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1
Godefroy, Olivier. "Contrôle cognitif et lobes frontaux." Lyon 1, 1996. http://www.theses.fr/1996LYO1T052.
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Kolling, Nils Stephen. "Decision making, the frontal lobes and foraging behaviour." Thesis, University of Oxford, 2015. http://ora.ox.ac.uk/objects/uuid:ea509f5e-dca4-44e5-9f3f-f7d6550e5b45.
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The aim of this thesis was to understand the function of the frontal lobes during different types of decisions thusfar mostly neglected in cognitive neuroscience. Namely, I sought to understand how decisions are made when comparisons are not about a simple set of concrete options presented, but rather require a comparison with one specific encounter and a sense of the value of the current environment (Chapter 2-3). Additionally, I wanted to understand how decisions between concrete options can be contextualized by the current environment to allow considerations about changing environmental constraints to factor into the decision making process (Chapter 4-5). At last, I wanted to test how the potential for future behaviours within an environment has an effect on peoples decisions (Chapter 6). In other words, how do people construct prospective value when it requires a sense of own future behaviours? All this work was informed by concepts and models originating from optimal foraging theory, which seeks to understand animal behaviours using computational models for different ecological types of choices. Thus, this thesis offers a perspective on the neural mechanisms underlying human decision making capacities that relates them to common problems faced by animals and presumably humans in ecological environments (Chapter 1 and 7). As optimal foraging theory assumes that solving these problems efficiently is highly relevant for survival, it is possible that neural structures evolved in ways to particularly accommodate for the solution of those problems. Therefore, different prefrontal structures might be dedicated to unique ways of solving ecological kinds of decision problems. My thesis as a whole gives some evidence for such a perspective, as dACC and vmPFC were repeatedly identified as constituting unique systems for evaluation according to different reference frames. Their competition within a wider network of areas appeared to ultimately drive decisions under changing contexts. In the future, a better understanding of those changing interactions between these prefrontal areas which generate more complex and adaptive behaviours, will be crucial for understanding more natural choice behaviours. For this temporally resolved neural measurements as well as causal interference will be essential.
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Robinson, Gail Annette. "The contribution of the frontal lobes to propositional language." Thesis, University College London (University of London), 2006. http://discovery.ucl.ac.uk/1445907/.
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A single case and group study methodology was adopted to investigate the cognitive mechanisms involved in propositional language and the underlying anatomical substrates. Patients with dynamic aphasia and patients with unselected focal frontal and posterior lesions have been investigated. Dynamic aphasia is characterised by a severe propositional language impairment despite well-preserved nominal language. The results obtained in three patients with dynamic aphasia (ANG, CH and KAS) suggest two functionally and anatomically distinct cognitive mechanisms. One set of cognitive mechanisms is responsible for high-level selection among competing verbal response options. This mechanism is specific to the language domain and is implemented by the left inferior frontal region. Evidence for this first mechanism comes from the dynamic aphasic patients ANG and CH and frontal patients with left inferior frontal gyrus lesions. These patients were severely impaired on word and sentence generation tasks only when a stimulus activated many competing verbal response options. By contrast, they were unimpaired when a stimulus activated a dominant response. The second set of cognitive mechanisms is responsible for generating a fluent sequence of novel thought. This mechanism encompasses novel verbal and non-verbal generation and is supported by bilateral frontal region. Evidence for this second set of mechanisms comes from the dynamic aphasic KAS and patients with frontal lesions. These patients were severely impaired in generating multiple connected sentences. These patients were also impaired in the voluntary generation of novel verbal and non-verbal responses. The convergence of findings from dynamic aphasia, patients with focal frontal lesions and neuroimaging are discussed. These data confirm a role of the frontal lobes in propositional language generation and specify at least two sets of cognitive mechanisms involved in this process.
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Chau, Ka-hung Bolton, and 周嘉鴻. "Relationships between perceptual-cognitive functions subserved by frontal regions." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2011. http://hub.hku.hk/bib/B4579019X.
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Schenker, Natalie Marie. "Comparative analysis of Broca's area in hominoids." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2007. http://wwwlib.umi.com/cr/ucsd/fullcit?p3283454.
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Thesis (Ph. D.)--University of California, San Diego, 2007.Title from first page of PDF file (viewed November 7, 2007). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references.
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Balchin, Ross. "Emotional biases in confabulation : the role of the frontal lobes." Master's thesis, University of Cape Town, 2004. http://hdl.handle.net/11427/7991.
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Bibliography: leaves 57-61.The neuropsychological understanding of confabulation has recently been enriched by the finding that confabulating patients present positive emotional biases in their false recollections. The exact mechanisms of this motivational phenomenon have been heuristically linked to the frontal lobe impairment accompanying confabulation. The present study aims at providing direct support for this claim. A patient with damage to the prefrontal cortex is examined and his performance is contrasted with two confabulating patients, a patient with non-frontal neurological damage and twenty matched controls on a number of tests of emotional processing.
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Miller, Laurie Ann. "The ability to generate or inhibit responses after frontal lobectomy /." Thesis, McGill University, 1987. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=75775.
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The ability to generate different responses, and the ability to inhibit inappropriate behaviour, were explored in patients with unilateral cerebral excisions. Site-of-lesion effects were found to interact with the sex of the subject, the time of test-administration, and the nature of the response criteria. In Part I, the Thurstone Word Fluency Test revealed impairments two weeks postoperatively in patients with frontal, temporal, or central-area lesions. In men, removals from the left cerebral hemisphere caused greater deficits than removals from the right, but only left central-area excisions resulted in long-lasting impairments. Patients with left frontal-lobe removals produced few words on a sentence-completion fluency task, but on visual-image fluency, no patient-group was impaired. In Part II, an inability to inhibit impulsive actions on risk-taking tasks was seen after frontal lobectomy, as was a tendency to disregard the instructions on a word-fluency task. These results are consistent with the fact that patients with frontal-lobe lesions described themselves on a behavioural-trait questionnaire as less flexible and more impulsive than did control subjects.
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Koski, Lisa Marie. "The role of frontal cortex in visual selective attention." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape10/PQDD_0017/NQ55350.pdf.
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Thaiss, Laila Maria. "A comparison of the role of the frontal cortex and the anterior temporal lobe in source memory and in the accurate retrieval of episodic information /." Thesis, McGill University, 2001. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=38424.
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It has been argued that patients with frontal lobe lesions are impaired in temporal context memory and, more generally, in retrieving the source of one's knowledge or ideas. Furthermore, it has been speculated that a failure to retrieve source information may result in an increased susceptibility to distortions of episodic memories in patients with frontal lobe lesions. The precise role of the frontal cortex, however, in source or episodic retrieval is not clear. Does this region of cortex play a primary role or a secondary, executive role in the processing of such memories? Studies of patients with temporal lobe lesions have also shown impairments in episodic memory, including difficulties in the retrieval of source information. An important issue, therefore, is whether these two brain regions make different contributions to the processing of source information and to the retrieval of episodic memories.In the present experiments, patients with unilateral excisions restricted to frontal cortex or to the anterior temporal lobe were compared on various tasks examining source memory performance and the accurate retrieval of episodic information. The results of these studies failed to support the general contention that patients with frontal cortex excisions have source (or temporal context) memory impairments. Instead, differences between these patients and normal control subjects appeared to be contingent on whether strategic organizational or control processes were necessary for efficient processing of episodic information. The memory of patients with left temporal lobe excisions, on the other hand, was significantly impaired for both content and source information in most tasks. Furthermore, these subjects showed high rates of inaccuracies and distortions of memory. The false memories of this patient group were attributed to a combination of their poor memory for the specific items of the task and their over-reliance on semantic "gist" or on inferential knowledge about the events. Patients with right temporal lobe excisions were generally less severely impaired on the verbal memory tasks compared with those with left-sided lesions, but were impaired in their memory for the contextual aspects of an event.
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Lee, Andy Cheung Hong. "The role of the human frontal lobes in memory encoding and retrieval." Thesis, University of Cambridge, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.621105.
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Rybarova, Dusana. "Frontal Mechanisms in Language Pragmatics: Neuropsychological and Electrophysiological Evidence." Diss., The University of Arizona, 2007. http://hdl.handle.net/10150/194525.
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Whereas some researchers claim that the holistic processing of the right hemisphere is essential for contextual integration in language pragmatics (Myers, 2001, Myers, 2005), results of other studies point to involvement of executive processes of the frontal lobes (McDonald & Pearce, 1998; Bernicot & Dardier, 2001). This study examined the role of frontal lobes in language pragmatics by testing performance of young adults and older adults on selected standardized pragmatic inferences called 'implicitures'. Implicitures were first presented free-standing and then embedded in contexts that either supported (enabling contexts) or cancelled (cancelling contexts) their preferred meaning. First, implicitures were examined using behavioral reaction time measures in young adults. The second part of the project addressed the question about involvement of frontal lobes in language pragmatics by testing older adults with varying degrees of frontal function on processing of implicitures. Finally, event-related potential responses to implicitures with and without context in young adults were explored. Results revealed a strong relationship between frontal lobes and performance on implicitures in canceling contexts in older adults. There was no significant effect for free-standing implicitures and implicitures presented in enabling contexts. In addition, an N400 was observed to free-standing implicitures, but implicitures in context elicited a negative component in the later 400 ms window at the anterior sites. These results indicate that frontal lobes are important for pragmatic processing requiring integration of linguistic context with an utterance for the correct interpretation. Consequences of our findings for models of impliciture processing and accounts of neural architecture underlying language pragmatics are considered.
