The deceptive response: effects of response conflict and strategic monitoring on the late positive component and episodic memory-related brain activity

The cognitive processes and neural mechanisms underlying deceptive responses were studied using behavioral responses (RT) and event-related brain potentials (ERPs) while participants made truthful and deceptive responses about perceived and remembered stimuli. Memorized words were presented in a recognition paradigm under three instructional conditions: Consistent Truthful, Consistent Deceptive, Random Deceptive. Responses that conflicted with the truth about both perceived and remembered items produced the same pattern of slower RTs and decreased LPC amplitudes. When long-term response patterns were monitored, RTs became much slower and LPC amplitudes decreased greatly. The different behavioral and ERP changes in the two deception conditions suggested that two dissociable executive control processes, each requiring additional processing resources, can contribute to deceptive responses. The parietal episodic memory (EM) effect, thought to reflect recollection, was unaffected by whether participants responded truthfully or deceptively suggesting that it provides a measure of guilty knowledge. (C) 2003 Elsevier B.V. All rights reserved.