Perceptual learning in maze discriminations

In Experiment 1, rats were trained on a discrimination between rubber- and sandpaper-covered arms of a maze after one group had been pre-exposed to these intra-maze cues. Pre-exposure facilitated subsequent discrimination learning, unless the discrimination was made easier by adding further discriminative stimuli, when it now significantly retarded learning. In Experiment 2, rats were trained on an extra-maze spatial discrimination, again after one group, but not another, had been pre-exposed to the extra-maze landmarks. Here too, pre-exposure facilitated subsequent discrimination learning, unless the discrimination was made substantially easier by arranging that the two arms between which rats had to choose were always separated by 135°. The results of both experiments can be explained by supposing that perceptual learning depends on the presence of features common to S+ and S-.     

Frequency selectivity for hearing-impaired and broadband-noise-masked normal listeners

When evaluating frequency selectivity, it is difficult to determine if the deviation from normal performance observed for hearing-impaired listeners reflects abnormal cochlear function or normal, level-dependent changes in frequency selectivity. This experiment was designed to investigate the dependence of frequency-selectivity measures on threshold and signal level. Auditory-filter characteristics, critical ratios, forward-masked psychophysical tuning curves, and narrowband-noise masking patterns were obtained from normal-hearing listeners in quiet and in the presence of broadband noise at five levels. These findings were then compared to previously obtained frequency-selectivity measurements for subjects with mild-to-moderate sensorineural hearing loss whose absolute thresholds are comparable to the normal-hearing listeners' masked thresholds. The results suggest that frequency selectivity deterioriates as threshold increases for all subjects. However, the poor frequency selectivity exhibited by hearing-impaired listeners may not be explained entirely by the effects of threshold and signal level. Nevertheless, because frequency selectivity is poorer in the normal auditory system at higher stimulus levels, the deviation from normal performance observed for hearing-impaired listeners may not be as large as previously suggested.     

Childhood peer rejection,aggression, withdrawal,and perceived competence as predictors of self-reported behavior problems in preadolescence

Childhood peer rejection, aggression, withdrawal, and perceived competence were compared as predictors of self-reported behavior problems. Peer sociometric status (Coie, Dodge, and Coppotelli, 1982), teacher ratings of behavior problems (Lorion, Cowen, & Caldwell, 1975), and perceived competence ratings (Harter, 1982) were obtained for 613 second-through fourth-grade children. Two years later, these students completed a modified version of the Youth Self-Report form (Achenbach & Edelbrock, 1987). Rejected children and neglected girls were more likely to have a self-reported nonspecific negative outcome than others. Neglected girls were at heightened risk for depression. A varied set of predictors obtained from different informants emerged for each sex for each of the specific self-reported outcomes of depression, unpopularity, delinquency, aggression, and self-destructive/identity problems. Results are discussed in terms of future directions for longitudinal research on the consequences of poor peer relationships in childhood.This research was supported in part by a grant from the W. Alton Jones Foundation and in part from Cooperative Agreement (G0087C3033) between the U.S. Department of Education, Office of Special Education and Rehabilitative Services, and the University of Virginia. However, the opinions expressed herein do not necessarily represent the opinions of the funding agencies. Portions of this paper were presented at the First Annual Meeting of the Society for Research in Child and Adolescent Psychopathology, Miami, Florida. The authors would like to thank Robert Terry, Ruth Axman, Pamela Griesler, Melissa DeRosier, Nancy Vaden, Charlene Eickholt, Amy Young, Emily Burhans, Eric Johnson, Renee Lorio, and Karen Welke for their assistance in conducting this research project.     

Microsecond resolution timing with Sun workstations

A high-resolution clock is often indispensable for the accurate measurement of millisecond or microsecond resolution intervals, and it is impossible to measure the probability distribution of short intervals without one. This paper describes a microsecond clock for Sun 3 and 4 workstations that we designed, built, and have made publicly available. It also explains how to measure intervals shorter than a computer’s clock resolution, and derives confidence intervals for such measurements.     

Sex and Race Bias in Employment Decisions: Black Women Considered

The purpose of this investigation was to explore sex and race discrimination in employment at the managerial level, with special focus on Black women.     

Personality Characteristics and Self-esteem in Pet Owners and Non-owners

Previous research suggests that pet owners are psychologically different than non-owners in terms of self-esteem and other personality characteristics. In this study, 82 pet owners and 48 non-owners were tested on self-esteem, extraversion, neuroticism, and social self-esteem. Special emphasis was placed on highly attached pet owners compared with non-owners. Level of attachment was determined by scores from the CENSHARE pet attachment survey. No significant differences were found between the groups using analysis of variance and multivariate analysis of variance statistical procedures. It was concluded that pet owners and non-owners may not be different in terms of personality but may have become victims of stereotyping by both the general population and scientific researchers. Discussion was given to related significant findings and recommendations for further research.     

The Mystery Spot Illusion and its Relation to Other Visual Illusions

Observations at The Mystery Spot, a roadside attraction near Santa Cruz, California, suggest intriguing visual illusions based on tilt-induced effects. Specifically, a tilted spatial background at The Mystery Spot induced misperceptions of the orientation of the cardinal axes (i.e., true horizontal and vertical), which then led to illusions in the perceived height of twoindividuals. This illusion was assessed at The Mystery Spot and replicated in the laboratory using pictorial and lined displays rotated in the picture plane. These findings are described in terms of the orientation framing theory, which suggests that these and other tilt-induced illusions (e.g., Ponzo illusion, Zöllner illusion) can be attributed to distorted frames of reference.     

The Humanizing Brain: An Introduction

The rediscovery of the sacred needs to take into account the neural underpinnings of faith and meaning and also draw on the insights of the emerging discipline of complexity studies, which explore a tendency toward adaptive self-organization that seemingly is inherent in the universe. Both neuroscience and complexity studies contribute to our understanding of the brain's activity as it transforms raw stimuli into recognizable patterns, and thus "humanizes" all our perceptions and understandings. The brain is our physical anchor in the natural environment— and its human capacities orbit us into the emerging world of culture (including religion), which provides a template for the brain's function of making sense of an ambiguous reality. The humanizing brain holds together scientific causality and religious meaning, working both bottom-up (linking the physical and the experiential) and top-down (beginning with the whole of things, or God). These processes we know as "mind" (experienced as intentionality, subjective consciousness, empathy, imagination, memory, adaptability). We maintain that such processes are not only subjective but built into "the way things really are." Thus, they carry the most privileged information about the nature of reality to which we human beings have access. For not only are we humans observers and logicians, but we are embedded in the larger reality; and as we strive to make sense of it all, we become both Homo sapiens and Homo religiosus .