Interplay of Biomechanical Constraints and Kinematic Strategies in Selecting Arm Postures

In this study, the authors examined the interplay between biomechanics and control strategies in the resolution of excess degrees of freedom at the joint level. Seven participants made aimed arm movements from 30 starting points and several starting postures to targets. Final arm postures for movements to a target exhibited substantial joint angle variation. Through regression modeling and by comparing observed final arm postures with biomechanically plausible postures, the authors identified 3 kinematic strategies: (a) Maintain deviations from the average angle at the starting point to the joint's final posture; (b) make torso rotations that are a fixed proportion of shoulder rotations; and (c) adopt a characteristic combination of 4 wrist-positioning approaches. The results demonstrated that kinematic strategies can account for substantial variance in final arm postures, if one takes into account 2 types of individual differences—those that arise inevitably from biomechanical constraints and those that reflect choices in movement strategy.     

A Dual Process Account of Coarticulation in Motor Skill Acquisition

Many tasks, such as typing a password, are decomposed into a sequence of subtasks that can be accomplished in many ways. Behavior that accomplishes subtasks in ways that are influenced by the overall task is often described as “skilled” and exhibits coarticulation. Many accounts of coarticulation use search methods that are informed by representations of objectives that define skilled. While they aid in describing the strategies the nervous system may follow, they are computationally complex and may be difficult to attribute to brain structures. Here, the authors present a biologically- inspired account whereby skilled behavior is developed through 2 simple processes: (a) a corrective process that ensures that each subtask is accomplished, but does not do so skillfully and (b) a reinforcement learning process that finds better movements using trial and error search that is not informed by representations of any objectives. We implement our account as a computational model controlling a simulated two-armed kinematic “robot” that must hit a sequence of goals with its hands. Behavior displays coarticulation in terms of which hand was chosen, how the corresponding arm was used, and how the other arm was used, suggesting that the account can participate in the development of skilled behavior.     

Mass and Shading Effects on Masculine-Feminine Judgments on the Rorschach

College students were used to test the hypotheses that judgment of an achromatic Rorschach Inkblot as ‘masculine’ is a function of largeness of mass, and darkness of shading, and judgment of one as ‘feminine’ is a function of smallness of mass and lightness of shading. It was also predicted that the sex of the judge does not influence these judgments.

The standard inkblots and mass and shading control blots were used with the semantic differential and a masculine-feminine sort technique.

The results generally supported the hypotheses tested with the ‘shading hypotheses’ receiving the strongest support. The results were related, with reservation, to the “father” and “mother” hypotheses of cards IV and VII.     

Gender Differences in Drinking Motivations and Outcomes

To investigate gender differences in the dynaijiics of alcohol use, we gathered self-report data from male and female college students. Results of our experiment showed that dominance power motivations were correlated with negative drinking outcomes for both men and women; assertiveness power motivations were associated with negative outcomes only for women. For both sexes, a higher proportion of positive social motivations was associated with fewer negative drinking outcomes. We expect that, in addition to the more traditionally defined needs for dominance power shown to be important for drinking among men, women may use alcohol in relation to needs for assertiveness and self-expression.     

Maintaining Order and Following the Rules: Gender Differences in Punishing Inmate Misconduct

For this article, we examine gender differences in how staff members address inmate misconduct. Using in-depth interviews with forty-three correctional employees, we focus on how their various disciplinary styles create interpersonal conflict between staff members. We find that over half of interviewees are identified as “formal responders” who consistently punish inmate misconduct with formal sanctions, even if doing so creates conflict within the organization. However, female formal responders also claim that they work closely with male inmates to explain the importance of following the rules. They state that this puts them at odds with their male co-workers who misinterpret this behavior as instigating sexual relationships.     

