No description available.

Probability learning is the ability to establish a relationship between stimulus and outcomes based on occurrence probabilities using repetitive feedbacks. Participants learn the task according to the cue-outcome relationship, and try to gain in depth understanding of this relationship throughout the experiment. While learning is at the highest level, people rely on their working memory. In this study 20 participants were presented a probability learning task, and their prefrontal cortex activity was measured with functional Near-Infrared Spectroscopy. It was hypothesized that as participants gain more knowledge of the probabilities they will learn cue-outcome relationships and therefore rely less on their working memory. Therefore as learning precedes a drop in the fNIRS signal is expected. We obtained results confirming our hypothesis: Significant negative correlation between dorsolateral prefrontal cortex activity and learning was found. Similarly, response time also decreased through the task, indicating that as learning precedes participants made decisions faster. Participants used either the frequency matching or the maximization strategy in order to solve the task in which they had to decide whether the blue or the red color was winning. When they use the frequency matching strategy they chose blue at the rate of winning for the blue choice. When they use the maximization strategy they chosed blue almost always. Our task was designed such that the frequency for blue to win was 80%. We had hypothesized that the people in frequency matching and maximization groups would show working memory differences which could be observed from the fNIRS signal. However, we were unable to detect this type of behavioral difference in the fNIRS signal. Overall, our study showed the relationship between probability learning and working memory as depicted by brain activity in the dorsolateral prefrontal cortex which widely known as the central executive component of working memory.

In addition to mood symptoms, major depressive disorder (MDD) is characterized by cognitive impairments that can have detrimental impacts on quality of life and daily function, and have been found to persist into remission. In particular, altered affective cognition (e.g. biased attention to negative stimuli) has been reported in MDD, and may continue into remission. Unfortunately, current pharmacotherapies do not adequately address cognitive dysfunction in acute or remitted MDD. Understanding the neurobiological underpinnings of affective cognitive dysfunction in remitted MDD may help inform the development of new interventions to address this lingering problem and the associated poorer functional outcomes. The triple network model posits that altered functioning of three key networks implicated in normal cognitive function – the default mode network (DMN), central executive network (CEN) and salience network (SN) – underlies cognitive dysfunction in a variety of psychiatric illnesses, including MDD. Though notable exceptions exist, work in acutely depressed MDD patients has found evidence of DMN hyperconnectivity, CEN hypoconnectivity and abberant SN connectivity both at rest and during the completion of various cognitive tasks. The evidence for triple network connectivity alterations persisting into remission is less robust, and warrants further investigation. Furthermore, there is a paucity of studies examining remitted MDD connectivity during affective tasks. As such, the primary objectives of this thesis were to: 1) compare resting-state and task triple network connectivity profiles in remitted MDD patients (rMDDs) and healthy volunteers (HVs) at rest, during an affective (emotional Stroop [eStroop]) task, and during rest vs. the task and, 2) assess the relationship between DMN and CEN connectivity and measures of daily functioning, quality of life and/or negative, self-relational rumination in the rMDD cohort. Behaviourally, there were findings of an affective attentional bias and impaired processing speed in the rMDD vs. HVs, as revealed by a computerized cognitive test battery. However, we found no evidence of DMN hyperconnectivity or CEN hyperconnectivity in the rMDD study sample. We did find evidence of altered intrinsic CEN and CEN-SN connectivity between the rest and task conditions that seemed driven by the rMDD sample, as well as positive CEN-DMN correlations across the entire sample both at rest and during the eStroop task. Suprisingly, we also found higher intrinsic DMN connectivity during the eStroop task vs. at rest across the whole sample. Finally, we found a positive relationship between task-based CEN connectivity and hopeless rumination, and a significant negative relationship between resting state and task-based DMN connectivity and psychosocial dysfunction in the rMDD sample. These findings contribute to our understanding of large-scale intrinsic network connectivity alterations during remitted depression, and their relationship to functional outcomes.

No description available.

