Importance of having agreeable friends in adolescence (especially when you are not)

Using the actor–partner interdependence model, we examined whether adolescent's agreeableness, best friend's agreeableness, and the interaction between adolescent‐friend agreeableness are important for interpersonal functioning. Adolescents (N = 158) in fifth to eighth grades who were part of best friend pairs completed personality and friendship measures. Adolescents' adjustment and victimization experiences were assessed by peer nominations. For boys, best friend's agreeableness moderated the relationship between the target boy's agreeableness and overt victimization, relational victimization, and externalizing problems. For girls, best friend's agreeableness moderated the relationship between the target girl's agreeableness and internalizing problems and prosocial skills. This study provides an initial glimpse into how traits of friends can influence outcomes beyond what would be expected from adolescents' personality alone.     

Psychometric properties of the Coping Strategy Indicator (CSI) in a study of coping behaviour amongst malawian students

Abstract

The Coping Strategy Indicator (CSI; Amirkhan 1990) is an inductively derived measure of responses to adverse circumstances. Although seeking to isolate “a few fundamental strategies with wide applicability” (Amirkhan 1990). the initial validation studies were all based on Californian populations. The present study repork findings from completion of the CSI by 415 Malawian students as part of their enrolment health check up. Factor analysis (principal components analysis with varimax rotation) identified three factors with very similar structure and loadings to those identified by Amirkhan, namely, Support Seeking, Problem Solving and Avoidance. As with the initial validation study, there was some evidence of withdrawal and distraction forming identifiable sub-components of Avoidance. The CSI does appear to provide a measure of core coping strategies which is robust across cultural settings, the theoretical implications of which are considered. The influence of factors such as age and gender on CSI scores is discussed     

Individuals with Autism can Categorize Facial Expressions

The ability of high-functioning individuals with autism to perceive facial expressions categorically was studied using eight facial expression continua created via morphing software. Participants completed a delayed matching task and an identification task. Like undergraduate male participants (N = 12), performance on the identification task for participants with autism (N = 15) was predicted by performance on the delayed matching task for the angry-afraid, happy-sad, and happy-surprised continua. This result indicates a clear category boundary and suggests that individuals with autism do perceive at least some facial expressions categorically. As this result is inconsistent with findings from other studies of categorical perception in individuals with autism, possible explanations for these findings are discussed.     

Objective assessment of the functional role of spike train correlations using information measures

The functional role of correlations between neuronal spike trains remains strongly debated. This debate partly stems from the lack of a standardized analysis technique capable of accurately quantifying the role of correlations in stimulus encoding. We believe that information theoretic measures may represent an objective method for analysing the functional role of neuronal correlations. Here we show that information analysis of pairs of spike trains allows the information content present in the firing rate to be disambiguated from any extra information that may be present in the temporal relationships of the two spike trains. We validate and illustrate the method by applying it to simulated data with variable degrees of known synchrony, and by applying it to recordings from pairs of sites in the primary visual cortex of anaesthetized cats. We discuss the importance of information theoretic analysis in elucidating the neuronal mechanisms underlying object identification.     

Practice Effects on Motor Control in Healthy Seniors and Patients with Mild Cognitive Impairment and Alzheimer's Disease

ABSTRACT

This research was designed to test the hypothesis that motor practice can enhance the capabilities of motor control in healthy controls (NC) and patients with a diagnosis of probable Alzheimer's disease (AD) and mild cognitive impairment (MCI), and consequently results in better motor performance. Approximately half of the subjects in the NC (n = 31), AD (n = 28), and MCI (n = 29) either received or did not receive practice on a task of fast and accurate arm movement with a digitizer. Changes in movement time (MT), movement smoothness (jerk), and percentage of primary submovement (PPS) were recorded and compared among the three groups across six blocks of trials (baseline and five training sessions). For all subjects, practice improved motor functions as reflected by faster and smoother motor execution, as well as a greater proportion of programming control. Compared to unaffected matched controls, AD and MCI subjects exhibited a greater reduction in movement jerk due to practice. Movement time and PPS data revealed that motor practice appeared to reduce the use of “on-line” correction adopted by the AD or MCI patients while performing the aiming movements. Evidently, their arm movements were quicker, smoother, and temporally more consistent than their untrained peers. The findings of this study shed light on how MCI and AD may affect motor control mechanisms, and suggest possible therapeutic interventions aimed at improving motor functioning in these impaired individuals.     

Dependence on Visual Feedback During Motor Skill Learning in Alzheimer's Disease

Three experiments examined the role of visual feedback on the performance of a fine motor task, namely the rotary pursuit, in patients with Alzheimer's disease (AD) and healthy older adults. After extensive practice tracking a fully visible target, participants in Experiments 1 and 2 were tested under restricted vision (RV) conditions. In both experiments, the two groups showed a drop in performance when vision was restricted, with AD patients showing a significantly larger decline. Tracking improved significantly in normal controls, but not AD patients across the RV trials after the initial drop. When difficulty of the rotary pursuit task was manipulated in Experiment 3 without restricting vision, AD patients and normal controls showed identical patterns of performance. Consequently, it could be concluded that AD patients in the first two experiments were relying more heavily on visual information for accurate performance of the tracking task than their healthy peers.