Scaling a motor skill through observation and practice

The authors examined the proposal that a motor skill is scaled through physical practice and not through observation of a model. In 4 groups, participants (N = 32) did or did not imitate a model bowling a ball to a target 8 m away. In an assessment phase, those groups did or did not observe the same model bowling a ball to a target 4 m away. Participants who viewed a model in the assessment phase were more accurate and consistent in terms of bowling accuracy than were those who did not. Their shoulder and wrist velocity profiles were more similar to those of the 4-m model than were those of the no-model group. Participants who had previous practice and viewed a demonstration were more accurate at scaling the wrist of the bowling arm. Observing a demonstration facilitates the acquisition of control-related features of a movement. Furthermore, early acquisition of coordination aids the use of velocity information for scaling the endpoint of the primary effector.     

Prior knowledge and subtyping effects in children's category learning

Two experiments examined how 5- and 10-year-old children revise their category representations when exposed to exemplars that are congruent or incongruent with existing knowledge. During training children were presented with exemplars containing features that were congruent or incongruent with children's social stereotypes together with a stereotype-neutral feature. In the knowledge-subtyping condition this neutral feature predicted the stereotype-congruence of the other features. In the knowledge-standard condition the neutral feature was uncorrelated with stereotype-congruence. At test children made judgements about feature co-occurrence within the learned category. In each experiment these judgements were influenced by both stereotypical beliefs and exemplar observation. Stereotypical beliefs, however, had a greater influence on co-occurrence judgements in the knowledge-subtyping than in the standard conditions. In Experiment 2 these effects were shown to generalize to judgements about features that were not presented during training. These results challenge current models of knowledge-based categorization by showing that exemplar structure determines whether novel exemplar features are incorporated into category representations.     

Vision-for-action: The effects of object property discrimination and action state on affordance compatibility effects

When a person views an object, the action the object evokes appears to be activated independently of the person’s intention to act. We demonstrate two further properties of this vision-to-action process. First, it is not completely automatic, but is determined by the stimulus properties of the object that are attended. Thus, when a person discriminates the shape of an object, action affordance effects are observed; but when a person discriminates an object’s color, no affordance effects are observed. The former, shape property is associated with action, such as how an object might be grasped; the latter, color property is irrelevant to action. Second, we also show that the action state of an object influences evoked action. Thus, active objects, with which current action is implied, produce larger affordance effects than passive objects, with which no action is implied. We suggest that the active object activates action simulation processes similar to those proposed in mirror systems.     

Demographic, criminal, and psychiatric factors related to inmate suicide

A review of 19 studies suggests that it may be feasible to identify prisoners with suicide risk on the basis of demographic, psychiatric, and criminal characteristics. The present study aimed to identify combinations of characteristics that are capable of identifying potential suicide victims. Characteristics of 95 suicide victims in the Dutch prison system were compared with those of a random sample of 247 inmates in ten jails. Combinations of indicators for suicide risk were also tested for their capability of identifying 209 suicides in U.S. jails and 279 prison suicides in England and Wales. A combination of six characteristics (age 40+, homelessness, history of psychiatric care, history of drug abuse, one prior incarceration, violent offence) was capable of correctly classifying 82% of the Dutch suicide victims (82% specificity). Less powerful combinations correctly classified 53% of the U.S. suicides and 47% of the U.K. suicides. It is concluded that a set of demographic and criminal characteristics and indicators of psychiatric problems is useful for the identification of suicide risk in jails and prisons.     

Systems for the Production of Plagiarists? The Implications Arising from the Use of Plagiarism Detection Systems in UK Universities for Asian Learners

This paper argues that the inappropriate framing and implementation of plagiarism detection systems in UK universities can unwittingly construct international students as ‘plagiarists’. It argues that these systems are often implemented with inappropriate assumptions about plagiarism and the way in which new members of a community of practice develop the skills to become full members of that community. Drawing on the literature and some primary data it shows how expectations, norms and practices become translated and negotiated in such a way that legitimate attempts to conform with the expectations of the community of practice often become identified as plagiarism and illegitimate attempts at cheating often become obscured from view. It argues that this inappropriate framing and implementation of plagiarism detection systems may make academic integrity more illusive rather than less. It argues that in its current framing – as systems for ‘detection and discipline’ – plagiarism detection systems may become a new micro-politics of power with devastating consequences for those excluded.     

Speeded induction under uncertainty: The influence of multiple categories and feature conjunctions

When people are uncertain about the category membership of an item (e.g., Is it a dog or a dingo?), research shows that they tend to rely only on the dominant or most likely category when making inductions (e.g., How likely is it to befriend me?). An exception has been reported using speeded induction judgments where participants appeared to use information from multiple categories to make inductions (Verde, Murphy, &; Ross, 2005). In two speeded induction studies, we found that participants tended to rely on the frequency with which features co-occurred when making feature predictions, independently of category membership. This pattern held whether categories were considered implicitly (Experiment 1) or explicitly (Experiment 2) prior to feature induction. The results converge with other recent work suggesting that people often rely on feature conjunction information, rather than category boundaries, when making inductions under uncertainty.     

Is it the symptom or the relation to it? Investigating potential mediators of change in acceptance and commitment therapy for psychosis

Cognitive and behavioral interventions have been shown to be efficacious when used as an adjunct to pharmacotherapy for psychotic disorders. However, little previous research has investigated potential mediators of change in psychological treatments for psychosis. Acceptance and mindfulness-based therapies do not focus on directly reducing the psychotic symptoms themselves, but instead attempt to alter the patient's relationship to symptoms to decrease their negative impact. The current study examined this issue with data from a previously published randomized trial comparing brief treatment with Acceptance and Commitment Therapy (ACT) versus treatment as usual for hospitalized patients with psychotic symptoms (Gaudiano & Herbert, 2006a). Results showed that the believability of hallucinations at posttreatment statistically mediated the effect of treatment condition on hallucination-related distress. Hallucination frequency did not mediate outcome. The current study is a first step toward understanding the potential mechanisms of action in psychological treatments for psychosis.     

Changes in proposed mechanisms of action during an acceptance-based behavior therapy for generalized anxiety disorder

Based on the theory that generalized anxiety disorder (GAD) is maintained through a reactive and fused relationship with one's internal experiences and a tendency towards experiential avoidance and behavioral restriction, an acceptance-based behavior therapy (ABBT) was developed to specifically target these elements. Since ABBT has been shown to be an efficacious treatment in previous studies, the current study focuses on proposed mechanisms of change over the course of therapy. Specifically, the current study focuses on session-by-session changes in two proposed mechanisms of change: acceptance of internal experiences and engagement in meaningful activities. Overall, clients receiving ABBT reported an increase in the amount of time spent accepting internal experiences and engaging in valued activities. Change in both acceptance and engagement in meaningful activities was related to responder status at post-treatment and change in these two proposed mechanisms predicted outcome above and beyond change in worry. In addition, change in acceptance was related to reported quality of life at post-treatment.