Definition of neurodevelopmental outcome from early brain imaging remains a priority for survivors of very preterm (VPT) birth given their persistently high rates of cognitive and motor difficulties. Volumes of the deep grey matter (DGM) structures were measured longitudinally using magnetic resonance imaging from 96 VPT infants studied within 2 weeks of birth and 70 at term-equivalent age. At 4 years of age, 36 children returned for neuropsychological assessments evaluating IQ, language function, and visual motor integration. Multiple hierarchical regressions examined associations of DGM growth with neuropsychological measures. Overall DGM growth, primarily attributed to the caudate and thalamus, predicted Full Scale IQ, core language and VMI scores after controlling for sex and total brain volume. Thalamic growth was additionally associated with measures of neonatal clinical severity, bronchopulmonary dysplasia, and white matter lesions. Longitudinal growth of the DGM, particularly the caudate and thalamus were established as early markers of long-term outcomes.

Rapid advances in hardware technology are making it possible to manufacture different types of Sensor Nodes (SN) that results in fast growing heterogeneous Wireless Sensor Networks (WSNs). These WSN’s are applicable for a wide range of applications relevant for military, industry and domestic use. However, WSNs have particular features such as scarce resources which can affect their performance. In addition, WSNs are subject to experience changes that can occur both within the condition of the network, due to factors such as node mobility or node failure (prevalent in harsh environments), and with regards to user requirements. Consequently, it is vital for WSNs to sense the current network conditions and user requirements to be able to perform efficiently. Cognition is necessarily introduced in WSNs as a response to this need. Cognition in the context of WSNs deals with the ability to be aware of the environment and user requirements and to proactively adapt to changes. This thesis proposes a hierarchical architecture along with a cognitive network management protocol capable of enabling cognition in WSNs. Specifically; this research introduces Cognitive Nodes (CN) into WSNs so that they can manage the cognitive network. The cognitive network management process is composed of three sub-processes: 1) scanning the network, 2) decision-making, and 3) updating the nodes from taken decisions.Scanning the network process aims to provide an awareness of current network conditions. Therefore, at the first execution, each CN creates a profile table for each node in its purview and updates the tables periodically during the network operation. In decision making process, CNs make necessary decisions in terms of the working state of SNs (active/sleep), the duration of this state, and the Frequency of Sensing (FoS). Decision making process uses an optimization scheme to find the optimal number of active SNs in order to prolong the lifetime of the network. Finally, the nodes will be informed of the taken decisions. Based on the simulation and implementation results, the proposed cognitive WSN shows a significant enhancement in terms of the network’s longevity, its ability to negotiate competing objectives, and its ability to serve users more efficiently. / Thesis (Master, Electrical & Computer Engineering) -- Queen's University, 2013-03-04 12:39:24.502

Attention is a cognitive process essential to daily function. As attention encompasses an extremely broad array of cognitive subprocesses, there remains much to be discovered about the brain regions related to attention with neuroimaging. This thesis presents two studies that used functional magnetic resonance imaging to examine neural activity associated with different forms of attentional control. In the first study, we scanned healthy young adults while they performed the Stroop task, which measures selective attention, to investigate neural responses underlying unanticipated conflict detection. We found several regions across the frontal, parietal, and occipital lobes that became more active during states of unanticipated conflicts, relative to states of anticipated conflicts. These regions included the anterior cingulate, dorsolateral prefrontal cortex, angular gyrus, inferior parietal lobule, precuneus, lingual gyrus, and fusiform gyrus. Activity in these regions has previously been associated with attentional processes such as conflict detection, attention, orientation, and oddball detection. Our results therefore suggest that widespread areas of the cortex serve several cognitive processes involved in successfully monitoring and responding to unanticipated conflicts. In the second study, we tested young and cognitively healthy older adults with the Stroop task to determine whether aging affects the neural mechanisms underlying attentional lapses, defined as relatively longer response times. Like previous studies in young adults, we found regions in the default mode network exhibited greater activity as reaction time to stimuli increased. Attentional lapses were also preceded by decreased activity in regions related to attention, including the anterior cingulate and prefrontal cortices. Most importantly, young adults showed greater positive reaction time-modulated activity in default mode areas, while older adults exhibited greater positive reaction time-modulated activity in more prefrontal areas. Our results suggest that the neural correlates of attentional lapses change with healthy aging, reinforcing the idea of functional plasticity to maintain high cognitive function throughout the lifespan. / Thesis (Master, Neuroscience Studies) -- Queen's University, 2013-08-22 11:33:32.418

