Consistency and error in motor performance

Two response measures that described the consistency and accuracy of motor performance were investigated. A pursuit tracking task was used as the vehicle whereby changes in perceptual motor performance could be monitored over several learning trials. The intra-individual variability of a subject's tracking response was compared to the root mean squared error that was accumulated during each block of trials. Whereas both response measures were sensitive to the changes in performance that occured as a result of practice, neither could be considered sufficiently informative as to be used as a sole indicator of skill acquisition. It appears that both consistency and error measures are needed to describe the subjects' performance as they acquire a perceptual motor skill.     

Chronic effects of electrical stimulation of muscle on the fractionated components of audio response time

Six male volunteer subjects underwent five weeks (15 sessions) of electrical stimulation (ES) of the triceps brachii muscle (medial head), participated in a pretest, and five weekly post-treatment performance tests of an elbow extension task. Response time (RSP) was electronically fractionated into the two components of reaction time (RT): premotor reaction time (PMT) and motor reaction time (MT): and movement time (MVT) for 45 degrees of elbow extension. Acceleration characteristics of the movement were quantified via a piezoelectric accelerometer mounted on a specially-built mechanism that allowed the desired motion in a transverse plane. Statistical analysis did not indicate significant treatment effects on the criterion measures, however, a significant linear trend for MT and significant linear and quadratic trends for MVT were indicated. Neuromuscular adaptation to the passage of electric current through nerve and muscle tissue was indicated by a significant quadratic trend and significant differences between all weekly accumulative (treatment) voltages. An unexpected significant negative correlation between PMT and MT was considered cause for further study. The particular technique of ES administration, although it produced consistant changes in RSP components (Ward and Grabiner 1981) was not as effective as methods described by other investigators for increased human performance.     

An Assessment of the Psychometric Adequacy of the British Adaptation of the Career Development Inventory

The concept of 'vocational maturity' is defined, and the development of methods for assessing it is briefly outlined. The adaptation of one such measure - Super's Career Development Inventory - is described, and some results are reported from a study designed to assess the psychometric adequacy of this adaptation. These showed the measure to be reliable enough for use with groups but not with individuals. Scores were found to be more highly related to concomitant variables than to direct measures of vocational maturity, though this may have been due to the poor quality of some of the latter. The convergent validity of the measure was supported, but the discriminant validity was not. The implications of these results for using the measure, and particularly the need for further development work, are briefly considered. It is suggested that such work will also need to address the utility of the construct itself for Britain in the 1980s.     

Expectancy of success on sex-linked tasks

College subjects undertook nine cognitive tasks with different perceived sex linkages, stating their expectancy of success prior to each task and attributing causality for their perceived performance following each task. As hypothesized, two components were present in the overall sex difference in expectancy of success, even when differences in actual task performance were statistically controlled. One component was attributable to a general tendency of females to state lower expectancies; the other was a function of the accord between the perceived sex linkage of the task and the subject's sex. The attribution data suggest that females tend to be more external for success and more internal for failure than males.The research reported here was partially supported by Grant #10692 from the Research Foundation of the City University of New York. The assistance of Bruce Eisman in testing subjects and of Rudy Lorber in data analysis is gratefully acknowledged.     

Crowding and stress: 2. A personal space approach

The concept of ‘personal space’ has sometimes been invoked in attempts to explain stressful effects of crowding; but the literature on personal space reveals divergent findings according to the definitions and methods of measurement used. Redefinitions are proposed whereby personal space preferences can be seen as mediating our reactions to the spatial proximity of others, according to a dynamic model which considers both task-related needs for physical space and privacy needs, together with concern over social norms and attributions. It is argued that perceived illegitimate invasion of the personal space one claims is likely to give rise to stress effects if coping responses fail. Thus crowding is likely to be stressful in many natural contexts where personal space is intruded upon frequently, especially when attributions of intentional thwarting are made. Further theoretical advances in this area must rest upon more precise specification of processes by which social relationships, situational variables, and subjective motivational, perceptual, and evaluative factors jointly determine an agent’s personal space claims and associated reactions to spatial invasion.     

Effects of household sex composition on the salience of one's gender in the spontaneous self-concept

It was hypothesized that being a boy or a girl becomes more salient in a child's self-concept to the extent the other sex numerically predominates in the child's household. This prediction was based upon an information-processing, distinctiveness postulate that a person contemplating a complex stimulus (such as the self) selectively notices and encodes its more distinctive, information-rich aspects. The spontaneous self-concept elicited by nondirective “Tell us about yourself” interviews of 560 school children were scored for spontaneous mention of one's gender. As predicted, boys spontaneously mentioned their maleness more often when they came from households where females were in the majority; girls mentioned their femaleness more often when from households with male majorities; boys mentioned their maleness more often when from father-absent than from father-present homes. Incidental findings are that gender is more salient in the negation self-concept (“Tell us what you are not”) than in the affirmation self-concept (“Tell us about yourself”) especially for girls and that gender becomes increasingly salient as the child grows older.     

Central progesterone induces female sexual behavior in estrogen-primed intact males rats

Progesterone induced high levels of female lordotic behavior in 10 of 17 intact, estrogen-primed male rats when it was applied directly to the medial preoptic-anterior hypothalamic area. All 17 males previously had shown lordosis when the serotonergic antagonist methysergide was applied to the same central sites. Few males responded to systemic progesterone and none to intracralial cholesterol. Intradiencephalic Metycaine, a local anesthetic, induced lordosis in eight male that previously had responded to central progesterone. These data indicate that estrogen and progesterone act synergistically to induce lordosis in male rats when progesterone is administered directly to sensitive brain sites.     

Laterality differences and practice effects under central backward masking conditions

Two experiments were conducted to examine laterality differences and practice effects under various central backward masking conditions. Critical stimulus onset asynchrony (SOA) was determined for subjects on 3 consecutive days using single letters as target stimuli (TS) and a pattern masking stimulus (MS). There was a right visual field (RVF) advantage on Day 1 but no difference between the visual fields on following days. The decline in the RVF advantage appeared to be dependent upon prior experience with laterally located letters, to be independent of initial experience with a particular set of letters, and to be more pronounced for females than for males. In addition, large improvements in performance were found, particularly between the first and second testing sessions. These practice effects were discussed in terms of the possible development of strategies for enhancing TS features or attenuating MS features.