Effect of aging on information processing of representation rotating in patients with major depressive disorder

Abstract

Objective To explore the effect of aging on the brain electrophysiological mechanism of information processing of representation rotating in patients with depressive disorder.Methods Twenty-seven patients with depressive disorders,admitted to our hospital from November 2011 and March 2011,were chosen in our study and they were divided into young-aged group (n=14) and old-aged group (n=13); and other 26 normal healthy participants (13 in young-aged group and 13 in old-aged group) were also chosen; they were performed the mental rotation tasks; the latency and amplitude of P500,and the wrong number and the response time by event-related potentials (ERP) system were measured.Results As compared with the control group,the patients in the young and old-aged patient group had higher error rates in normal and in lower error rates in mirror (P＜0.05),and longer reaction times in normal and longer reaction times in mirror (P＜0.05).As compared with the control group,the patients in the young and old-aged patient group had lower P500 amplitude in normal and higher P500 amplitude in mirror (P＜0.05); the P500 latency in the young-aged patient group was longer than that in the old-age patient group (P＜0.05).As compared with the young-aged control group,the error rates in the old-age control group were higher (P＜0.05),the reaction times were longer (P＜0.05),the P500 amplitude was lower (P＜0.05),and P500 latency was longer in the old-aged control group(P＜0.05); no significant difference was found on the error rates,reaction times,P500 amplitude and latency in the old-aged patients group (P＞0.05).Conclusion The information processing of representation rotating is impaired in patients with depressive disorder,and its aging effect disappears; the young-aged patients has a greater extent of damage than the elderly patients; it is suggested that the aging brain nerve system in a certain degree can protect the system on information processing of representation rotating. Key words: Depressive disorder; Representation; Information processing; Aging effect; Mental rotation; Event-related potential