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Koppel, Sjaanie, and Sjaanie Koppel@general monash edu au. "False memory in a list learning paradigm : a maturational test of a putative relationship to frontal lobe function." Swinburne University of Technology, 2004. http://adt.lib.swin.edu.au./public/adt-VSWT20050301.092349.
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The principal aim of this thesis was to test the conjecture of Schacter et al. (1995) that the false memory effect in the Deese-Roediger-McDermott (DRM) paradigm is generated by errors in source monitoring and is mediated by frontal lobe circuits. In support of their conjecture, Schacter et al. cited evidence from elderly populations with presumed frontal dysfunction, however this thesis studied children over an age range over which the frontal lobes are believed to be maturing. This thesis represents the first attempt to specifically test Schacter�s hypothesis based on the developmental trajectory of �frontal� functioning. Moreover, the use of a developmental trajectory in such a manner is relatively novel, and a key issue within this thesis is how to operationalise �frontal� functioning in the sense intended by Schacter et al. Extrapolating from Schacter�s conjecture, it was predicted that the strength of the false memory effect is directly proportional to the degree of frontal maturation, as estimated by both chronological age and by performance on a range of neuropsychological tests of �frontal� executive functioning. False memory and executive functioning were compared in children aged 8 to 12 years and in adults using a modified DRM paradigm with a source monitoring extension after Payne et al. (1996). The modified DRM elicited false memory effects comparable to those reported in adolescents by Newstead and Newstead (1998) and in adults by Roediger and McDermott (1995) and by Payne et al. (1996). Three experiments that demonstrate a strong developmental trajectory for false memory effect are reported, but the pattern of results is not consistent with all of the premises of the conjecture. Although false recognition rates increased significantly with age, source monitoring accuracy did not change across the age groups. Consistent with the principal assertion of the conjecture by Schacter et al., age and a general �frontal� factor were found to be significantly related to the size of the false memory effect. In addition, veridical memory performance was always a predictor of false memory performance. The IAR (Underwood, 1965) theory can best account for the significant covariation between veridical and false memory development, as well as being able to account for the dissociation between false memory and source monitoring.
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Lau, Mark 1959. "Neuropsychological performance, acute alcohol intoxication and aggression in adult males." Thesis, McGill University, 1995. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=29070.
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Epidemiological and laboratory research supports a relationship between acute alcohol intoxication and aggression. Recent data suggest that alcohol disrupts cognitive abilities associated with frontal lobe function. Moreover, neuropsychological research provides suggestive evidence that frontal lobe dysfunction may predispose an individual to increased aggression. The research recounted in this thesis was conducted to investigate the role of individual differences of cognitive abilities associated with the dorsolateral frontal cortex in aggressive behaviour and to test the hypothesis that alcohol indirectly potentiates aggression by impairing these cognitive abilities. The three experiments included in this thesis demonstrated that: (1) acute alcohol intoxication interferes with the ability to integrate previously acquired knowledge in the formulation of behavioral strategies; (2) individuals grouped according to performance on two neuropsychological tests of cognitive abilities associated with frontal lobe function differ in degree of aggressive response. Specifically, individuals in the lower versus upper performance quartiles became more aggressive when provoked; and (3) individuals in the upper cognitive performance quartile demonstrate significantly greater reductions of unprovoked aggression in response to monetary reward.
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Crawford, Sarah Jane. "Real life problem solving and executive function in relation to the frontal lobes." Thesis, University College London (University of London), 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.271740.
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Leonard, Thomas Gabriel. "The role of the frontal lobes in the encoding and recall of kinesthetic information /." Thesis, McGill University, 1987. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=75703.
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Patients with unilateral temporal- or frontal-lobe excisions and normal control subjects were tested on four kinesthetic and two visual recall tasks. The first two studies required subjects to monitor peripheral feedback, in order to duplicate the distance or the end-position of examiner-defined arm movements. In the next two tasks, the subjects selected the movements to be recalled, and hence reliance on feedback was reduced. On the visual tests the subjects had to recall the distance traversed by a dot on a screen, or its end-position. Temporal lobectomy did not interfere with performance of the tasks, except for examiner-defined kinesthetic location. On this task, large left- or right-hippocampal resection produced an impairment following 30 s of counting. Patients with left frontal-lobe or small right frontal-lobe excisions performed normally on all tests, whereas those with large right frontal-lobe removals were impaired with both hands on the examiner-defined kinesthetic tasks. Patients with large right frontal-lobe lesions also demonstrated a delayed-recall deficit for visual distance. The results point to an important role played by the right frontal lobe in the monitoring of kinesthetic feedback both during the presentation of the movements and during the recall attempt.
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Macleod, Mairi S. "Cognitive ageing and the role of the frontal lobes in prospective memory and planning." Thesis, University of Aberdeen, 2001. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU137019.
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A recent theory postulates that the cognitive functions associated with the frontal lobes are likely to selectively deteriorate with age (West, 1996). In line with this theory, it was predicted that an age-related decline in measures of prospective memory and planning would be observed. In order to investigate this hypothesis, a series of five experiments were conducted using groups of young, middle aged and older normal participants. In Experiment 1, participants were asked to follow a recipe while remembering to do various prospective memory tasks at the same time. Older participants performed significantly worse on all measures of prospective memory. Significant age differences in measures of planning were observed in the computerised &'34;Tower of London&'34; planning task in Experiment 2. In Experiment 3, participants were given an open-ended planning task involving allocating a list of tasks to three friends. Older participants made significantly more overall planning errors. In Experiment 4, few age differences were observed in general executive function. In Experiment 5, the role of attention in prospective memory and planning was examined. Older participants performed significantly worse than the younger participants at the prospective memory and planning tasks. Speed of information processing was more highly associated with performance on the planning and prospective memory tasks than the attentional measures. There was not enough evidence available from the two patient studies to suggest that prospective memory was differentially impaired in patients with frontal lesions. The overall results confirmed the experimental hypothesis that there is an age-related decline in prospective memory and planning. However, the extent to which these age-related declines can be attributed to selective declines in the frontal lobes remains unclear.
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Kramer-Stutts, Traci A. "Frontal Lobe Functions in Attention Deficit Hyperactivity Disorder from Children to Young Adults." Thesis, University of North Texas, 1996. https://digital.library.unt.edu/ark:/67531/metadc278933/.
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Individuals with attention deficit hyperactivity disorder (ADHD) with and without a learning disorder (LD) and a control group of clinically referred individuals with behavioral problems were compared on four neuropsychological tests of frontal lobe functioning. Test results were collected to examine if ADHD individuals with and without LD have deficits in frontal lobe functioning. Two age groups were used to examine developmental differences. In the six to ten age group there were 27 ADHD, 17 ADHD/LD and seven other clinically referred individuals. In the 11 -20 age group there were 12 ADHD, 23 ADHD/LD and 24 other clinically referred individuals. The ADHD and ADHD/LD groups performed at a lower level than the other diagnostic group on the freedom from distractibility factor of the WISC-R and the omission and commission errors of the Gordon Diagnostic system. Differences for the ADHD and ADHD/LD groups were also found on the number of correct responses for the Gordon Diagnostic system, the Speech Sounds test and the Seashore Rhythm test. The developmental differences that were found were not influenced by diagnosis. The deficits that the ADHD individuals with and without LD demonstrated were not affected by age.
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Baird, Brenda Ratcliff. "EEG activation patterns in the frontal lobes of stutterers and nonstutterers during working memory tasks." Diss., Virginia Tech, 1996. http://hdl.handle.net/10919/40327.
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Developmental stuttering is a physiological disorder of speech motor control. Unlike acquired conditions, developmental stuttering is responsive to fluency-inducing conditions involving the manipulation or elimination of auditory feedback. It was hypothesized that stutterers experience interference effects from competing sensory
feedback during the working memory interval in which contextual information is held on-line in order to prepare subsequent motor responses. Behavior and EEG activity of stutterers and non stutterers were compared during working memory tasks.
Participants were 22 male, right-handed stutterers, mean age 28.2 years, age matched with 22 male, right-handed nonstutterers. Behavioral measures included a written verbal fluency task, an auditory delayed match-to-sample key press task, and a written digit span task. As hypothesized, there were no group differences in verbal
fluency. Also as hypothesized, stutterers had higher error scores (more false positives) on the auditory delayed match-to-sample key press task. This suggests increased sensitivity to auditory stimuli and difficulty inhibiting response to stimulation. Groups did not differ in digit span, but there was a trend toward significance (p=.07).
If stutterers do experience overlapping or excessive sensory stimulation during the working memory phase of speech motor plan assembly, the EEG of stutterers should evidence differences consistent with excessive or inefficient processing of "extra" sensory stimuli. Monopolar recordings were collected from 19 sites in accordance with the international 10-20 system of electrode placement. EEG was recorded during 60
seconds of resting-eyes-closed and resting-eyes-open~ 60 seconds during a silent backwards-subtraction math task; 120 seconds during an auditory delayed match-to-sample key press task.
