Hemispheric control of attention and arousal: A review

D. Papakostopoulos,

MODELS Gillian

ed. / Psychophysiology

OF HEMISPHERIC

Society Abstracts,

313

1982

SPECIALIZATION

COHEN

The Open University, Milton Keynes, UK

Models of hemispheric specialization include both fixed structural models, and dynamic process models. A combined model incorporating both structural and dynamic elements is needed to account for observed patterns of laterality effects. Several aspects of this model are, it is argued, vague and confused, and behavioural evidence is powerless to clarify them. Questions about the locus of processing, inter-hemispheric transfer of information, and the nature of activation effects can only be resolved by psychophysiological research.

HEMISPHERIC REVIEW

CONTROL

OF ATTENTION

AND AROUSAL:

A

Jeff JUTAI Department of Psychiatry, London, UK

Charing Cross and Westminster

Medical

School, University

of London,

In a recent discussion of hemispheric specialization Kinsbourne (1982) emphasized complementarity and reciprocity in the lateralized control of attention and affect. A review of the relevant psychophysiological literature provides general support for this position, although some reservations are in order, particularly when autonomic and electrocortical studies are considered separately. Despite some neurophysiological ambiguity, research on phasic electrodermal activity seems to be in line with a notion of reciprocal hemispheric control of activation and attention. Electrocortical investigations provide further support for a broad concept of complementarity in the control of attention. However, the more precise delineations of hemispheric roles in this process put forward by Kinsbourne and by others have rarely been examined by psychophysiologists. The few scattered reports which do exist do not present a coherent picture, but are tantalizing nonetheless. These points will be elaborated, and directions for future research suggested.

314

Reference Kinsbourne, American

M. (1982). Hemispheric specialization Psychologist, 37. 41 I-420.

and

the growth

of human

understanding.

A REVIEW OF DEVELOPMENTS IN TASK INDUCED EEG ASYMMETRIES

Stuart

BUTLER

The Medical School, ~~rrnin~~arn,UK

Many reports have appeared during the last decade which describe task related lateral asymmetry in the cranial distribution of EEG rhythms. The usual finding is that power in the alpha bandwidth is attenuated over the cerebral hemisphere presumed to play the major role in the performance of a particular task. Some of the work has achieved no more than a reaffirmation of the ‘ verbal-visuospatial’ dichotomy and some of it has been marred by meth~ologi~al flaws. Several such issues remain controversial. NevertheIess the induced asymmetries have been described repeatedly and for the most part consistently in spite of, rather than because of, the problems. Advantage has been taken of the effect to ask questions about what is lateralised, the ontogeny of laterahty, sex differences in hemispheric function, and how cortical activation changes with cognitive strategy and in psychopathology. Serial order effects and speed of thinking have been found to have major effects on the magnitude and even the direction of asymmetry. As a measure of laterality, it seems to correlate poorly with tachistoscopy and well with neurological signs. The most significant recent development has been the suggestion that the asymmetries are related only to motor and not to perceptual or cognitive processes. Although this view ignores much of the literature and is not supported by attempts directly to test it, it is in harmony with emer~ng ideas about the biological advantage of lateralisation in terms of the need for unitary control of expressive and manipulative processes.