Supporting Evidence: New Research
Supporting Jaynes' Bicameral Mind Theory
Right Hemisphere Language Comprehension & Related Topics
Supporting Evidence > Right Hemisphere Language Comprehension & Related Topics
Julian Jaynes describes an earlier mentality prior to the development of subjective consciousness called the bicameral mind, in which the brain's hemispheres operated in a less integrated manner than they do today. Jaynes argues that the brain used language to convey experience in the right hemisphere to the left hemisphere in the form of what we would today call an auditory hallucination. Language in the right hemisphere at the time was considered controversial, but has since been confirmed in numerous studies. Below is a small sample of research supporting this aspect of Jaynes's theory.
The Role of the Right Hemisphere in the Interpretation of Figurative Aspects of Language: A Positron Emission Tomography Activation Study
Bottini, G., R. Corcoran, R. Sterzi, E. Paulesu, P. Schenone, P. Scarpa, R.S. Frackowiak, and C.D. Frith. Brain, 1994, 117 (6): 1241-1253.
We investigated cerebral activity in six normal volunteers using PET to explore the hypothesis that the right hemisphere has a specific role in the interpretation of figurative aspects of language such as metaphors. We also mapped the anatomical structures involved in sentence comprehension. During regional cerebral blood flow measurement subjects were asked to perform three different linguistic tasks: (i) metaphorical comprehension; (ii) literal comprehension of sentences; and (iii) a lexical-decision task. We found that comprehension of sentences compared with the lexical-decision task, induced extensive activation in several regions of the left hemisphere, including the prefrontal and basal frontal cortex, the middle and inferior temporal gyri and temporal pole, the parietal cortex and the precuneus. Comprehension of metaphors was associated with similar activations in the left hemisphere, but in addition, a number of sites were activated in the right hemisphere: the prefrontal cortex, the middle temporal gyrus, the precuneus and the posterior cingulate. We conclude that the interpretation of language involves widespread distributed systems bilaterally with the right hemisphere having a special role in the appreciation of metaphors.
Metaphor and Metacommunication in Schizophrenic Language
Frow, J. Social Semiotics, 2001, 11 (3): 275-287.
Since the beginning of this century, psychiatrists and linguists, assuming a correlation between disordered talk and disordered cognition, have sought to devise language tests with diagnostic efficiency for mental 'illnesses'. Schizophrenia in particular has been assumed to be characterized by disorders of cohesion, of reference, and of symbolization. Much of this work is flawed by its a priori assumptions about the reality of the category of schizophrenia and about the relation between 'normal' (non-figurative, 'logical') and 'deviant' (figurative, 'magical') uses of language, as well as by particular methodological problems such as the failure to control for experimental context and for the effects of psychotropic drugs. Nevertheless, the debates within psychiatry and linguistics over communicative disorders have a good deal to tell us about the 'normal' uses of figurative language in social interaction. In particular, they raise complex questions about the metacommunicative functions of metaphor: How does figuratively coded language work to convey multiple simultaneous and sometimes contradictory messages? What kinds of discursive relations does it thereby establish or maintain or disrupt? How does it contribute to narrative cohesion, and are there tensions between figure and story? On what basis, if any, is it possible to distinguish between 'appropriate' and 'inappropriate' uses of metaphor?
Poetry As Right-Hemispheric Language
Kane, Julie. Journal of Consciousness Studies, 2004, 11 (5-6): 21-59.
The human brain is divided into two hemispheres, right and left, that are joined by a thick 'cable' of neural fibres called the corpus callosum. It has long been observed that injury to the left hemisphere in the average adult damages speech, speech comprehension, and reading, and causes paralysis on the right side of the body. Injury to the right hemisphere, on the other hand, seems to leave linguistic capabilities intact, but causes paralysis on the left side of the body. These observations have given rise to the twin concepts of contralaterality of hemispheric control (i.e., that each hemisphere controls the opposite side of the body) and cognitive specialization of hemispheric function. As far back as the nineteenth century, it was recognized that the left hemisphere's specialty was language. Pioneering British neurologist John Hughlings Jackson asserted in 1868 that the left hemisphere was the 'leading side' in most people, responsible for the control of speech and will. In the decade of the 1940s, French neurologist Henry Hecaen and British psychologist Oliver Zangwill demonstrated that the right hemisphere, far from being passive, controlled visuospatial processing (Benton, 1991). ... In the following pages, each of the major literary devices characteristic of 'poetry' will be shown to be either dependent upon the right hemisphere for comprehension/production, or capable of being processed by the right hemisphere as well as by the left. Definitions of the linguistic features characterizing 'poetry' and examples of their usage in actual poems will be drawn from John Frederick Nims' lucid introduction to the subject for college students, Western Wind: An Introduction to Poetry (2000), now in its fourth edition, supplemented where appropriate by Alex PremingeRAnd T.V.F. Brogan's more technical New Princeton Encyclopedia of Poetry and Poetics (1993). Following the presentation of neurological evidence for poetry as 'right- hemispheric language', the question of why poets, in particular, produce language so rich in right-hemispheric content will be addressed and possible answers proposed.
