No dual-task practice effect in Alzheimer's disease

Diagnosis of Alzheimer's disease (AD) requires evidence of progressive decline in cognitive function. However, many tests used to assess cognitive function suffer from considerable practice effects, reducing their reliability. Several studies have reported that the ability to do two things at once, or dual tasking, is impaired in AD, but unaffected by healthy ageing. The apparent specificity of this impairment suggests that this assessment may be particularly useful in the early diagnosis of AD, but the reliability of this assessment remains unknown. Therefore, this study investigated simultaneous performance of digit recall and tracking tasks across six testing sessions in eight people with AD, eight healthy older adults and eight healthy younger adults. The results found that dual-task performance was unaffected by healthy ageing, but significantly impaired in AD, with no effect of repeated exposure. The absence of any improvements in performance despite increased familiarity with the task's demands suggests that not only is the dual-task assessment well suited for monitoring progression over time, but also that dual tasking involves a specific cognitive function which is impaired in the AD brain.     

Working Memory Capacity and the Development of Quantitative Central Conceptual Structures

Abstract

This article reconsiders Case’s theory of central conceptual structures (CCS), examining the relation between working memory and the acquisition of quantitative CCS. The lead hypothesis is that the development of working memory capacity shapes the development of quantitative concepts (whole and rational numbers). Study I, with 779 children from preschool to grade 5, validated a measure of the whole number CCS and found that children’s understanding of whole number advances by one developmental level per additional unit of working memory capacity. Study II, with 92 sixth- and seventh-graders, found that a test of the rational number CCS was predicted by working memory capacity and, to a lesser extent, by intrusion errors in the listening span. We also identified 2 subsets of items that demand a capacity of 4 or 5 units, respectively. Overall, the results support Case’s CCS theory and clarify the role of working memory in the acquisition of numerical concepts. The relevance of these results in relation to the current debate is discussed, with extensive connections to other current theories of whole or rational number comprehension.     

Do as you’re told! Facets of agreeableness and early adult outcomes for inner-city boys

With data from the middle cohort of the Pittsburgh Youth Study, a prospective longitudinal study of inner-city boys, we examined whether Big Five agreeableness facets could be reliably recovered in this sample, and whether facets predicted educational, occupational, social, and antisocial life outcomes assessed a decade later. Caregivers described their adolescent boys’ personalities using the Common California Q-Set; twelve years later, participants were interviewed and court records were obtained. Factor analyses recovered two facets: compliance and compassion. Compliance predicted more schooling and lower risk of unemployment, teenage fatherhood, and crime; compassion related to longer committed relationships. Findings highlight the value of studying personality at the facet level.     

The structure of working memory and how it relates to intelligence in children

This study explored the structure of working memory, and its relationship with intelligence in 176 typically-developing children in the 4th and 5th grades at school. Different measures of working memory (WM), and intelligence (g) were administered. Confirmatory factor analyses showed that WM involves an attentional control system and storage aspects that rely on domain-specific verbal (STM-V) and visuospatial (STM-VS) resources. The structural equation models showed that WM predicts a large portion (66%) of the variance in g, confirming that the two constructs are separable but closely related in young children. Findings also showed that only WM and STM-VS are significantly related to g, while the contribution of STM-V is moderate. Theoretical implications for the relationship between WM and g are discussed.     

A longitudinal study of psychosocial distress in breast cancer: Prevalence and risk factors

This longitudinal study was conducted among 102 women with non-metastasic breast cancer to identify the time evolution and prevalence of distress at specific times through diagnosis and treatment of disease: preliminary diagnosis, surgery, definitive diagnosis and chemotherapy. Additionally, the study aimed to examine the role of demographic, medical and psychosocial factors on distress. The results indicated that prevalence of distress was higher at initial diagnosis (25%) than the following time points (approximately 17%). The differences inter-individuals in the levels of distress were observed over the four assessments. No relation between distress and demographic and medical factors was found. However, psychosocial aspects were significant risk factors. Patterns of emotional suppression and specific coping responses like helplessness/hopelessness, anxious preoccupation, cognitive avoidance and fatalism were positively related to distress, whereas fighting spirit and perceived social support showed a protective role. Moreover, helplessness/hopelessness and anxious preoccupation jointly predicted 75% of cases and 98% non-cases of distress. Finally, a mediational model between emotional suppression and distress through helplessness/hopelessness was tested. Results support the necessity of routine distress screening all through the illness. Implications of data for psychosocial interventions with breast cancer patients are highlighted.     

