Document Detail


Larger variability of saccadic reaction times in schizophrenia patients.
MedLine Citation:
PMID:  19501412     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Slower mean reaction time (RT), known as psychomotor slowing, is well documented in patients with schizophrenia. Fewer studies have shown increased variability of RT in these patients suggesting a basic difference in the distribution of RT. In this study median RT and its variability were measured for visually guided saccades performed by 53 patients and 1089 control subjects. Then average cumulative RT distributions were derived for each group and the RT distribution for each group was modeled using a decision signal rising linearly to a threshold signaling the beginning of the visually guided saccade. There was a small increase in the median RT for patients while their RTs were much more variable from trial to trial leading to a difference in the average RT distribution of the patient group. The model application led to the conclusion that this difference in the distribution of RT for patients could be attributed to a basic difference in information processing leading to the decision to move the eyes to the visually presented target. This information-processing difference could be the result of a difference in the build-up of neuronal activity involved in the generation of visually guided saccades in the frontal cortex.
Authors:
Nikolaos Smyrnis; Thomas Karantinos; Ioannis Malogiannis; Christos Theleritis; Asimakis Mantas; Nicholas C Stefanis; John Hatzimanolis; Ioannis Evdokimidis
Publication Detail:
Type:  Comparative Study; Journal Article; Research Support, Non-U.S. Gov't     Date:  2009-06-05
Journal Detail:
Title:  Psychiatry research     Volume:  168     ISSN:  0165-1781     ISO Abbreviation:  Psychiatry Res     Publication Date:  2009 Jul 
Date Detail:
Created Date:  2009-06-22     Completed Date:  2009-09-02     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  7911385     Medline TA:  Psychiatry Res     Country:  Ireland    
Other Details:
Languages:  eng     Pagination:  129-36     Citation Subset:  IM    
Affiliation:
Psychiatry Department, National and Kapodistrian University of Athens, Eginition Hospital, 72 Vassilisis Sofias Ave., 11528, Athens, Greece. smyrnis@med.uoa.gr
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MeSH Terms
Descriptor/Qualifier:
Adolescent
Adult
Attention / physiology
Decision Making / physiology
Frontal Lobe / physiopathology
Functional Laterality / physiology
Humans
Male
Photic Stimulation
Psychomotor Performance / physiology*
Reaction Time / physiology*
Saccades / physiology*
Schizophrenia / diagnosis*,  physiopathology
Schizophrenic Psychology
Signal Detection, Psychological / physiology
Visual Fields / physiology
Visual Perception / physiology*

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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