Use of landmarks and allocentric reference frames for the control of locomotion

In the present study we assessed the use of landmarks and scene layout information for the control of locomotion. Observers were presented displays simulating forward locomotion through a random dot field with the horizontal position perturbed by a sum-of-sines function and were asked to steer and null out the horizontal disturbance of the path of locomotion. The results indicate greater control gain and accuracy when presented with a repeating layout of landmarks as compared to a changing layout of landmarks. Debriefing responses suggest that observers may have implicitly learned the layout of the repeating pattern. These results suggest that observers use an allocentric representation of the scene for steering control. A model for the control of locomotion is discussed that utilizes both scene-based information and optic flow.     

The effects of stressors and coping resources on anxiety and peripheral narrowing

Abstract

The purpose of the study was to examine possible mechanisms which might help explain why individuals with high life stress and/or low coping resources are at greater risk for incurring athletic injuries. The effects of life events, daily hassles (DH), and coping resources (CR) on state anxiety and peripheral vision narrowing during a stress condition were examined. Subjects were 74 recreational athletes who completed the Life Events Survey, Daily Hassles Scale (DHS), Vulnerability to Stress Questionnaire (CR), and state portion of the State-Trait Anxiety Inventory. Peripheral vision was measured alone during baseline and while simultaneously performing a Stroop Color-Word Test accompanied by distracting noise during the stress condition. State anxiety was assessed during baseline and the stress condition. Analyses of covariance revealed that high negative life events (NLE) (p = .01) were related to greater peripheral narrowing during the stress condition. High TLE (p = .01) and DH (p = .005) were related to elevated state anxiety during the stress condition. The peripheral vision TLE main effect (p = .03) and the state anxiety interactions of NLE × CR and DHS × CR (ps = .05) approached significance. High CR tended to reduce perceived state anxiety during the stress condition for high NLE and DH subjects compared to similar subjects with low CR. Thus, partial support was offered for the mechanisms proposed in the Andersen and Williams (1988) stress-injury model. The results are discussed in terms of future research needs.     

Social cognitive influences on Mexican Americans’ career choices across Holland’s themes

This study examined several propositions of social cognitive career theory ( [Lent et al., 1994] and [Lent et al., 2000]) with a sample of 393 Mexican American college students. It was hypothesized that person input (i.e., age) and background contextual variables (i.e., Anglo orientation, Mexican orientation, familism, instrumentality, and expressivity) would predict career self-efficacy across Holland’s (1997) six RIASEC types. In addition, we examined the proposed relations between career self-efficacy, career interests, and career choice goal across the six RIASEC areas. Our results indicated that (a) Artistic, Social, Enterprising, and Conventional career models were similar across gender and university affiliation groups, (b) gender differences were found in the Realistic career model, (c) institutional affiliation differences were found in the Investigative career model, and (d) the models were a good fit to the data. Implications for future vocational research and career interventions are discussed.     

Aging and the perceptual organization of 3-D scenes

In the current study, the authors investigated whether the ground dominance effect (the use of ground surface information for the perceptual organization of scenes) varied with age. In Experiment 1, a scene containing a ground, a ceiling, and 2 vertical posts was presented. The scene was either in its normal orientation or rotated to the side. In Experiment 2, a blue dot was attached to each post, with location varied from bottom to top of the posts. In Experiment 3, a scene similar to that in Experiment 1 was presented in different locations in visual field. Observers judged which of the 2 objects (posts in Experiments 1 and 3, blue dots in Experiment 2) appeared to be closer. The results indicated that both younger (mean age = 22 years) and older observers (mean age = 73 years) responded consistently with the ground dominance effect. However, the magnitude of the effect decreased for older observers. These results suggest a decreased use of ground surface information by older observers for the perceptual organization of scene layout.     

Intercultural Study of Personal Space: A Case Study

The study of intercultural differences in personal space attempts to identify factors that could be helpful in guiding people from different cultures to live and work together in international ventures. The objective of this research was to measure interpersonal distance in a cross-cultural environment. Twenty-three participants classified in 4 cultural groups answered an 11-questions interview where the personal distance and orientation between seated interactants were measured. Results showed that Anglo Saxons used the largest zone of personal space, followed by Asians, then Caucasians, and, as expected, Mediterraneans and Latinos used the shortest distance. Where Latinos adopt a face-to-face position, Caucasians tend to orient themselves to the side of the interviewer, which has an impact on interpersonal communication.     

Stress and Coping Among Displaced Bosnian Refugees: An Exploratory Study

Traumatic experiences associated with the recent war in Bosnia (1992–1995) have impacted the lives of many Bosnian refugees and displaced people. Approximately 25% of Bosnians were forced to leave their homes and resettle in other areas of Bosnia or abroad. In this study, 82 displaced Bosnians living in the area of Tuzla, Bosnia, and 53 refugees living in the San Francisco Bay area completed the same questionnaire in the Bosnian language. The study describes war-related stress and the association of marital status, anxiety, depression, and sensitivity levels. Furthermore, being single, having lower anxiety ratings, finding and adapting to a new environment easily, and moving on with their lives indicated better self-reported health. Findings also revealed that being divorced or separated, better self-reported health, and lower anxiety, depression, and sensitivity ratings were predictors of more effective coping.     

A counterexample to the rigidity assumption in the visual perception of structure from motion

It has been proposed that the human visual system prefers perceptions of objects that are rigid or undergo minimum form change. A counterexample is presented in which a rigid two-dimensional figure rotating in the frontal plane is perceived as a distorting three-dimensional shape. It is argued that this perception results from the stimulation of automatic processes for perceiving size change, and that these processes are not subject to a general rigidity assumption.     

Men's sexual self-schema

Sexual self-schemas are cognitive generalizations about sexual aspects of oneself. In Part 1, a measure of men's sexual self-schema is developed. Studies of test-retest and internal consistency reliability and validity studies of factor analysis, internal structure, convergent and discriminant validity, process, group difference, and change are provided. The construct consists of 3 dimensions: passionate-loving, powerful-aggressive, and open-minded-liberal traits. In Part 2, the data suggest that men's sexual schema is derived from past sexual experience, is manifest in current sexual experience, and guides future sexual behavior. In Part 3, the data document the cognitive processing aspects of sexual schema. Consistent with the investigators' schema research with women, these data substantiate the importance of cognitive representations of sexuality.     

The discrimination of heading from optic flow is not retinally invariant.

Three experiments were conducted to determine whether the discrimination of heading from optic flow is retinally invariant and to determine the importance of acuity in accounting for heading eccentricity effects. In the first experiment, observers were presented with radial flow fields simulating forward translation through a three-dimensional volume of dots. The flow fields subtended 10 degrees of visual angle and were presented at 0 degree, 10 degrees, 20 degrees, and 40 degrees of retinal eccentricity. The observers were asked to indicate whether the simulated movement was to the right or the left of a target that appeared at the end of the display sequence. Eye movements were monitored with an electrooculogram apparatus. In a second experiment, static acuity thresholds were derived for each of the observers at the same retinal eccentricities. There was a significant increase in heading detection thresholds with retinal eccentricity (from 0.92 degree at 0 degree retinal eccentricity to 3.47 degrees at 40 degrees). An analysis of covariance indicated that the variation in sensitivity to radial flow, as a function of retinal eccentricity, is independent of acuity. Similar results were obtained when the Vernier acuity of observers was measured. These results suggest that the discrimination of heading from radial flow is not retinally invariant.