As hypothesized, stutterers exhibited more theta activity than nonstutterers in frontal regions in all conditions, both in the low theta subband (3-5 Hz) and the high theta subband (5.5-7.5 Hz). Also as hypothesized, stutterers produced more alpha activity in the low alpha subband (8-10 Hz) in frontal regions in all conditions. There were no group differences in the high alpha subband (10.5-13 Hz). There were no hemispheric differences in frontal regions. Increased cortical activity and inl;;reased sensitivity to stimuli support the proposed hypothesis that stutterers experience excess sensory stimulation while attempting motor plan assembly, suggestive of stuttering as a disorder
of attention.Ph. D.
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Thompson, Naeem Renaud-Phillip. "A Functional Cerebral Systems Approach to Depression: Contributions of the Left and Right Frontal Lobes." Thesis, Virginia Tech, 2010. http://hdl.handle.net/10919/33575.
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In the majority of the depression literature, there has been little attention paid to the mechanisms underlying the differences that occur among individuals with this label. In a theoretical paper by Shenal, Harrison, and Demaree (2003), they proposed that the differences in depression symptomology may be due to differences in the function (and dysfunction) of the right and left frontal lobes. They go on to explain that each frontal lobe may have a direct influence on patterns of depression symptomology. In the current experiment there was an effort to look at performance differences among depressed and non-depressed males on a tests of affective memory (AAVLT) and functioning for the left (COWAT) and right (RFFT) frontal lobes. Results were non-significant for group based differences but other significant effects were found. Reliable findings included a primacy effect for the recall of words from the negative word list from the AAVLT, whereas t a â normalâ primacy and recency effects were found for the recall of positive and neutral word lists. There were also significant differences (across trials) for both groups suggesting a â normalâ learning curve. It is thought that the non-significant comparisons among the groups are likely due to the qualitatively mild depression scores among participants, which is likely not adequate to capture the level of dysfunction discussed in the original hypothesis.Master of Science
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Badenhorst, Tania. "Dreaming and the dorsolateral frontal lobes : towards a better understanding of the mechanism of dreaming." Master's thesis, University of Cape Town, 2006. http://hdl.handle.net/11427/10150.
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Includes bibliographical references.The exact mechanism of dream production is still poorly understood. Based on exploratory findings that damage to the dorsolateral prefrontal cortex does not cause changes in these patients subjective experience of their dreams (Solms, 1997), a study was conducted in order to investigate the role of this area in dream production. The dreams of seven patients with damage to tile dorsolateral prefrontal cortex were compared with those of normal participants. A content analysis found no significant quantitative differences between the dreams of dorsolateral prefrontal patients and normal controls. In addition, none of the patients with damage to the dorsolateral prefrontal cortex reported any subjective changes in their dreams since falling ill. These findings are congruent with those or numerous neuro-imaging studies, which indicate that the dorsolateral prefrontal cortex is deactivated during dreaming, and provide support for the theory that deactivation of the dorsolateral prefrontal cortex during sleep accounts for many of the formal features of dreams.
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Bisbee, Molly. "The Role of the Medial Temporal Lobes in Older Adults' Associative Deficit: A Behavioral Study." Thesis, The University of Arizona, 2012. http://hdl.handle.net/10150/228468.
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It is well established that older adults show a deficit in episodic memory. The associative deficit hypothesis (ADH) (Naveh-Benjamin, 2000) suggests that an age-related reduced ability to create links between units of information is a major contributor to the episodic deficit. It has been a robust finding that older adults show a disproportionate decline in associative memory relative to item memory when compared to young adults. Previous researchers have investigated the role of the frontal lobes (FL) by studying the effect of reduced attentional resources in the associative deficit. However, they have not found that divided attention in young adults produces the disproportionate associative decline seen in aging and it is thought that some cognitive process other than the allocation of attentional resources may contribute to the associative deficit. The present study intended to use a divided attention (DA) task that also engages medial temporal brain regions (MTL) in order to tax additional parts of the network involved in creating associations and provide indirect support for the role of the MTL in the associative deficit. However, the associative memory deficit in older adults was not replicated due to unique poor associative memory performance of some young adults in the study. Analyses excluding these participants show support for the role of the MTL in the associative deficit. However, the young poor performers may provide support for the role of FL function in the associative deficit and show that poor associative memory may not be limited to the older adult cohort.
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Oelke, Lynn Elizabeth. "Source Memory and Generation Effects in Parkinson's Disease." Scholar Commons, 2013. http://scholarcommons.usf.edu/etd/4552.
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The primary aim of this study was to investigate source memory performance in individuals diagnosed with Parkinson's disease (PD). The secondary goal was to explore how memory was impacted when subjects were asked to generate responses during encoding. Fifty idiopathic PD patients and fifty healthy control subjects completed a task measuring item memory and source memory which also included a generation manipulation. Relative to controls, PD patients exhibited deficits in source memory but not item memory. Both groups demonstrated enhanced memory performance in the generative condition of the item memory task. The PD group displayed a marginally significant trend toward improvement in source memory when instructed to generate a response. These findings lend support to the notion of a selective pattern of source memory impairment in PD, highlighted by a dissociation between item and source memory performance. Generative tasks may be related to increased activation of key frontal regions that facilitate memory performance. These results could inform new perspectives for cognitive rehabilitation in PD, although further research is necessary.
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Daugherty, Susan AtLee. "Neurophysiological Differences in Pain Reactivity: Why Some People are Tolerant to Pain." Diss., Virginia Tech, 2005. http://hdl.handle.net/10919/29025.
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Pain is a complex, ubiquitous phenomenon that can be debilitating and costly. Although it is well known that some individuals can easily tolerate pain while others are more intolerant to pain, little is known of the neurophysiological bases of these differences. Because differences in sensory information processing may underlie variability in tolerance to pain and because measures of sensory gating are used to explore differences in sensory information processing, sensory gating among college students (N = 14) who are tolerant or intolerant to pain was investigated. This investigation explored the hypothesis that those who were more tolerant to pain would evidence greater sensory gating. Pain tolerance was first determined using a cold pressor task. Sensory gating was then determined by the amount of attenuation of the amplitude of a second painful, electrical, somatosensory stimulus (S2) in relation to the amplitude of an identical first stimulus (S1) in a paired-stimulus evoked potential (EP ) paradigm. The results obtained showed the intolerant group exhibiting greater physiological reactivity than the tolerant group, indicating that the tolerant group attained greater sensory gating than the intolerant group.Ph. D.
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Wodushek, Thomas R. "Psychopathy Symptom Profiles and Neuropsychological Measures Sensitive to Orbitofrontal Functioning." Thesis, University of North Texas, 2003. https://digital.library.unt.edu/ark:/67531/metadc4280/.
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This study analyzed the relationship between the OF functioning of 100 incarcerated male offenders and their psychopathy symptoms. The study's rejected hypothesis had predicted a significant relationship between measures of OF functioning and the Defective Affective Experience (DAE) and Impulsive and Irresponsible Behavioral Style (IIB) factors of the Cooke and Michie (2001) three-factor model of psychopathy. Regression analysis failed to demonstrate a relationship between OF functioning and the DAE and IIB factors. Group differences on OF functioning were not demonstrated between participants in the upper and lower quartiles of a summed DAE and IIB factor score. A general role for OF functioning in criminal behavior was suggested as two OF measures accounted for 14.9% of the variance of criminal convictions.
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Nacin, Corinne Virginia. "The emotional divide Alpha wave asymmetry of the frontal lobes during mild, moderate and high fear commercials /." [Ames, Iowa : Iowa State University], 2009.
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Smith, Mary Louise. "Memory for spacial location and frequency of occurrence after frontal or temporal lobectomy in man." Thesis, McGill University, 1985. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=72054.
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In Part I, recall of spatial location was studied in an incidental-learning situation, where patients with unilateral brain lesions, the amnesic patient, H. M., and normal control subjects were asked to estimate the prices of objects in an array. All patient groups could encode location normally, but patients with right temporal-lobe lesions that included extensive hippocampal removal showed abnormally rapid forgetting. For all groups, and for H. M., location-recall did not differ under automatic and under effortful encoding conditions. It is argued that these results point to the importance of hippocampal-ceocortical interactions in spatial memory. In Part II, patients with frontal-lobe lesions were shown to be impaired in judging the frequency with which words or designs occurred in a list. With words, the deficits were demonstrable for both examiner-provided and self-generated stimuli. This impairment may be attributable either to a disorderly search process or to a deficit in cognitive estimation, or both.
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Mitsis, Effie M. "Construct validity of executive functions in normal adults and in adults with mild cognitive impairment." Full text available, 2003. http://images.lib.monash.edu.au/ts/theses/mitsis.pdf.
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Davidson, Lara. "Neurobiology of the frontal and temporal lobes in schizophrenia, a meta-analytic review of neuroimaging and neuropathological findings." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ56170.pdf.
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Follador, Halima. "DTI study of the frontal lobes, hippocampus, amygdala and neurocognitive assessment in patients with bipolar-schizophrenic spectrum disorders." Doctoral thesis, Università degli studi di Padova, 2015. http://hdl.handle.net/11577/3423972.