Language Lateralization in Healthy Right-Handers
Knecht, S., M. Deppe, B. Dräger, L. Bobe, H. Lohmann, E.-B. Ringelstein, and H. Henningsen. Brain, January 2000, 123 (1): 74-81.
Our knowledge about the variability of cerebral language lateralization is derived from studies of patients with brain lesions and thus possible secondary reorganization of cerebral functions. In healthy right-handed subjects 'atypical', i.e. right hemisphere language dominance, has generally been assumed to be exceedingly rare. To test this assumption we measured language lateralization in 188 healthy subjects with moderate and strong right-handedness (59% females) by a new non-invasive, quantitative technique previously validated by direct comparison with the intracarotid amobarbital procedure. During a word generation task the averaged hemispheric perfusion differences within the territories of the middle cerebral arteries were determined. (i) The natural distribution of language lateralization was found to occur along a bimodal continuum. (ii) Lateralization was equivalent in men and women. (iii) Right hemisphere dominance was found in 7.5% of subjects. These findings indicate that atypical language dominance in healthy right-handed subjects of either sex is considerably more common than previously suspected.
Right Hemisphere Language Functions and Schizophrenia: The Forgotten Hemisphere?
Mitchell, Rachel L. C. & Tim J. Crow. Brain, 2005, 128, 963-978.
This review highlights the importance of right hemisphere language functions for successful social communication and advances the hypothesis that the core deficit in psychosis is a failure of segregation of right from left hemisphere functions. Lesion studies of stroke patients and dichotic listening and functional imaging studies of healthy people have shown that some language functions are mediated by the right hemisphere rather than the left. These functions include discourse planning/comprehension, understanding humour, sarcasm, metaphors and indirect requests, and the generation/comprehension of emotional prosody. Behavioural evidence indicates that patients with typical schizophrenic illnesses perform poorly on tests of these functions, and aspects of these functions are disturbed in schizo-affective and affective psychoses. The higher order language functions mediated by the right hemisphere are essential to an accurate understanding of someone's communicative intent, and the deficits displayed by patients with schizophrenia may make a significant contribution to their social interaction deficits. We outline a bi-hemispheric theory of the neural basis of language that emphasizes the role of the sapiens-specific cerebral torque in determining the four-chambered nature of the human brain in relation to the origins of language and the symptoms of schizophrenia. Future studies of abnormal lateralization of left hemisphere language functions need to take account of the consequences of a failure of lateralization of language functions to the right as well as the left hemisphere.
The Unintegrated Right Cerebral Hemispheric Consciousness as Alien Intruder: A Possible Mechanism for Schneiderian Delusions in Schizophrenia?
Nasrallah, Henry A. Comprehensive Psychiatry, 1985, 26 (3): 273-282.
The author proposes that one of the vital components of interhemispheric integration is the inhibition of any awareness by the verbally expressive hemispheric consciousness (usually the left) that it actually receives and sends thoughts, intentions, and feelings from and to another (right hemispheric) consciousness. This inhibition guarantees the unity of the right and left hemispheres into one "self" in the normal person. In schizophrenia, defective interhemispheric integration, probably neurochemical, may lead to disinhibition of the awareness by the left hemisphere that it is being "influenced" by an unknown "external force" which is fact the right hemisphere. Schneiderian delusions such as thought insertion and withdrawal and passivity feelings may be a direct outcome of such a deficit. Some lines of evidence and tests for the hypothesis are presented and discussed.