Application of operant conditioning procedures to the behaviour problems of an autistic child

An account is given of the treatment of a pre-school child who had serious behavioural and physical handicaps. In a sense this is a study involving both psychotherapy and rehabilitation. The treatment consisted of applying laboratory-developed techniques through the attendants and the parents over a seven-month period.     

Costs and benefits in perceptual categorization

Observers categorized perceptual stimuli when the category costs and benefits were manipulated across conditions, and costs were either zero or nonzero. The cost-benefit structures were selected so that performance across conditions was equivalent with respect to the optimal classifier. Each observer completed several blocks of trials in each of the experimental conditions, and a series of nested models was applied to the individual observer data from all conditions. In general, performance became more nearly optimal as observers gained experience with the cost-benefit structures, but performance reached asymptote at a suboptimal level. Observers behaved differently in the zero- and nonzero-cost conditions, performing consistently worse when costs were nonzero. A test of the hypothesis that observers weight costs more heavily than benefits was inconclusive. Some aspects of the data supported this differential weighting hypothesis, but others did not. Implications for current theories of cost-benefit learning are discussed.     

Social complexity can drive vocal complexity: group size influences vocal information in Carolina chickadees

One hypothesis to explain variation in vocal communication in animal species is that the complexity of the social group influences the group's vocal complexity. This social-complexity hypothesis for communication is also central to recent arguments regarding the origins of human language, but experimental tests of the hypothesis are lacking. This study investigated whether group size, a fundamental component of social complexity, influences the complexity of a call functioning in the social organization of Carolina chickadees, Poecile carolinensis. In unmanipulated field settings, calls of individuals in larger groups had greater complexity (more information) than calls of individuals in smaller groups. In aviary settings manipulating group size, individuals in larger groups used calls with greater complexity than individuals in smaller groups. These results indicate that social complexity can influence communicative complexity in this species.     

Editing (out) generated study words in a recognition exclusion task: Effects of response signal delay and generation procedure

Three experiments investigated participants' ability to exclude generated study words from "old" judgements on an exclusion task in which a response signal delay (RSD) was manipulated. In Experiment 1, words were generated by mentally conjoining components of two compound words, and a conjunction test condition was included (e.g., presentation of the lure checkpoint after studying checklist and needlepoint without generating the target). The exclusion error rate for generated words was higher than the conjunction error rate for a short RSD group but lower than the conjunction error rate for a long RSD group. The decrease in the familiarity effect across RSDs was extended to a conceptual cue generation procedure in Experiments 2 and 3, but an anagram generation procedure did not show similar evidence of recollection-based exclusions. The earliest indication of recollection-based editing of generated words occurred in a 2250-ms RSD (Experiment 3). An extension of a multi-factor transfer appropriate processing theory (deWinstanley, Bjork, & Bjork, 1996) of generation effects that incorporates influences of familiarity and recollection is advocated.     

Psychosocial Adaptation to Chronic Illness and Disability: A Preliminary Study of its Factorial Structure

This study examined the factorial structure of psychosocial adaptation to chronic illness and disability in a sample of 313 individuals who sustained spinal cord injury (SCI). Three models were examined. The first model tested the hypothesis that psychosocial adaptation is composed of a single, global factor, in which positive (adaptive) and negative (nonadaptive) reactions define two opposing poles of the same dimension. The second model tested the validity of two distinguishable factors, representing adaptive and nonadaptive dimensions. The third model examined the relationship between the 2-factor model and a third dimension, that of denial. The data from the instruments measuring psychosocial adaptation to trauma and disability (the Reactions to Impairment and Disability Inventory and the Purdue Posttraumatic Stress Disorder-Revised) were submitted to a series of confirmatory factor analyses, and the results from the goodness of fit tests and fit indices provided strong support to the validity of the latter two models. The findings indicated that the structure of adaptation to SCI can be best conceptualized as representing two, moderately linked but clearly distinguishable, factors and that the construct of denial of disability further elucidates our understanding of the structure of adaptation to loss of body integrity.

When do auditory/visual differences in duration judgements occur?

