The purpose of the present research was threefold: 1) to investigate whether natural aging affects the movements to remembered targets when participants make reaching movements under closed-loop feedback conditions, 2) to determine if experience with visually-guided movements facilitates memory-guided reaching and 3) to determine if age affects this facilitation. Two groups of 10 participants (healthy older and healthy younger) performed a manual aiming task with a mouse on a graphics tablet. A target appeared in one of 6 possible locations on a computer screen and participants had to make aiming movements with a visible cursor in 3 different visual conditions: full vision, immediate recall and delayed recall. In the full vision condition vision of the target was available throughout the movement. In the delay conditions the target disappeared either at the initiation of the aiming movement (immediate recall) or 2 seconds before movement onset (delayed recall). Vision of the hand (cursor) was available in all conditions. Each memory condition was divided into 2 blocks; block 1 was presented before the full vision condition and block 2 was presented after. Endpoint accuracy and variability were measured along with movement kinematics. Results showed no age differences in the kinematics in the full vision condition. For memory dependent pointing age also did not affect the movement kinematics or endpoint accuracy. Movements to remembered targets were significantly more variable in the delay recall compared to the immediate recall condition. A Block by Condition effect showed that the delay effect was present in the first block, but not in the second block, suggesting that variability did not increase with memory delay once participants had experience from full vision reaching. A Group by Condition effect showed the older adults were more variable than younger, although this difference was smaller in the delay condition due to the increase in variability as a function of delay seen in younger but not older adults. These findings suggest that aging does not affect how movements are controlled whether pointing to visible or remembered targets. They also suggest that aging does not affect the accuracy in pointing to remembered targets. Aging does affect the variability of these pointing movements. Finally, experience in pointing at targets with full vision modulates the increase in variability of pointing as a function of delay.

The purpose of the present research was threefold: 1) to investigate whether natural aging affects the movements to remembered targets when participants make reaching movements under closed-loop feedback conditions, 2) to determine if experience with visually-guided movements facilitates memory-guided reaching and 3) to determine if age affects this facilitation. Two groups of 10 participants (healthy older and healthy younger) performed a manual aiming task with a mouse on a graphics tablet. A target appeared in one of 6 possible locations on a computer screen and participants had to make aiming movements with a visible cursor in 3 different visual conditions: full vision, immediate recall and delayed recall. In the full vision condition vision of the target was available throughout the movement. In the delay conditions the target disappeared either at the initiation of the aiming movement (immediate recall) or 2 seconds before movement onset (delayed recall). Vision of the hand (cursor) was available in all conditions. Each memory condition was divided into 2 blocks; block 1 was presented before the full vision condition and block 2 was presented after. Endpoint accuracy and variability were measured along with movement kinematics. Results showed no age differences in the kinematics in the full vision condition. For memory dependent pointing age also did not affect the movement kinematics or endpoint accuracy. Movements to remembered targets were significantly more variable in the delay recall compared to the immediate recall condition. A Block by Condition effect showed that the delay effect was present in the first block, but not in the second block, suggesting that variability did not increase with memory delay once participants had experience from full vision reaching. A Group by Condition effect showed the older adults were more variable than younger, although this difference was smaller in the delay condition due to the increase in variability as a function of delay seen in younger but not older adults. These findings suggest that aging does not affect how movements are controlled whether pointing to visible or remembered targets. They also suggest that aging does not affect the accuracy in pointing to remembered targets. Aging does affect the variability of these pointing movements. Finally, experience in pointing at targets with full vision modulates the increase in variability of pointing as a function of delay.

