Philip K. Oltman

Field dependence and lateralization of verbal and configurational processing.

With tachistoscopic presentation, relatively field-dependent 18- to 30-year-old males were found to show a significant right-visual-field advantage in reaction-time in a letter discrimination task, while relatively field-dependent subjects did not show a significant hemifield difference. In a second study, relatively field-independent 18- to 30-year-old males again showed a significant right-visual-field superiority in reaction time to letter discrimination, and in addition showed a significant left-visual-field superiority in tachistoscopic face discrimination, while relatively field-dependent subjects showed no significant hemifield difference on either task. The results are interpreted as indicating a link between Witkins concept of psychological differentiation and differentiation at the neural level, as manifested by specialization of function of the cerebral hemispheres.

Social Conformity and Psychological Differentiation

Abstract This study examined the role of socialization experiences in the development of psychological differentiation. In each of three countries (Holland, Italy, Mexico) two villages were selected as presenting a contrasting picture with regard to degree of emphasis on conformity to family, religious and political authority. It was hypothesized that within the pair of villages in each country children from the village which stressed social conformity would tend to be more field dependent and show other signs of less developed differentiation than children from the village in which social conformity was less emphasized. In each of the six villages approximately 100 children (boys and girls, aged 9–11 and 13–15) were studied. Differentiation was assessed by a battery of tests of field-dependence-independence and the figure-drawing test. In every comparison of mean test scores between pairs of villages, in each of the three countries, children from the village in which social conformity was stressed obtain...

Psychological differentiation as a factor in conflict resolution.

Previous studies have shown that persons matched in level of differentiation are likely to develop greater interpersonal attraction in the course of an interaction than are mismatched persons. These studies were all conducted in situations where the interacting persons were working toward a common goal. To test the hypothesis that situational variables may moderate match-mismatch effects, the present study investigated these affects when the interacting persons were in conflict. Based on their performance in tests of field dependence-independence, subjects were selected as relatively high or relatively low in level of differentiation. Three kinds of dyads were composed-high-differentiation/high-differentiation, low-differentiation/low-differentiation, and high-differentiation/low-differentiation--and their task was to reconcile conflict on an issue about which they were known to disagree. It was predicted that because of the more accommodating quality of low-differentiation persons, dyads including one or two such subjects would more often reconcile their disagreements and show greater interpersonal attraction than would dyads consisting of two high-differentiation subjects. Both predictions were confirmed, supporting the hypothesis that the outcome of match or mismatch is mediated by situational variables.

Eye torsion in response to a tilted visual stimulus

When the head is tilted laterally the eyes rotate in the opposite direction and come to rest at a less tilted position than the head with respect to the gravitational vertical (e.g. Howard and Templeton, 1966). This tonic countertorsion response occurs in the absence of visual stimulation and appears to be controlled primarily by the vestibular otolith (e.g. Graybiel, 1974). A visual stimulus is also capable of inducing eye torsion in a stationary observer, if it rotates around the observer’s line of sight (e.g. Howard and Templeton, 1964). It has generally been accepted, however, that eye torsion does not occur in response to a stationary visual field which is tilted with respect to the gravitational vertical (Howard and Templeton, 1964). Recent evidence suggests that this conclusion may not be correct under all conditions. Evidence of eye torsion in the direction of a tilted visual stimulus was reported in early studies using subjective afterimage techniques (Greenberg, 1960; Mesker, 1953). The subjective method of recording ‘torsion was criticized by Woward and Templeton (19643, however, who could find no objective, photographic evidence of visually induced torsion. The work of Howard and Templeton was carefully done and is often cited to support the conclusion that a stationary visual stimulus induces no eye torsion. Some positive photographic evidence has been reported in several recent studies, however. In an unpublished dissertation study, Hughes (1973) found torsional responses averaging about 0.5”. and Crone (1975) found up to I” of torsion in the direction of a tilted visual field. The question of whether eye torsion may occur in response to a stationary visual stimulus is of interest for several reasons. Recent evidence indicates that a variety of vestibular responses can be induced by visual stimuli (e.g. Dichgans and Brandt, 1974; Ebenholtz and Benzschawel, 1977; Henn er al., 1974). The most pertinent of these studies for the question at issue have shown that a stationary tilted visual display is capable of inducing an illusion of self-tilt in the opposite direction. It seems reasonable to suppose that this self-tilt illusion is due to a visual driving of the vestibular otolith system. If so, then torsional responses might also be expected, and would provide an objective method for the study of visual effects on the otolith system. Visually induced torsion would also be of some interest in the attempt to account for a variety of illusions. For example, the well-known rod-and-frame illusion could be partly due to torsional responses that are uncompensated perceptually. In this illusion an objectively vertical line (rod) looks tilted away from a surrounding tilted frame {e.g. Witkin et al., 1962/1974). Hughes (1973) found that individual differences in degree of torsion were highly related to differences in susceptibility to this illusion. Hughes concluded that part of the frame effect on apparent rod orientation can be attributed to torsional effects. In view of the discrepancies in results reported so far, and the interesting implications involved, it seemed useful to re-examine the question of visually induced torsion. In the present study, eye position was recorded photographically while observers viewed the standard rod-and-frame display (e.g. Witkin er al., 1962/1974).