Three experiments were conducted to investigate the hypothesis that young infants? failures to search for occluded objects arises, not from deficiencies in their object representations, but from limitations in experience with the physical world. Successful means-end search is typically found at 8 months of age and is traditionally taken as the hallmark of object permanence. However, recent evidence suggests that infants much younger than 8 months of age are able to represent and reason about objects that are no longer visible. In Experiment 1, successful means-end search was found for 8. 5-, but not 6. 5-month-old infants in a traditional task, but younger infants showed successful search ability when the task was made familiar to them in Experiment 2 (i. e. , when the toy and occluder are first presented as a single composite object), and when they were given the opportunity to watch a demonstration of the solution to the task in Experiment 3. These results are taken as evidence for the ?experiential limitation? hypothesis and suggest that young infants are more apt at solving manual search tasks than previously acknowledged.

No description available.

This PhD thesis examines the relationship between Amyotrophic Lateral Sclerosis (ALS) and Frontotemporal dementia (FTD). ALS is a rapidly progressive neurodegenerative movement disorder characterized by muscle weakness, spasticity and abnormal reflexes. In a very small subset of patients (5-15%), ALS is associated with FTD. Furthermore, a larger subset of patients who do not suffer from overt dementia, develop subtle deficits in cognition and behaviour (up to 50%). The changes have mostly been observed in the domains of executive functions, language and behavioural functioning. These observations have led some researchers to propose a continuum of dysfunction between ALS and FTD, ranging from an absence of neuropsychological abnormalities to mild, subclinical changes to a profile consistent with a full-blown FTD-syndrome in ALS. FTD consists of three subsyndromes; the first ‘executive-behavioural’ type, frontal variant FTD (fvFTD), is predominantly characterized by behaviour abnormalities, difficulties with using strategies and social judgement. In contrast, the other two types mainly involve problems with ‘language’, including a central degradation of knowledge for words, objects, people (semantic dementia; SD) as well as complications with speaking, spelling and the sounds of language (progressive non-fluent aphasia; PNFA). The current study aims to explore whether the cognitive-behavioural deficits found in nondemented ALS-patients can be classified as subclinical forms of the first two FTDsyndromes, i.e. fvFTD and SD. In addition, the study further examined whether executive and language impairments co-exist or rather occur independently. To answer the research questions, a battery of neuropsychological tests was employed, adapted to patients’ speech and motor disabilities, as well as behavioural questionnaires. The data revealed there was evidence of both executive and language involvement characteristic of FTD, albeit to a subtle extent. ALS-patients showed deficits on a test of Theory of Mind (ToM). On this test, participants were asked to judge the thoughts and feelings of another, using the direction of eye gaze, a cue considered to be important for social interaction. Results indicated that ALS patients had difficulties with affective ToM, i.e. recognizing feelings of others, and this effect was not driven by perceptual or attentional difficulties. In addition, patients exhibited a subtle deficit with empathy as well as a range of behavioural abnormalities. Furthermore, ALS-patients showed abnormal performance on a complex multi-modal semantic association task which involved assigning the correct picture iii to the sound of an object. This central deficit emerged in the presence of normal audio-visual information processing and episodic memory functions. Moreover, a category-specific deficit for man-made objects was detected in patients. Individual case-analyses showed that various subsets of patients were impaired on the language and executive tasks. These analyses also showed that executive and language problems can occur independently as well as simultaneously in patients with ALS. In addition, analysis of individual cases revealed that some patients’ performance on the decision making tasks was similar to that found in patients with either orbitofrontal or dorsolateral dysfunction, while there was little if any evidence of a pattern of impairment similar to that seen with anterior cingulate dysfunction. The observed difficulties with social cognition and semantic processing indicate that executive and language problems, characteristic of the two FTD syndromes, can be detected in patients with classical ALS.

