COGNITIVE NEUROSCIENCE AND NEUROPSYCHOLOGYSequence representation during response preparation in the serial reaction time taskHu, Weia; Lu, Yonga; Wang, Lihongb; Zhang, John X.c Author Information aAcademy of Psychology and Behavior bCollege of Foreign Language, Tianjin Normal University, Tianjin cCentre for Psychology Studies, Fudan University, Shanghai, China Wei Hu and Yong Lu should be regarded as joint first authors. Correspondence to Yong Lu, PhD, Academy of Psychology and Behavior, Tianjin Normal University, No. 241, Weijin Road, Hexi District, Tianjin 300074, China Tel: +86 22 23540172; fax: +86 22 23540063; e-mail: [email protected] Received February 20, 2013 Accepted April 9, 2013 NeuroReport: July 10, 2013 - Volume 24 - Issue 10 - p 544-549 doi: 10.1097/WNR.0b013e3283621329 Buy Metrics Abstract The type of representations involved in implicit learning during the response preparation stage of sequence learning was studied using the response-locked lateralized readiness potential (LRP-R) as an index. Participants performed a modified serial reaction time task on an eight-letter sequence; half were informed to look for patterns in the sequence and half were not. The standard sequence was occasionally replaced by one of two deviant sequences and the LRP-R elicited was analyzed. When comparing across three sequence conditions, namely, a perceptual deviant sequence, a motor deviant sequence, and a standard sequence (as control), the onset latency and the mean amplitude of the LRP-R were similar for all three conditions and for both explicit and implicit learners. The perceptual deviant sequence group showed a longer response preparation time than the motor deviant group and the standard sequence group, but the latter two were not significantly different. The perceptual deviant sequence group showed more negative LRP-R amplitude than the other two groups that did not differ from each other. The finding of similar LRP-R profiles between implicit and explicit learners suggests that stimulus representation (S–S association) is the main form of representation supporting sequence learning in the response preparation stage. © 2013 Lippincott Williams & Wilkins, Inc.