Asymmetries in the discrete and pseudocontinuous regulation of visually guided reaching.

An experiment was conducted to examine the contribution of the hemispheres to the organization of aiming movements. The spatial positions of targets were obtained by extrapolating from brief visual displays of geometric patterns. The patterns comprised linear, quadratic, cubic, and quartic mathematical functions and varied in spatial complexity. Vision of the hand was also manipulated. While the hands did not differ in spatial accuracy, movements made by the right hand were of shorter duration and had higher peak velocities. The stimulus pattern strongly influenced kinematics, in particular the number of discrete modifications of the movement trajectory. Vision of the hand resulted in superior accuracy, although subjects were unable to compare the relative positions of the limb and the target. Vision of the hand did not lead to an increase in discrete adjustments, suggesting that visual information was used in a continuous fashion. Movements into ipsilateral space differed from those into contralateral space with respect to a number of parameters.     

Is there a temporal basis of the word length effect? A response to Service (1998)

Service (1998) carried out a study of the word length effect with Finnish pseudowords in which short and long pseudowords were identical except for the inclusion of certain phonemes differing only in pronunciation length, a manipulation that is impossible in English. She obtained an effect of phonemic complexity but little or no word duration effect per se - a discrepancy from the expectations generated by the well-known working memory model of Baddeley (1986). In the present study using English words, we controlled for phonemic complexity differences by using the same words for the short- and long-word sets, but with instructions inducing shorter or longer pronunciation of the words. We obtained substantial word duration effects. Concerns raised by Service are addressed, and we conclude that both duration and complexity are likely to contribute to the word length effect in serial recall.     

SIMPLIFIED HABIT REVERSAL TREATMENT FOR CHRONIC HAIR PULLING IN THREE ADOLESCENTS: A CLINICAL REPLICATION WITH DIRECT OBSERVATION

Three developmentally normal adolescents with chronic hair pulling were treated with a simplified habit reversal procedure consisting of awareness training, competing response training, and social support. Treatment resulted in an immediate reduction to near-zero levels of hair pulling, with one to three booster sessions required to maintain these levels. The results were maintained from 18 to 27 weeks posttreatment, although 1 participant reported difficulty at follow-up. The effectiveness of simplified habit reversal and suggestions for future research are discussed.     

Exploring the edges: boundaries and breaks

In this article, we examine conceptual and practical issues pertaining to relationship boundaries within the helping profession. Although our focus is primarily on relationships between mental health professionals and clients, there are considerable implications for a new approach to ethically structuring and understanding the construct of "required distance" in many human-interactive professions, such as teaching, religious leadership, public administration, and others. We define the concept of boundary as applied to human relationships, provide examples of boundary breaks, and raise questions regarding how to evaluate the significance and morality issues raised by specific boundary breaks. Questions and dilemmas are presented regarding boundary setting and accidental or deliberate boundary breaking. Representative dangers present in boundary breaks are identified, and examples are provided. Possible beneficial outcomes are also discussed. Finally, a suggested protocol for assessing a proposed boundary break is provided, much of which is drawn from the work and thinking of Laura Brown, applied more generally in this article, with additions from our perspectives.     

CAT: A tool for eliciting knowledge on how to perform procedures

Procedural tasks involve context-sensitive sequences of actions that are performed in pursuit of goals. Procedural knowledge specifies how to do something (e.g., repairing a car) but not how the physical system works (e.g., how the engine works). We have developed a computer program that elicits procedural knowledge from individuals with varying amounts of domain knowledge (ranging from novices to experts) and varying amounts of computer literacy. The tool is called CAT (cognitive analysis tool). CAT is an extension of a class of cognitive models known as GOMS, which stands for goals, operators, methods, and selection rules. The tool guides the user in articulating the goals (and subgoals) the user wants to accomplish, the operators (actions, steps) to accomplish each goal, the alternative methods of accomplishing goals, the conditions in which each method is applied, and exceptional circumstances when goals are suspended and restarted. CAT can be used on most IBMcompatible microcomputers.     

Sensitivity to sucrose in smokers and nonsmokers: A comparison of TSD and percent correct measures

Ten smokers and 10 nonsmokers were compared for taste sensitivity to sucrose on two discrimination tasks, one at near-threshold (NT) concentration level and one at suprathreshold (ST) concentration level. The data were analyzed using the d_s and area under ROC curve measures based on the theory of signal detection (TSD). and by using the percentage correct responses. Analysis of both TSD measures showed smokers to be significantly more sensitive than nonsmokers on the NT .task and more sensitive on the ST task, but not significantly so. Comparison of mean percent correct responses showed no significant differences. A reflexive enhancement phenomenon was suggested as a possible interpretation. A decreased sensitivity to the bitter taste in smokers apparently results in an increased sensitivity to the sweet taste.