Syftet med studien var att undersöka om regelbunden fysisk aktivitet respektive kognitiv aktivitet hade samband med kognitiva funktioner i åldersgruppen 65+. Mer specifikt har sambandet mellan regelbunden fysisk aktivitet i termer av total träningsmängd, träningsintensitet (mycket/måttligt ansträngande och promenader) samt total tid stillasittande och de kognitiva funktionerna; exekutiva funktioner, bearbetningshastighet och analytiskt tänkande studerats. 28 individer i åldrarna 65–85 (M = 75.52, SD = 5.15) deltog i studien, varav 14 var kvinnor och 14 var män. Deltagarna rekryterades på lokala gym samt öppna mötesplatser och besvarade ett frågeformulär med bakgrundsfrågor (kön, ålder, utbildningsnivå), deras fysiska aktivitetsvanor (International Physical Activities Questionnaire, IPAQ) samt kognitionsvanor (Florida Cognitive Activities Scale, FCAS). Efter att ha besvarat frågorna genomförde deltagarna kognitiva test som mäter tre olika kognitiva funktioner; exekutiv funktion (via Trail Making Test B, TMT B), bearbetningshastighet (via Trail Making Test A, TMT A, samt Symbol Digit Modalities Test, SDMT) och analytiskt tänkande (via Cognitive Reflection Test, CRT). Modell 2 med prediktorerna total fysisk aktivitet och kognitiv aktivitet var signifikant och förklarade 36% av variansen i TMT A. Modell 3 med prediktorn mycket ansträngande fysisk aktivitet var signifikant och förklarade 11% av variansen i CRT rätt. Modell 7 med prediktorerna mycket ansträngande fysisk aktivitet, måttligt ansträngande fysisk aktivitet och promenader var signifikant och förklarade 25% av variansen i CRT rätt. Positivt signifikanta samband hittades för kognitiv aktivitet och bearbetningshastighet, samt för promenader och analytiskt tänkande. Negativt signifikant samband hittades mellan mycket ansträngande fysisk aktivitet och analytiskt tänkande. Inga signifikanta resultat hittades för de exekutiva funktionerna. Resultaten från föreliggande studie tyder på att en högre grad av kognitiv aktivitet är relaterat till bättre bearbetningshastighet, mer promenader är relaterat till bättre förmåga till analytiskt tänkande, samt att en högre grad av mycket ansträngande fysisk aktivitet är relaterat till sämre förmåga till analytiskt tänkande. / The purpose of the study was to examine the association between regular physical and cognitive activity and cognitive functioning in an older population. More specifically the association between regular physical activity in terms of total amount of exercise, exercise intensity (vigorous / moderate strenuous and walks), plus total amount of time spent sitting during a day and the cognitive functions; executive function, processing speed and analytical thinking. Twenty-eight participants between 65-85 years of age (MD = 75.52, SD = 5.15) partook in the present study, of which 14 were women and 14 were men. The participants were recruited at local gyms and public meeting places and answered a questionnaire including background questions (gender, age, educational level), their physical activity habits (International Physical Activities Questionnaire, IPAQ) and cognitive activity habits (Florida Cognitive Activities Scale, FCAS). After answering the questions, the participants performed cognitive tests to measure the three cognitive functions; executive function (through Trail Making Test B, TMT B), processing speed (through Trail Making Test A, TMT A, and Symbol Digit Modalities Test, SDMT) and analytical thinking (through Cognitive Reflection Test, CRT). Model 2 with the predictors' total physical activity and cognitive activity was significant and explained 36% of the variance in TMT A. Model 3 with the predictor vigorous strenuous physical activity was significant and explained 11% of the variance in CRT Correct. Model 7 with the predictors' vigorous strenuous physical activity, moderate strenuous physical activity and walks was significant and explained 25% of the variance in CRT Correct. Positive significant associations were found between cognitive activity and processing speed, as well as between walks and analytical thinking. Finally negative significant associations between vigorous strenuous activity and analytical thinking was found. No significant results were found for executive functions in the present study. The results from the current study suggests that higher degrees of cognitive activity is related to better processing speed, more walks are related to better analytical thinking, and that a higher degree of vigorous physical activity is related to poorer ability of analytical thinking.