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Schizophrenic and bipolar disorders are complex and disabling psychiatric diseases whose recent neurobiological, neuropsychological and genetic findings is in contrast with the traditional categorical approach of psychiatric nosography.
The multiple threshold model describes the complex relationship between the shared genetic background and the wide phenotypic expression in the various disorders ascribed to the bipolar schizophrenic spectrum. This model assumes that common genes are involved in a spectrum of disorders ranging from major depression, to bipolar and schizophrenia and that their effect is additive along a continuum of risk: when a certain threshold is exceeded the quantitative difference becomes a qualitative difference that manifests itself as a different disorder (eg. switching from major depression to bipolar disorder to schizo-affective disorder than schizophrenic) (Kelsoe 2003).
A field of great interest in neuroscience and psychiatric research is finding evidence of shared clinical features and pathophysiological pathways between these disorders. Genetics, histopathological and MRI in vivo studies have consistently revealed abnormalities in brain neural networks among these disorders.
The Diffusion tensor imaging (DTI) is a fundamental brain imaging technique to investigate white matter‘s structural connectivity, despite its relative recently introduction in clinical practice and research.
AIM OF THE STUDY: to investigate the DTI measures of WM integrity in specific brain regions and the cognitive performances in a group of patients with the bipolar-schizophrenic spectrum disorders and a group of healthy control subjects. In order to verify or exclude specific diagnosis-related differences, we performed cross-sectional comparisons between the sub group of bipolar patients, schizophrenic patients and healthy controls.
METHODS: 64 patients -32 schizophrenic (SZ), 25 bipolars (BP)-, and 31 healthy controls underwent 1,5 T MRI scanning, comprehending DTI acquisitions and volumetric T1 3D with a specifically designed acquisition protocol, at the Neuroradiology Unit of Conegliano Hospital. Then we calculate DTI indices of bilateral frontal lobes, hippocampus and amygdala using ANALYZE 10.0 software, all recruited subjects underwent clinical and standardized, thorough neurocognitive assessment (ENB, Mondini et al; WCST).
RESULTS: we found statistically significant alterations of the DTI indicies for the regions of interest (ROIs), that pointed out shared abnormalities among the patients with bipolar schizophrenic-spectrum disorder regarding frontal lobes with respect to healthy control subjects; more interesting, we find a complex pattern of alterations among the hippocampal region and amygdala between the patients and the control group and also comparing the schizophrenic with the bipolar patients. Moreover we found out a significant impairment on the performances during the neurocognitive and neuro psychological assessment across all tests in the patients opposed to healthy controls.
We also pointed out some interesting correlations between the scores of the battery test administrated (ENB, Mondini et al; WCST) and the FA and ADC indices for the frontal lobes, as expected from the abundant current literature, but also for the hippocampus and amygdala. This approach could help to the understand some aspects of the complexity of the Bipolar-schizophrenic spectrum disorders
CONCLUSION: in this study we highlighted shared tracts among the spectrum disorders such as the common neurocognitive and neuropsychological impairment, the compromised structural integrity of the white matter in the frontal regions and probably, in some degree, even of the right hippocampus, implying that these two disorders may share some common pathophysiological mechanisms, further demonstrating how alterations in the cerebral white matter networks, involving the frontal regions and also subcortical structures, such as the hippocampus and amygdala, contribute to the pathophysiological process of schizophrenia and bipolar disorder.
Our findings also bring out differences among the two groups of patients, with the bipolars showing a most prominent alteration of the left amygdala and the schizophrenics a predominant deficit on the right hippocampus and amygdala.
In the bipolar-schizophrenic spectrum disorders it might be speculated that the alteration and disruption of white matter connectivity, and their correlation with neurocognitive performances, could be interpreted as a possible “biological marker”. This might help to specifically define the common and the different aspects of these disorders in order to better understand their complex pathophysiological mechanisms, jet to be clearly defined.Schizofrenia e disturbo bipolare sono malattie psichiatriche complesse e invalidanti, nelle quali il tradizionale approccio categoriale della nosografia psichiatrica entra in continuo dibattito in relazione alle più recenti scoperte nei campi della neurobiologia, della genetica, della neuropsicologia e del brain imaging. Il modello delle soglie multiple descrive le complesse relazioni tra l’assetto genetico e l’ampia espressione fenotipica nei vari disturbi appartenenti allo spettro. Esso parte dal presupposto che i geni comuni siano coinvolti in tali disturbi lungo uno spettro che va da dalla depressione maggiore al disturbo bipolare alla schizofrenia e che il loro effetto sia additivo lungo un continuum di rischio: quando una determinata soglia è superata, la differenza ‘quantitativa’ diventa ‘qualitativa’ e si manifesta come un disturbo diverso. Un campo di grande interesse nell’ambito delle neuroscienze e della ricerca in psichiatria è quello di scoprire caratteristiche cliniche e pattern psicopatologici condivisi tra questi disturbi. Studi istopatologici, di genetica e di neuroimaging hanno evidenziato in modo rilevante alterazioni a livello dei network neuronali di questi disturbi, tramite diverse metodiche. In particolare tra gli studi di brain imaging in risonanza magnetica, la tecnica non convenzionale di DTI si è rilevata, fin dalla sua introduzione, uno strumento estremamente promettente per gettare luce in particolare sulla complesse proprietà della sostanza bianca cerebrale e l’analisi dell’integrità dei fasci assonali. SCOPO DELLO STUDIO: investigare, tramite metodica DTI e calcolo degli indici di diffusione l’integrità della sostanza bianca in specifiche regioni cerebrali, e valutare le alterazioni neurocognitive in due gruppi di pazienti appartenenti allo spettro bipolare-schizofrenico (rispettivamente schizofrenici e bipolari) e un gruppo di soggetti sani. MATERIALI E METODI: 64 pazienti (32 SZ-25 BP) e 31 controlli sani sono stati sottoposti ad una procedura di Risonanza Magnetica cerebrale ad 1,5 Tesla, secondo un protocollo di acquisizione di acquisizione dedicato, comprendente sequenze T1 3D volumetriche e DTI, presso l’Unità Operativa di Neuroradiologia del Presidio Ospedaliero di Conegliano. Mediante l’utilizzo del Software ANALYZE 10.0, sono stati calcolati gli indici di diffusione DTI, in specifiche regioni regioni cerebrali con metodo di delineamento delle ROIs, in particolare soffermandoci sui lobi frontali e sul complesso amigdala-ippocampo. Tutti i soggetti sono stati sottoposti a valutazione neurocognitiva tramite la somministrazioone di una batteria di test tratti dall’esame neuropsicologico breve (ENB) e al Wisconsin Card Sorting Test (WSCT) RISULTATI: sono state riscontrate alterazioni statisticamente significative degli indici di diffusione per le regioni di interesse (ROIs) che hanno evidenziato anormalità degli indici di diffusione nelle regioni frontali nei pazienti dello spettro (e condivise tra bipolari e schizofrenici) rispetto ai controlli sani. È stato evidenziato un pattern complesso di alterazioni degli indici di diffusione a livello dell’ippocampo e dell’amigdala tra i due gruppi di pazienti e i controlli sani. Oltre a questo, è stato riscontrato un peggiore funzionamento cognitivo e delle prestazioni al WSCT nei pazienti rispetto ai controlli sani. Si sono inoltre evidenziate alcune correlazioni tra i punteggi ottenuti ai test e gli indici di diffusione, in particolare per le regioni frontali condivise tra pazienti schizofrenici e bipolari. CONCLUSIONI: I pazienti dello spettro schizofrenico-bipolare condividono le ridotte prestazioni ai test neuropsicologici, le alterazioni degli indici FA e ADC a livello dei lobi frontali e di ADC dell’ippocampo di sinistra, ma gli schizofrenici, rispetto ai bipolari hanno un pattern differente di alterazioni a livello della formazione ippocampale di destra dell’amigdala sinistra. La disconnettività appare quindi avere un ruolo centrale nella patogenesi dei disturbi dello spettro. L’identificazione di alterazioni degli indici di diffusione di specifiche regioni cerebrali potrebbe rappresentare un passo cruciale nell’individuare un correlato neurobiologico presente nei disturbi dello spettro bipolare-schizofrenico.
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Cook, Shaun P. "Are All Sources Equal? Examining the Roles of Aging and the Frontal Lobes on Multiple Types of Source Memory Using a Repeated-Measures Design." Diss., The University of Arizona, 2006. http://hdl.handle.net/10150/195539.
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This paper reports a series of experiments designed to compare memory for multiple kinds of source information in young and older adults. The older adults in these studies were classified as having well or poorly functioning frontal lobes. In EXPERIMENTS 1-3, three different sources that provided independent cues to item information were examined using a repeated-measures design. In particular, participants' memory for voice source information, spatial source information, and temporal source information was tested in separate blocks. The results indicated that the performance of both young and older adults depended upon the type of source tested: Voice source memory was superior to spatial source and temporal source memory, which did not differ. There was also an age effect that was mediated by frontal functioning. Only the low frontal older adults showed impairments in source memory. High frontal older adults were equivalent to young. In EXPERIMENT 4, sources that provided redundant cues to item information were investigated. Voice sources and spatial sources were perfectly matched during encoding such that Voice A always came from Location 1 and Voice B always came from Location 2. When sources provided redundant information in this manner, young and high frontal older adults improved their spatial source memory by making use of redundant voice information, whereas the low frontal older adults not only performed more poorly than both young and high frontal older adults, but were unable to benefit from the redundancy. No differences in item memory were found. The findings were interpreted in terms of the executive and working memory functions involved in the integration of various contextual elements of an experience with its content.
