Base-rate effects in category learning: a comparison of parallel network and memory storage-retrieval models

Exemplar-memory and adaptive network models were compared in application to category learning data, with special attention to base rate effects on learning and transfer performance. Subjects classified symptom charts of hypothetical patients into disease categories, with informative feedback on learning trials and with the feedback either given or withheld on test trials that followed each fourth of the learning series. The network model proved notably accurate and uniformly superior to the exemplar model in accounting for the detailed course of learning; both the parallel, interactive aspect of the network model and its particular learning algorithm contribute to this superiority. During learning, subjects' performance reflected both category base rates and feature (symptom) probabilities in a nearly optimal manner, a result predicted by both models, though more accurately by the network model. However, under some test conditions, the data showed substantial base-rate neglect, in agreement with Gluck and Bower (1988b).     

Beliefs and inferences: A test of a rational-emotive hypothesis 1. Performing in an academic seminar

Subjects were asked to imagine that they were going to present an academic seminar. They were further asked to imagine (a) that they adhered to a rational belief or an irrational belief; (b) that they had made or had not made an effort in preparing for the seminar and (c) that their performance counted or did not count towards their final examination grade. Whilst in role, subjects were asked to make inferences about various aspects of their performance and the responses of others. While the results supported the hypothesis that imagining that one is holding an irrational belief leads to more negative inferences than holding a rational belief, it was also found that not making an effort in preparing for the siminar led subjects to make more negative inferences than making an effort. In addition, there were several two-way and three-way significant interactions between the independent variables. The results supported Ellis's (1985) recent formulation concerning the complex relationship between events and inferences (A), beliefs (B) and emotional and behavioral consequences of beliefs (C).Windy Dryden PhD is Senior Lecturer in the Department of Psychology, Goldsmiths' College, University of London, England. Julia Ferguson is Research Assistant in the Department of Psychology, Goldsmiths' College, University of London, England. Tony Clark was an Undergraduate Student in the Department of Psychology, Goldsmiths' College, University of London, England. He graduated in 1987.     

Profile analysis of standardized intelligence test performance of very low functioning individuals

Practitioners are frequently faced with the need to evaluate the intellectual skills of individuals with very low levels of functioning. Owing to the statistical rarity of these persons, few tests have sufficient range of scores for a detailed analysis of intraindividual differences in performance. This paper describes a method that uses are equivalents and standard scores to recreate the full range of variability in the scores of low-functioning individuals. The method allows for a more complete interpretation of performance that can lead to better educational and therapeutic programming.     

Neuroticism,life stress and concern about eating,body weight and apperance in a non-clinical population

Studies with clinical populations have shown a high level of neuroticism amongst those with an eating disorder. It is unclear however whether the elevated neuroticism is a function of the disorder, or if it is an aetiological factor in the disorder's development. The present survey of a non-clinical female population revealed that those high in neuroticism gave higher—but not abnormally high—scores on a measure of concern about eating. The high-N group also reported a significantly greater number of undesirable life events; a greater familiarity with ‘diet literature’; increased dieting; but no difference in body weight from those in the middle and lower ranges on the N scale. On the basis of these findings it is suggested that neuroticism is an aetiological factor in disordered eating, at least with secondary if not primary disorders. It is propesed that neuroticism is one mediating psychological factor in a triadic relationship between personal environment contingencies, socio-cultural pressures for thinness and psychological variables. Suggestions are made for future investigation of the role of neuroticism in eating disturbance, with note of potential therapeutic application of such knowledge.     

Separate verbal memory and naming deficits in attention deficit disorder and reading disability

In this study, verbal memory and naming abilities were investigated in reading disabled (RD) and control children who were characterized according to the presence or absence of attention deficit disorder (ADD). Results indicate that deficits in learning and memory for recently acquired information occur as a function of ADD rather than RD while deficits in naming are specific to RD rather than ADD. We conclude that ADD is a major source of additional and separate cognitive morbidity in RD children.     

The type a behavior pattern and the need to prove oneself: A correlational study

This study set out to investigate the relationship between the Type A behavior pattern, the need for approval, and the need to prove oneself. One hundred and two subjects completed four questionnaires: two measuring A-type behavior, one social desirability, and one—especially devised for this study—the belief in the need to prove oneself consistently. Results showed that Type A’s have significantly lower needs for approval than Type B’s, yet appear to show considerably greater interest in comparing their achievements with others. It seems that Type A’s do not have any special need to prove their worth to others, but that they must constantly prove themselves to themselves. Limitations of this preliminary study are discussed.     

Similarity and uniqueness: the effects of attribute type, relevance, and individual differences in self-esteem and depression

On the basis of a self-validation perspective, it was predicted that distortions in consensus estimates would vary as a function of attribute type (opinions versus abilities), relevance of the attribute, and individual differences in self-esteem and depression. Students rated themselves on seven opinion and ability dimensions using 5-point Likert scales. Then they estimated the percentage of the other students who held each opinion/ability position, and rank ordered the opinions/abilities for personal relevance. Absolute and directional accuracy scores were computed (comparing estimated percentages with actual percentages in the sample), as well as false consensus (FCE) scores (comparing estimates of subjects holding and not holding a particular position). Subjects overestimated consensus for their opinions and low abilities, but underestimated consensus for their high abilities. Although subjects exhibited a larger FCE on opinions than abilities, there was a reliable FCE for both attributes. Relevance affected the magnitude of these biases. Higher opinion relevance was associated with increased accuracy, lower FCE scores, and smaller overestimates. Higher ability relevance was associated with decreased accuracy, greater overestimation on low abilities, and greater underestimation on high abilities. Finally, low self-esteem and depressed subjects overestimated consensus on opinions and underestimated consensus on abilities less than high self-esteem and nondepressed subjects.