Distributed and massed practice effects on motor performance and learning of autistic children

The purpose of this study was to examine the effect of massed and distributed practice upon the learning by 8 autistic children of rotary pursuit tracking at 20 rpm. The massed practice group of four completed 10 30-sec. trials with 5-sec. rests for 10 consecutive days on the Photoelectric Pursuit Rotor. The distributed practice group completed 10 30-sec. trials with 30-sec. rests for 10 consecutive days on the same device. The results of a 2 x 10 x 10 (group x practice days x trials) analysis of variance with repeated measures on the last two factors indicated that learning occurred for both groups but no differences between groups were significant. It is suggested that further investigations into the applicability of motor learning principles to special populations be conducted using larger groups.     

Creating new memories that are quickly accessed and confidently held

In two experiments involving a total of 542 subjects, a series of slides depicting a burglary was shown. After the initial event, subjects were exposed to one or more narratives about the event that contained some misinformation or neutral information about four critical details. Finally, subjects were tested on their memories of what they saw, and their reaction times and confidence levels were measured. When subjects took a standard test in which the misinformation item was a possible response option, they responded very quickly and confidently when making this incorrect choice. Misled subjects responded as quickly and confidently to these "unreal" memories as they did to their genuine memories. It does not seem, then, that the misinformation effect arises from a large proportion of subjects who must resolve a conflict between two memories when they are tested, a conflict that would be expected to take time. When subjects took a modified test in which the misinformation item was not a possible response, misled subjects were as accurate as were controls, but they responded more slowly, regardless of whether they ultimately chose the right or wrong option. These findings indicate that misinformation does introduce some form of interference not detected by a simple test of accuracy.     

Can dyslexia be treated? Treatment-specific and generalized treatment effects in dyslexic children's response to remediation

A total of 178 reading disabled children were randomly assigned to one of three treatment conditions providing training in word recognition and decoding skills (DS), oral and written language (OWLS), or classroom survival skills (CSS. an alternative treatment control). Pre- and post-treatment comparisons on an array of standardized and experimental measures indicated that the two experimental treatments (DS, OWLS) resulted in improvement on selected tests significantly greater than that resulting from a third treatment intervention which controlled for treatment time and individual attention (CSS). Effects specific to each experimental treatment were identified, as well as some generalized treatment advantages shared by both experimental groups at post-test. These results indicate that some of the deficits associated with developmental dyslexia are amenable to treatment. Greater generalization of treatment effects was observed following the DS than the OWLS treatment. While DS-instructed children exhibited better word recognition skills, however, their knowledge of grapheme-phoneme correspondence rules was not improved. Several OWLS-specific effects observed on experimental reading and language measures were not replicated on standardized tests which purport to measure the same skills. These results are discussed with respect to (i) possible mechanisms by which disabled readers may acquire word recognition skills, (ii) their failure to acquire and use grapheme-phoneme correspondence rules, and (iii) a possible reduced tendency in the present population to generalize newly acquired specific knowledge to related knowledge domains.     

Chronic stress, leukocyte subpopulations, and humoral response to latent viruses

Psychological stress has been shown to affect immune system status and function, but most studies of this relationship have focused on acute stress and/or laboratory situations. The present study compared total numbers of leukocytes and lymphocyte subpopulations (determined by flow cytometry) and antibody titers to latent and nonlatent viruses among a group of chronically stressed individuals living near the damaged Three Mile Island (TMI) nuclear power plant with those of a demographically comparable control group. Urinary catecholamine and cortisol levels were also examined. Residents of the TMI area exhibited greater numbers of neutrophils, which were positively correlated with epinephrine levels. The TMI group also exhibited fewer B lymphocytes, T-suppressor/cytotoxic lymphocytes, and natural killer cells. Antibody titers to herpes simplex were significantly different across groups as well, whereas titers to nonlatent rubella virus as well as IgG and IgM levels were comparable.     

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).     

Developmental and individual differences in preschoolers' recognition memories: The influences of gender schematization and verbal labeling of information

Eighty-three 37-92-month-old children's gender schematization and recognition memories for gender-typed content were assessed. Verbal labeling of stimuli and age were positively associated with children's memories. Highly gender schematic children displayed better memories for gender-role consistent information and committed more gender transformation errors than less gender schematic children. Interactions between children's gender schematization, age, and labeling condition were observed. Labeling of stimuli facilitated less schematic children's memories for gender-role consistent information. Gender schematization was positively associated with younger children's memories, suggesting younger children's memories are more strongly mediated by gender schematization than older children's. Results support the position that studies of gender schema development require an integrated approach recognizing individual and developmental differences in gender schematic processing.Completion of this project was facilitated by funds received while the author was a National Institute of Mental Health Postdoctoral Fellow at the University of Denver: Grant 5T32 MH 15780-09. This support is gratefully acknowledged. An earlier version of this paper was presented at the Conference on Human Development, Charleston, South Carolina, 1988. The author would like to thank the faculty and staff of the Tiny Tot, Jack & Jill, Little Learners II, Plymouth and Upstate preschools for their assistance and cooperation. The author wishes to recognize James Aber, Rosanne David, Melisa Shack, and Susan Zigelbaum for their exceptional service in conducting the project; and would also like to thank Joan Barth, D. Bruce Carter, Gail S. Goodman, Carol L. Martin, William J. Meyer, Kathy Park, Ralph J. Roberts, Jaipaul L. Roopnarine, Margaret L. Signorella, and the anonymous reviewers for their comments and suggestions on earlier drafts of this article.     

Recall by expert medical practitioners and novices as a record of processing attention

Using recall of clinical protocols as a measure of expertise in medicine has yielded disappointingly small effects. Experiments using recall of clinical laboratory data are presented to provide an explanation. In one experiment, subjects either deliberately memorized or first diagnosed and then were incidentally asked for memory. With incidental instructions, experts recalled over twice as much data as did students, but with memorization instructions, student performance approximated that of experts. Experts also showed a large advantage over students in incidental recall of data that were not relevant to the problem solution. These results suggest that expert processing in this "discrete, independent inputs" domain requires effortful analysis with minimal reliance on default values, rather than relatively effortless pattern perception reported in highly visual areas of expertise. For this area, intentional memory is a misleading measure of expertise. However, incidental memory is a valuable measure of processing during diagnosis.