Hemispheric Imbalances Masquerading as Paranoid and Nonparanoid Syndromes?

Abstract

Evidence from psychophysiological and behavioral investigations of lateralization in psychosis separates two clinical syndromes. A speculative model is offered in which the syndromes approximate the clinical features of paranoid compared with nonparanoid patients in investigations in which the groups have been distinguished in the psychology laboratory (Magaro 1980), and encompass the distinction between acute functional psychoses and classical schizophrenia (Kety 1980). A parsimonious account is provided of the hemispheric imbalances of function tht underpin the syndromes.

Perceptual Asymmetries in Schizophrenia: Subtype Differences in Left Hemisphere Dominance for Dichotic Fused Words

“…These results are consistent with previous dichotic recall studies that compared patients with paranoid and nonparanoid schizophrenia (6,7). Differences in dichotic listening and cognitive function between these subtypes led to hypotheses that paranoid schizophrenia is characterized by left hemisphere overactivation and that nonparanoid schizophrenia is associated with reduced left hemisphere processing or right hemisphere overactivation (7,15,16). Although the patients with nonparanoid schizophrenia in the current study did show a smaller left hemisphere advantage than those with paranoid schizophrenia and healthy subjects, patients with paranoid schizophrenia did not differ significantly from healthy subjects.…”

A formal analysis of stressor and stress‐proneness effects on simple information processing

“…An interpretation comprising superior performance of verbal stimuli in the right visual field is one that comes to the fore (for a review, see Sergent, 1982). Moreover, it has been suggested that anxiety proneness may erode attentional resources specifically of the contralateral, left hemisphere (Phelan & Gruzelier, cited in Gruzelier, 1981 ;Tucker, Antes, Stenslie & Barnhardt, 1978). The present instrumentation, was not designed expressly to tap differential processing of stimulation in the alternate hemifields (cf.…”

Attentional resources and hemispheric functional asymmetry in schizophrenia

“…Concerning schizophrenic subtypes, a general finding has been that left hemisphere anomalies tend to be associated with the paranoid subtype (e.g. Gruzelier & Hammond, 1980;Nachshon, 1980;Gruzelier, 1981). The second hypothesis above suggests that at very low load levels the left hemisphere functioning of paranoids and non-paranoids would be equivalent.…”

“…The basis for this hypothesis is somewhat more tentative. Recent research has indicated that anxiety, unlike other emotional reactions, imposes a processing load specifically on the left hemisphere (Tucker et af., 1978; Phelan & Gruzelier, cited in Gruzelier, 1981); an associated feature of paranoid * Note that the existence of hemispheric dilierenccs in task performance may be parsimoniously interpreted as indicating separate 'processing mechanisms or modes', rather than 'attentional pools' (see also Bryden. 1978).…”