Instrumental learning and cognitive flexibility processes are impaired in children exposed to early life stress

Children who experience severe early life stress show persistent deficits in many aspects of cognitive and social adaptation. Early stress might be associated with these broad changes in functioning because it impairs general learning mechanisms. To explore this possibility, we examined whether individuals who experienced abusive caregiving in childhood had difficulties with instrumental learning and/or cognitive flexibility as adolescents. Fifty‐three 14–17‐year‐old adolescents (31 exposed to high levels of childhood stress, 22 control) completed an fMRI task that required them to first learn associations in the environment and then update those pairings. Adolescents with histories of early life stress eventually learned to pair stimuli with both positive and negative outcomes, but did so more slowly than their peers. Furthermore, these stress‐exposed adolescents showed markedly impaired cognitive flexibility; they were less able than their peers to update those pairings when the contingencies changed. These learning problems were reflected in abnormal activity in learning‐ and attention‐related brain circuitry. Both altered patterns of learning and neural activation were associated with the severity of lifetime stress that the adolescents had experienced. Taken together, the results of this experiment suggest that basic learning processes are impaired in adolescents exposed to early life stress. These general learning mechanisms may help explain the emergence of social problems observed in these individuals.     

A simultaneous test of the relationship between identified psychosocial risk factors and recurrent events in coronary artery disease patients

Psychosocial factors are increasingly recognized as risk indicators for coronary artery disease (CAD) prognosis and they are likely interrelated. The objective of this study is to simultaneously test the relationship between key psychosocial constructs as independent factor scores and recurrent events in CAD patients. There were 1268 CAD outpatients of 97 cardiologists surveyed at two points. Recurrent events or hospitalization in the intervening nine months were reported. Factor analysis of items from the Hospital Anxiety and Depression Scale, Perceived Stress Scale, the ENRICHD Social Support Inventory, and Hostile Attitudes Scale was performed to generate orthogonal factor scores. With adjustment for prognostic variables, logistic regression analysis was performed to examine the relationship between these factor scores and recurrent events. Factor analysis resulted in a six-factor solution: hostility, stress, anxiety, depressive symptoms, support, and resilience. Logistic regression revealed that functional status and anxiety, with a trend for depressive symptoms, were related to experiencing a recurrent event. In this simultaneous test of psychosocial constructs hypothesized to relate to cardiac prognosis, anxiety may be a particularly hazardous psychosocial factor. While replication is warranted, efforts to investigate the potential benefits of screening and to investigate treatments are needed.     

Kindergarten children's sensitivity to geometry in maps

Geometrical concepts are critical to a host of human cognitive achievements, from maps to measurement to mathematics, and both the development of these concepts, and their variation by gender, have long been studied. Most studies of geometrical reasoning, however, present children with materials containing both geometric and non-geometric information, and with tasks that are open to multiple solution strategies. Here we present kindergarten children with a task requiring a focus on geometry: navigation in a small-scale space by a purely geometric map. Children spontaneously extracted and used relationships of both distance and angle in the maps, without prior demonstration, instruction, or feedback, but they failed to use the sense information that distinguishes an array from its mirror image. Children of both genders showed a common profile of performance, with boys showing no advantage on this task. These findings provide evidence that some map-reading abilities arise prior to formal instruction, are common to both genders, and are used spontaneously to guide children's spatial behavior.     

Understanding Middle School Students Life Satisfaction: Does School Climate Matter?

This study of 461 middle school students explored associations between perceived school climate and life satisfaction. At the bivariate level, higher life satisfaction co-occurred with greater perceptions of each aspect of school climate. Taken together, students’ perceptions of school climate accounted for 19 % of the variance in their life satisfaction. When controlling for the commonality amongst school climate dimensions, four of six dimensions (i.e., student interpersonal relations, student-teacher relations, order and discipline, and parent involvement in schooling) emerged as unique predictors of life satisfaction. Follow-up analyses clarified that parent involvement in schooling co-occurred with greater life satisfaction for girls only. Preventative strategies to promote youth life satisfaction by targeting the most salient aspects of school climate are suggested.     

