Disparity detection in anticorrelated stereograms.

Recent physiological observations in which stimuli with opposite contrast signs in the two eyes have been used (anticorrelated stereograms) show that these stimuli evoke responses in primary visual cortex which are the reverse of responses to correlated stimuli. Psychophysical investigations reveal no such reversals: reversed-contrast bars with crossed disparities are seen in front of those with uncrossed disparities. For anticorrelated random-dot stereograms human subjects perceive no depth at all, except at low dot densities. However, these human studies were carried out with stimuli that differed in several ways from those used in physiological studies. We therefore reexamined psychophysical responses using stimuli similar to those used for physiological recordings. Our results confirm the previous findings: there is no evidence of a reversed depth sensation for bar stereograms (crossed disparities are never seen behind uncrossed disparities), and subjects are unable to detect depth in anticorrelated random-dot stereograms at the densities used for the physiological recordings. The discrepancy between the psychophysical data and the responses of single neurons in primary visual cortex suggests that further processing outside area V1 is necessary to provide the signals that produce the sensation of stereoscopic depth.     

Dimensions of driver anger, aggressive and highway code violations and their mediation by safety orientation in UK drivers

Aggressive behaviour on the roads is reported to be on the increase. This study administered Driving Anger Scale (Deffenbacher et al. (1994). Development of a driving anger scale. Psychological Reports, 74, 83–91.), the Driver Behaviour Questionnaire, and the Driving Skill Inventory to a sample of 270 British drivers. Factor analysis of the Driving Anger Scale items yielded three factors measuring anger generated by the reckless driving, direct hostility and impeded progress by others—contrary to the six subscales found with the original US sample. Younger drivers and low mileage drivers were more likely to exhibit all three types of driving anger, but no differences between male and female drivers were found. In addition, a driver’s safety orientation predicted (negatively) anger evoked by impeded progress and direct hostility whereas self-assessed perceptual-motor skills were positively related to anger generated by impeded progress. Both Highway Code and aggressive violations were significantly related to the anger factors, and, using the procedure by Baron and Kenny (Baron & Kenny (1986). The moderator–mediator variable distinction in social psychological research: conceptual, strategic, and statistical considerations. Journal of Personality and Social Psychology, 51, 1173–1182.), the prediction of violating behaviour (Driver Behaviour Questionnaire) by reported anger was shown to be mediated by the self-assessed safety skill scale but not the perceptual-motor skill scale (Driver Skill Inventory), and moderated by neither. Implications for driver education countermeasures are noted.     

Perfectionism and Suicidal Preoccupation

ABSTRACT One hundred twenty-nine undergraduate students were assessed for suicidal preoccupation, using the Alabama Adolescent Health Survey (AAHS) and selected cards from the Thematic Apperception Test (TAT). They were also administered the Multidimensional Perfectionism Scale (MPS) to assess perfectionistic tendencies. Objective scoring of the TAT was found to be highly reliable. Canonical correlational analyses were nonsignificant for a relationship between perfectionism and suicidal themes on the TAT. However, the more direct questions of the AAHS relating to suicide were significantly related to perfectionism. Results suggest that passive perfectionists who procrastinate out of fear of making mistakes are more likely to be preoccupied with suicide, unlike perfectionists whose strivings produce achievement. High personal standards and parental expectations do not appear related to suicidal preoccupations.     

Pupillary response as a general measure of activation

Pupil size was measured while 30 male college students undertook five tasks respectively concerning, (a) muscle tension induced by the lifting of weights, (b) fear induced by threat of a gunshot, (c) intense stimulation induced by loud pure tones, (d) heightened attention from viewing novel pictures, and (e) pleasantness and unpleasantness in reaction to pictures that differed in terms of their affect-inducing characteristics. Highly regular relationships were found between pupil size and degree of muscle strain and between pupil size and the temporal ordering of events during threat of a gunshot. Significant effects on pupil size also were found for the other three types of stimulation.     

TOWARDS AN INTERNATIONAL PROFESSION OF CLINICAL PSYCHOLOGY: AN ANGLO-SWEDISH PERSPECTIVE

Previous reviews of the international trends in the development of clinical psychology as a profession have identified the United Kingdom and the Nordic States as countries where the role of the psychologist is approximating that in North America. The article presents a review of the historical and current influences on the development of clinical psychology in the United Kingdom and in Sweden. In Europe, where clinical psychology is mainly a Health Service profession rather than a private practice, independence of the management and medical responsibility of the psychiatrist has become more of a key issue. Of the two major ‘schools’ of clinical psychology, identified in Britain with the behavioral approach of the Maudsley Institute of Psychiatry and the psychodynamic approach of the Tavistock Clinic, the behavioral school tended to dominate in Britain until the 1970s. In Sweden, the psychodynamic approach importing many of the aspects of British Object Relations Theory, gained ascendence. This resulted in a split between the more academic form of clinical psychology in Sweden, which had produced research of international importance (e.g. the role of psychological factors in stress-related illness), and professional education in psychology with its emphasis on psychotherapeutic training. Whereas in Britain, during the 1970s, clinical psychology broke away from psychiatry, became more eclectic, and entered the general medical and health areas, these changes failed to take place in Sweden. On the other hand, private practice amongst psychologists in Sweden has shown a dramatic increase during recent years and there are now some clear trends towards eclecticism in the education of psychologists. The issue of medical responsibility remains unresolved in Sweden. That British clinical psychology has reached more progressive and cordial professional relationships in this respect may be, in part, due to the status of the scientist-practitioner role that the initial behavioral emphasis achieved. The major contributions of and trends in British and Swedish clinical psychology are discussed with a view to identifying international trends.     

Intensity discrimination and loudness for tones in broadband noise

In two previous papers (Parker & Schneider, 1980; Schneider & Parker, 1987), we developed a model, based on Fechner's assumption, which successfully predicted the relationship between loudness and intensity discrimination for tones presented in quiet and in notched noise. In the present paper, pure-tone intensity-increment thresholds and loudness matches were determined for several levels of a standard tone in the presence of a broadband masker whose spectrum level was set to 35 dB below that of the standard tone. The model was unable to relate loudness to intensity discrimination under these conditions. Thus, the spectral composition of the masker affects the relationship between loudness and intensity discrimination in ways that cannot be accounted for by the model.     

A scale-invariant treatment for recursive path models

A reparameterization is formulated that yields estimates of scale-invariant parameters in recursive path models with latent variables, and (asymptotically) correct standard errors, without the use of constrained optimization. The method is based on the logical structure of the reticular action model.     

Stability and change in children's skill

Summary This paper explores age-related performance variability, both within trials and between sessions, in repetitive hopping. The mean, the standard deviation (SD), and the coefficient of variation (CV) of several timing and ground-reaction-force variables of hopping were analysed by repeated-measures ANOVA for age-related effects across test sessions and foot used. Forty-five subjects in five age groups (3–4 years, 4–5 years, 6–7 years, 8–9 years, or Adult) performed self-paced, one-footed hopping on three occasions within one week. As was expected, the results showed main effects for Age in all force and time variables, with the exception of CV of medio-lateral force. No significant main effects for Feet were revealed. However, significant Feet x Session interactions were found in flight-time measures, with higher flight-time SD and lower CV for the non-preferred foot in Session 1, a reversal in Session 2, and a negligible difference in Session 3. Across sessions, decreased SD and CV for both vertical and medio-lateral force and shorter flight time indicated more efficient hopping. Overall, it was concluded that SD and CV measures were more sensitive measures of children's performance across repeated sessions than were mean scores and that the order of testing the limbs is an important consideration in experimental protocols when lateralized tasks are measured.