Filling-in in schizophrenia: a high-density electrical mapping and source-analysis investigation of illusory contour processing
Details
Serval ID
serval:BIB_21EE95AA6DE4
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Filling-in in schizophrenia: a high-density electrical mapping and source-analysis investigation of illusory contour processing
Journal
Cerebral Cortex
ISSN
1047-3211
Publication state
Published
Issued date
12/2005
Peer-reviewed
Oui
Volume
15
Number
12
Pages
1914-27
Notes
Journal Article
Research Support, N.I.H., Extramural --- Old month value: Dec
Research Support, N.I.H., Extramural --- Old month value: Dec
Abstract
Evidence is accumulating that patients with schizophrenia exhibit relatively severe deficits in early visual sensory processing within the dorsal stream, while processing within the ventral stream appears to be relatively more intact. Here, illusory contour (IC) processing was investigated in a cohort of schizophrenia patients and age-matched healthy controls using high-density visual evoked potentials (VEPs), spatiotemporal topographic analyses and the Local Auto-Regressive Average distributed linear inverse source estimation. IC processing was assessed because it is now known to be an excellent metric of early processing within regions of the ventral visual stream. Results in the present study show that IC processing (106-194 ms) is spared in patients with schizophrenia, providing strong evidence that early ventral stream processing is essentially normal. This is so despite equally strong evidence that early dorsal stream processing is severely impaired in this population, as indexed by a robust decrement in amplitude of the P1 component in patients and a large topographic difference between groups for this component (54-104 ms). Source analysis confirmed that the flow of activity into the dorsal stream was substantially decreased in patients. As such, these results suggest that some aspects of early ventral processing are not entirely reliant on intact inputs from the dorsal stream. Lastly, we show that later phases of visual processing (240-400 ms) also rely on the activity of different brain networks in controls and patients, with the latter recruiting strong frontal activity perhaps as compensation for impaired ventral stream processing during this period. We interpret the present findings in the context of a two-stage processing model. Under this model, it is suggested that the second stage of ventral stream processing is dependent on the fidelity of inputs from the dorsal visual stream and that impairment of this critical modulatory input may underlie the failure of 'higher-level' ventral stream processes in this population.
Keywords
Adult
*Brain Mapping
Cerebral Cortex/pathology/physiopathology
*Evoked Potentials, Visual
Female
*Form Perception
Frontal Lobe/pathology/physiopathology
Functional Laterality
Humans
Male
Middle Aged
Models, Neurological
Schizophrenia/*pathology/*physiopathology
Visual Pathways/pathology/physiopathology
Pubmed
Web of science
Open Access
Yes
Create date
21/01/2008 10:23
Last modification date
20/08/2019 12:58