Spatial judgments in the horizontal and vertical planes from different vantage points

Todorovi? (2008 Perception 37 106-125) reported that there are systematic errors in the perception of 3-D space when viewing 2-D linear perspective drawings depending on the observer's vantage point. Because these findings were restricted to the horizontal plane, the current study was designed to determine the nature of these errors in the vertical plane. Participants viewed an image containing multiple colonnades aligned on parallel converging lines receding to a vanishing point. They were asked to judge where, in the physical room, the next column should be placed. The results support Todorovi? in that systematic deviations in the spatial judgments depended on vantage point for both the horizontal and vertical planes. However, there are also marked differences between the two planes. While judgments in both planes failed to compensate adequately for the vantage-point shift, the vertical plane induced greater distortions of the stimulus image itself within each vantage point.     

Event asynchrony and signal regularity in sustained attention

Subjects monitored the repetitive presentation of a vertically oriented line of light (background events) for occasional increments in the height of the line (critical signals). Signals for detection occurred in either a temporally regular or an irregular manner and were blended within a background of temporally synchronous (regular) or asynchronous (irregular) background events. The vigilance decrement, as reflected by a decline in perceptual sensitivity (A‘), during the watch was eliminated when critical signals appeared regularly within a synchronous event context. By contrast, in the context of event asynchrony, regular signal appearances exacerbated the decrement. The results highlight the importance of event asynchrony as a factor in vigilance performance, and link vigilance to a growing list of psychological processes that are dependent upon contextual rhythmicity. This report was completed while Joel S. Warm was a National Science Foundation senior postdoctoral fellow at the National Institute of Occupational Safety and Health Taft Laboratory, Cincinnati, Ohio.     

Reward dominance and passive avoidance learning in adolescent psychopaths

This study tests predictions that adolescent psychopaths are hyperresponsive to rewards (Quay, 1988) and deficient in passive avoidance learning (Newman & Kosson, 1986). Forty male adolescent juvenile offenders were divided into psychopaths and nonpsychopaths using cluster analysis. Subjects were administered a passive avoidance learning task which required learning when to respond to cards associated with either reward or punishment. Results showed a greater responsivity to reward in psychopaths, with no group differences in passive avoidance errors. Results lend support to the view that psychopaths tend to focus on the prospect of reward under conditions of mixed incentives and, when sufficiently motivated, are capable of improved performance. Together with findings of recent psychophysiological studies, these results suggest that adolescent psychopaths may have latent abilities which could have treatment implications.The authors are greatly indebted to the boys and staff of the testing institution for their kind cooperation in this study. Thanks are also due to Dr. Rand Wilcox for statistical consultation and Cheryl Eurton and Marni Ayers for assistance in data coding.     

Reduced lateralization in verbal dichotic listening in adolescent psychopaths

One possible explanation for previous findings of abnormal linguistic processing in psychopaths is that they are less lateralized for verbal processes. This study tests the hypothesis that adolescent psychopaths show evidence of reduced lateralization on a verbal dichotic listening task. Four self-report and behavioral measures of psychopathy were used to define psychopathy using cluster analytic techniques in 40 juvenile offenders aged 13 to 18 years. Psychopaths were found to have reduced ear asymmetries relative to nonpsychopaths, a result indicating reduced lateralization for verbal material. The effect does not appear to be mediated by group differences in age, ethnic background, IQ, overall performance, left-handedness, selective attention to one ear, or interhemispheric transfer deficits. This result suggests that the previous finding by Hare and McPherson is robust, provides some preliminary validity for the assessment of psychopathy before age 18, and indicates initial support for the utility of cluster analytic techniques in the assessment of psychopathy.