Effects of visual aids on acquisition of selected tennis skills

The study compared the effects of supplemental visual aids on the acquisition of selected tennis skills. The forehand and backhand drive placement tests of the Hewitt Tennis Achievement Test were used to pretest, midtest, and posttest 55 subjects who were assigned to one of three treatments: control (instructor's verbal feedback only), videotaped replay viewing (with instructor's feedback), and loop-film viewing (modeling, with instructor's feedback). Each received 1200 min. of instruction. There were no statistically significant differences among groups; however, empirical evidence suggested that the use of videotaped replay and loop-film technique has merit and might be given consideration for use in instructional settings.     

An availability bias in professional judgment

When branches of a fault tree are pruned, subjects do not fully transfer the probability of those branches to the ‘all other’ category. This underestimation of the catch-all probability has been interpreted as an ‘out of sight, out of mind’ form of the availability bias. The present work replicates this underestimation bias with professional managers. It then demonstrates the effectiveness of a corrective tactic, extending the tree by generating additional causes, and also reveals that more easily retrieved short-term causes dominate the generation process. These results do not differ across managers' culture, education or experience. After evaluating such alternative explanations as category redefinition, we conclude that availability is a major cause, though possibly not the sole cause, of the underestimation bias.     

MMPI profiles of adolescents charged with homicide

Study of adolescent violence has been impeded by failure to distinguish among the circumstances in which youth engage in violent behavior. The present study investigated MMPI profiles of 36 adolescent murderers and a control group of 18 adolescents charged with larceny. Homicide cases were subgrouped into those who committed homicide secondary to another crime (e.g., robbery or rape) and those who acted in the context of interpersonal conflict with the victim. While there were no significant differences between homicide and larceny groups, crime and conflict subgroups were significantly different on scales F, Hs, Hy, and Sc.     

Validity of the Threat Index.

The validity of the Threat Index was examined in a study of 42 students and 15 HIV+ clients. When completing the Threat Index, subjects rate the self and death on 30 bipolar adjectives. A count is made of the number of times the same adjective poles are used to describe the self and death. Uses of the same poles are called matches, while uses of different poles are called splits. The Threat Index is based on the assumption that splits indicate threat. Analysis showed that neither splits nor matches were usually threatening and that neither was necessary or sufficient for the experience of threat. These results did not support the validity of the Threat Index.     

AN ANALYSIS OF MAINTENANCE FOLLOWING FUNCTIONAL COMMUNICATION TRAINING

The multiple and long-term effects of functional communication training relative to a common reductive procedure (time-out from positive reinforcement) were evaluated. Twelve children participated in a functional analysis of their challenging behaviors (Study 1), which implicated adult attention as a maintaining variable. The children were then matched for chronological age, mental age, and language age and assigned to two groups. One group received functional communication training as an intervention for their challenging behavior, and the second group received time-out as a contrast. Both interventions were initially successful (Study 2), but durable results were achieved only with the group that received functional communication training across different stimulus conditions (Study 3). Students whose challenging behaviors were previously reduced with time-out resumed these behaviors in the presence of naive teachers unaware of the children's intervention history. The value of teaching communicative responses to promote maintenance is discussed as it relates to the concept of functional equivalence.     

Effects of preliminary perceptual output on neuronal activity of the primary motor cortex.

Observations of single neurons in the primary motor cortex of 1 monkey provided evidence that preliminary perceptual information reaches the motor system before perceptual analysis is complete. Neurons were recorded during a task in which 1 stimulus was assigned to a wrist flexion response and another was assigned to wrist extension. Two stimuli were assigned to a no-go response; each was visually similar to either the flexion or the extension stimulus. When a no-go stimulus was presented, neurons responded with weaker versions of the discharge patterns exhibited to the visually similar stimulus requiring a movement, suggesting that neurons receive partial perceptual information favoring that movement. Functionally separable neuronal populations were identified, and differences in the activations of these provide evidence about the functional effects of preliminary perceptual output on movement control processes.     

Representation by counsel: Right or obligation?

Since the Supreme Court's decision in Faretta v. California (1975), courts have generally permitted defendants to represent themselves, as long as they are competent to do so. The problem lies in the definition of competency to waive counsel, which has been vaguely defined by the courts. Little is known about the frequency of, or reasons for, attempts to waive counsel, about the process of forensic evaluation of such competency, and about the success of such attempts. The authors briefly review the case law on competency to waive representation, report on a longitudinal prospective study of these issues in a population of defendants referred to an inpatient forensic facility for evaluation of all types of competency related to their criminal prosecutions, and discuss the significance of the issue for forensic clinicians. A key question for courts, lawyers, and clinicians is whether a competency evaluation can be invoked to overcome a defendant's constitutional rights to self-representation and bail.