Response conformity in recognition testing

In a recognition memory test for a just-studied word list, subjects responded positively or negatively to each test word in the presence of another subject, with the two taking turns to call out their responses. Responses given second tended to conform to those given first. This was so for responses to both targets and lures and following both positive and negative first responses, although the effect was sharply reduced for targets given a negative first response. The same pattern of results was obtained in a second experiment, in which an incognito confederate replaced one of the subjects and so brought one set of responses under full experimenter control. These experiments illustrate a powerful effect of social pressure on recognition responses.     

Adjunctive brainstem behaviors in the rat

Adjunctive behaviors refers to behaviors that are “out of context” and/or excessive in amount. The terminology was first used for unexplained behaviors associated with food pellet ratio contingencies in food deprived rats (Falk, 1971). Clinically, unrelated and complex excessive behaviors were also noted with brainstem and diencephalic discharges (Andy, 1986, 1989 and 1995; Andy and Jurko, 1986). The objective of this study was to develop a model of brainstem generated adjunctive behaviors in the rat. Method: Sixty-one adult rats were used. Kindling was induced by mechanical and DC electrical perturbations in the midbrain. Nine different treatment groups were established in which lesions and drugs were used separately and in different combinations. Cocaine was used to accentuate, and dextrorphan to attenuate the kindling process. Behaviors were visually analyzed and recorded by video camera; they were not quantified. DC stimulation and EEGs were done with Grass instruments. Recording and stimulation sights were verified histologically. Results: A total of 45 different behaviors were elicited. DC stimulation kindled subjects had significantly more behaviors than did electrode insertion alone and cocaine alone. However, cocaine combined with DC stimulation increased the number and intensity of the kindled behaviors. Dextrorphan tended to facilitate catatonic and sleep states. Behaviors occurred randomly and were unrelated, even when they occurred in clusters. The behaviors were associated with four abnormal EEG discharge patterns. Conclusion: We speculate that brainstem behaviors are innate adjunctive drives that are generated in the brainstem reticular formation. They are monitored by the cortex and partially modified by environmental and cortical inputs.     

‘Attentional Bias’ in correlation judgments? Smedslund (1963) revisited

Smedslund (1963) reports one of the first studies that investigated human judgments of correlation. Smedslund's conclusion, that people reason about correlation mostly from a consideration of the number of times two variables co-occur, has become textbook wisdom (e.g. Baron's "attentional bias", 1994). Yet the data reported in Smedslund's paper fall short of endorsing such a conclusion. After reviewing the original paper, we present the method with which we replicated Smedslund's main experiment. In Experiment 1 subjects were presented with symptom-disease correlation data through a simulated medical diagnosis task. Subjects clearly discriminated between data sets which shared an equal number of symptom-disease co-occurrences but which otherwise showed different levels of correlation. Subjects' diagnoses showed a propensity to predict the disease in the presence of the symptom, and symptom-disease co-occurrences were overestimated in two of the five data sets presented to the subjects. Experiment 2 used a novel abstract scenario with a symmetric predictor variable. Judgments again indicated good discrimination, and biases in prediction responses and case recall were eliminated. In both experiments, judgments of zero correlation were a function of the outcome base rate. We evaluate and contrast the extent to which Cheng's (1997) model of causal induction and two associative models, Rescorla and Wagner (1972) and Pearce (1987) can anticipate the observed pattern in the mean judgments.     

Recognition failure of words with a single meaning

Recognition failure of recallable words was demonstrated with single-meaning target words after a 7-day retention interval. When overall levels of recognition were equated, the magnitude of the effect was the same as that observed with high-frequency words of multiple meanings in other experiments. It was concluded that, contrary to suggestions of Reder, Anderson, and Bjork (1974), encoding specificity is not limited to words that have several semantic senses. The experiment also provided evidence contrary to the hypothesis that recall of unrecognized items comes about because of additional learning opportunities afforded by the recognition test.     

Depression,restraint and eating behavior

Contrary to the belief that weight loss is a principal symptom of depression, several recent studies have suggested that certain people gain rather than lose weight when depressed. The present experiment concerned the effects of experimentally induced mood states on the eating behavior of high- and low-restraint persons. Sixty-eight female undergraduates were randomly assigned to one of three groups each designed to induce a different mood state (depressed, neutral or elated), and were classified as high or low restraint based on their responses to a questionnaire. During the mood induction procedure subjects were provided with the opportunity to eat. High-restraint persons induced into a depressed mood ate significantly more than high-restraint persons induced into neutral or elated moods, and more than low-restraint persons induced into a depressed mood. This effect was most prominent among subjects who scored high on the weight-fluctuation factor of the restraint scale. There was no evidence that this effect occurred among subjects who scored high on the concern for dieting factor. The role of emotional arousal on the self-control over eating behavior of high weight-fluctuation persons, and the implications of these findings for the evaluation of depression were discussed.     

SEX ROLE PERCEPTIONS OF FILIPINO ADOLESCENTS*

Sex role perceptions of 118 male and 118 female Filipino adolescents with respect to self-esteem and locus of control were investigated under two sets of instructions: (a) a standard set and (b) a set in which subjects were asked to respond as they thought a pupil at the same school and in the same academic year but of the opposite sex would respond. Evidence of the positive self-perceptions of Filipino adolescent males relative to females came from responses to both sets of instructions. On the locus of control scale, females perceived themselves to be more internal than males under standard instructions. Both sexes tended to attribute less internal control to the opposite sex than to themselves but again this tendency was much stronger for the males. The results are discussed in the context of previous U.S. and Filipino research.     

The opponent-process theory of motivation: VIII. Quantitative and qualitative manipulations of food both modulate adjunctive behavior

The present studies extend the opponent-process theory of acquired motivation to the schedule-induced polydipsia paradigm and more generally to adjunctive behavior. The theory suggests that manipulations of the quality and the size of the pellet presented on an intermittent schedule should be important modulators of polydipsia. In Experiment 1, presenting animals with preferred, less preferred, or least preferred food pellets on a fixed-time 120-sec schedule resulted in progressively lower levels of water intake. In Experiment 2, the quality and size of the pellet were manipulated factorially. These variables were found to interact in the control of both the development and maintenance of schedule-induced drinking. Thus, predictions from the opponent-process theory were supported by these findings.     

A game-based formal system for Ł∞

A formal system for , based on a game-theoretic analysis of the ukasiewicz prepositional connectives, is defined and proved to be complete. An Herbrand theorem for the predicate calculus (a variant of some work of Mostowski) and some corollaries relating to its axiomatizability are proved. The predicate calculus with equality is also considered.     

A portable micro-based system for the study of associated movements

This paper describes a microcomputer-based system for the on-line study of associated movements. The system is portable, provides hard copy, includes a backup system, is relatively inexpensive, can be used with simple or choice reaction time paradigms, and is simple to operate.