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Emerald Group Publishing Limited
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The Neuropsychiatry of Consciousness
Article Type: Resource reviews From: Social Care and Neurodisability, Volume 3, Issue 1
Cavanna, A. E. and Monaco, F.,2007,Nova Science Publishers, Inc.,New York,€53.78,ISBN 9781600218606
Reviewed by Louise RoperUndergraduate Psychological Medicine Student at Birmingham University
“Consciousness” has long been discussed among academics of many genres. Whilst this text was published some time ago, Cavanna and Monaco take the reader on an insightful journey through this conceptual minefield by drawing on an intriguing mix of philosophy and science, reflecting the nature of consciousness itself. Having given a flavour of the fundamental differences between the ideas of consciousness, from Descartes’ seventeenth century theory of “dualism” to Jaynes’ (1976) “bicameral mind”, the authors go on to discuss the three fundamental states of consciousness: sleeping, dreaming, and waking. They describe consciousness as music and dreams; a free expression of the product of neuronal firing, with the brainstem reticular formation and the diencephalic nuclei as the conductors of this neural orchestra!
The work of Baars et al. (2003) compared four causally distinct states of unconsciousness. All states presented with widely synchronized, slow waveforms, as seen in epilepsy, contrary to the fast and flexible waveforms necessary for consciousness. All unconscious states showed transient blocking of reciprocal thalamic and cortical connections. Although not highlighted in the text, there are clear similarities to the brain regions involved in deep sleep and those disturbed by general anesthesia. The finding that conscious level and conscious content are not directly correlated is discussed extensively within this text. The complexity of the relationship between the level and contents of consciousness is typified by “status limbic epilepticus”: a person may continue performing their daily tasks but in an inflexible and uncreative way (Penfield, 1975). Thus, the subjective content of their “consciousness” is negligible. If the person was entirely unconscious more cases would result in accidents, therefore the authors cite Searle’s proposal (Searle, 1992); that patients have lost only “phenomenal consciousness”. The capacity for qualia is lost, but “cognitive consciousness” remains intact. For example, someone driving a car on autopilot could be described as unconscious of their individual actions. The authors call for systematic evaluation of experiential phenomena to be included in a complete diagnostic protocol for epilepsy.
The authors analyse the clinical implications of the discrepancies between ICD-10 and DSM-IV classifications of dissociative disorders. Hysteria, intimately related to dissociative disorders, is “unexplained by an organic neurological lesion or medical disease”. These disorders are distinguished from factitious disorders because they are “not consciously produced or intentionally feigned”. A loss of motor command, but with intact volition, due to “the dynamic reorganization of neuronal circuits that link volition, movement and perception” may be responsible for a number of disorders.
In conclusion the authors suggest that collaboration between scientists, philosophers, neurologists and psychiatrists is the way to achieve further advances in understanding both the science and individual nuisances of human consciousness. Thus, whilst very specialized and complex in its content, this book is extremely useful for any professional interested in unraveling such mysteries. Other states of altered consciousness discussed by the authors in the text include coma and coma-like states; general anesthesia, and other forms of epilepsy and dementias, particularly Alzheimers’s disease.
Baars, B., Laureys, S. and Ramsoy, T.Z. (2003), “Brain, consciousness and the observing self”, Trends Neuroscience, Vol. 26, pp. 671–5
Jaynes, J. (1976), The Origins of Consciousness and in the Breakdown of the Bicameral Mind, Houghton MifflinBoston, MA
Penfield, W. (1975), The Mystery of the Mind: A Critical Study of Consciousness and the Human Brain, Princeton University PressPrinceton, NJ
Searle, J. (1992), The Rediscovery of the Mind, MIT PressCambridge, MA