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Ekovich, Muriel. "Contrôle exécutif et mémoire : inférences probabilistes et récupérations mnésiques dans les lobes frontaux." Thesis, Paris 6, 2014. http://www.theses.fr/2014PA066383/document.
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Les humains doivent sans cesse s’adapter à des environnements incertains, changeants et ouverts. Pour ce faire, il est nécessaire d’explorer, d’ajuster et d’exploiter plusieurs task-sets, c’est-à-dire des associations sensorimotrices flexibles entre des stimuli, des actions et des résultats. Collins et Kœchlin ont proposé un modèle computationnel qui contrôle la création, l’apprentissage, le stockage, la récupération et la sélection de tels task-sets pour guider le comportement (Collins & Kœchlin, 2012, PloS biology). Le modèle met à jour les fiabilités d’un ensemble de task-sets, c’est-à-dire leur capacité à prédire correctement les conséquences des actions. Cette mise à jour des fiabilités est réalisée par inférence bayésienne en intégrant les résultats des actions et l’information contextuelle. Elle permet d’arbitrer entre l’exploitation du task-set le plus fiable et l’exploration de nouveaux task-sets. En l’absence d’information contextuelle, la fiabilité des task-sets appris est maintenue et mise à jour dans le cortex frontopolaire (Donoso, Collins & Kœchlin, Science, 2014). Ce travail de thèse a pour but d’élucider les mécanismes neuraux permettant le monitorage et la récupération de task-sets stockés en mémoire, que ce soit selon les indices contextuels ou les résultats des actions. Pour ce faire, nous avons élaboré une expérience d’IRM fonctionnelle dans laquelle des sujets sains doivent apprendre, par essais et erreurs, plusieurs task-sets associés à divers indices contextuels, puis réutiliser les task-sets appris. Les conditions expérimentales varient de façon non prédictible de telle sorte que : (i) des task-sets précédemment appris doivent être réutilisés soit avec le même indice contextuel, soit avec un indice contextuel nouveau ; (ii) de nouveaux task-sets doivent être appris soit avec de nouveaux indices contextuels, soit avec des indices connus. Les résultats comportementaux montrent que les sujets apprennent, maintiennent, mettent à jour et réutilisent un répertoire grandissant de task-sets tel que le prédit le modèle computationnel. Plus précisément : (i) les indices contextuels connus sont utilisés de façon proactive (avant l’exécution d’une action) pour sélectionner le task-set correspondant ; (ii) lorsque les indices contextuels sont inconnus, les sujets sélectionnent le task-set de façon réactive, selon les résultats des actions. Les résultats d’imagerie révèlent que la fiabilité des task-sets est mise à jour dans le cortex frontopolaire et le cortex préfrontal dorso-latéral. De plus, le cortex préfrontal latéral est impliqué dans le processus de sélection proactif et réactif. Cependant, les récupérations proactives et réactives dépendent de réseaux distincts : (i) d’une part la récupération proactive repose sur un réseau ventral qui inclut le cortex préfrontal ventro-médian, le striatum et l’hippocampe ;(ii) d’autre part, la récupération réactive repose sur un réseau frontal incluant notamment le cortex frontopolaireHumans need to adapt to uncertain, changing, and open-ended environ- ments. In such situations, decision-making involves exploring, adjusting and ex- ploiting multiple task-sets – defined as flexible sensorimotor mappings associating stimuli, actions, and expected outcomes. Collins and Kœchlin proposed a computational model that controls the crea- tion, learning, storage, retrieval, and selection of such task-sets for driving action (Collins & Kœchlin, 2012, PloS biology). The model monitors the reliability of a collection of concurrent task-sets - i.e., the ability of alternative task-sets to correctly predict action outcomes. Task-set reliability is updated in a Bayesian manner according to outcomes and contextual information and arbitrates between exploiting the most reliable task- set or exploring new ones to drive action. It has recently been shown that, without contextual information, the reliability of alternative learned task-sets is monito- red in frontopolar cortex (Donoso, Collins & Kœchlin, Science, 2014). The goal of this study is to investigate the neural mechanisms that subserve the monitoring and retrieval of stored task-sets according to both contextual cues and action outcomes. We designed an fMRI experiment requiring healthy human subjects to learn by trials and errors and to switch between multiple task-sets associated with va- rious contextual cues. Experimental conditions varied unpredictably such that: (i) previously learned task-sets re-occurred with either the same or new contextual cues, (ii) new task-sets that needed to be learned occurred with new cues or pre- viously encountered ones. Behavioral results and model fits show that subjects learned, monitored and switched across an expanding repertoire of task-sets as predicted by the compu- tational model. More specifically : (i) Known contextual cues were used proactively (before performing any action) to select the corresponding task-set ; (ii) When previously learned task-sets re-occurred with unknown contextual cues, subjects selected the stored task-set reactively based on action outcomes. Model-based fMRI results revealed that task-set reliability is updated in the frontopolar cortex and the lateral prefrontal cortex. Moreover, lateral prefrontal cortex is engaged in the selection process in both cases. However distinct networks are involved depending on whether the retrieval is cue or outcome-based: (i) on the one hand, proactive retrieval relies on a ventral pathway including ventromedial prefrontal cortex, striatum and bilateral hippocampus ;(ii) on the other hand, reactive retrieval relies on a frontal network including frontopolar cortex
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Jovanovski, Diana. "Cognitive set shifting using functional magnetic resonance imaging (fMRI) and virtual reality (VR) a comparison between a traditional and a novel ecologically-valid executive function task /." Full text available, 2005. http://images.lib.monash.edu.au/ts/theses/jovanovski.pdf.
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Chavez, Candice Monique. "Top-down modulation by medial prefrontal cortex of basal forebrain activation of auditory cortex during learning." CSUSB ScholarWorks, 2006. https://scholarworks.lib.csusb.edu/etd-project/3053.
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The experiment tested the hypothesis that the acetylcholine (ACh) release in the rat auditory cortex is greater in rats undergoing auditory classical conditioning compared to rats in a truly random control paradigm where no associative learning takes place and that this is mediated by prefrontal afferent projections influencing the nucleus basalis magnocellularis (NBM), which in turn modulates ACh release in neocortex. Rats with bilateral ibotenic acid lesions of medial prefrontal and agranular insular cortices were tested in an auditory classical conditioning task while ACh was collected from the primary auditory cortex. It was hypothesized that lesions of these prefrontal areas would prevent learning-related increases of ACh release in the primary auditory cortex. The hypothesized results were supported. Results from this experiment provide unique evidence that medial prefrontal cortex projections to the NBM are important for mediating cortical ACh release during associative learning.
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Gregory, Nicola Jean. "The influence of socio-biological cues on saccadic orienting." Thesis, University of Exeter, 2011. http://hdl.handle.net/10036/3231.
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Previous research has suggested that viewing of another’s averted eye gaze causes automatic orienting of attention and eye movements in observers due to the importance of eye gaze for effective social interaction. Other types of visual cues with no social or biological relevance, such as arrows, are claimed not to produce such a direct effect on orienting behaviour. The finding that processing of eye gaze is reduced in individuals with Autistic Spectrum Disorders as well as following damage to the orbitofrontal cortex of the brain, suggests that gaze processing is indeed critical for effective social behaviour and therefore eye gaze may constitute a “special” directional cue. This thesis tested these ideas by examining the influence of socio-biological (eye gaze and finger pointing) and non-social cues (arrows and words) on eye movement responses in both healthy control participants and those with damage to the frontal lobes of the brain. It further investigated the relationship between orienting to gaze and arrow cues and autistic traits in a healthy population. Important differences between the effects of socio-biological and non-social cues were found on saccadic eye movements. Although in the pro-saccade tasks, arrow cues caused a similar facilitation of responses in the cued direction as eye gaze and pointing cues, in the anti-saccade tasks (in which participants have to respond away from the location of a peripheral onset), arrows had a greatly reduced effect on oculomotor programming relative to the biologically relevant cues. Importantly, although the socio-biological cues continued to influence saccadic responses, the facilitation was in the opposite direction to the cues. This finding suggests that the cues were being processed within the same "anti-response" task set (i.e. "go opposite") as the target stimulus. Word cues had almost no effects on saccadic orienting in either pro- or anti-saccade tasks. Schematicised eye gaze cues had a smaller magnitude effect than photographic gaze cues suggesting that ecological validity ("biological-ness") is an important factor in influencing oculomotor responses to social cues. No relationship was found between autistic traits and orienting to gaze or arrow cues in a large sample of males. However, findings from the neurological patients point to a possible double-dissociation between the neural mechanisms subserving processing of socio-biological and non-social cues, with the former reliant on the orbitofrontal cortex, and the latter on lateral frontal cortex. Taken together, these results suggest that biologically relevant cues have privileged access to the oculomotor system. The findings are interpreted in terms of a neurocognitive model of saccadic orienting to socio-biological and non-social cues, and an extension to an existing model of saccade generation is proposed. Finally, limitations of the research, its wider impact and directions for future work are discussed.