Eating Disorder research has highlighted the role of neuropsychological functioning, informing the treatment of Anorexia Nervosa. There is ambiguity in the data relating to cognitive impairment in Bulimia Nervosa, with the latest review providing inconclusive results. Executive function impairments in the area of set shifting and inhibition reported in BN are proposed to relate to traits of compulsivity and impulsivity. Other psychological disorders have also demonstrated executive function impairments. Among anxiety disorders, only PTSD and OCD have strong evidence of executive function deficits while a number of studies point towards executive function deficits in depression. This thesis aims to investigate the specificity of cognitive impairments seen in a group of female outpatients with bulimia nervosa, using a clinical comparison group of anxious and/or depressed female outpatients. Methods A systematic review was conducted to address a gap in the anxiety disorder literature and assess the neuropsychological profile of panic disorder. In order to address the main study aims, a comparison between a group of patients with BN and an anxious depressed group was conducted on neuropsychological measures of the Trail Making Test, Wisconsin Card Sorting Test, Hayling and Brixton tasks, Stroop and Verbal Fluency. In addition, psychological symptoms were assessed using SCL-90-R, Yale- Brown Obsessive Compulsive Scale and the Self-liking Self Competence scale. Social problems solving skills were assessed as a potential real world effect of executive function difficulties associated with eating disorders. The relationships between psychological and neuropsychological variables were investigated. Results The systematic review concluded that there was limited evidence of specific impairment in short term memory in panic disorder. The empirical study indicated no group differences on the above neuropsychological measures. Groups also did not differ on NART estimated IQ or self reported psychological symptoms. No relationships were found between psychological symptoms and neuropsychological measures. Few individual participants were found to be impaired on neuropsychological measures in either group. However, those impaired in the BN group were exclusively impaired on the non-perseverative errors and categories completed variables of the WCST, which is thought to be related to impulsivity. Conclusion These findings suggest that the neuropsychological profile of bulimia is broadly similar to that of an anxious and/or depressed clinical group on measures of set shifting and inhibition. Although there was evidence of a deficit in inhibition among patients with bulimia further investigation is required.

This thesis investigated whether a food-storing mammal, the eastern grey squirrel (Sciurus carolinensis), uses social cognitive skills in relation to its caching behaviour and explored whether social cognition really is a specialized adaptation that differs from other cognition by examining how social and non-social learning differ. The influence of social factors on the natural caching behaviour of wild squirrels was studied in the field and the effects of conspecific presence on specific aspects of caching behaviour (learning, memory and recovery) were investigated by testing captive squirrels in the laboratory on social learning and one-trial learning tasks. The squirrels were found to be able to learn by observing a conspecific and learned to make a logical choice more readily than an illogical one. They showed no such bias in a comparable non-social task. They responded flexibly to the presence of conspecifics both in the wild and in the laboratory but the results can be interpreted in terms of responses to observable cues rather than as evidence of higher cognitive skills. In total, this thesis suggests that squirrels use unsophisticated social cognitive strategies in relation to their caching but, the difference found in learning under social and non-social conditions suggests that, although not a highly social species, grey squirrels are particularly prepared to form certain associations with social cues. This offers some support to the theory that factors other than social complexity may lead to the development of the ability to process social information highly effectively.

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

The purpose of this dissertation was to investigate teachers’ beliefs about a fundamental aspect of foreign language teaching: grammar. Whilst progressively reinstated in the national curriculum and consistently sustained by foreign languages teachers’ practices, grammar’s perceived irrelevance for assessment criteria of the nationally adopted method of assessment - the General Certificate of Secondary Education – kept it caught in conflicting discourses of policy, linguistic research and teaching practices. Whilst foreign languages policy and practice kept converging towards increasing focus on forms in language education along correspondences with linguistic research, the assessment has remained focused on generic communicative, skill-focused criteria. My small-scale research aimed to find how foreign languages teachers translated grammar teaching policy and possible theoretical guidelines in their teaching practices, by collecting data through interviews, observations and think-alouds. The findings revealed disparate educational contexts, approaches, as well as interpretations of grammar teaching. It led me to realise the necessity to probe further into a much more thorough theoretical and methodological underpinning of foreign languages education. As this study concludes, the secondary foreign languages curriculum has become disapplied, and schools and teachers have been left to devise their idiosyncratic foreign language learning strategies and rationales. As foreign languages teaching becomes anchored in the primary education curricular provision, this research hopes to document the need to frame theoretical and methodological guidelines, a consistent foreign languages education rationale, leading to a consistent and convincing education and provision of future foreign language teachers.