<p> </p><p>Den socialt kompetente har hög social status, många vänner, ett funktionellt beteende och sociala förmågor så som empati och hjälpsamhet. Avsaknad av social kompetens innebär bland annat känslomässiga och beteendemässiga problem. I denna studie medverkade totalt 30 gymnasieelever som genomgick två arbetsminnestest samt fyllde i en självvärderingsenkät som mäter social kompetens. Syftet var att undersöka om det finns ett samband mellan en tonårings arbetsminne och sociala kompetens. Studien begränsades till att mäta arbetsminnets fonologiska och visuellspatiala lagringsenheter samt två sociala förmågor; prosocialt beteende och initiativtagande. Inga signifikanta korrelationer mellan arbetsminne och social kompetens kunde påvisas. Eventuellt kan de icke existerande korrelationerna bero på att fel del av arbetsminnet eller fel del av den social kompetens stod i fokus för studien.</p>

Den socialt kompetente har hög social status, många vänner, ett funktionellt beteende och sociala förmågor så som empati och hjälpsamhet. Avsaknad av social kompetens innebär bland annat känslomässiga och beteendemässiga problem. I denna studie medverkade totalt 30 gymnasieelever som genomgick två arbetsminnestest samt fyllde i en självvärderingsenkät som mäter social kompetens. Syftet var att undersöka om det finns ett samband mellan en tonårings arbetsminne och sociala kompetens. Studien begränsades till att mäta arbetsminnets fonologiska och visuellspatiala lagringsenheter samt två sociala förmågor; prosocialt beteende och initiativtagande. Inga signifikanta korrelationer mellan arbetsminne och social kompetens kunde påvisas. Eventuellt kan de icke existerande korrelationerna bero på att fel del av arbetsminnet eller fel del av den social kompetens stod i fokus för studien.

Patients with amnestic type of mild cognitive impairment (aMCI) are diagnosed mainly on the basis of performance in verbal memory tests. This thesis deals with the use of a nonverbal test called the Brief Visuospatial Memory Test-Revised (BVMT-R) for the diagnosis of mild cognitive impairment (MCI). This research compared the performance of patients with clinical diagnosis of MCI (N=79) using the BVMT-R with the performance of these patients using the Auditory Verbal Learning Test (AVLT), the AVLT being a validated instrument for differentiating aMCI patients from healthy control patients. Both tests follow a similar design paradigm, but they differ in the type of stimuli measured: the BVMT-R tests memory for nonverbal material and the AVLT tests for verbal material. Results showed that there is a moderate correlation between scores (total score, delayed recall score) of the BVMT-R and equivalent scores of the AVLT. Further analyses of performance of MCI patients in both tests (in total scores and delayed recall scores) identified that there was a proportion of patients tested using the BVMT-R with memory impairment that did not show any memory impairment using the AVLT. Our findings indicate a favorable diagnostic potential of BVMT-R in the diagnostics of mild cognitive impairment. Keywords:...

Estimates of the capacity of visuospatial short-term memory (VSTM) have ranged from less than 1 item to 4 +/- 1 items. The purpose of the present study was to find the capacity of VSTM by looking at the contribution of the other working memory systems (phonological loop and central executive) and determine the factor that limits VSTM capacity (either number of objects or object complexity). In this study, the psychophysiological measure of cerebral blood flow velocity also was incorporated to determine whether changes in cerebral blood flow velocity were indicative of VSTM performance and capacity. Both performance measures and cerebral blood flow velocity indicate that capacity for random polygons is approximately one object. Complexity of the objects affected capacity, such that simple objects had higher capacities and lower cerebral blood flow velocity than complex objects. Other working memory systems were not found to have an effect on performance.

