Differential Hemispheric Specialization and its Relationship to Repression

Shirley K. Tyler

This thesis has been withdrawn as it is a duplicate, the original can be found here:

https://commons.und.edu/theses/2617/

Abstract

In Freud’s early formulations regarding a model of the mind, he suggested that repressed material functioned in a separate realm of the mind which was inaccessible to conscious recall or verbal inquiry. Based on studies of split-brain patients and studies of the differential functioning of the cerebral hemispheres, Galin (1977) has suggested that the right cerebral hemisphere may be the locus of unconscious mental contents.

Research with patient populations and normals has shown that each cerebral hemisphere is specialized for a different cognitive style. Right hemisphere cognition is similar in many respects to primary process thinking: global, nonverbal, imaginal, nonlinear association, non- propositional speech, less concerned with perception of sequence and time. Other data which suggests that the right hemisphere may be implicated in repressed mental contents comes from research on the dissociation of mental contents of the two hemispheres in commissurotomy (split- brain) patients.

Galin (1977) has proposed that in normal intact individuals the mental events of the right hemisphere can become disconnected functionally (repressed) from the left hemisphere by inhibition of neuronal transmission across the cerebral commissures. Recent evidence regarding differential hemispheric functioning during anxiety suggests another mechanism that may result in repression. Tucker, Antes, Stenslie and Barnhardt (1978) have found that when subjects are anxious the left cerebral hemisphere becomes overactive but dysfunctional. The neuropsychological model proposed in the present paper suggests that "repression" is a function of this restricted perception during anxiety. According to the model, when an unconscious conflict is aroused, the ensuing anxiety serves to overactivate and render dysfunctional the left hemisphere. As a result, perception and processing proceed along right hemisphere lines. Because of their special modes of organization, the knowledge of one hemisphere may not translate readily into the language of the other. Thus, the information stored in the right hemisphere while the left was dysfunctional may not be readily accessible to conscious, verbal left hemisphere thought. As a result, this information may remain "repressed" in the right hemisphere.

The present study attempted a first step in the evaluation of this formulation by evaluating whether left hemisphere perception/ processing is hampered more by anxiety than is right hemisphere perception/processing when material is presented simultaneously to both hemispheres. To evaluate the effects of anxiety high and low trait anxious subjects were employed. The effects of state anxiety were studied by experimentally induced arousal. Subjects were asked to perform tasks which require either predominantly left or predominantly right hemisphere functioning and a task that combines both analytic (left hemisphere) and global (right hemisphere) features.

It was hypothesized that under conditions of increased anxiety, performance on left hemisphere tasks would be more negatively affected than would performance on right hemisphere tasks. Contrary to prediction, right hemisphere task performance actually declined significantly more under conditions of increased anxiety than did left hemisphere task performance. Also contrary to prediction, performance on the analytic (left hemisphere) aspect of the combined task improved significantly with increased anxiety whereas there was a nonsignificant decline in performance on the global (right hemisphere) aspect of the task with increased anxiety. Findings are discussed in terms of reciprocal inhibition of hemispheric function, cognitive style and state dependent memory phenomena.