Event-Related Potentials Study of Incidental Encoding in Obsessive-Compulsive Disorder

Original Article

Psychiatry Investigation 2005;2(2):70-9.

Eun Nam Kim, MA1;Young Youn Kim, PhD1;Kyung Jin Lee, MD2;Yong-Wook Shin, MD2;So Young Yoo, MD3;Myung-Sun Kim, PhD4; and Jun Soo Kwon, MD, PhD1,2,3;

¹;Institute for Neuroscience, Seoul National University College of Medicine, Seoul, ²;Clinical Cognitive Neuroscience Center, Seoul National University Hospital, Seoul, ³;Department of Psychiatry, Seoul National University College of Medicine, Seoul, ⁴;De

Abstract

The difference in event-related potentials (ERPs) according to subsequent memory performance has generally been regarded as a reflection of encoding processing in memory. The objective of this study was to determine whether patients with Obsessive-compulsive disorder (OCD) experience difficulties with regard to incidental encoding processing by subsequent memory paradigm. Twelve OCD patients and twelve healthy subjects ultimately participated in this study. ERPs were recorded while all subjects incidentally encoded 125 words, during tasks involving focus on structural features. The ERPs in the study phase were averaged separately for subsequent memory performance during the recognition phase (remembered/forgotten). We noted no significant differences in subsequent memory performance between the OCD patients and the control group. However, the magnitude of subsequent memory effect in the OCD patients was determined to be less than that of the control groups. The observed lack of reliable subsequent memory effects in the OCD patients may show that they experience difficulties in encoding, on the basis of an inability to identify the meaningful information to be stored.

Key words Subsequent memory effect;Obsessive-compulsive disorder;Event-related potentials;Incidental encoding.