Syftet med den aktuella studien var att undersöka om det finns något samband mellanfysisk aktivitet och kognitiv aktivitet kopplat till den kognitiva förmågan i åldersgruppen 65+.Det har studerats om det finns något samband mellan olika mängd på fysisk aktivitet (mycketansträngande, måttligt ansträngande, promenader) samt stillasittande och den kognitivaförmågan (exekutiva funktioner, analytiskt tänkande, bearbetningshastighet). Totalt deltog 30personer, varav 63% kvinnor, i åldrarna 65 till 84 år (M = 73,93, SD = 5.85) som rekryteradesvia offentliga mötesplatser för åldersgruppen samt via personliga kontakter. Deltagarnabesvarade frågeformulär med bakgrundsfrågor (kön, ålder, utbildningsnivå) samt ettsjälvskattningsformulär om fysiska aktivitetsvanor (International Physical ActivitiesQuestionnaire, IPAQ) och ett självskattningsformulär om kognitiva aktivitetsvanor (FloridaCognitive Activities Scale, FCAS). Efter detta fick deltagarna genomföra de fyrakognitionstesterna; Trail Making Test A (TMT A), Symbol Digit Modalities Test (SDMT)som mäter bearbetningshastigheten, Trail Making Test B (TMT B) som mäter exekutivfunktion samt Cognitive Reflection Test (CRT) som mäter analytiskt tänkande.Resultatet visade på signifikant samband mellan ålder och bearbetningshastighet samtexekutiv funktion. Signifikant samband fanns även mellan kognitiv aktivitet ochbearbetningshastighet samt exekutiv funktion. Signifikant samband kunde även identifierasmellan promenader och analytiskt tänkande. Inga signifikanta resultat kunde hittas förresterande variabler och kognitiv förmåga.Resultatet från aktuell studie tyder på att högre grad av kognitiv aktivitet har ettsamband med bearbetningshastighet och exekutiva funktioner. Resultatet visar även attpromenader är relaterat till analytiskt tänkande. Ålder visade sig signifikant ha ett sambandmed bearbetningshastighet och exekutiva funktioner. / The purpose of the current study was to investigate whether there is any relationshipbetween physical activity and cognitive activity linked to cognitive ability in the age group65+. The study investigated whether there is any relationship between different amounts ofphysical activity (very strenuous, moderately strenuous, walking) as well as sedentary timeand cognitive ability (executive functions, analytical thinking, processing speed). A total of 30people participated, of which 63% were women, aged between 65 to 84 years (M = 73.93, SD= 5.85), who were recruited via public meeting places for the age group as well as viapersonal contacts. The participants answered questionnaires with background questions(gender, age, level of education) as well as a self-assessment questionnaire on physicalactivity habits (International Physical Activities Questionnaire, IPAQ) and a self-assessmentquestionnaire on cognitive activity habits (Florida Cognitive Activities Scale, FCAS). Afterthis, the participants had to complete the four cognitive tests; Trail Making Test A (TMT A),Symbol Digit Modalities Test (SDMT) which measures processing speed, Trail Making TestB (TMT B) which measures executive function and the Cognitive Reflection Test (CRT)which measures analytical thinking.The results showed a significant relationship between age and processing speed aswell as executive function. There was also a significant relationship between cognitiveactivity and processing speed as well as executive function. A significant relationship couldalso be identified between walking and analytical thinking. No significant results could befound for the remaining variables and cognitive ability.The results from the current study indicate that a higher degree of cognitive activityhas a relationship with processing speed and executive functions. The result also shows thatwalking is related to analytical thinking. Age was found to be significantly related toprocessing speed and executive functions.

No description available.