Four experiments examined judgements of the duration of auditory and visual stimuli. Two used a bisection method, and two used verbal estimation. Auditory/visual differences were found when durations of auditory and visual stimuli were explicitly compared and when durations from both modalities were mixed in partition bisection. Differences in verbal estimation were also found both when people received a single modality and when they received both. In all cases, the auditory stimuli appeared longer than the visual stimuli, and the effect was greater at longer stimulus durations, consistent with a “pacemaker speed” interpretation of the effect. Results suggested that Penney, Gibbon, and Meck's (2000) “memory mixing” account of auditory/visual differences in duration judgements, while correct in some circumstances, was incomplete, and that in some cases people were basing their judgements on some preexisting temporal standard.     

Do we know how we cope? Relating daily coping reports to global and time-limited retrospective assessments

The current study examined the concordance among daily, trait (global retrospective), and time-limited retrospective reports of coping. A sample of 93 adults completed the COPE (C. S. Carver, M. F. Scheier, & J. K. Weintraub, 1989) prior to recording coping with the day's most negative event for 30 consecutive days. At the end of daily data collection, participants recalled to what extent they used each of 16 coping strategies over the past 30 days. Whereas findings indicate generally good concordance between daily and time-limited retrospective reports, concordance between global and daily reports was weak. Only limited evidence was found for systematic individual differences in concordance. Time-limited reports appear to be an adequate, though not ideal, method of determining usual patterns of coping with stress.     

Sociotropy and perceptions of interpersonal relationships as predictors of eating disturbances among college women: two prospective studies

The authors examined the relationship between sociotropy and perceptions of interpersonal relationships and subsequent eating disorder symptoms among young women. In Study 1, 118 women from a liberal arts college in northern Wisconsin completed self-report measures of sociotropy, perceived close social support, and eating disorder symptoms. The women returned 6 weeks later to complete the same measures. After controlling for initial levels of reported eating disturbances, higher levels of Time 1 sociotropy and reductions in perceived social support at Times 1 and 2 made unique contributions to eating disturbances at Time 2, although the interaction of Time 1 sociotropy and Time 2 social support did not add to the model. In Study 2, 138 women completed measures of eating disturbances, sociotropy, and interpersonal hassles on two occasions, 10 weeks apart. Self-reported eating pathology at Time 1 accounted for most of the variance in Time 2 eating disorder symptoms, but increased eating disturbances also were predicted by measures of interpersonal hassles. A final regression analysis using combined samples indicated that both T1 and T2 measures of interpersonal functioning made unique contributions to changes in reported eating disturbances. In sum, the findings suggested that perceptions of reduced support in close relationships and increased interpersonal hassles contribute to increases in reported eating disturbances among college-aged women, independent of baseline levels of eating disturbances and a highly sociotropic personality style.     

Effects of category diversity on learning,memory, and generalization

In this study, we examined the effect of within-category diversity on people's ability to learn perceptual categories, their inclination to generalize categories to novel items, and their ability to distinguish new items from old. After learning to distinguish a control category from an experimental category that was either clustered or diverse, participants performed a test of category generalization or old-new recognition. Diversity made learning more difficult, increased generalization to novel items outside the range of training items, and made it difficult to distinguish such novel items from familiar ones. Regression analyses using the generalized context model suggested that the results could be explained in terms of similarities between old and new items combined with a rescaling of the similarity space that varied according to the diversity of the training items. Participants who learned the diverse category were less sensitive to psychological distance than were the participants who learned a more clustered category.     

The neurobiology of adaptive learning in reading: A contrast of different training conditions

fMRI was used to investigate the separate influences of orthographic, phonological, and semantic processing on the ability to learn new words and the cortical circuitry recruited to subsequently read those words. In a behavioral session, subjects acquired familiarity for three sets of pseudowords, attending to orthographic, phonological, or (learned) semantic features. Transfer effects were measured in an event-related fMRI session as the subjects named trained pseudowords, untrained pseudowords, and real words. Behaviorally, phonological and semantic training resulted in better learning than did orthographic training. Neurobiologically, orthographic training did not modulate activation in the main reading regions. Phonological and semantic training yielded equivalent behavioral facilitation but distinct functional activation patterns, suggesting that the learning resulting from these two training conditions was driven by different underlying processes. The findings indicate that the putative ventral visual word form area is sensitive to the phonological structure of words, with phonologically analytic processing contributing to the specialization of this region.