Field independence and laterality in the perception of faces.

For a sample of 28 college males the degree of left visual-field bias in the perception of faces correlated .45 (p < .01) with extent of field-independent performance, as assessed by a composite score based on the Embedded-Figures Test, the Rod-and-Frame Test, and ratings on the Articulation-of-Body-Concept Scale. In a second study with 16 female and 10 male college subjects using the Group Embedded-Figures Test, field-independent subjects again showed greater left visual-field lateralization of face perception (r = .43, p < .05). Based on Witkins view of field independence as a manifestation of psychological differentiation, possible links between extent of differentiation at the psychological and neurophysiological levels are suggested.

The nature of individual differences in field dependence

Abstract Factor analyses were conducted on measures of field dependence and cognitive abilities to test some hypotheses about the nature of individual differences in orientation perception. Some hypotheses were also tested about relationships between the rod-and-frame and embedded-figures tests that are commonly used to measure the field-dependence dimension. The data are consistent with a model of the rod-and-frame test in which errors are attributed to two effects of the frame. The first is mediated by a rotation of perceptual axes, normally involved in the maintenance of orientation constancy, and the second involves a distortion in perceived angles between the rod and the frame sides. Individual differences in orientation perception are related to the embedded-figures test as expected, but they are just as highly related to many other tests of spatial-visual abilities. These relationships appear due to the constancy component of the RFT.

Orientation contrast effects in the rod-and-frame test

Previous research indicates that a tilted visual display is capable of inducing eye torsion and an illusion of self-tilt in objectively upright observers. These effects may contribute to performance errors on the rod-and-frame test by rotating the perceived axes of visual space toward the tilted frame. The kinesthetic-matching method was used in the present study to see whether an effect of the visual orientation contrast between red and frame sides might also contribute to rod-and-frame test performance. Observers aligned invisible hand-held rods with the visual rod at various tilts under a control condition when the frame was absent, and under experimental conditions with the frame upright or set at 45°. The frame induced matching errors in the direction away from the frame sides which were most nearly parallel to the rod. Since no rotation of apparent visual axes should occur under these conditions, the data suggest that an orientation contrast effect is involved in the rod-and-frame test.

The rod-and-frame illusion in erect and supine observers

Previous studies have found that the effect of a tilted frame on egocentric rod adjustments is greater when an overhead display in a horizontal plane is viewed from a supine body position than when a vertical display is viewed from an erect body position. The present studies were designed to see whether this phenomenon could be attributed to an intravisual orientation contrast effect or to the effects of visually induced eye torsion. No significant erect-supine differences were found on measures of either effect. Errors in the direction of frame tilt were significantly greater in the supine position when observers were asked to align a visible rod or an unseen hand-held disk with the head, but no effect of body position was found in matching the orientation of the disk with the rod. The data suggest that erect-supine differences in frame effects are not attributable simply to intravisual factors. The results are discussed in terms used by Harris (1974) to describe “straight-ahead shifts” in judging spatial directions with respect to the median plane.

Cognitive style and interhemispheric differentiation in the EEG.

Abstract The field-dependence-independence cognitive style, that component of the psychological differentiation dimension which subsumes spatial ability and certain aspects of personality and social behavior, was found to be associated with variations between individuals in the extent of differentiation of EEG activity between the two hemispheres. Fluctuations over time in integrated EEG amplitudes recorde from the left and right hemispheres were more similar to each other (i.e. less differentiated) in individuals with a field-dependent cognitive style than in those who were field independent.

Analyzing test structure by multidimensional scaling.

Multidimensional scaling was used to analyze item response data for the Test of English as a Foreign Language (TOEFL) to uncover the dimensions underlying the test