126).
Human language is notable for its expressivity; syntax is powerful and allows for potentially unlimited new sentences. But even simple transitive sentences like "I broke the lamp" provide a sophisticated tool for communication, capture the basic building blocks of syntax and semantics that are widely agreed to be part of our linguistic capacity like agent or subject. With this relatively simple machinery, we are able to move a cognitive representation of an event from one person's head to another. How is this possible? In this dissertation, I examine both adult and child language to understand this capacity. Paper 1 examines the link between non-linguistic cognition and preschoolers' expectations about the meaning of novel verbs. We find that even though transitive verbs can refer to many event types, 3- and 4-year-olds are more likely to associate them with scenes with spatiotemporal features indicating causation. Papers 2 and 3 ask a second question: how do people organize language to facilitate communication? Paper 2 probes how adults order the basic elements (Subject, Verb, Object) in a task that appears to be independent of native language constraints, and tests whether the content of the message leads gesturers to reorganize their utterances. Paper 3 asks whether adults and children are aware that the relative informativity of arguments depends on context, and whether they can successfully make decisions in a novel communication task. By limiting the expression of transitive sentences to just two words (e.g. MONKEY EAT), we discover which elements people consider to be most informative. Both adults and children flexibly adjust their expectations about informative sentences according to which arguments are the most ambiguous in context. Together, these case studies help us understand how human language accomplishes its communicative goals, both in terms of the cognitive representations recruited for processing complex events in language, and the strategies used for expressing them. Whatever the formal nature of the representations involved in syntax and semantics, they must ultimately allow us to form predicates over nonlinguistic representations of the world, and they must support the kinds of pragmatic inferences that we know people can make.
by Melissa Kline.
Ph. D.

Non reparative solutions to damaged or impaired sensory systems have proven highly effective in many applications but are generally underutilized. For auditory disorders, traditional reparative solutions such as hearing aids and implant technology are limited in their ability to treat neurological causes of hearing loss. A method to provide auditory information to a user via the lingual nerve is proposed. The number of mechanoreceptors in the tongue exceeds the number of inner hair cells in the cochlea and the dynamic range of neurons in both systems is comparable suggesting that the achievable throughput of information in the lingual nerve is comparable to that of the auditory nerve. This supports the feasibility of transmitting audio information to the brain via the lingual nerve. Using techniques implemented in similar successful technology, the achievable throughput of the dorsal surface of the tongue using existing stimulation methods without additional innovation was estimated to be as high as 1,800 bits per second for an experienced user, in the same range required by many audio codecs used for spoken language. To make a more accurate estimation of achievable throughput, devices were developed to stimulate the tongue electrically, and an experiment to map the sensitivity of the tongue to a form of electrotactile stimulus was performed. For the population tested, discrimination ability of the tongue varied greatly. For all participants estimates for the immediately achievable throughput for the surface of the tongue was sufficient to communicate basic phonetic information to the participant. The estimated throughput for an experienced user was estimated to be as high as 1,400 bits per second. Lingual sensitivity maps were generated that will allow researchers and developers to manufacture electrode arrays that can reliably stimulate lingual nerve endings in a discriminatory manner. In another study we tested the feasibility of sending audio information to a person via the tongue. Preliminary data are presented on participants in a learning study that were able to discern stimuli generated from recorded voices, supporting our hypothesis on immediately achievable throughputs.

This portfolio comprises three parts. Part one is a systematic meta-analytic review of the relationship between cognition, including social cognition, and the pragmatic aspects of language comprehension and production following traumatic brain injury. Part two is an empirical paper which presents novel data pertaining to the characterisation of moral judgement disturbance following traumatic brain injury, and the relationship of these disturbances to social cognition. Part three comprises the appendices, which contain information supplementary to parts one and two, in addition to an epistemological and reflective statement.

The past decade has witnessed a proliferation of internet use for socialising with dedicated websites such as Facebook, and also for maintaining relationships using computer mediated communication. Individuals can extend the boundary associated with traditional forms of communication, and use technology to meet strangers online to share interests, or maintain existing relationships remotely. One of the most significant functions of computer-mediated communication (CMC) is its contribution to the evolution of social communication. CMC is “communication that takes place between human beings via the instrumentality of computers” (Thurlow, Lengel, & Tomic, 2004). As a consequence of the convenience and flexibility that this channel provides, CMC can be effectively used to orchestrate a variety of communication situations. Furthermore, social networks sites are becoming the choice in which individuals are maintaining relationships or meeting new people. The potential distinctions between these relationships and their offline counterparts remain contradictory. Online relationships may face different challenges, such as anonymity, restricted interaction (Walther, 1992), and the lack of physical presence. For example, sharing activities online such as playing games or visiting Web sites together differs from offline activities, such as going to the movies or dining together. These observations question whether CMC relationships have any parallels with real world relationships. Dunbar (1992) structured real world relationship by strength of ties and formulated the social brain hypothesis (SBH). This work uses the SBH as an interpretive lens in analyzing CMC relationship ties. Thus, a major focus of this work is to investigate implications of the SBH (Dunbar, 1992) within the context of CMC usage. It is recognised that CMC allows for the maintenance of a large number of friendships. Thus potentially, the use of CMC could alter the SBH ratios. Within the main findings consistency with SBH was found. Furthermore, CMC has many parallels with real world communication methods. Face-to-face communications were strongly preferred for maintenance of strong ties. Also phone usage was analysed and identified as an indicator of strong tie relationships, for both local and distant communications. The findings also address questions on displaced communities communication habits and their use of CMC. The phone was found to be most popular media and culture had a strong influence on communication content. The research used a mixed method approach, combining data collection via questionnaires, semi structured interviews and a diary study completed by participants. Based on the findings, a framework is proposed categorising groups on their level of real world socialising and CMC use. There are four essential contributions impacting on current theory. The findings offer new knowledge within the research of CMC and relationship maintenance theory. In our understanding these exploratory questions have not yet been addressed and therefore the findings of this research project are significant in their contributions.

The non-profit sector is growing, where NPOs compete for scarce resources. Meanwhile, innovation in communication technology requires resources and creativity. Can social media work as an efficient tool for communicating organizational goals and values and how does it enhance trust in NPOs relationship with donors? How do NPOs use ICT and social media in communication to donors and how do they implement functional and emotional communication online?  The research area is approached through a deductive, qualitative, and constructivist perspective. Interviews with two leading NPOs were held, as well as a number of interviews with potential donors. The theoretical framework builds upon Morgan and Hunts and MacMillan et al’s models of trust and commitment. Functional and emotional communication was developed through various theories on online communication. The main findings of this thesis are that Swedish NPOs mainly focus on emotional communication in order to obtain emotional commitment before further developing trust, which is created from functional communication. The investigated NPOs use functional communication to a very little extent.

Communication scholars, psychologists, teachers and social scientists recognize the importance of empathy to effective communication; however, its essential nature remains a mystery. The nonverbal and subjective aspects of empathic perception make it difficult to study with traditional Western scientific tools. Existing studies of empathic process concentrate primarily on the early or the latter stages. The central steps are seldom addressed. A method is needed for following empathic perception to its core processes and exploring the principles that govern its nature. Systems science offers a viable alternative method of studying empathy through analysis of models, emphasizing principles of interaction and process.