Cross-modal working memory binding and learning of visual-phonological associations in children with reading difficulties

Reading decoding requires the association of a visual input (the printed word) with a verbal output (the spoken word), and the learning of visual-phonological associations via repeated exposure occurs both explicitly (by instruction and training) and implicitly (by exposure to written material). However, a general ability to implicitly learn visual-phonological associations (or cross-modal bindings) in children with reading difficulties (RD) has not been deeply explored. The present paper examined this issue in two studies comparing groups of children with RD with matched groups of control children in a working memory binding task involving sequences of variable combinations of nonsense shapes and nonwords (odd trials), as well as fixed combinations (even trials). Stimuli presentation was followed by a recognition test in which the nonwords were given one at a time and the children were required to mouse click on their respective shapes. In Study 1, fixed bindings were presented in random sequences across even trials, and the recognition test presented the nonwords at random. In Study 2, fixed bindings were presented in the same order across even trials, and the recognition test presented the nonwords following the same sequence order. In both studies, a consistent and strong learning effect of fixed bindings was observed for the control groups, with significantly better performance than the groups with RD. Such results suggest that poor cross-modal binding learning is associated with reading difficulties. Implications for the study and treatment of dyslexia are discussed.     

Working Memory Failures in Children with Arithmetical Difficulties

A large body of literature has examined the relationship between working memory and arithmetic achievement, but results are still ambiguous. To examine this relationship, we compared the performance of third and fifth graders with arithmetic difficulties (AD) and controls of the same age, grade, and verbal intelligence on a battery of working memory tasks, differentiating between different aspects of working memory. Children with AD scored significantly lower on active working memory tasks requiring manipulation of the to-be-recalled information (Listening Completion task, Corsi Span Backwards, Digit Backwards), but not in passive working memory tasks, requiring the recall of information in the same format in which it had been presented (Digit, Word, and Corsi Forwards Span tasks), nor in tasks involving word processing (word articulation rate, forwards and backwards word spans). A regression analysis showed that the best predictors of differences between AD children and the control group were the Corsi Span Backwards, the Listening Completion task, and the rate of articulation of pseudowords. The analysis of strategies used by children in mental calculation revealed the greater tendency of children with AD to rely on more primitive strategies: finger use never appeared as the most frequent strategy in skilled children, whereas it was the most used strategy in children with AD. Verbal and visual strategies appeared associated with successful performance in third graders, but in fifth grade, the most successful strategy was verbalization.     

Working memory in event‐ and time‐based prospective memory tasks: Effects of secondary demand and age

An experiment is reported examining the role of working memory in two laboratory‐based prospective memory (PM) tasks. Participants viewed a film for a later recognition memory task while simultaneously monitoring auditorially presented arithmetic problems for incorrect solutions. The arithmetic verification task was either low demand or high demand. In addition, participants were required either to indicate whenever an animal appeared in the film (event‐based PM task), or whenever 3 min had elapsed (time‐based PM task). PM performance was higher when the arithmetic task was low demand than when it was high demand. Young participants were more successful in both PM tasks than older participants, but only under high demand. Age did not interact with PM task type overall, and the young participants were faster overall in both types of PM task. Taken together, the results indicate that working memory plays an important role in PM tasks.     

Biasing decision making by means of retrieval practice

Decision making requires the recruitment of several cognitive processes. So far, however, few studies have dealt with the role of inhibitory control in this domain. In this study, we aim to examine this issue in a memory-based decision task by using an adaptation of the retrieval practice paradigm (Anderson, Bjork, & Bjork, 1994 Anderson, M. C., Bjork, R. A. and Bjork, E. L. 1994. Remembering can cause forgetting: Retrieval dynamics in long-term memory. Journal of Experimental Psychology: Learning, Memory, and Cognition, 20: 1063–1087. [Crossref], [PubMed], [Web of Science ®] , [Google Scholar]). The retrieval-induced forgetting found through this task is normally explained in terms of inhibition. Specifically, we analyse how retrieval practice may affect what alternatives are selected as well as the choice probability and attribute recall. Our data show a relation between the recall impairment of the attributes due to retrieval practice and biased decisions.     

Wittgenstein running: neural mechanisms of collective intentionality and we-mode

In this paper we discuss the problem of the neural conditions of shared attitudes and intentions: which neural mechanisms underlie "we-mode" processes or serve as precursors to such processes? Neurophysiological and neuropsychological evidence suggests that in different areas of the brain neural representations are shared by several individuals. This situation, on the one hand, creates a potential problem for correct attribution. On the other hand, it may provide the conditions for shared attitudes and intentions.