Detection and recognition of emotional expressions: Effects of traits of personality disorder and gender

A problem in the processing of emotions has long been thought to be strongly associated with the aetiology and maintenance of personality disorders. Previous research has demonstrated a hyposensitivity to the faces expressing fear in those high on the traits of psychopathy, while patients with BPD have been shown to be hypersensitive to expressions in general. However, many previous studies could be explained by a bias in reporting particular expressions rather than a change in sensitivity to these expressions. Using two tasks, the present study examined both the detection and the recognition of four emotional expressions (anger, happy, sad, and fear) in a community sample of males and females. Measures of self-reported psychopathy and Borderline Personality traits were administered. The results showed marked gender differences. Psychopathy was negatively related to performance in both the detection and recognition of fear, but only for males. Borderline Personality traits were positively related to overall performance in the recognitions task, but only for females. The results suggest strong differences in the role that emotional processing might play between the genders.     

Suppressor effects and age differences in the expression of anxious emotion

This study examined the role of suppressor effects on age differences in anxious emotion. Children and adolescents (n = 1099) ages 7–18 years were assessed for separation anxiety, social anxiety, and generalized anxiety. Results of zero-order correlations indicated a significant negative association between age and separation anxiety but no association for social anxiety and generalized anxiety. However, semi-partial correlations indicated the presence of a cooperative suppressor effect such that the associations between age and social anxiety as well as age and generalized anxiety symptoms became significant and positive and the association with separation anxiety became larger in a simultaneous regression analysis of each facet with age. Similar effects occurred when controlling for hyperarousal in an ANCOVA across grade levels. Results suggest that attempts to understand developmental differences in anxious emotion in childhood and adolescence will be facilitated by parsing facets of anxious emotion and attention to potential suppressor effects.     

Group Treatment of Sexually Abused Adolescent Girls: A Review of Outcome Studies

Abstract

This paper considers factors that make children “at risk” for postdivorce maladjustment. The risk factors include (a) demographic variables of sex, age and socioeconomic status; (b) predivorce family functioning; (c) postdivorce relationship with the ex-spouse; (d) postdivorce parentchild interaction; and (e) social support systems. Treatment programs incorporating these factors are briefly described. Recommendations are provided for the clinician and researcher.     

The effect of limited attention and delay on negative arousing false memories

ABSTRACT

Previous research has shown that, in comparison to neutral stimuli, false memories for high arousing negative stimuli are greater after very fast presentation and limited attention at study. However, full compared to limited attention conditions still produce comparably more false memories for all stimuli types. Research has also shown that emotional stimuli benefit from a period of consolidation. What effect would such consolidation have on false memory formation even when attention is limited at study? The aim of the present study was to investigate the effect of fast presentation on false memory production for negatively-arousing and neutral items over time using the DRM paradigm. Sixty-eight participants studied Negative and neutral DRM lists with fast or slow presentation conditions. Half completed a recognition test immediately and half completed a recognition test after one-week. Results revealed that, for fast presentation, negative critical lures increased after one week and were comparable to negative critical lures in the slow presentation encoding conditions. Neutral critical lures in the fast presentation condition did not change and remained lower compared to the slow presentation condition. These findings are the first demonstration that arousing negative false memories can increase over time when attention at encoding is limited.     

Anxiety and expectancy violations: Neural response to false feedback is exaggerated in worriers

This study investigated how individual differences in anxiety modulate the neural response to errors and performance feedback. The design included false feedback on some trials in order to test the hypothesis that anxious people show stronger neural reactions to feedback that is worse than expected. Participants completed a trial-and-error learning task that required learning the correct key to press in response to face images. EEG was recorded during the task, and the response-locked error-related negativity (ERN) and feedback-locked ERN were computed to measure neural responses to error commission and feedback. As expected, errors produced a response-locked ERN and false feedback produced a feedback-locked ERN in the group as a whole. High levels of trait worry predicted a disproportionately larger ERN following false feedback, but did not predict the magnitude of the response-locked ERN following errors. These results imply that worry-prone people react more strongly to violations of expectations, rather than to errors themselves.