The conceptual basis of function learning and extrapolation: Comparison of rule-based and associative-based models

The purpose of this article is to provide a foundation for a more formal, systematic, and integrative approach to function learning that parallels the existing progress in category learning. First, we note limitations of existing formal theories. Next, we develop several potential formal models of function learning, which include expansion of classic rule-based approaches and associative-based models. We specify for the first time psychologically based learning mechanisms for the rule models. We then present new, rigorous tests of these competing models that take into account order of difficulty for learning different function forms and extrapolation performance. Critically, detailed learning performance was also used to conduct the model evaluations. The results favor a hybrid model that combines associative learning of trained input—prediction pairs with a rule-based output response for extrapolation (EXAM).     

The group therapist's shame: a much undiscussed topic

The topic of shame in group therapy has received limited attention in the group therapy literature. When the topic has been addressed, the focus has been on the shame of the group members. The shame of the group leader and its effect on leadership efficacy and group process has received inadequate attention, given what seems to be its power and prevalence. In this article we examine shame and the group therapist with regard to (1) potentially shameful topics and (2) dynamics that evoke shame. Suggestions for both the mitigation of shame and the enhancement of the leader's self-esteem in dispatching the role and functions of group therapist are offered. In discussing this subject, we propose to normalize group therapist shame by emphasizing the challenges and complexity of group leadership. While the examples illustrate an array of emotions, our purpose is to focus on their shameful elements because they are (1) frequently ignored or overlooked; (2) not made explicit; or (3) discussed in other terms, such as narcissism. In doing so, we invite the reader to consider the clinical utility of the hypothesis that shame has a powerful presence and impact on our leadership image and effectiveness.     

The relationship of mental illness to targeted contact behavior toward state government agencies and officials

Research in the burgeoning field of threat assessment has illuminated the importance of mental illness factors when considering risk of targeted violence-particularly related to government agencies and officials. The authors analyzed 127 cases investigated by a state law enforcement agency regarding threatening or other contacts toward public officials or state agency employees prompting security intervention. Univariate and discriminant analysis indicated that mentally ill subjects were significantly more likely to engage in more contacts as well as to make specific demands during such contacts. Mentally ill subjects were also more likely to articulate help-seeking concerns and employ religious themes, as opposed to using insulting, degrading, or ominous language toward the target or issuing complaints regarding policy issues. Contrary to other research, the mentally ill subjects within this sample were not significantly more likely to engage in approach behavior, a threshold for higher risk of violence. Implications for threat assessment activity are discussed.     

Chunking versus foraging search patterns by rats in the hierarchically baited radial maze

Rats were exposed to a radial maze containing six black smooth arms and six wire-grid-covered arms and a striped 'exit arm' in experiment 1. The probability of a black or grid arm being baited (5/6 vs 1/6) with sunflower seeds was associated with its proximal cue for some rats (the Relevant Arm Cue group) but not for others (the Irrelevant Arm Cue group). All rats could terminate a trial and receive a highly preferred morsel of apple by entering the exit arm only after having sampled all six seed-baited arms. Relevant Arm Cue rats usually chose some arms from the more densely baited set before choosing an arm from the less densely baited set and made fewer reentries than Irrelevant Arm Cue rats. Although such clustered, higher choice accuracy in the Relevant Arm Cue group corresponds to human clustered, better recall of verbal items from lists hierarchically organized by categories, these rats did not similarly exhaustively retrieve items (arm locations). That is, when required to terminate a trial by entering the 'exit' arm for an apple morsel after having sampled all seed-baited arms, both groups were equally unable to withhold making nonrewarded premature exits. This nonexhaustive foraging search pattern was maintained in the next two experiments in which the radial maze was reduced to three black and three grid arms along with the striped 'exit' arm and in which black and grid arm cues were paired with number of seeds (eight or one) in an arm for Relevant Arm Cue rats. Although Relevant Arm Cue rats displayed perfect clustering by entering all eight-seeded arms before a one-seeded arm, they made more premature exits and reentries into eight-seeded arms in experiment 2 or when forced to enter all eight-seeded arms in experiment 3 than did Irrelevant Arm Cue rats. These foraging tendencies prevent accurate estimations of the amount of information (i.e., arm locations) rats can 'chunk'. Electronic Publication     

Psychological Reactions to the Drunk Driver: Associations With Intervention and Their Success1

Research on psychological factors in helping behavior has been undertaken primarily in laboratory settings. Although this work has been instrumental in identifying psychological factors that influence helping, their role in naturally occurring helping behavior, such as informal drunk-driving intervention, is largely unknown. College students (N= 192) completed a questionnaire that assessed 11 possible reactions to the drunk driving situation, types of interventions, and their success. Over half of the students (55%, N= 10) reported having intervened to prevent someone from driving drunk. Using structural modeling, we examined the effect of various emotions and affective and cognitive reactions on the frequency and success of different types of informal drunk-driving intervention. Different reactions to the drunk driving situation influenced the number, type, and success of interventions used.     

MODELING PROBABIUSTIC CATEGORIZATION DATA:

Abstract— In probabilistic categorization tasks, the correct category is determined only probabilistically by the stimulus pattern Data from such experiments have been successfully accounted for by a simple network model, but have posed difficulties for exemplar models In the present article, we consider an exemplar model, CLEM (concept learning by exemplar memorization), which differs from previously tested exemplar models in that exemplar traces are assumed to be stored only when the subject has guessed or made a classification error Fits of CLEM to both learning and test data were comparable to those of the network model, and better than those obtained for a version of CLEM in which encoding was independent of the subject's response The implications of these results for the processes underlying classification decisions are discussed.     

MODIFICATION OF ACTIVITY LEVEL THROUGH BIOFEEDBACK AND OPERANT CONDITIONING1

The biomotometer, an electronic device that simultaneously measures activity and provides auditory feedback to the subject, was used in combination with material reinforcers in two experiments attempting to modify activity level in children. In the first study the activity level of an 11-year-old highly active boy was decreased below mean baseline during conditioning in a classroom setting. His level of activity returned to baseline when feedback was withdrawn. In the second study, activity level of a 10-year-old hypoactive boy was increased over mean baseline level during conditioning in a free-play setting, and returned to slightly below baseline during five extinction trials. Results of these studies indicate that the biomotometer is a useful instrument for modification of activity level.     

Activity level: A comparison between actometer scores and observer ratings

Activity level of 13 boys (aged 9–13) from a day hospital program was measured using actometers in classroom, gym, woodshop, and group therapy settings. Ratings of Ss' activity were obtained from mothers using the Werry scale, and from six clinical staff familiar with the Ss using the Davids scale. It was predicted that activity ratings would have situationally specific relationships with actometermeasured activity level according to the rater's opportunities for observation. Comparisons between measures indicated that all clinical staff ratings correlated significantly with actometer activity in the classroom (r=.49 to r=.73), while mothers' ratings correlated significantly with actometer activity in gym (r=.67), and woodshop (r=.77), and with overall activity (r=.65), a combined measure derived from actometer scores in the four conditions tested. Five of six clinical staff raters showed significant interrater reliability (r=.58 to r=.83). Results are discussed in terms of their implications for solution of current problems in assessment of activity level and hyperactivity.