Learning and memory impairments are among the most common and enduring cognitive consequences of traumatic brain injury (TBI). Researchers have yet to reach a consensus with regard to the basic cognitive mechanism underlying new learning and memory disturbances after TBI. The purpose of the present study was to investigate the current views regarding the cognitive processes thought to explain impairments in verbal learning and memory subsequent to brain injury. Specifically, this study sought to examine the roles of the central executive component of working memory and processing speed in verbal learning ability following TBI. Latent variable structural equation modeling (SEM) was used to analyze the data of 70 post-acute care TBI patients between the ages of 16 and 65, who completed a full neuropsychological evaluation. Results indicated that verbal learning and memory difficulties following TBI were explained primarily in terms of the central executive aspects of working memory, after accounting for the relative contributions of processing speed in the model. The direct effect of processing speed on verbal learning and memory was not significant when working memory was taken into account in the model. Rather, the effects of processing speed on verbal learning ability were largely indirect through the central executive component of working memory. Results highlight the importance of both working memory and processing speed in supporting verbal learning and memory processes after TBI. Practical implications for targeting remediation efforts and directing approaches to memory rehabilitation are discussed in light of the study’s findings. / text

Esta pesquisa investiga processos cognitivos envolvidos na aprendizagem. Para isso, compara-se o desempenho acadêmico, o desempenho matemático, o executivo central da memória de trabalho e o raciocínio lógico-matemático em trinta e cinco adolescentes do primeiro ano do Ensino Médio do Colégio Júlio de Castilhos. O desempenho acadêmico é representado pela média obtida por cada um de 35 alunos, no primeiro trimestre do ano letivo de 2010 nas disciplinas que compõem o programa, excetuando-se a matemática. O desempenho matemático é representado pela nota final na disciplina no mesmo trimestre. O executivo central da memória de trabalho é avaliado por meio de dois subtestes selecionados da Bateria de Avaliação da Memória de Trabalho da Universidade Federal de Minas Gerais. O raciocínio lógico-matemático é avaliado com a tarefa piagetiana o equilíbrio da balança. Os dados obtidos através dos testes para avaliação do executivo central da memória de trabalho são estudados com análise estatística inferencial. Os dados obtidos com o método clínico piagetiano na aplicação da tarefa o equilíbrio da balança são estudados por meio de análise descritiva, além de serem transformados em escores a fim de serem incluídos na análise estatística inferencial. Encontrou-se correlação entre as quatro funções estudadas através do teste de correlação de Pearson. Os alunos são agrupados conforme o desempenho acadêmico, em alunos com desempenho alto, intermediário e baixo e, com esta categorização, é realizada a comparação entre grupos quanto ao desempenho matemático, o executivo central da memória de trabalho e o raciocínio lógico-matemático, por Análise de Variância. Encontrou-se que as funções diferem nos três grupos na maioria das comparações. Conclui-se que o executivo central da memória de trabalho e o raciocínio lógico-matemático têm um papel importante no desempenho acadêmico do aluno adolescente. / This research investigates the cognitive processes involved in learning. For this purpose, it compares academic performance, mathematical performance, the central executive of working memory and logical-mathematical reasoning in thirty-five teenagers in their first year of High School in a public school. Academic performance for each student is assessed through the average grade obtained in the first quarter of the 2010 academic year, in the subjects that comprise the program, except mathematics. The mathematical performance is represented by the final grade in the subject in the same quarter. The central executive of working memory is assessed by two subtests selected from the Working Memory Assessment Battery from the Federal University of Minas Gerais. The logical-mathematical reasoning abilities are assessed by the Piagetian task called the balance equilibrium. The data obtained through tests to assess the central executive of working memory are interpreted by means of inferential statistical analysis. The data obtained by the clinical method of application of the Piagetian task the balance equilibrium are studied through descriptive analysis and are converted into scores, which are then included in the inferential statistical analysis. There is a correlation between the four functions studied by the Pearson correlation test. The mathematical performance, the central executive of working memory and logical-mathematical reasoning are analysed among groups of students with above-, lower- and average academic performances. The functions in the three groups differed on most comparisons. The central executive of working memory and logical-mathematical reasoning play an important role in the academic performance of teenage students.

