Speech without conscious awareness
Abstract
Following commissurotomy, it is usually the case that information presented to the left hemisphere can be named and described, while information presented to the mute, right hemisphere cannot be spoken about. In the present study, it was discovered that under special test conditions, an MRI-verified, callosally sectioned adult could name or write about information presented to the right hemisphere. Studies revealed this was not an instance of right hemisphere expression. Rather, the right hemisphere was somehow able to program the left hemisphere for a spoken or written response. Further, the studies also showed that the left hemisphere was not consciously aware that it possessed the information transmitted to it by the right half brain.
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Approximately 7 years after full callosal section, J.W.'s right hemisphere had gained enough access to the left hemisphere speech apparatus to initiate some simple responses, although the left hemisphere remained unaware that its speech system was expressing right hemisphere knowledge.
“Approximately 7 years later, J.W.'s right hemisphere had gained enough access to the left hemisphere speech apparatus to initiate some simple responses, although the left hemisphere remained unaware that its speech system was expressing right hemisphere knowledge (Gazzaniga et al., 1987).”
From Collaboration between the hemispheres of a callosotomy patient: Emerging right hemisphere speech and the left hemisphere interpreter (1996) · cites this paper as Gazzaniga et al., 1987
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Self-citation
- Authors
- Gazzaniga, M. S., Holtzman, J. D., & Smylie, C. S.
- Affiliations
- Cornell University (US)
- Venue
- Neurology
- Published
- 1987-04
- Volume
- 37
- Issue
- 4
- Pages
- 682-682
- ISSN
- 0028-3878 (ISSN-L)
- 1526-632X
- OpenAlex
- W2012812001
- Cited by
- 24
- References
- 0
- Citations by year
- 2025: 1 · 2022: 1 · 2021: 1 · 2012: 2
- FWCI
- 0.73
- Type
- journal article
- Language
- en
- Open access
- closed
- Locations
- Neurology (publishedVersion)
- PubMed (publishedVersion)
- Funders
- National Institutes of Health (2p01ns017778-13, 5r01ns022626-07)
- National Institute of Neurological Disorders and Stroke (2-PO1 NS 17778-04, 1-RO1 NS 22626-01)
- Topics
- Life Sciences › Neuroscience › Cognitive Neuroscience › Hemispheric Asymmetry in Neuroscience
- Life Sciences › Neuroscience › Cognitive Neuroscience › Neurobiology of Language and Bilingualism
- Life Sciences › Neuroscience › Cognitive Neuroscience › Spatial Neglect and Hemispheric Dysfunction
- Keywords
- commissurotomy, corpus callosotomy, hemispheric lateralization, covert speech, conscious awareness, interhemispheric communication
- MeSH terms
- Adult, Awareness, Cognition, Consciousness, Corpus Callosum, Humans, Functional Laterality, Male, Speech, Writing
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