A System for Relational Reasoning in Human Prefrontal Cortex

The integration of multiple relations between mental representations is critical for higher level cognition. For both deductive- and inductive-reasoning tasks, patients with prefrontal damage exhibited a selective and catastrophic deficit in the integration of relations, whereas patients with anterior temporal lobe damage, matched for overall IQ but with intact prefrontal cortex, exhibited normal relational integration. In contrast, prefrontal patients performed more accurately than temporal patients on tests of both episodic memory and semantic knowledge. These double dissociations suggest that integration of relations is a specific source of cognitive complexity for which intact prefrontal cortex is essential. The integration of relations may be the fundamental common factor linking the diverse abilities that depend on prefrontal function, such as planning, problem solving, and fluid intelligence.     

Processing order in visual perception

Initial increases in the availability of items for report following tachistoscopic presentation of centrally-fixated rows of seven random letters were directly evaluated by measuring report accuracy following exposure durations of 10, 20, 40, 80 and 160 ms. A partial-report technique was used, and each presentation of a letter row was immediately followed by the presentation of a masking stimulus. Each of 10 subjects received 840 trials which reflected 24 trials for each exposure-duration by position-probed combination. The letters at both ends of a row became available for report prior to the centre letters. In addition, report of the left-most letter was consistently better than report of the right-most letter, and report of the centre item at fixation improved at a more rapid rate with increased exposure duration than report of the other centre letters. This pattern of results provides support for certain components of several different previous proposals concerning the order in which individual items from multi-element displays become available for report.     

Predicting outcome of insanity acquittees released to the community

This research developed a model for forensic release decisions that incorporated actuarial and psychiatric predictors. The model was based on research that compared 127 insanity acquittees in the State of Maryland with a matched control group of 127 convicted felons and a comparison group of 135 mentally disordered prison transfers. The three cohorts were followed for an average of 10 years after release from hospital or prison. Findings on two outcome indicators are reported in this article: rearrests within 5 years after release and overall functioning in the community during 2½ years after release. Discriminant analysis was performed on the outcome variable of rearrest; it was found to accurately predict the outcome of 75% of the subjects with the following six variables: adjustment in hospital, clinical assessment of hospital staff, Global Assessment Scale score at release, functioning prior to instant offense, heroin addiction, and birth order. A second discriminant analysis identified seven variables that accurately predicted the overall functioning of 80.4% of the insanity acquittees.     

Hyperactive children and peer interaction: Knowledge and performance of social skills

This study investigated hyperactive children's peer relations using the framework of social skills theory. Subjects' (15 hyperactive and 15 control boys aged 7 through 11) knowledge of socially appropriate behavior was assessed using the Social Knowledge Interview (Geraci & Asher, 1980). Additionally, performance of social skills with peers was rated by independent judges during free play, a cooperative puzzle task, and a persuasion task. Peers also rated subjects'desirability as partners for work, play, and friendship. Analyses showed that hyperactive subjects had deficits in knowledge of how to maintain relationships and handle interpersonal conflict, and demonstrated more negative behavior in the cooperative puzzle task than did controls. Hyperactive subjects also were rated by judges as less likely to achieve academic success than controls and were rated by peers as less desirable potential work partners in school. Significant correlations between social knowledge and performance with peers were found. It was concluded that hyperactive boys exhibit deficits both in their social knowledge and in their performance of socially skilled behavior.This research was conducted as part of doctoral research by the first author, under the supervision of the second and third authors. We are grateful for the assistance of Diane Arnkoff, who served on the committee, for her helpful comments and suggestions. Thanks also go to Al Farrell for his statistical consultation. We gratefully acknowledge the support and assistance of the Georgetown University Child Development Center, where the data were collected.     

A Panel Study of Subjective Expected Utility for Adolescent Sexual Behavior1

The relationship between subjective expected utility (SEU) for intercourse and sexual behavior was examined in a 3-year panel study of adolescents. Linear structural equation models were used to evaluate the causal priority of these variables for 225 junior high school students. Panel data allowed this examination, which is not possible in more common cross-sectional studies. It was found that SEU had a significant relationship to subsequent sexual behavior in each of the 1-year intervals, but intercourse was significantly related to subsequent SEU in only the first interval. This pattern was explained as a result of the process of development of utility during adolescent initial experience with sexual behaviors.     

Are there developmental differences in reality-monitoring?

The question addressed by the present experiment is whether the ability to distinguish between veridical and imaginal memory representations changes with age. Second-grade, fourth-grade, and sixth grade children (8, 10, and 12 years old) and college students were shown pictures of familiar objects. Each picture was presented one, two, or three times and, interspersed with these presentations, subjects were asked to imagine each picture zero, one, or three times. Subsequently they were asked to judge the presentation frequency of each picture. For all groups, imagining the pictures resulted in inflated estimates of event frequency. However, contrary to the idea that children have a particularly difficult time discriminating externally generated from internally generated memories, one analysis indicated adults were actually somewhat more affected than children by the imagination trials.     

Repetition of cues in children's oddity learning and transfer

The hypothesis that repetition of specific cues interferes with oddity learning was directly tested by comparing two groups of preschool (3 to 5 years of age) children, one with repeated cues and the other with new cues on every trial. Repetition of cues retarded oddity learning confirming previous speculation based on error analyses. Performance on postsolution transfer trials with repeated cues was not affected by conditions of acquisition. Significant age effects were found in oddity acquisition, while there was only weak evidence for agerelated performance differences on transfer trials. Transfer performance on trials with repetition of cues was not related to whether or not the children were informed of such repetition. The results were related to theories of oddity acquisition and transfer.