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Kemper, Birgit. "Neuropsychologische Untersuchung bei Frontallappenepilepsien ein Vergleich kognitiver Leistungen zwischen Patienten mit Frontal- und Temporallappenepilepsie im Rahmen der prächirurgischen Diagnostik /." Münster : Universität Münster, 1995. http://catalog.hathitrust.org/api/volumes/oclc/64528329.html.
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Naqvi, Nasir Hasnain. "The effects of lesions in the ventromedial prefrontal cortex and related areas on emotional responses to cigarette smoking." Diss., University of Iowa, 2007. http://ir.uiowa.edu/etd/173.
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Tsuchida, Ami. "Fractionating frontal lobe function." Thesis, McGill University, 2012. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=110341.
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The prefrontal cortex (PFC) is thought to play a central role in higher order executive function important in everyday life, such as planning, problem solving and decision-making. Disturbances in such abilities are seen after frontal lobe damage as well as in a variety of neuropsychiatric conditions, ranging from drug addiction to Parkinson's disease, and can have a significant impact on autonomy and quality of life. Despite this broad clinical importance, the component processes underlying executive function and their neural substrates within the PFC are poorly understood. Recent advances in cognitive neuroscience provide the opportunity to develop a more detailed understanding of the component processes of executive function, and to relate these processes to particular sub-regions within the frontal lobes. This doctoral work examined the frontal lobe substrates of executive function in human participants with focal brain damage. The hypothesis of this thesis was that specific cognitive processes would be affected by damage to specific sub-regions within PFC. This hypothesis was tested by administering a set of tasks isolating specific cognitive processes to a large group of patients with lesions affecting various sectors of the frontal lobes. Individual findings from different tasks identified several specific structure-function relationships. These included novel findings regarding distinct roles of left lateral and dorsomedial PFC in n-back task performance, a role for ventromedial PFC in flexible stimulus-reinforcement learning, and separable contributions of left lateral and ventromedial PFC to facial emotion recognition. In addition to the findings from individual tasks, this work also identified shared and dissociable PFC contributions to performance of three classic tests of executive function hypothesized to measure distinct component processes. These findings validate behavioural measures of region-specific component processes that will be applicable to other conditions marked by executive dysfunction. This work provides converging evidence for component process accounts of executive function, and contributes to our understanding of human frontal lobe function in both health and disease.Le cortex préfrontal joue un rôle central dans la fonction exécutive quotidienne de haut niveau telles que la planification, la résolution de problème et la prise de décision. Ces aptitudes peuvent être perturbées lorsque les lobes frontaux sont endommagés, ou lorsque le patient est atteint de conditions comme la dépendance de drogue ou la maladie de Parkinson; la perturbation de ces aptitudes peut avoir d'importantes conséquences sur l'autonomie et la qualité de vie du patient. Bien que les dommages aux lobes frontaux aient des répercussions cliniques significatives, notre compréhension des processus sous-jacents et des substrats neuronaux de la fonction exécutive affectée demeure insatisfaisante. Les récents avancements en neurosciences cognitives nous ont permis de développer une compréhension beaucoup plus détaillée des fonctions exécutives et de leurs processus sous-jacents. Ils nous ont aussi permis de lier ces processus à des subdivisions spécifiques des lobes frontaux. Ce travail de doctorat examine les substrats neuronaux des fonctions exécutives frontales chez des sujets humains ayant subi des dommages localisés au cerveau. Cette thèse stipule que des dommages à certaines subdivisions spécifiques du cortex préfrontal mènent, à leur tour, au disfonctionnement de processus cognitifs spécifiques. Nous avons vérifié cette hypothèse en soumettant un large groupe de patients avec des lésions aux lobes frontaux à une série de tests cognitifs. Les résultats de ces expériences ont permis d'associer des processus cognitifs à des secteurs spécifiques des lobes frontaux, identifiant ainsi des relations entre structure et fonction dans les lobes frontaux. Celles-ci incluent les découvertes de rôles distincts pour les cortex préfrontal gauche latéral et dorsomédial dans la performance du n-back task, du rôle que joue le cortex préfrontal ventromédial dans l'apprentissage flexible du renforcement du stimulus, et des contributions différentielles du cortex préfrontal gauche latéral et ventromédial dans la reconnaissance des émotions faciales. Mis à part les découvertes des tests individuels, cet ensemble de travail a aussi identifié des contributions partagées et dissociables du cortex préfrontal à la performance des trois tests classiques de fonctions exécutives. Ces découvertes servent aussi à valider les tests utilisés comme des mesures comportementales des différentes composantes des fonctions exécutives régies par des subdivisions spécifiques des lobes frontaux. Ces mesures pourront ensuite s'appliquer aux autres conditions marquées par la dysfonction exécutive. Ce travail doctoral fournit des preuves convergentes pour un processus composant de fonction exécutive, et contribue à notre compréhension du fonctionnement normal et pathologique des lobes frontaux.
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Beteta, Pacheco Edmundo. "Frontal Lobe and Psychoanalysis." Pontificia Universidad Católica del Perú, 2013. http://repositorio.pucp.edu.pe/index/handle/123456789/99968.
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Through an attractive hypothesis of work, we present the relaTionship between the frontal lobes and the neurobiological bases of Freud's psychoanalytic theory. We review and discuss the psycophysiological and clinical aproachs, in order to understand this relationship, arriving to the final examination of the organic and functional "disolutions" of the brain. We study and discuss the clinical progressive symptoms of the dementia and the differencial diagnosis of abnormal behavior, inrerpreted under the bases of Freud's theory. In this way it would be possible to arrive through some tempting interpretation of the psychopatic behavior, drug addiction and the last "syndrome of terrorism".Se trata de establecer mediante una atractiva hipótesis de trabajo, las relaciones entre los lóbulo frontales y las bases neurobiológicas de la teoría freudiana del psicoanálisis. Se presenran y discuten las aproximaciones psicofisiológicas y clínicas, en la interpretación de estas relaciones, llegando al análisis final de las "disoluciones" orgánicas y funcionales del cerebro, pasando revista a los síntomas de la demencia y cuadros clínicos diferenciales, por los cuales se puede llegar a la interpretación freudiana de la psicopatía, la farmacodependencia y el síndrome del terrorismo.
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Malva, Connie Della. "Sequencing in frontal lobe patients." Thesis, University of Ottawa (Canada), 1990. http://hdl.handle.net/10393/5809.
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An experimental neuropsychological study was undertaken to investigate whether frontal damage selectively affects the ability to carry out sequencing tasks. Thirteen patients, assigned to an Anterior Group on the basis of locus of brain lesion, were compared to nine patients assigned to a Posterior Group. Each of these groups was compared to a Normal Control Group, matched for age, sex and level of education, on two sequencing tasks. In the first, Increasing Span Task, subjects were required to organize sequences of increasing length. Verbal and pictorial subtests, consisting of four, six, nine and twelve unit sequences, were presented separately. The second, Capture Error Task, was designed to assess sequencing performance on tasks where a potential for capture errors exists. A capture error, in this study, was defined as the incorrect successive pairing of two items which tend to be frequently and routinely associated with one another but which, in the context of the present task, should be separated and used in a less characteristic way. The potential for a capture error was created by presenting a series of six unit sequences in which a special association existed between two successive units; this association was sometimes valid (i.e., the units should remain together in the final solution) and sometimes invalid (i.e., the units should be taken apart and used separately in the final solution). Twenty verbal sequences and twelve pictorial sequences were administered separately in two subtests. The results on the Increasing Span Task showed that while neither Anterior nor Posterior groups had difficulty organizing short (4 unit) sequences, subjects in the Anterior group were particularly sensitive to sequencing tasks at normal span and beyond. The results of the Capture Error Task showed that the Anterior group differed from their Control group and from the Posterior group in their ability to arrange sequences correctly when a potential for capture errors was present. The theoretical implications of these results for the role of the frontal lobes in behavior are discussed.
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Charlesworth, G. "Neuropsychology of frontal lobe dementia." Thesis, University of East Anglia, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.296874.
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Upton, Dominic Richard Barrie. "Neuropsychological aspects of frontal lobe epilepsy." Thesis, University College London (University of London), 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.309291.
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Derry, C. P. "Frontal lobe epilepsy, sleep and parasomnias." Thesis, University College London (University of London), 2007. http://discovery.ucl.ac.uk/1445467/.