La mémoire à court terme visuelle (MCTv) est un système qui permet le maintien temporaire de l’information visuelle en mémoire. La capacité en mémoire à court terme se définit par le nombre d’items qu’un individu peut maintenir en mémoire sur une courte période de temps et est limitée à environ quatre items. Il a été démontré que la capacité en MCTv et les habiletés mathématiques sont étroitement liées. La MCTv est utile dans beaucoup de composantes liées aux mathématiques, comme la résolution de problèmes, la visualisation mentale et l’arithmétique. En outre, la MCTv et le raisonnement mathématique font appel à des régions similaires du cerveau, notamment dans le cortex pariétal. Le sillon intrapariétal (SIP) semble être particulièrement important, autant dans la réalisation de tâches liées à la MCTv qu’aux habiletés mathématiques. Nous avons créé une tâche de MCTv que 15 participants adultes en santé ont réalisée pendant que nous enregistrions leur activité cérébrale à l’aide de la magnétoencéphalographie (MEG). Nous nous sommes intéressés principalement à la composante SPCM. Une évaluation neuropsychologique a également été administrée aux participants. Nous souhaitions tester l’hypothèse selon laquelle l’activité cérébrale aux capteurs pariéto-occipitaux pendant la tâche de MCTv en MEG sera liée à la performance en mathématiques. Les résultats indiquent que l’amplitude de l’activité pariéto-occipitale pendant la tâche de MCTv permet de prédire les habiletés mathématiques ainsi que la performance dans une tâche de raisonnement perceptif. Ces résultats permettent de confirmer le lien existant entre les habiletés mathématiques et le fonctionnement sous-jacent à la MCTv. / Visual short-term memory (VSTM) is a memory system that permits the temporary retention of visual information. Short-term memory capacity can be defined by the amount of information that an individual can remember over a short period of time and is limited to about four items. It was shown that VSTM capacity and mathematical abilities are closely related. VSTM is useful for a lot of components linked to mathematical skills like word problem solving, mental visualisation and arithmetic. Moreover, VSTM and mathematical reasoning activate similar brain regions, mainly within the parietal cortex. The intraparietal sulcus (IPS) appears to be particularly important both in the realization of VSTM tasks and mathematical reasoning tasks. We created a VSTM task which 15 healthy adult participants completed while we recorded their brain activity using magnetoencephalography (MEG). We were mainly interested in the SPCM component. A neuropsychological assessment was also administrated to the participants. We wanted to verify the hypothesis stipulating that cerebral activity recorded at parieto-occipital sensors during the VSTM task should be linked to performance in mathematics. The results indicate that parieto-occipital activity during the VSTM tasks predicted mathematical abilities as well as performance on a perceptive reasoning task. These results confirmed the link existing between mathematical abilities and VSTM functioning.

En plus de la triade de symptômes caractérisant l’autisme, ce trouble neurodévelopmental est associé à des particularités perceptives et motrices et, au niveau cérébral, par une connectivité atypique entre les différentes régions du cerveau. Au niveau anatomique, un des résultats les plus communs est la réduction du corps calleux. Toutefois, des effets directs de cette altération anatomique sur l’intégrité et l’efficacité du transfert interhémisphérique restent à être démontrés. Pour la présente thèse, trois différentes études investiguent différents aspects du traitement de l’information visuomotrice : le transfert interhémisphérique entre les régions bilatérales motrices et visuelles, la vitesse de traitement perceptif, et les habiletés motrices visuellement guidées. Dans la première étude, le paradigme visuomoteur de Poffenberger a été utilisé pour mesurer le temps de transfert interhémisphérique (TTIH). L’imagerie par résonnance magnétique fonctionnelle (IRMf) et structurale ainsi que l’imagerie de diffusion ont aussi été utilisées pour étudier les réseaux cérébraux impliqués dans la tâche de Poffenberger. Les autistes ont été comparés à un groupe d’individus à développement typique. La deuxième étude avait pour but d’investiguer la vitesse de traitement perceptif en autisme. Dans la troisième étude, deux tâches motrices (Purdue et Annett) ont été utilisées pour examiner la nature et l’importance des déficits moteurs. La tâche de Purdue inclut deux conditions bimanuelles utilisées comme indice additionnel d’intégration interhémisphérique. Dans les études 2 et 3, le groupe d’autistes a aussi été comparé à un groupe d’individus Asperger afin de voir si, et comment, les deux sous-groupes peuvent être distingués en ce qui concerne le traitement visuel et les déficits moteurs. Aucune différence entre les groupes n’a été observée en termes de TTIH. Les résultats de l’étude IRMf révèlent des différences d’activations corticales en lien avec la tâche de Poffenberger. Dans les groupes d’autistes et de typiques, l’efficacité de la communication interhémisphérique était associée à différentes portions du corps calleux (frontales/motrices chez les typiques, postérieures/visuelles chez les autistes). De façon globale, les résultats de cette étude démontrent un patron atypique de transfert interhémisphérique de l’information visuomotrice en autisme, reflétant un rôle plus important des mécanismes visuels dans le comportement sensorimoteur possiblement en lien avec une réorganisation cérébrale. Les résultats des études