Orientadora: Profa. Dra. Maria Teresa Carthery-Goulart / Dissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Neurociência e Cognição, São Bernardo do Campo, 2017. / Apesar de bastante explorada na literatura, a memória operacional (MO) ainda tem lacunas não preenchidas, principalmente em seu componente não verbal. O modelo de MO de múltiplos componentes de Baddeley e Hitch (1974) é o mais completo e amplamente usado. Fundamentada neste modelo, esta pesquisa teve como objetivo principal explorar uma amostra de idosos saudáveis com diferentes níveis de escolaridade, de forma a ser a mais representativa possível da população. A tarefa verbal de span utilizada foi o digit span auditivo da escala Wechsler Adult Intelligence Scale ¿ terceira edição (WAIS-III) e a tarefa visuoespacial foi um teste de rastreio cognitivo computadorizado ¿ CompCog (Computerized Cognitive Screening Test), similar à tarefa Blocos de Corsi. Além da extensão de cada componente da MO, houve também o registro do tempo de reação mediano na tarefa computadorizada. Participaram da pesquisa 87 idosos e 42 jovens universitários. Foram realizadas comparações intra e intergrupos. No estudo 1, comparouse um grupo de idosos (N=32) com o de jovens (N=42), ambos com escolaridade igual ou superior a 12 anos. Foram observados efeitos da idade nas medidas de MO e percebeuse que o declínio da MO com a idade é mais evidente no componente visuoespacial. Houve diferença significativa entre jovens e idosos, com melhor desempenho dos jovens em todas as tarefas. Entretanto, no tempo de reação, o grupo de idosos apresentou desempenho inesperado através da diminuição do tempo na tarefa visuoespacial mais complexa. No estudo 2, 87 idosos foram subdivididos em faixas de escolaridades (variação entre 0 e 17 anos de escolaridade). Foram feitas correlações entre as variáveis escolaridade e nível socioeconômico. Foram testados modelos de regressão linear que puderam explicar, parcialmente, algumas das medidas de MO. A idade não influenciou os desempenhos, mas a escolaridade e a pontuação socioeconômica atuaram como preditoras destas medidas. Na comparação entre os grupos, houve diferença de desempenho nas tarefas de span inverso explicadas pela escolaridade. Os idosos mais escolarizados também foram, em média, mais rápidos que os demais. As maiores diferenças estão entre o grupo de analfabetos quando comparados com os demais, indicando ligação entre a preservação do funcionamento do executivo central e a escolarização. / In spite of widely explored, working memory (WM) data still has few unexplored components, specially the non-verbal one. The WM multicomponent model proposed by Baddeley & Hitch (1974) is considered the most complete and it is vastly found in previous literature. The present study is grounded on this multicomponent model and had as main objective analyse the performance of a group of health elders with different educational levels at 2 WM tasks. This group was selected in a way that fully represented Brazilian population, including low to high educational levels. The 2 applied tasks were: (1) verbal span task - the auditive digit span of the third edition Wechsler Adult Intelligence Scale (WAIS-III) and (2) visuospatial task - a cognitive screening test was used, the CompCog (Computerized Cognitive Screening Test), similar to Corsi blocks task. Besides the extension of each WM component, the median reaction time at the computerized task was also considered. 87 Elders and 42 undergraduate students participated in the present study. Analysis were ran considering within and between-group factors. At study 1, one Elder group (N=32) was compared to the undergraduate group (N=42), both groups having participants with 12 or higher education years. Main effects of age were observed at WM measures and the WM decline is more evident at the visuospatial component. There was a significant difference between young and elders, where younger participants showed better performance in all tasks. However, analyzing reaction time, the elders¿ group showed an unexpected performance with faster reaction times at the most complex visuospatial task. At study 2, 87 elders were subdivided in schooling levels (varying between 0 and 17 years of study). Analysis were performed considering educational levels and socioeconomic status as variables. Linear regression models were tested, and they could partially explain WM measures. Age did not influence performance, but education years and socioeconomic status were found to be predictors of these measures. In between-group analysis there was a difference in performance at inverse span tasks, explained by educational levels. Elders with more study years showed faster reaction times than the others. The more pronounced difference was between the illiterates group and the other groups, indicating a link between executive centre functions preservation and educational levels.