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A close relationship exists between sleep and epilepsy. While many forms of epilepsy may be influenced by the sleep-wake cycle, this phenomenon is particularly evident in frontal lobe epilepsy where affected individuals may experience seizures exclusively during sleep (nocturnal frontal lobe epilepsy, NFLE). In this thesis, three aspects of the relationship between sleep and frontal lobe epilepsy are examined. Firstly, serotonergic neurotransmission across the human sleep-wake cycle was studied using the novel PET ligand l8F-MPPF, a serotonergic 5HT)A receptor radioligand sensitive to endogenous serotonin release. Fourteen individuals with narcolepsy underwent 18F-MPPF PET scans during sleep and wakefulness. The study demonstrated a 13% increase in 18F-MPPF binding potential (p < 0.01) during sleep, indicating a reduction in serotoninergic neurotransmission, in line with existing animal data. Secondly, the characterisation of benign, non-epileptic parasomnias and their distinction from nocturnal frontal lobe seizures was addressed in two studies. The first comprised an analysis of the historical features of these conditions, and included the development and validation of a clinical scale for the diagnosis of nocturnal events. The second comprised a detailed semiological analysis of a series of parasomnias recorded on video-EEG monitoring, and a statistical comparison with seizures in NFLE. Although similarities between NFLE and parasomnias were observed, the results provide an evidence base for the confident distinction of these disorders. Finally, the familial form of NFLE (autosomal dominant nocturnal frontal lobe epilepsy, ADNFLE) is associated with mutations in genes for nicotinic acetylcholine receptor subunits, but recognised mutations account for only a minority of reported cases. The last study presented here is a clinical and genetic analysis of two large families with an unusually severe ADNFLE phenotype. Affected individuals had refractory epilepsy and increased rates of mental retardation and psychiatric disorders and, in one family, linkage studies suggest a previously unrecognised underlying mechanism.
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García, López Beatriz. "Frontal lobe epilepsy and EEG: Neurophysiological approach." Doctoral thesis, Universitat Autònoma de Barcelona, 2015. http://hdl.handle.net/10803/298310.
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La epilepsia del lóbulo frontal es la segunda más frecuente en la mayoría de las series publicadas, después de la epilepsia temporal. Sus características clínicas y electroencefalográficas son muy variadas, lo que hace de su diagnóstico y tratamiento un reto en la práctica clínica.
Las crisis frontales suelen aparecen en “clusters”, con frecuencia generalizan y el aspecto electroencefalográfico de la actividad intercrítica y crítica suele ser difícil de interpretar por la gran difusión que suele acompañar a la actividad paroxística en este tipo de epilepsia.
En este trabajo se han estudiado 175 casos con alteraciones intercríticas en el electroencefalograma, realizando un análisis exhaustivo de todos sus aspectos morfológicos. Se ha dividido la muestra en función de tres aspectos morfológicos para estudiar la actividad intercrítica: Su morfología (puntas; ondas agudas simples; ondas agudas difásicas; polipuntas; ondas lentas irregulares), su voltaje (menor de 50 μV, entre 50-100 μV, 100-20 0μV y más de 200 μV) y la actividad que sigue a ésta actividad paroxística. Las ondas agudas tanto simple como difásicas de 50-200 μV fueron el grupo más frecuente en la morfología intercrítica. A continuación, mucho menos frecuentes, las puntas, especialmente de menos de 50 μV. En cuanto a la actividad crítica se han estudiado en detalle sus características morfológicas al inicio de la crisis y sus frecuencias, con el propósito de disponer de una clasificación útil desde el punto de vista electroencefalográfico en el estudio de este tipo de crisis. Morfológicamente el ritmo reclutante fue la característica morfológica más frecuentemente observada al inicio de las crisis, seguida de un ritmo reclutante de baja amplitud. Las crisis registradas fueron cortas, frecuentemente de segundos de duración, comenzando con un ritmo reclutante de 15 Hz de frecuencia media y progresivo enlentecimiento desde el inicio. El enlentecimiento frontal observado en el postcrítico ayudó a localizar el foco. Algunos presentaron clusters de varias crisis en el mismo registro y los cambios en la poligrafía respiratoria y ECG fueron frecuentes durante las crisis frontales registradas. Encontramos que la localización del foco predice la localización del inicio crítico y que el patrón crítico desde un punto morfológico se mantiene a lo largo del tiempo para cada paciente.
Una parte fundamental del trabajo se encuentra en el anexo incluido a modo de “atlas”, en el que se exponen alguno de los casos objeto de estudio, detallando observaciones electroencefalográficas de interés.Frontal lobe epilepsy (FLE) is the second most common type of epilepsy after temporal lobe one. Clinical and electroencephalographic (EEG) features are also very varied, being its diagnose usually a challenge in clinical practice. Frontal lobe seizures appear frequently in cluster, with secondary generalization, and its EEG appearance is usually difficult to determine, due to the widespread the interictal and ictal activity usually achieves. This is an electroencephalographic study, where 175 cases with frontal lobe EEG interictal epileptiform activity have been carefully studied regarding an electroencephalographic point of view, with special emphasis in the morphology of the waveforms. We have divided the sample regarding three different aspect for studying the interictal activity: Its morphology (spike; simple sharp wave; diphasic sharp waves; poly-spikes; irregular slow waves) its voltage (less than 50 μV, 50-100 μV, 100-200 μV and more than 200 μV) and the activity that follows the waveform. The main interictal waveform in our sample was the sharp wave group, both simple and diphasic between 50 to up to 200 μV. Afterwards, much less frequently, the spikes, specially of less than 50 μV. Regarding the ictal activity, some morphologic details at onset are studied with the aim to make available a practical EEG classification for these seizures. Morphologically the synchronized rhythm was the most frequent morphology observed at seizure onset, followed by a low amplitude synchronized rhythm. –recorded seizures were short, frequently of seconds of duration, and they started with a synchronized rhythm of 15 Hz mean frequency, with a progressive slowing after onset. Postictal frontal slowing activity was meaningful, adding value information for locating the focal epileptiform activity. Some patients presented clusters of several seizures within the same recording and changes in breathing polygraphy and EKG were very common during the frontal lobe recorded seizures. We found that the focus location predicts the location of seizure onset, and that the seizure pattern from a morphological point of view remains the same for each patient along time. A major point of interest of this work is included in the graphical appendix, where some interesting EEG features are detailed.
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D'Anna, Lucio. "White matter disconnection in frontal lobe disorders." Thesis, King's College London (University of London), 2017. https://kclpure.kcl.ac.uk/portal/en/theses/white-matter-disconnection-in-frontal-lobe-disorders(d3375b51-9431-4d54-bce3-62664bfbaff3).html.
Full textAbstract:
In the recent years our understanding of the frontal lobe functions has greatly advanced. The advances in the field of the neuropsychology, neuroimaging and neurosciences all contributed to a rapidly changing perspective on the role of the frontal lobes in behaviour and cognition and they also changed clinical approaches to the evaluation of patients with frontal lobe disorders. The structure of the brain can be non-invasively assessed in vivo using magnetic resonance imaging (MRI). The MRI diffusion tensor imaging (DTI) can be used to reconstruct the human brain white matter and to quantify their microstructural integrity. The aim of this thesis is to investigate the anatomy of the frontal networks underlying cognitive and behavioural functions and includes three studies: an investigation of the association between extra-motor white matter tracts and cognitive and behaviour symptoms in Motor Neuron Disease (MND); a study of the ventral fronto-temporal network and its association with behavioural symptoms in Primary Progressive Aphasia (PPA); a study to investigate the association between white matter abnormalities in several long association tracts and deficits in non-verbal and verbal communication in Autism Spectrum Disorders (ASD). Overall, the findings of this thesis indicate that both uncinate fasciculus and cingulum are frontal lobe structures particularly vulnerable to disease regardless the nature of the underlying pathology. Damage to these tracts could manifest with abnormalities in several aspects of social behaviour and cognition. These considerations will help to broaden our understanding of the frontal lobe function beyond motor and language functions.
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West, Robert. "Inhibition, Distraction & the Aging Frontal Lobe." TopSCHOLAR®, 1993. https://digitalcommons.wku.edu/theses/2979.
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lbeories in both the fields of ognstsvc aging and human neuropbychology have suggested that an impairment in the ability of an individual to inhibit irrelevant or distracting information either present in the environment or generated within the individual can ha‘ e detrimental effects on performance on a wide variety of cognitive tasks including text processing, inference formation, planning, and selective attention A number of researchers have attributed this increased distractibility in both clinical populations and health\ older individuals to a decline in or impairment of the functioning of the frontal lobes The present study extends findings suggesting a decline in frontal lobe function and increased susceptibility to distraction in healthy older individuals In addition, the possible relationship between these two phenomena is explored in a systematic fashion, an analysis absent in previous literature.
Individuals ranging in age from 20 to 80 years completed a battery of tests designed to appraise frontal lobe function (WCST, FAS Word Fluency Test, Cognitive Estimation Test, and Stroop Color/Word Test) and to determine the effects of distractors on task performance (Useful Field of View, Negative Priming Task). To equate for general verbal intelligence and short term memory span, individuals also completed the Ammons Quick IQ Test and the Digit Span Forward subtest of the WAIS-R.
Consistent with previous research, older individuals generally showed a decline in frontal lobe function as well as increased susceptibility to distraction when compared to the young individuals. The decline in frontal lobe function can be seen by increased repetitions and elaborations on the FAS, increased perseverative errors on the WCST, greater degrees of Stroop distraction and a decreased number of categories being obtained on the WCST, with age. Increased susceptibility to distraction is suggested by the impairment of many older individuals on UFOV task 3 and the distraction measure of the negative priming task. There was also a decline in negative priming with increasing age for some older individuals. However contrary to past research, several of the older individuals demonstrated negative priming effects equal to those found in the younger subjects. The expected relationship between frontal lobe function and susceptibility to distraction was found to be significant. UFOV task 3 shared approximately 1/3 of its variance with the frontal lobe composite measure.