comportementales 2 et 3 indiquent que les autistes excellent dans la tâche mesurant la vitesse de traitement perceptif alors que les Asperger accomplissent la tâche à des niveaux similaires à ceux des typiques. La nature des déficits moteurs diffère aussi entre les deux sous-groupes; la dextérité et la coordination bimanuelle est affectée chez les individus Asperger mais pas chez les autistes, qui eux sont plus atteints au niveau de la rapidité unimanuelle. Les sous-groupes d’autistes et de syndrome d’Asperger sont caractérisés par des profils cognitifs différents dont les particularités perceptives et motrices font partie intégrante. / In addition to the triad of symptoms characterizing autism, this neurodevelopmental condition is characterized by visual and motor atypicalities and, at the cerebral level, by atypical connectivity between the different brain areas. Anatomically, one of the most replicated finding is a reduction of the corpus callosum. However, evidence of a direct effect of the corpus callosum reductions on integrity and efficiency of interhemispheric transfer is lacking. Three different studies were designed to investigate different aspect of visuo-motor processing: interhemispheric transfer between bilateral motor and visual brain areas, perceptual processing speed, visually guided motor performance. In the first study, the visuo-motor Poffenberger paradigm was used to measure interhemispheric transfer time (IHTT). Structural and functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI) were also used to study the brain networks involved in the Poffenberger task. Autistics were compared to typically developing individuals. The second study investigates whether perceptual processing speed (Inspection Time task) is atypical in autism. In the third study, two visually-guided motor tasks (the Purdue pegboard and Annett peg moving task) were used to verify the nature and magnitude of motor deficits. The Purdue task includes two bimanual conditions used as additional measures of interhemispheric communication integrity. Moreover, in studies 2 and 3, behavioral differences between autistic and Asperger individuals were investigated in order to see if and how the two subgroups can be distinguished in terms of perceptual processing and motor deficits. No group difference was observed in terms of IHTT. The fMRI results reveal a different pattern of cortical activations associated to the Poffenberger task. In the autism and typical groups, the efficiency of interhemispheric communication was associated with different portions of the corpus callosum (frontal/premotor in typicals, posterior/visual in autistics). These results demonstrate an atypical pattern of interhemispheric visuo-motor information transfer, possibly reflecting a more prominent role of visual mechanisms guiding sensorimotor behavior in autism, related to cerebral reorganizations. Results of the behavioral studies indicate that autistics have an excellent visual processing speed while Asperger individuals performed like typicals. Motor impairments also differed between the two subgroups; dexterity and bimanual coordination was impaired in Asperger individuals but not in autistics, who presented more difficulties in unimanual conditions. Autism and Asperger subgroups are characterized by different cognitive profiles in which visual processing and motor deficits are important factors.

The aim of this thesis was to help elucidate the mechanisms that underlie age-related decline in visual selective attention and working memory (WM). Older and younger adults completed a behavioural WM task, after which electroencephalogram (EEG) was recorded as participants perform a localized attentional interference (LAI) task – competition/attentional interference was manipulated by systematically altering the distance between targets and distractors. Older adults showed impaired accuracy and reaction time on the WM and LAI tasks. Two event-related-potentials, indexing spatial attention (N2pc) and target processing (Ptc), displayed attenuated amplitude and increased latency in older adults. Thus, spatial selection, target enhancement and processing speed deficits may contribute to age-related attentional impairments. Furthermore, an unexpected component was found between the N2pc and Ptc in the older adult waveforms. Preliminary analyses suggest this may be the PD, implicated in distractor suppression, which may be differentially contributing to older and younger adults’ electrophysiology and attentional processing.

The aim of this thesis was to help elucidate the mechanisms that underlie age-related decline in visual selective attention and working memory (WM). Older and younger adults completed a behavioural WM task, after which electroencephalogram (EEG) was recorded as participants perform a localized attentional interference (LAI) task – competition/attentional interference was manipulated by systematically altering the distance between targets and distractors. Older adults showed impaired accuracy and reaction time on the WM and LAI tasks. Two event-related-potentials, indexing spatial attention (N2pc) and target processing (Ptc), displayed attenuated amplitude and increased latency in older adults. Thus, spatial selection, target enhancement and processing speed deficits may contribute to age-related attentional impairments. Furthermore, an unexpected component was found between the N2pc and Ptc in the older adult waveforms. Preliminary analyses suggest this may be the PD, implicated in distractor suppression, which may be differentially contributing to older and younger adults’ electrophysiology and attentional processing.

