Prism adaptation to dynamic events

In the present study, we explored adaptation to prism-displaced dynamic and static events under conditions of minimal information. Many of our interactions with the world are dynamic and involve reaching for or intercepting moving objects. The consequences (or feedback) of those interactions entail the presence or absence of physical contact with the moving objects. In this study, humans learned, with only heptic feedback, to intercept optically displaced falling balls. To eliminate visual feedback, the falling balls disappeared behind an occluder (which systematically varied in size across groups) prior to either striking or missing a subject's hand. As occluder size decreased, adaptation increased. With minimum occluder sizes, the greatest adaptation occurred around the training position, and adaptation decreased as distance between training and testing positions increased. The results can best be described in terms of a generalization gradient centered around the training position. This generalization gradient was not present when subjects were trained with ecologically similar static arrays. Implications for models of adaptation are discussed.     

Recovery of the US representation over time during extinction

Four experiments used a conditioned suppression procedure in rats to explore changes in the US representation over time during the course of extinction. They employed two previously reported effects: reinstatement of responding to an extinguished CS by separate US presentation, and the erasure of that effect by interposed nonreinforcement of a second excitatory CS. These effects have been interpreted as enhancing and depressing the US representation, respectively. Experiment 1 found the erasing effect to decrease but still to remain substantial after over a 4-day period, suggesting a partial recovery with time of a deliberately depressed US representation. Experiment 2 implicated this change as a contributor to the phenomenon of spontaneous recovery by showing that recovery to be sensitive to erasure effects. Experiments 3 and 4 found evidence for an interaction between the state of the US representation and the amount of associative change which results from nonreinforcement of an excitatory CS. When the US representation was strong, either because of reinstatement or the passage of time, nonreinforcement of a CS was especially effective in producing associative change. When the US representation had been depressed by erasure, those nonreinforcements produced relatively less associative loss. Moreover, these effects upon associations were reasonably stable in the sense that they left asymptotic differences in the strength of associations after extinction. Together with previous findings, these results point to an important role for the US representation in the performance and learning which occurs during extinction.     

A multiprocessor system for generating visual displays and controlling experiments

A laboratory is described that is based on an IMSAI 8080 microcomputer and an IMLAC graphics display system. Procedures for using the system are described and illustrated.     

Spatial contiguity facilitates Pavlovian second-order conditioning

Two experiments investigated the effects of spatial contiguity upon the formation of second-order conditioning in pigeon subjects. Experiment 1 used an autoshaping procedure to pair two visual stimuli, S2 and S1, after S1 had previously been paired with food. The resulting second-order conditioning of S2 was superior when both stimuli appeared on the same response key within a trial, compared with their appearing on different keys. Experiment 2 found a similar importance of spatial contiguity between S2 and S1 in a conditioned suppression paradigm. In addition, consistently presenting S2 and S1 in the same spatial location produced superior conditioning compared with varying their spatial relation from trial to trial. The design of these experiments was such as to imply that spatial contiguity facilitates performance by improving the formation of association rather than by promoting stimulus generalization or pseudoconditioning. Moreover, the observation of a facilitative effect of spatial contiguity between S1 and S2 in two different paradigms that use qualitatively different unconditioned stimuli and evoke different responses implies some generality for these findings. Consequently, these results suggest that spatially contiguous stimuli are especially associable in Pavlovian conditioning paradigms.     

Is there really very rapid forgetting from primary memory? The role of expectancy and item importance in short-term recall

In two experiments, subjects recalled one of two letter segments following a digit-filled retention interval. In Experiment 1, recall expectancy was manipulated by using precues that correctly informed or misinformed subjects concerning which letter segment wou;d be tested for recall. In Experiment 2, item importance was varied by precuing one segment as important but requiring that the uncued segment be recalled first. Recall performance was very low under conditions of low expectancy and low segment importance, but the slopes of the retention-functions did not demonstrate more rapid forgetting than under standard -conditions. The previous observations of very rapid forgetting from primary memory may be a function of an elevated initial recall level in the earlier studies. Our retention functions were compared with predictions of the Estes perturbation model. The findings suggested that when secondary memory processes were reduced, forgetting order information from primary memory occurred at the same rate as that estimated on the basis of previous studies using the standard distractor task.     

The influence of parenting stress and child behavior problems on parental estimates of expressive and receptive language development

This study examined the relative contributions of parental reports of child-related and parent-related stress to their estimates of expressive and receptive language skills on the Minnesota Child Development Inventory in 152 children referred to a communicative disorders clinic. Correlational analysis showed moderately high agreement between parental estimates and objective measures of expressive and receptive language ability. Multiple-regression analyses revealed that independent measures of language acquisition accounted for the greatest amount of variance in parental estimates of expressive and receptive language skills. Stressful child behavior accounted for a small but statistically significant proportion of the variance in estimates of expressive and receptive language skills. Parental stress, in contrast, did not contribute significantly to language estimates. These findings suggest that parents are able to formulate estimates of language development which are relatively independent of personal or child-related stressors.     

Cognitive variables related to suicidal contemplation in adolescents with implications for long-range prevention

In a series of studies with college and high school students (Total N=808) consistent and strong relationships were found between suicidal contemplation and the irrational beliefs considered by Rational-Emotive Theory & Therapy (RET) to underlie emotional distress. Suicidal contemplation was measured first by an item from the Beck Depression Inventory and subsequently by the Suicide Probability Scale. Irrational beliefs were measured by the Jones Irrational Beliefs Test and, in the third study, by the new Attitudes & Belief Scale-II as well. Groups formed on the basis of increasing indices of suicidal contemplation were found to be consistently, increasingly more irrational on both measures. Also groups created according to low, medium, and high levels of irrational beliefs (the B in RET) were found to be markedly different on C variables such as anxiety, depression, hopelessness, anger, psychosomoatic symptoms and suicidal contemplation. The findings were interpreted as strongly inferring a causational relationship from attitudes and beliefs to emotional distress and the contemplation of suicide. The implications of the findings for RET theory and for therapeutic and preventive strategies related to emotional distress and suicidal contemplation are clear. Other approaches to the explanation of suicide are cited and reference is made to a previous critical summary of them (Woods & Muller, 1988).Paul J. Woods, Ph.D., Co-Editor of this Journal, is a Fellow of the Institute for Rational-Emotive Therapy in New York City, a Professor of Psychology at Hollins College, and a Licensed Psychologist in independent practice in Roanoke, Virginia.Ellen S. Silverman, R. N., C. & M.A. collaborated in Study III for a Master's thesis at Hollins College. She is currently in a Ph.D. program in psychology at Virginia Polytechnic Institute & State University.Julia M. Gentilini, B. A. collaborated on Study I for an Honors' thesis in psychology at Hollins College.Deborah K. Cunningham, M. A. collaborated on Study II for a Master's thesis at Hollins College. She is currently in a Ph.D. program in psychology at the University of Memphis.Russell M. Grieger, Ph.D., Co-Editor of this Journal, is a Licensed Clinical Psychologist in independent practice in Charlottesville, Virginia, and a Fellow of the Institute for Rational-Emotive Therapy in New York City.     

The Importance of Perceived Body-Inclusiveness among Physically Active Women in Larger Bodies

Sex Roles - Despite the many benefits of physical activity, women participate less frequently than men do, and this is particularly the case among women in larger bodies. The purpose of the present...