Telling stories: The structure of adults' narratives

Abstract

Adults' narratives were analysed to study life-span changes in their structure. The narratives were collected from a group of adults in their 60s, 70s, and 80s. Four separate analyses were performed on the narratives' (1) hierarchical structure, (2) syntactic structure, (3) propositional content, and (4) cohesion. Age-group differences were obtained for the measures of hierarchical structure, syntactic structure, and cohesion. Further analyses revealed that the structural complexity of the narratives influenced their syntactic structure and cohesion. Interactions between the effects of age group and structural complexity suggest that elderly adults minimise the syntactic complexity of their narratives, reducing their cohesion, when producing structurally complex narratives. Finally, ratings of the quality of the narratives were strongly correlated with their structural complexity, suggesting that telling a “good” story involves constructing complex plots.     

Impaired frontostriatal cognitive functioning following posteroventral pallidotomy in advanced Parkinson's disease

We investigated the long-term effects of posteroventral pallidotomy on tests sensitive to the functional integrity of frontostriatal neural systems in a sample of 11 patients with advanced Parkinson's disease (PD). Patients were assessed within 1 month prior to surgery and at 12 months following pallidotomy. Changes in outcome measures were compared to a control sample of equally performing PD patients receiving nonsurgical medical management assessed over a 12-month period. Measures of cognitive abilities sensitive to frontostriatal functional integrity tested psychomotor processing speed, executive components of working memory, and reasoning. Additional tests of general mental status and semantic memory ability were utilized to assess the specificity of the effect of pallidotomy on cognitive function. Significant declines in performance on all measures sensitive to frontostriatal integrity were found for the surgery group but not the PD control group. No significant changes in performance were found on the measures of general mental status or semantic memory for either the surgery or PD control samples. These results suggest that the posteroventral pallidotomy selectively impairs performance on tests of frontostriatal cognitive abilities.     

Neural synchrony in stochastic resonance, attention, and consciousness.

We describe briefly three of our lab's ongoing projects studying the role of neural synchrony in human perception and cognition. These projects arise from two main interests: the role of noise both in human perception and in neural synchrony, and neural synchrony as a basis for integration of functional modules in the brain. Our experimental work on these topics began with a study of the possibility that noise-influenced neural synchrony might be responsible for the fact that small amounts of noise added to weak signals can enhance their detectability (stochastic resonance). We are also studying the role of neural synchrony in attention and consciousness in several paradigms. On the basis of our own and related work by others, we conclude that (1) neural synchrony plays an important role in the integration of functional modules in the brain and (2) neural synchrony is profoundly affected and possibly regulated, in part, by the "noisiness" of the brain.     

Adolescent Girls’ and Boys’ Science Peer Relationships and Perceptions of the Possible Self as Scientist

Girls tend to have less peer support for their science interests than do boys, which may contribute to gender differences in science motivation. The effect of science peer relationships on adolescents visions of their possible personal future lives as scientists was studied in 161 female and 163 male gifted high school students who participated in summer science enrichment programs. Student reports of having positive science peer relationships were associated with more positive expectations of the possible personal self as scientist prior to the programs, and both program-related and nonprogram-related science peer relationships were associated with changes in the possible self at posttesting and at 6 month follow-up. These relations held for both male and female students. At follow-up, girls reported a stronger social niche with fellow program participants and stronger science peer relationships than did boys. Implications of the findings are discussed within the larger gendered societal context for science achievement.     

Question asking and eye tracking during cognitive disequilibrium: Comprehending illustrated texts on devices when the devices break down

The PREG model of question asking assumes that questions emerge when there is cognitive disequilibrium, as in the case of contradictions, obstacles, and anomalies. Participants read illustrated texts about everyday devices (e.g., a cylinder lock) and then were placed in cognitive disequilibrium through a breakdown scenario (e.g., the key turns but the bolt does not move). The participants asked questions when given the breakdown scenario, and an eyetracker recorded their fixations. As was predicted, deep comprehenders asked better questions and fixated on device components that explained the malfunction. The eye fixations were examined before, during, and after the participants' questions in order to trace the occurrence and timing of convergence on faults, causal reasoning, and other cognitive processes.