Dietary N-3 PUFA plays a key role in brain maturation, development, stress response and cognitive abilities (Weiser et al., 2016; Devarshi et al., 2019). As adolescent’s prefrontal cortex is maturating, the period becomes sensitive to external factors such as environment, nutrition, and stress (Petrovich et al., 2001; Calabro et al., 2020). In this thesis, we aim to expand our knowledge of the influence of external factors, such as dietary omega-3 supplementation and enriched environment, during this critical maturation period. By designing four distinct studies, we tested the hypothesis that visible sex-specific alterations would arise from adolescence targeted diet n-3 PUFA supplementation and enriched environment, which would act to modify physiological and stress responses, as well as socio-emotional and cognitive performance. Our first study characterized the impact n-3 PUFA and n-6 PUFA regimen on corticosterone secretion and behavioural responses in adolescent male rodents. Additionally, it assessed the effects of delivery method (gavage versus restricted feeding) during this sensitive maturation period to ensure using a method with limited stress-mediated outcomes. This study highlighted gavage to induce reduced effects on corticosterone (CORT) secretion, regardless of the provided supplementation. On the last day of feeding, CORT secretion was diminished in fish oil (FO) fed rats exposed to restricted feeding, suggesting FO diet to promote physiological adjustments. Data also demonstrated that FO and soybean (CSO) rich diets were able to reduce anxiety-like behaviour compared to a high-fat diet intake (Hydrogenated Vegetal Fat - HVF), highlighting the role of n-3 PUFA dietary supplementation during adolescence on stress regulation. Our second study assessed sex-specific impact of adolescence targeted dietary supplementation on brain Docosahexaenoic Acid (DHA), Arachidonic Acid (AA) and Linolenic acid (LA) concentrations immediately following supplementation and during adulthood. Our findings demonstrated overall elevated DHA, AA and LA brain tissue concentrations in female compared to male rats, regardless of dietary supplementation. Benefit of supplementation were most apparent in adolescent males, where FO led to higher DHA concentrations compared to soybean oil supplementation, supporting a positive influence of FO dietary supplementation in males during intensive hormonal fluctuation and brain maturation. However, adolescent male rats showed reduced ability to extract nutrient essential fatty acids compared to female counterparts. Our third study characterized sex-specific coping strategies, socioemotional responses, and glucocorticoid regulation following an n-3 PUFA rich diet and enriched environment (EE) during the adolescent period. While basal CORT secretions were not significantly altered by supplementation in males, a gradual increase in CORT was observed during supplementation, peaking at DAY21. Passive coping strategies was preferred in the FST in RC (Regular Cage)- housed females exposed to FO while RC-housed CSO-fed males opted for an active climbing coping strategy. Increase locomotion and anxiolytic behaviour were observed in CSO-supplemented males (exposed to EE), while CSO by itself promoted social recognition in males. In contrast, sociability was improved in FO EE exposed females, indicating possible synergic effects. Adulthood hippocampal GR-ir expression was reduced at the hippocampal CA3 region in FO/RC and CSO/EE rat groups, which could have influenced memory consolidation and stress resilience. Overall, results from this study provided insights on positive effects associated with short-term adolescent n-3 PUFA supplementation in females, while male appeared to most benefited from soybean diet supplementation. Our fourth and last study assessed age- and sex-dependent influences of dietary supplementation on cognitive performance in the Barnes Maze Test. Our results showcase a gradual decrease in latencies to the escape box, as well as progressive decrease in working memory errors (WME) in adult compared to adolescent rats. Over the testing period, the FO females and CSO males showed improved performance through reduction of WMEs on specific days, which could subtend sex-related effects of dietary supplementations. However, while discrete effects of n-3 PUFA were more apparent in female rats, short-term supplementation appeared insufficient to promote consistent enhancement of visuospatial performance or cognitive flexibility that could be observed throughout the testing period. In conclusion, our findings support the importance of studying single and combined factors to understand overall impact. We were able to consistently demonstrate beneficial effects on coping strategies, stress reactivity, sociability, and cognitive performance of adolescence-targeted fish oil supplementation, especially in female rodents.