The current study explored how hot and cool executive functions (EF) could predict resting-state connectivity of the Default Mode Network (DMN) and Central Executive Network (CEN) in a mixed clinical and typically developing sample of adolescents. It was hypothesized that hot EF would predict a quadratic, inverted U-shaped, relationship between connectivity of the major regions of the DMN: the Posterior Cingulate Cortex (PCC) and the Medial Prefrontal Cortex (MPFC). It also was hypothesized that cool EF would predict a quadratic, inverted U-shaped, relationship between the connectivity of the major regions of the CEN: the right Posterior Parietal Cortex (right PPC) and the right Dorsal Lateral Prefrontal Cortex (right DLPFC). The results suggested that hot EF, specifically emotional regulation, predicted a quadratic relationship in DMN connectivity. However, this relationship was U-shaped instead of an inverted U-shaped. Thus, participants who scored well or poorly in emotional regulation generally had higher connectivity than those with average scores in emotional regulation. There were no significant results between cool EF and the CEN. Additional exploratory analysis suggested that the main hypotheses were not driven or suppressed by group differences. Further exploration observed other brain regions involved in resting-state activity that may play a role in hot or cool EF. Overall, findings support the Internal Mentation Hypothesis of DMN activity and are indicative of a relationship between emotional regulation and DMN resting-state connectivity.

Esta pesquisa investiga processos cognitivos envolvidos na aprendizagem. Para isso, compara-se o desempenho acadêmico, o desempenho matemático, o executivo central da memória de trabalho e o raciocínio lógico-matemático em trinta e cinco adolescentes do primeiro ano do Ensino Médio do Colégio Júlio de Castilhos. O desempenho acadêmico é representado pela média obtida por cada um de 35 alunos, no primeiro trimestre do ano letivo de 2010 nas disciplinas que compõem o programa, excetuando-se a matemática. O desempenho matemático é representado pela nota final na disciplina no mesmo trimestre. O executivo central da memória de trabalho é avaliado por meio de dois subtestes selecionados da Bateria de Avaliação da Memória de Trabalho da Universidade Federal de Minas Gerais. O raciocínio lógico-matemático é avaliado com a tarefa piagetiana o equilíbrio da balança. Os dados obtidos através dos testes para avaliação do executivo central da memória de trabalho são estudados com análise estatística inferencial. Os dados obtidos com o método clínico piagetiano na aplicação da tarefa o equilíbrio da balança são estudados por meio de análise descritiva, além de serem transformados em escores a fim de serem incluídos na análise estatística inferencial. Encontrou-se correlação entre as quatro funções estudadas através do teste de correlação de Pearson. Os alunos são agrupados conforme o desempenho acadêmico, em alunos com desempenho alto, intermediário e baixo e, com esta categorização, é realizada a comparação entre grupos quanto ao desempenho matemático, o executivo central da memória de trabalho e o raciocínio lógico-matemático, por Análise de Variância. Encontrou-se que as funções diferem nos três grupos na maioria das comparações. Conclui-se que o executivo central da memória de trabalho e o raciocínio lógico-matemático têm um papel importante no desempenho acadêmico do aluno adolescente. / This research investigates the cognitive processes involved in learning. For this purpose, it compares academic performance, mathematical performance, the central executive of working memory and logical-mathematical reasoning in thirty-five teenagers in their first year of High School in a public school. Academic performance for each student is assessed through the average grade obtained in the first quarter of the 2010 academic year, in the subjects that comprise the program, except mathematics. The mathematical performance is represented by the final grade in the subject in the same quarter. The central executive of working memory is assessed by two subtests selected from the Working Memory Assessment Battery from the Federal University of Minas Gerais. The logical-mathematical reasoning abilities are assessed by the Piagetian task called the balance equilibrium. The data obtained through tests to assess the central executive of working memory are interpreted by means of inferential statistical analysis. The data obtained by the clinical method of application of the Piagetian task the balance equilibrium are studied through descriptive analysis and are converted into scores, which are then included in the inferential statistical analysis. There is a correlation between the four functions studied by the Pearson correlation test. The mathematical performance, the central executive of working memory and logical-mathematical reasoning are analysed among groups of students with above-, lower- and average academic performances. The functions in the three groups differed on most comparisons. The central executive of working memory and logical-mathematical reasoning play an important role in the academic performance of teenage students.

