NEUROSCIENCE ABSTRACT, 2002
Binocular Rivalry, Bipolar Disorder, and Aging:
Perceptual Alternation Rate Correlates with Age as well as with Psychiatric Diagnosis

David G. King, Ph.D., Associate Professor
Jeannie G. Killian, M.S., Assistant Scientist
Southern Illinois University School of Medicine
Carbondale, IL, USA

Following a report that bipolar disorder is associated with a slow rate of perceptual alternation during binocular rivalry (Pettigrew & Miller 1998, Proc Roy Soc B 265:2141-2148), we have (by the time of abstract preparation) measured alternation rate in a sample of 332 adult human subjects including 38 with diagnoses of bipolar disorder and some with various other diagnoses.  Volunteers were recruited from the diverse community around Southern Illinois University and were each offered a $10 gratuity.  Confirmation of self-reported mental health status was requested from each subject's health-care provider.  The stimulus for binocular rivalry (0.7 degree circular spot of moving horizontal or vertical bars) was presented on a computer monitor and viewed through stereoscopic glasses for 20 minutes (12 periods of 100 seconds each) with perceptual responses indicated by pressing buttons on the computer's mouse, using software provided by Keith White (Univ Florida).  Rate of alternation was calculated as the number of rivalrous cycles divided by the total time in rivalry.  Preliminary analysis confirmed Pettigrew & Miller's finding that mean rate of alternation is lower for subjects with bipolar disorder than for controls, although we have found a greater range of rates for control subjects and more overlap between bipolar and control groups than reported by Pettigrew & Miller.  Our data also revealed an unexpected negative correlation between alternation rate and age.  Any diagnostic application of perceptual alternation rate should take this age effect into account. 
Supported by the National Alliance for Research on Schizophrenia and Depression and by SIU School of Medicine.