The present study extends previous work suggesting that one function of the trontal lobes is to modulate the effects of irrelevant or distracting information on efficient cognition It also suggests that declines in inhibitory mechanisms, as assessed with the negative priming paradigm, can vary widely between older individuals.
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Aubin, Ghislaine. "Résolution de problèmes numériques et syndromes frontaux : étude de différents niveaux cognitifs." Lyon 1, 1997. http://www.theses.fr/1997LYO1T327.
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Gow, Catherine Ann. "Source amnesia in patients with frontal lobe damage." Thesis, University of Ottawa (Canada), 1994. http://hdl.handle.net/10393/6560.
Full textAbstract:
Frontal lobe lesions do not produce a classical amnesia syndrome, although such damage has been associated with some forms of disordered memory processing. This study examined the phenomena of source amnesia in patients with frontal lobe damage. Patients with focal lesions to the frontal lobe, and age- and education-matched normal control subjects were compared on two memory tasks for their recall of both fact and source. In the first experiment, subjects learned fictitious facts about famous and nonfamous individuals and were tested for their recall of both the fact and the source following a 15 minute, and one week delay. In the second experiment, subjects were tested for their recall of the placement of objects on two surfaces under both plain and enhanced conditions. Subjects' ability to recall the board, as well as the exact placement of the objects on the board was tested. Additionally, subjects were required to discriminate experimental objects, from those not seen during the learning session. In both experiments, patients' ability to recall the facts, and the overall placement of objects was as good as that of normal control subjects, but the patients tended to commit more source errors than the normal control subjects. Results from experiment 1 indicated that some patients with lesions of the right hemisphere tended to have more difficulty recalling the presenter source (intra-experimental source) while some patients with left hemisphere damage tended to have more difficulty recalling where they had learned a fact (extra-experimental source). Subtle language impairments were found to be associated with acquisition but not delayed recall of the verbal material. Intra-experimental source errors were related to poor performance on the WCST, while extra-experimental source errors were related to non-verbal measures such as WMS-R, Visual Memory Index, and WAIS-R, PIQ. The data suggest that recall of contextual features such as the modality of presentation and time and place of a learned event can be dissociated from the contents of the learning episode, and that source recall may be disproportionately impaired in some patients with frontal lobe damage. The second experiment revealed deficits in the ability of patients, particularly those with left hemisphere damage, to determine the exact placement of objects on the board to the left. The use of color to enhance learning did not result in increased recall for any of the subjects, however, the patients with damage to the left hemisphere were more likely to incorrectly attempt to place an object under these conditions. Recall of object placement was associated with classical frontal lobe measures, while discrimination of the sets of objects, and placing an object on the wrong board were related to the BNT in the enhanced condition. In fact, although significant correlations were found between the spatial memory measures in the plain condition and the Visual Memory Index, these measures were correlated with the Verbal Memory Index. The results suggest that enhanced context does not increase the accuracy of recall in either patients or normal control subjects. However, the addition of color to the learning situation increased erroneous attempts at placement in the group of patients with left hemisphere damage. This propensity was attributed to a combined effect of use of verbal strategies in the enhanced condition, and poor language decoding abilities in the left hemisphere damaged-patients.
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Noonan, MaryAnn Philomena. "Linking actions to outcomes in the frontal lobe." Thesis, University of Oxford, 2010. http://ora.ox.ac.uk/objects/uuid:e1bcccd1-2182-4f1d-94bd-b80ce67efb0e.
Full textAbstract:
Behaviour is guided by accumulated experience, valuation and comparison. While many aspects associated with these functions are mediated by the frontal lobes, the precise contribution from particular regions remains debated. This thesis will deal with how an organism comes to select an option and will specifically focus on the role of the orbitofrontal cortex (OFC) in two mechanisms in this process: learning of outcome specificities and selecting between multiple options based on their expected values. Despite evidence emphasizing anatomical and connective heterogeneity within this structure, the OFC is often regarded as a uniform region. This thesis aims to resolve some of this uncertainty by assuming that the medial and lateral regions of the OFC contribute differentially to learning and decision-making. Two distinct methodologies were used in these investigations. First, the contribution of the medial OFC to social and emotional processing was examined. The findings from this study disprove previously held beliefs that the medial regions of the OFC guide social and emotional behaviours, but indicted a role for this region in value-guided decision-making. The second study examined functional differences between the lateral and medial OFC by making circumscribed lesions to either region in macaque monkeys. The animals performed a number of 3-armed bandit tasks which were designed to investigate different aspects of value assignment and comparison. The results show that while lateral OFC was required for "credit assignment" – the correct assignment of values to visual cues – medial OFC was critical for comparison of the cues' values during decision-making. In unchanging probabilistic environments, mOFC lesions induced decision-making impairments when value comparison was difficult without affecting credit assignment and associative learning. By contrast, lateral OFC lesions caused the opposite pattern of impairment. The final study used human-neuroimaging techniques to investigate the differential representation of outcome-specific contingency learning and found not only that the expectation of a unique outcome facilitated learning and memory recall but that this was supported by a neural network which included the lateral regions of the OFC and the anterior cingulate cortex. Activity in the mOFC did not correlate with outcome-specific contingency learning but instead reflected both the value associated with the receipt and expectation of a reward. Taken together, the results from this thesis suggest that specific parts of the OFC make markedly different contributions to these very different cognitive functions.
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Turner, Martha. "Confabulation and memory impairments following frontal lobe lesions." Thesis, University College London (University of London), 2005. http://discovery.ucl.ac.uk/1446667/.
Full textAbstract:
Neuroimaging studies have provided considerable evidence for frontal lobe involvement in memory processing. Memory impairments arc also frequently reported in patients with frontal lobe lesions. However detailed anatomical localisation is rare, making integration of lesion and imaging findings difficult. An investigation of the functional and anatomical contributions of the frontal lobes to memory was conducted in 42 patients with frontal lobe lesions, examining memory processes identified in previous imaging and neuropsychological research. The results revealed frontal impairments in recall and recognition memory, increased false recognition and intrusions, and confabulation. To investigate specific lesion-behaviour relationships, patients were grouped according to the presence of damage in Right Lateral, Left Lateral, Medial and Orbital frontal regions. The Medial group had impairments in recognition and recall on several tasks, which were due at least in part to deficits at encoding. This group may have a pure memory deficit arising from disruption of cholinergic projections from the basal forebrain to the medial temporal lobe system. The Right Lateral group on the other hand had a strategic retrieval deficit which was aided by cueing at recall. Marked intrusion and confabulation effects were found in the Orbital and Medial groups, providing strong support for an inferior medial localisation for confabulation. In addition an investigation of Schnider and colleagues' theory of confabulation was conducted in three confabulating patients. Strong support was found for a characteristic pattern of performance on their continuous recognition task, with confabulators showing a constant hit rate accompanied by an increasing false positive rate. However the suggestion that the critical impairment is an inability to suppress currently irrelevant memories that intrude into the present was not supported. Instead these patients had a complete inability to place remembered information in its correct temporal context. There was also evidence of a tendency to misidentify imagined experiences as real. It is argued that retrieval process theories incorporating these factors are best able to account for the features of confabulation.
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McGlynn, Susan Mary. "Metamemory and frontal lobe function in the elderly." Diss., The University of Arizona, 1992. http://hdl.handle.net/10150/185946.
Full textAbstract:
Several measures were used to investigate age differences in metamemory, and to examine the relation between metamemory and frontal lobe function in the elderly. Three age groups were included in the study to address these issues: a Young Control group (18-30 yrs); a Young-Old group (60-75 yrs); and an Old-Old group (76-90 yrs). Metamemory was assessed in two ways. Subjects completed the Metamemory in Adulthood questionnaire (MIA; Dixon, Hultsch, & Hertzog, 1988), and subjects were asked to predict their performance on a variety of memory tasks that provided information both about awareness of their own memory functioning and knowledge of general memory processes. The relation between frontal lobe function and metamemory was assessed by administering a number of neuropsychological tests of frontal lobe abilities, and performing statistical analyses to determine how well these frontal measures predict metamemory performance. Results of the MIA questionnaire revealed that elderly subjects view their memory abilities as declining with age, whereas young subjects perceive their memory abilities to be relatively stable. On most other questionnaire dimensions, the three age groups did not differ. Age differences in metamemory were observed on the task performance predictions component of the study. Although no age differences in predictions were found for the majority of memory tasks, the elderly subjects demonstrated a significant decline in actual memory performance, particularly on the recall tasks. Significant differences in prediction-performance relations were only found between the Old-Old group and the Young Control group, reflecting a tendency for the Old-Old to overestimate their memory abilities and the Young Controls to underestimate their abilities. All subjects appeared sensitive to the effects of various manipulations on memory, indicating equivalent knowledge of general memory processes. Regression analyses demonstrated a significant relationship between frontal lobe measures and prediction-performance relations on most of the memory tasks, suggesting that a degradation in frontal lobe function with age may play a role in altered metamemory performance. The results of this study are discussed in terms of a breakdown in metacognition associated with frontal lobe dysfunction in the elderly that prevents them from updating knowledge about their own memory functioning.