Esta pesquisa investiga processos cognitivos envolvidos na aprendizagem. Para isso, compara-se o desempenho acadêmico, o desempenho matemático, o executivo central da memória de trabalho e o raciocínio lógico-matemático em trinta e cinco adolescentes do primeiro ano do Ensino Médio do Colégio Júlio de Castilhos. O desempenho acadêmico é representado pela média obtida por cada um de 35 alunos, no primeiro trimestre do ano letivo de 2010 nas disciplinas que compõem o programa, excetuando-se a matemática. O desempenho matemático é representado pela nota final na disciplina no mesmo trimestre. O executivo central da memória de trabalho é avaliado por meio de dois subtestes selecionados da Bateria de Avaliação da Memória de Trabalho da Universidade Federal de Minas Gerais. O raciocínio lógico-matemático é avaliado com a tarefa piagetiana o equilíbrio da balança. Os dados obtidos através dos testes para avaliação do executivo central da memória de trabalho são estudados com análise estatística inferencial. Os dados obtidos com o método clínico piagetiano na aplicação da tarefa o equilíbrio da balança são estudados por meio de análise descritiva, além de serem transformados em escores a fim de serem incluídos na análise estatística inferencial. Encontrou-se correlação entre as quatro funções estudadas através do teste de correlação de Pearson. Os alunos são agrupados conforme o desempenho acadêmico, em alunos com desempenho alto, intermediário e baixo e, com esta categorização, é realizada a comparação entre grupos quanto ao desempenho matemático, o executivo central da memória de trabalho e o raciocínio lógico-matemático, por Análise de Variância. Encontrou-se que as funções diferem nos três grupos na maioria das comparações. Conclui-se que o executivo central da memória de trabalho e o raciocínio lógico-matemático têm um papel importante no desempenho acadêmico do aluno adolescente. / This research investigates the cognitive processes involved in learning. For this purpose, it compares academic performance, mathematical performance, the central executive of working memory and logical-mathematical reasoning in thirty-five teenagers in their first year of High School in a public school. Academic performance for each student is assessed through the average grade obtained in the first quarter of the 2010 academic year, in the subjects that comprise the program, except mathematics. The mathematical performance is represented by the final grade in the subject in the same quarter. The central executive of working memory is assessed by two subtests selected from the Working Memory Assessment Battery from the Federal University of Minas Gerais. The logical-mathematical reasoning abilities are assessed by the Piagetian task called the balance equilibrium. The data obtained through tests to assess the central executive of working memory are interpreted by means of inferential statistical analysis. The data obtained by the clinical method of application of the Piagetian task the balance equilibrium are studied through descriptive analysis and are converted into scores, which are then included in the inferential statistical analysis. There is a correlation between the four functions studied by the Pearson correlation test. The mathematical performance, the central executive of working memory and logical-mathematical reasoning are analysed among groups of students with above-, lower- and average academic performances. The functions in the three groups differed on most comparisons. The central executive of working memory and logical-mathematical reasoning play an important role in the academic performance of teenage students.

Mathematics is an important skill that is taught to all children in the UK in a structured manner from a very early age. The purpose of this thesis was to examine how working memory (Baddeley & Hitch, 1974a; Baddeley & Hitch, 1994) and UK curricular mathematics are related, if specific components of working memory were more impactful upon performance in mathematics than others, and if we can predict mathematics outcomes using working memory measures. With reference to the influence of working memory on overall curricular mathematics performance, a cohort of 70 children from two primary schools in the North West of England was tested annually from their Reception year (mean age 5yrs 1m) at school to Year Two (mean age 6yrs 11m ). The study used a number of working memory tasks, a UK curricular mathematics test, and two Performance Measures. This allowed data to be analysed both in a cross-sectional manner and longitudinally (Chapter 5).The thesis also differentiates UK curricular mathematics into four separable “strands”, Number, Calculation, Measures, Shape and Space, and Problem Solving. These strands are described consistently throughout the UK mathematics curricular literature (DfEE, 1999; DfEE & QCA, 1999a; DfES, 2003a) and the cohort data was used to statistically analyse the relationships between working memory and each strand in turn using a correlational design in Chapters 6 to 9.Results indicated that working memory is a robust predictor of overall mathematics performance (Chapter 5), and of the Calculation Strand (Chapter 7). This finding was demonstrated in both the cross-sectional analyses and also in the longitudinal regression analyses. Of the working memory measures a distinct pattern of association was revealed. In particular the data imply that there is a strong role for the central executive at each age range, but in Year One verbal short-term memory emerges as an important predictor variable. Working memory also showed significant predictive influence over the remaining three curricular mathematics strands that were measured, particularly at the youngest age grouping, but working memory was not found to be a robust longitudinal predictor of Number, Problem Solving or Measures, Shape and Space. The overarching conclusion is that working memory, and in particular the central executive, may support the development of early curricular mathematical skills independent of the influence of age and Performance Measures. The practical and theoretical implications are considered.