Adaptation in Visuomanual Tracking Depends on Intact Proprioception

The role of arm proprioception in motor learning was investigated in experiments in which, by moving the arm, subjects followed the motion of a target displayed on a monitor screen. Adaptive capabilities were tested in visuomanual tracking tasks following alterations in the relationship between the observer's actual arm movement and visual feedback of the arm movement given by a cursor motion on the screen. Tracking performance and adaptive changes, measured in terms of spatiotemporal error, tracking trajectory curvature, and spatial gain, were compared in 7 control subjects (CSs) and in 1 deafferented subject (DS). CSs adapted appropriately to altered visuomanual relationships; those changes were present in trials immediately after restoration of normal scaling. In contrast, although the DS modified his tracking strategy from trial to trial according to the altered conditions, he did not show plastic changes in internal visuomanual scaling. Like the results of prismatic adaptation experiments, the present results suggest that arm proprioception contributes to the plastic changes that follow alterations in the scaling of visuomanual gain.     

Neuropsychological functioning in kleptomania

Kleptomania is characterized by the failure to resist impulses to steal objects not needed for personal use or their monetary value. The objective of this study was to examine cognitive and executive functioning in subjects with kleptomania. Fifteen women with a primary DSM-IV diagnosis of kleptomania underwent a detailed psychiatric examination, including measures of kleptomania severity, and a battery of neuropsychological tests that emphasized executive functions. Correlational analyses were computed between measures of kleptomania severity and tests of executive functioning. Kleptomania subjects reported a mean duration of illness of 17.9 years and shoplifting a mean of 1.7 times per week. All subjects reported an inability to resist urges to shoplift. Neuropsychological testing revealed group mean test scores within 0.5 standard deviations of normative standards for age. Five subjects (33.3%), however, had below-average performance on at least one measure of executive functioning, and 4 (26.7%) had below-average scores on two executive measures. Correlational analyses revealed a statistically significant correlation between kleptomania severity and Wisconsin Card Sorting Test performance (r=-0.693, p=0.004). As a group, subjects with kleptomania did not demonstrate deficits on neuropsychological testing. Greater kleptomania symptom severity, however, was correlated with impairment in executive functioning.     

Intervention Styles With Suicidal Callers at Two Suicide Prevention Centers

Callers to suicide prevention centers are mainly helped by volunteers trained to face these crisis situations. This study evaluated this process of intervention in order to better understand the nature of the interventions and their determinants. A total of 617 calls with suicidal clients were classified with a 20-category rating instrument, the Helper's Response List. Cluster analysis determined that the 617 intervention profiles could match one of two styles: nondirective (“Rogerian”-391 calls) or directive (226 calls). Further analyses indicated that the particular style of intervention was related more to the characteristics of the callers themselves than to characteristics of volunteers.     

Learning about environmental geometry: a flaw in Miller and Shettleworth's (2007) operant model

Many studies have examined how humans and other animals reestablish a sense of direction following disorientation in enclosed environments. Results showing that geometric shape of an enclosure is typically encoded, sometimes to the exclusion of featural cues, have led to suggestions that geometry might be encoded in a dedicated geometric module. Recently, Miller and Shettleworth (2007) proposed that the reorientation task be viewed as an operant task and they presented an associative operant model that appears to account for many empirical findings from reorientation studies. In this paper we show that, although Miller and Shettleworth's insights into the operant nature of the reorientation task may be sound, their mathematical model has a serious flaw. We present simulations to illustrate the implications of the flaw. We also propose that the output of a simple neural network, the perceptron, can be used to conduct operant learning within the reorientation task and can solve the problem in Miller and Shettleworth's model.     

Do behavioural self-blame and stigma predict positive health changes in survivors of lung or head and neck cancers?

Survivors of lung or head and neck cancers often change tobacco and alcohol consumption after diagnosis, but few studies have examined other positive health changes (PHCs) or their determinants in these groups. The present study aims to: (a) document PHCs in survivors of lung (n?=?107) or head and neck cancers (n?=?99) and (b) examine behavioural self-blame and stigma as determinants of PHCs. We hypothesised that: (a) survivors would make a variety of PHCs; (b) behavioural self-blame for the disease would positively predict making PHCs; and (c) stigma would negatively predict making PHCs.

Methods: Respondents self-administered measures of PHC, behavioural self-blame, and stigma. Hierarchical multiple regression analysis tested the hypotheses.

Results: More than 65% of respondents reported making PHCs, the most common being changes in diet (25%), exercise (23%) and tobacco consumption (16.5%). Behavioural self-blame significantly predicted PHCs but stigma did not. However, both behavioural self-blame and stigma significantly predicted changes in tobacco consumption.

Conclusions: Many survivors of lung or head and neck cancers engage in PHCs, but those who do not attribute the disease to their behaviour are less likely to do so. Attention to this problem and additional counselling may help people to adopt PHCs.     

Psychometric Properties of the Locus of Control of Behaviour Scale (LCBS) among Australians Seeking Alcohol and Other Drug (AOD) Treatment

Despite a paucity of studies evaluating the psychometric properties of the Locus of Control of Behaviour Scale (LCBS), it continues to be widely used in behavioural research. The present study sought to redress this gap in the literature. The 17‐item LCBS was administered to 373 Australians attending Alcohol and Other Drug (AOD) treatment agencies in the northern metropolitan region of Perth. Confirmatory factor analyses were conducted in order to determine which of several plausible measurement models provided the best fit for the data. A unidimensional model, recommended by the authors of the LCBS, and a two‐dimensional (Internal Locus of Control vs External Locus of Control) model provided poor fits. Other multidimensional models, differing only in the dimensionality of the externality factor, were also tested. A multidimensional model consisting of an Internal Locus of Control factor and four component External Locus of Control factors provided the best fit; however, the fit is probably best described as “reasonable” rather than “good.” A subsequent exploratory factor analysis using parallel analysis indicated a cohesive internality factor; however, the externality factor showed a tendency to fragment into smaller components. Results were discussed in terms of the problematic externality factor.