Author: Kotchoubey, Boris

Source: Neuropsychological Rehabilitation, Volume 15, Numbers 3-4, -4/July-Sept 2005 , pp. 333-356(24)

Publisher: Psychology Press, part of the Taylor & Francis Group

Abstract:

Initial conceptualisation about the nature of vegetative state (VS) assumed at least temporary loss of the entire cortical functioning. Since a broad range of stimulus-related cortical activations was demonstrated in VS patients, this simplified idea is not tenable any longer, but no alternative concept emerges instead. Two recent hypotheses, empirically testable and well grounded, could fill this vacuum: (1) In VS, isolated cortical areas may work, but their integration into a distributed network is lacking. (2) In VS, complex stimulus processing is limited to primary sensory and motor areas; the co-ordination between them and the secondary and tertiary areas is lacking. To test these hypotheses, we estimated the frequency of occurrence of late event-related potential components P3 and N400, presumably indicating activity of complex distributed networks including high-level sensory and associative areas. Both components occurred in VS with above-chance frequencies, but less frequently than in two control groups. Besides these frequent normal brain activations, some VS patients exhibit highly significant but abnormal activations, whose functional meaning remains unclear. A methodological analysis leads to the conclusion that any neurophysiological assessment of VS patients is biased toward under-, rather than over-estimation, of their remaining information processing abilities.

Document Type: Research article

DOI: http://dx.doi.org/10.1080/09602010443000416

Affiliations: 1: Institute of Medical Psychology and Behavioural Neurobiology, Eberhardt-Karls-University of Tübingen, Germany

Publication date: 2005-07-01

More about this publication?

• Editorial Board
• Information for Authors
• Subscribe to this Title
• ingentaconnect is not responsible for the content or availability of external websites

Related content

• In this: publication
• By this: publisher
• In this Subject: Neurology & Psychiatry
• By this author: Kotchoubey, Boris

Website © Publishing Technology. Article copyright remains with the publisher, society or author(s) as specified within the article.

• Terms and conditions
• Privacy policy
• Information for advertisers