Binocular cues in the perception of distance of a point source of light

The ability to make egocentric distance estimates of a single point source of light, seen in darkness and without the cues of changing size and luminance, was investigated in sixteen observers. The attenuation required to maintain constant luminance, when the target was viewed from different distances, was shown to follow the inverse square law providing the angle subtended by the light was less than 20 s arc. Distance changes were also simulated by means of a split mirror which produced vergence cues, or by test lenses to provide accommodation cues. Over the range 0.5 to 9.2 m distance estimates were surprisingly accurate, although there was some overestimation of near and underestimation of far distances. Most observers made good judgements when only convergence cues were varied, whereas no observers made consistently good judgements when only accommodation cues were varied. The difficulties are discussed in terms of the accommodation-convergence link. When distance was simulated by changing convergence and accommodation cues, estimates were not as good as when real distance was changed. Since good estimates were made with brief target exposures, these judgements were not based on subsequent convergence or accommodation changes. It is suggested that the metric or reference against which the apparently absolute judgements were made was the efferent demand signal associated with a 'resting' position of convergence in darkness.     

Executive Career Counselling

Executive career counselling is relatively new. Some of its implications are examined and a three-tiered approach by organisations is advocated. Executives are verbally fluent, and this highlights the importance of the 'opening paragraph' of words they use in counselling. Neuro-linguistic programming offers a useful set of tools to the executive career counsellor. Left-handedness, probably overlooked in most types of counselling, is briefly considered. However, counselling is not only about problems, but also offers executives a welcome chance to review their lives and careers.     

Predicting diagnosis performance with measures of cognitive style

This study examines the relationship between performance on a context-independent fault diagnosis task and two dimensions of cognitive style: field dependence/independence (D-I) and focusing/scanning (F-S). The effects on diagnosis performance of training and the ability of both dimensions of style jointly to predict fault-finding ability were considered. The results showed that field independents and focusers were superior fault diagnosticians. Training, in the form of verbal feedback messages, was uniformly effective for the D-I dimension although field independents maintained a superior level of performance, over field dependents. In general, for the F-S dimension, training had little effect on either the focusers or scanners. A combination of scores on the F-S and D-I dimensions significantly enhanced the proportion of the variance in testing efficiency that could be accounted for during fault-finding. Finally it is argued that the F-S and D-I dimensions should be recognized as measures of ability, not style. Future research should be directed at identifying between subject differences on fault diagnosis tasks with reference to theories of information processing.     

On estimating processing variance: commentary and reanalysis of Kail's "Developmental functions for speeds of cognitive processes".

A recent paper by Kail (1988) in this journal appears to contain a significant error in the data analysis. The "goodness-of-fit" coefficients reported which suggest that overall about 94% of the variance can be accounted for by the model seem to be a substantial overestimation as a result of inappropriate procedures for statistical modeling. Using the data made available to us by Kail, we have reanalyzed these results. The corrected values range from 0.9 to 92.1% for the individual tasks with an overall average between 40 and 60%. We suggest that the support for the original conclusions is considerably weaker than reported.     

Beliefs and inferences: A test of a rational-emotive hypothesis 1. Performing in an academic seminar

Subjects were asked to imagine that they were going to present an academic seminar. They were further asked to imagine (a) that they adhered to a rational belief or an irrational belief; (b) that they had made or had not made an effort in preparing for the seminar and (c) that their performance counted or did not count towards their final examination grade. Whilst in role, subjects were asked to make inferences about various aspects of their performance and the responses of others. While the results supported the hypothesis that imagining that one is holding an irrational belief leads to more negative inferences than holding a rational belief, it was also found that not making an effort in preparing for the siminar led subjects to make more negative inferences than making an effort. In addition, there were several two-way and three-way significant interactions between the independent variables. The results supported Ellis's (1985) recent formulation concerning the complex relationship between events and inferences (A), beliefs (B) and emotional and behavioral consequences of beliefs (C).Windy Dryden PhD is Senior Lecturer in the Department of Psychology, Goldsmiths' College, University of London, England. Julia Ferguson is Research Assistant in the Department of Psychology, Goldsmiths' College, University of London, England. Tony Clark was an Undergraduate Student in the Department of Psychology, Goldsmiths' College, University of London, England. He graduated in 1987.     

Cardiovascular reactivity and interpersonal influence: active coping in a social context

Previous studies have demonstrated that effortful attempts to secure positive outcomes or avoid negative outcomes produce significant increases in systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate (HR). Although these effects of active coping on cardiovascular reactivity are central in current psychosomatic theories, virtually all of the research to date has used impersonal, asocial tasks. Our two studies examined the cardiovascular effects of effortful attempts to influence other people. In Study 1, male subjects attempting to influence the opinions of their discussion partner to improve their own chances of winning money displayed significantly greater SBP, DBP, and HR reactivity. In Study 2, we obtained similar effects on SBP and DBP reactivity in men and women, while both preparing an influence attempt and making that attempt. Furthermore, reactivity levels were larger as the magnitude of incentive for successful persuasion increased. Implications of this interpersonal equivalent of active coping for the development of cardiovascular disease are discussed.     

Predicting Contraceptive Efficacy: A Discriminant Analysis of Three Groups of Adolescent Women1

The relationship of knowledge and attitudes to adolescent contraceptive efficacy was investigated in a multivariate study, with demographic and sexual history variables covaried. Subjects were unmarried, sexually active 15- to 19-year-old women. Two studies were conducted: one using a large and representative sample and the second using a smaller, high socioeconomic status sample that is more typical of samples generally used in earlier research. Subjects were classified as effective, ineffective, or nonusers of contraception, based on both frequency of use and effectiveness of the method(s) they used. Two discriminant function analyses were performed to determine (a) whether knowledge and attitudes contributed to discrimination among the groups over and above discrimination attributable to demographic and sexual history variables, and (b) which variables distinguished ineffective users from both other groups. The results of both studies indicate that attitudes, particularly attitudes toward contraception, are strong predictors of patterns of contraceptive use. Ineffective users were distinguished from nonusers by their greater knowledge of contraception, and from both other groups by their greater sexual activity and more positive attitudes toward intercourse. The discussion focuses on the theoretical implications of the results, the usefulness of the effective/ineffective/nonuser categorization, and applications of these findings to design of interventions.     

The Role of Intentions, Social Norms, and Attitudes in the Performance of Dental Flossing: A Test of the Theory of Reasoned Action

The theory of reasoned action proposed by Fishbein and Ajzen (1975) was tested as an explanatory model for a preventive dental behavior, dental flossing, in a sample of 65 undergraduate students. Intentions and direct attitudes were found to be the strongest predictors of flossing. Social influences exerted their influence by way of direct attitudes. Flossers (>1/week) and non-flossers (<1/week) were observed to agree with belief statements referring to the health value of flossing. However, statements referring to the social and sensory aspects of flossing were found to effectively discriminate the two groups. Implications for health education strategies are discussed in which a greater focus is placed on more immediate social and sensory benefits of flossing rather than on long-term health benefits.