Some evidence for correlated separate activation in a simple letter-detection task

This study investigates the separate activation versus coactivation issue for redundant targets in a simple letter-detection paradigm with latency as the dependent variable. The results of a one-response visual-search task are reported. Since, on single-target trials, only the target was presented and no accompanying noise element, no “distraction decrement” caused by irrelevant noise elements (Grice et al., 1984) was to be expected. The data obtained showed a clear redundantsignal effect. Subsequent detailed analysis of the latency data using Miller’s (1982) procedure indicated that the results were consistent with a separate activation model and failed to provide convincing evidence in favor of coactivation models. A further analysis of the data indicated that, in the present study, the separate channels were negatively correlated for a range of fast RTs and positively correlated for intermediate and larger RTs. No evidence in favor of Grice et al.’s (1984) distraction-decrement hypothesis was found. The conclusions of this study are that (1) a separate activation model summarizes the essential features of information processing in this simple visual search task, and (2) no convincing evidence in favor of coactivation in visual search tasks has been reported in the literature up to now.     

Minicomputer-administered tasks in the study of effects of sustained work on human performance

Six tasks administered on a MINC-11 minicomputer were used in studying the effects of long, continuous work periods and fatigue on physical and cognitive task performance. Submaximal physiological workload measurement was done during one of these tasks for a subject walking on a treadmill. The MINC-11 system is described, as are the six tasks programs. Four of these tasks measured various types of reaction times, another involved complex information processing, and one appraised moods, physical symptoms, fatigue, and the physiological status of subjects.     

Schizotypy and hemisphere function—I : Theoretical considerations and the measurement of schizotypy

This paper brings together, in the context of individual-differences theory, two developing themes in schizophrenia research. One concerns the manifestation, in normal people, of ‘psychotic’ characteristics and their measurement using scales which, unlike the Eysenck P scale, draw their items from the clinical symptomatology of psychosis. Recent work on the so-called ‘borderline states’ is considered especially relevant and a new two-scale questionnaire (STQ) is described which was modelled on the current distinction, in DSM-III, between ‘schizotypal personality disorder’ and ‘borderline personality disorder’. The second theme addressed concerns the possible biological basis of individual differences in ‘schizotypy’. It is argued, in the light of some emerging views about the nature of schizophrenia, that this may lie in the functional and structural properties of hemisphere organization. A suggested strategy for evaluating this theory is an examination of the performance of schizotypal normal Ss on tests of hemisphere function.     

Abnormal and normal obsessions—A replication

A replication of previous work on the incidence and characteristics of intrusive cognitions in non-clinical populations was carried out. The results closely reflected those obtained previously, and further relationships between variables were found. The importance of distinguishing between- and within-S data is stressed.     

Stress, externality, and depression

Previous research has found mixed support for the possibility that locus of control moderates the effects of life stress on depression. Two methodological choices may have influenced previous findings: the use of a unidimensional rather than a multidimensional locus of control scale, and reliance on linear statistical methods using median splits. We attempted to correct these choices by using the Levenson IPC scale (1974) and multiple regression analyses in a female undergraduate population (N = 158). The results supported use of a multidimensional scale, since Stress, Internality, and Powerful Others were found to have main effects on depression whereas Chance interacted with life stress. The question of whether locus of control refers to responsibility for causing an event, i.e., self-blame, or belief in control over future events, i.e., coping behavior, was discussed.     

Sex differences in problems related to depression

The study investigated possible sex differences in the types of problems that are correlated with Beck Depression Inventory (BDI) scores, using a sample of college students. Problems related to assertiveness and feeling ill at ease were positively correlated with BDI scores for males, but not for females. In contrast, conflicts with parents, feelings of being boxed in and of boredom, lack of money, and chronic physical complaints were positively related to BDI scores for females, but not for males.     

Attitudes toward women,personality rigidity,and idealized physique preferences in males

The idealized physique preferences of a group of 94 male college students were measured and correlated with scales measuring attitudes toward women and personality rigidity. Three hypotheses, derived from sex-role research, were tested and confirmed: (1) Males who have negative attitudes toward women would like most to have a tapering V physique. (2) Males who have a rigid personality structure have stronger preference for an idealized muscular physique than males with more flexible personalities. (3) Males have a generally greater preference for a tapering V physique than women. It was concluded, from the results of this and other studies, that body preference is related to certain aspects of sex-role attitudes.