On the nature of perceptual limits in vision

Summary Studies of attention have generally assumed that the principal limit to visual perception involves the capacity to identify a stimulus. Analyses of responses in visual tasks, however, suggest that errors can arise from a loss of position information, as well as a loss of identity information, and that these two types of errors may be affected by different variables. Based on this, we have proposed that the difficult aspect of perception is not that of recognizing the form of the stimulus but rather determining its position relative to other items in the field. To demonstrate this, we conducted a series of experiments on lateral masking that showed that the failure to perceive a parafoveal stimulus surrounded by other items is due to two quite separate components: a loss of identity information induced by the immediately adjacent items and a loss of position information induced by both adjacent and non-adjacent items.This research was supported by grant A-9581 from the Natural Sciences and Engineering Research Council of Canada to the senior author. The first two experiments were reported in a paper to the annual meeting of the Psychonomics Society, San Antonio, 1984     

Cognitive addition and multiplication: Evidence for a single memory network

In an experiment using verification task procedures, 100 subjects responded to simple and complex problems of addition and multiplication. Identical structural parameters were found to model reaction time accurately to both addition and multiplication problems. Slope estimates for a memory network parameter did not differ significantly between simple and complex problems within an operation or between addition and multiplication problems. Both complex addition and complex multiplication problems were processed columnwise, with column sums or products being retrieved from an interrated memory network. The two types of complex problems included similar processes for carrying and for encoding of single digits, and both were self-terminated when an error in the units column was encountered. Addition and multiplication facts appear to be retrieved from a single interrelated memory network. A conceptual model for this interrelated network is discussed.     

Personality and Personal Projects: Linking Big Five and PAC Units of Analysis

This article examines the relationships between classical trait units as represented by the five-factor model (e.g., Digman, 1990) and personal action construct (PAC) units as measured by Personal Projects Analysis (Little, 1983). One hundred and forty-seven students were administered the NEO Personality Inventory (Costa & McCrae, 1985) and two components of Personal Projects methodology during their first term in university. Neuroticism and Conscientiousness were related to problematic and positive project systems, respectively, with these effects generalizing across the academic and interpersonal project domains. Extraversion and Agreeableness were also associated with positive evaluations of personal projects, particularly in the interpersonal domain. Openness was distinctively linked with project initiation and value congruency. We suggest theoretical and applied implications of using PAC methods to expand and refine the classical trait research agenda.     

Validation of physical ability tests for high pressure cleaning occupations

This paper describes the development and validation of a physical performance test battery to select high pressure cleaning workers at Tennessee Eastman Company. The research uses a concurrent, criterion-related validation strategy to demonstrate the relationship between test performance and job performance. The study proceeded through four stages, with data collected in one stage used in subsequent stages. The two types of predictor measures included ability tests and work sample simulations. For some analyses, the work sample simulations were also used as criteria. Four samples of incumbents (N=63) were tested on all experimental measures. Using criterion groups of successful incumbents and unsuccessful former incumbents (N=33), all of the work simulation tests and the ability-referenced tests were significant predictors of successful versus unsuccessful job status. In addition, the ability tests predicted performance on the work sample simulations, particularly for those requiring strength and endurance. A battery of three ability tests resulted in R=.68 for job status and in R=.43, .73, .80, and .84, respectively, for each of the work sample simulations. Two of the three ability tests in the final test battery are likely to result in adverse impact against females. However, data collected on female maintenance technicians indicated women, as a group, would not be screened out categorically as a result of implementing the physical ability test battery.     

SEPARATE AND COMBINED EFFECTS OF METHYLPHENIDATE AND A BEHAVIORAL INTERVENTION ON DISRUPTIVE BEHAVIOR IN CHILDREN WITH MENTAL RETARDATION

We investigated the separate and combined effects of a behavioral intervention and methylphenidate (Ritalin®) on disruptive behavior and task engagement in 3 children with severe to profound mental retardation. The behavioral intervention involved differential reinforcement of appropriate behavior and guided compliance. All 3 children demonstrated decreased disruptive behavior and improved task engagement in response to the behavioral intervention. Two of the 3 children demonstrated similar improvement in response to methylphenidate. Although both interventions were highly effective for these 2 participants, the relative efficacy of the interventions varied between the 2 children. There was no evidence of an additive or synergistic effect of the two interventions, but the high efficacy of each intervention alone limited our ability to detect such effects.     

The Preconditions and Consequences of Relative Deprivation: Two Field Studies1

Two field studies assessed the preconditions and behavioral consequences of relative deprivation. A sample of single mothers receiving government assistance participated in Study 1, and a sample of working women participated in Study 2. We found general support for a 2-factor model of the preconditions of relative deprivation, in which wanting the desired state and deserving the desired state were the best predictors of discontent. In both studies, discontent regarding the status of one's group (i.e., single mothers or working women) was specifically predictive of reports of group-directed protest behaviors. In Study 2, discontent regarding one's own status was specifically predictive of willingness to engage in self-improvement behaviors. Participants in both studies reported more group discontent than personal discontent. These findings provide support from naturalistic settings for the construct of relative deprivation.     

A Systems Approach to the Social Difficulties of Transsexuals in Hong Kong

This paper identifies social difficulties commonly faced by a group of forty-two Hong Kong transsexuals who had applied for sex reassignment surgery. It describes the use of a systems perspective to conceptualize their problems and a structural family therapy approach to social work intervention.     

Classical conditioning and retention of the infant's eyelid response: effects of age and interstimulus interval

Independent groups of 10-,20-, and 30-day-old infants were subjected to a classical eyelid conditioning procedure involving either a 500- or a 1500-msec interstimulus interval (ISI). Ten days later, all received a second conditioning session. A reliable increase in conditioned responding was observed at all ages but only by infants receiving the 1500-msec ISI. Although age was not a significant factor in any conditioning measure except final performance level, which was greater for the oldest than for the youngest group, it did influence long-term retention. A reliable memory component was observed in the Session 2 performance of infants initially trained at 20 and 30 days but not at 10 days. These data demonstrate the importance of temporal parameters in the formation of conditioned associations very early in infancy and provide evidence for the long-term behavioral consequences of those associations.     

TV commercials as achievement scripts for women

This study suggests that sex stereotypes implicitly enacted, but never explicitly articulated, in TV commercials may inhibit women's achievement aspirations. Men and women (N=180) viewed locally produced replicas of four current, sex-stereotyped commercials, or four replicas that were identical except that the sex roles were reversed, or (control) named their favorite TV programs. All subjects then wrote an essay imagining their lives “10 years from now.” The essays were coded for achievement and homemaking themes. Women who viewed traditional commercials deemphasized achievement in favor of homemaking, compared to men and compared to women who had seen reversed role commercials. The reversed role commercials eliminated the sex difference in net achievement focus. Control subjects were indistinguishable from their same-sex counterparts in the traditional condition. The results identified some social changes needed to make “equality of opportunity” a social reality for women as well as men.