[pt] O envelhecimento em todo o mundo é um dos maiores desafios da saúde. Nesse contexto, condições clínicas como demências e Comprometimento Cognitivo Leve (CCL) também aumentam suas prevalências. A causa de demência mais frequente e estudada é demência de Alzheimer (DA). Tradicionalmente, DA é caracterizada pelo déficit precoce na memória episódica. Entretanto, estudos atuais mostram que a DA apresenta heterogeneidade neuropsicológica e alguns pacientes apresentam déficits cognitivos precoces não-amnésticos. Essas apresentações são chamadas por alguns autores de DA atípica. Dessa forma, a primeira parte dessa tese dedicou-se a estudar a heterogeneidade neuropsicológica na DA através de dois estudos: uma revisão sistemática sobre heterogeneidade neuropsicológica na DA (publicado) e um estudo de casos sobre perfis típico e atípico na DA (publicado). A revisão sistemática tornou-se necessária já que foi a primeira revisão sistemática publicada sobre o tema. Os achados dos dois estudos mostraram que aspectos atípicos na DA precisam ser mais explorados, já que DA não é uma condição homogênea. Compreender esses perfis cognitivos na DA irá interferir nos métodos diagnósticos e intervenções terapêuticas, seja farmacológica ou comportamental. A segunda parte dessa tese explora esses aspectos atípicos em três amostras: envelhecimento normal, CCL e AD. Assim, um estudo transversal foi realizado para comparar medidas de velocidade de processamento (VP), controle inibitório e automonitoramento nas três amostras. Os resultados desse estudo mostram que medidas de VP podem ser indicadores precoces do declínio cognitivo envelhecimento. Ao comparar CCL com o grupo de envelhecimento saudável, os dados mostram diferença nas medidas de VP e erros cometidos nos testes de VP. Entretanto, as duas amostras não apresentaram diferenças nas medidas de funções executivas (FEs) e nas medidas de funcionalidade. CCL versus AD mostraram diferenças nas medidas de VP, funções executivas e funcionalidade. Dessa forma, esse estudo traz resultados relevantes para o diagnóstico precoce de CCL e novas diretrizes para o cenário clínico e pesquisa. Além disso, na segunda parte desta tese foi realizado um artigo sobre acurácia diagnóstica das medidas de VP nos casos de CCL e AD. A literatura mostra falta de estudos sobre diferenças nas medidas de VP no envelhecimento e parâmetros diagnósticos dos instrumentos de VP. Esse estudo mostrou que medidas de VP apresentam habilidades discriminativas, para DA e CCL. Esses dados são necessários, já que apresentamos um cenário de escassez de instrumentos com elevados parâmetros diagnósticos para medidas de VP no envelhecimento. Esse cenário torna-se ainda mais drástico, quando falamos de Brasil. / [en] Aging is a major healthcare challenge worldwide. With aging, the prevalence of conditions such as dementia and Mild Cognitive Impairment increase. The most frequent and studied cause of dementia is Alzheimer s dementia (AD). Traditionally, AD is characterized by early deficit in episodic memory. However, current studies show that AD presents heterogeneity in clinical manifestations, especially cognitive manifestations. Thus, some patients present a non-amnestic cognitive profile. These profiles are called by some authors as atypical AD. The first part of this thesis was aimed at studying the neuropsychological heterogeneity in AD by means of 2 studies: a systematic review on neuropsychological heterogeneity in AD (published) and cases of study with typical and atypical AD patients (published). The systematic review was necessary, as it was the first published review about the topic. The findings of the two studies show that atypical aspects in AD need to be further explored, since AD is not a homogeneous condition. Understanding these cognitive profiles in AD will interfere in diagnostic methods and therapeutic interventions, either pharmacological or behavioral ones. The second part of this thesis explores atypical aspects in three samples: normal aging, MCI and AD. Thus, a cross-sectional study was conducted to compare measures of processing speed (PS), inhibitory control, working memory and cognitive flexibility in the three samples. The results of this study showed that PS measures may be early indicators of cognition decline in aging. MCI versus normal aging showed differences in PS measures and errors in tests of PS. However, these samples did not show differences in executive function measures (EFs) and functional measures. Nevertheless, MCI versus AD show differences in PS measures, executive functions and functionality. Thus, this study showed relevant results for the diagnosis process of MCI and new guidelines for clinical settings and research. In addition, in the second part of this thesis an article was written on diagnostic accuracy of the PS measures used in cases of MCI and AD. The literature shows a lack of studies on differences in PS measures in aging and diagnostic parameters of PS instruments. This study showed that PS measures present discriminative abilities in AD and MCI. These data are important, as there is a lack of diagnostic tools for PS in aging, especially in the Brazilian scenario.