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.     

Counseling,Risk Taking,and the Learning Process

It is crucial that counselors recognize that the problem-solving process that occurs in a counseling situation is synonymous with classroom learning. It is imperative that counselors understand the nature of the problem-solving process and how to guide and nurture this process, to increase their own effectiveness and their counselees' growth. Understanding the concepts of risk taking and intrinsic and extrinsic reinforcement and their relationships to the counselees' problem-solving processes will allow counselors to establish their own counseling approaches and respond to the counselees' learning needs. Jerome Niles is an assistant professor of curriculum and instruction at Virginia Polytechnic Institute and State University in Blacksburg. Marianne DeVoe is an assistant professor of educational foundations at the University of Wyoming in Laramie.     

Intelligence tests on trial: An “interview” with judges Robert F. Peckham and John F. Grady

The issue of culturally biased intelligence tests has been heard in two federal courts. Judge Robert F. Peckham, in the Larry P., et al. v. Wilson Riles, et al. case, ruled that intelligence tests were culturally biased. In contrast, Judge John F. Grady, in the Parents in Action on Special Education, et al. v. Joseph P. Hannon, et al. case, ruled that intelligence tests were not culturally biased. A mock “interview” based on the judges' written opinions, shows similarities and differences in their approach to various issues involved in the trials.     

Relations between nutrition and cognitive performance in Egyptian toddlers

Two relatively unexplored questions--which specific components of chronic mild child malnutrition are associated with specific behavioral and cognitive deficits and do psychosocial child rearing factors moderate the nutrition-development relationship?--were investigated in a longitudinal study involving 153 toddlers from the Egyptian village of Kalama. Beginning at study entry at age 18 months and continuing until 30 months, food intake information was obtained for 2 consecutive days each month. During the same period, researchers visited the homes twice a month to observe both toddler behavior and caregiver styles. Finally, standardized infant development tests were administered at 24 months and 30 minutes and the capacity for exploratory, symbolic play was assessed. Specific components of nutritional intake at 18-23 months of age were confirmed to be uniquely related to specific developmental outcomes at 24 months of age. Changes in toddler intake from 18-30 months also predicted 30-month cognitive performance. At 24 months, general mental competence was associated positively with fat intake, total kilocalories, and total protein intake while symbolic play capacity was related only to total protein intake. Significant increases in predictive variance occurred when the model was expanded to encompass caregiver behaviors as well as nutritional factors. For example, when nonverbal response to child vocalizations was used as the environmental measure, there was evidence of both coactive and synergistic interactions for comparisons involving cognitive development indicators. For symbolic play, an increase in predictive variance was found when the model included the multiplicative interaction of animal kilocalories by nonverbal response to vocalizations. Also observed was a buffering effect against poor psychosocial rearing conditions given the presence of adequate nutritional intake. These findings suggest the feasibility of multidimensional risk profiles, the provision of specific nutrients targeted at specific deficits, and multidisciplinary interventions.     

A validational note on the revised Socialization Scale of the California Psychological Inventory

The revised (1987) Socialization Scale of the California Psychological Inventory was studied in a sample of 121 delinquent and nondelinquent males to determine if the revised scale, compared to the original version of the scale (1957), could differentiate among a group of nonoffenders and a comprehensive typology of offenders. Results of an ANOVA and product-moment correlations provided significant and considerable support for the discriminability of the revised So Scale. Obtained results indicate that the revised instrument can differentiate offenders from nonoffenders to about the same, or a greater, degree than the original scale.