Poster E15, Monday, March 27, 2:30 – 4:30 pm, Pacific Concourse
The late positive potential (LPP) as a novel method for assessing fear conditioning in humans
Felix Bacigalupo1, Steven J. Luck1; 1Center for Mind and Brain, University of California - Davis
Introduction: For more than sixty years, the gold standard for assessing fear conditioning in humans has been the skin conductance response (SCR). Although the SCR has been proven useful, it has three main limitations: 1) it is an indirect response of the peripheral nervous system rather than a direct response of the central nervous system; 2) it is slow, reaching a peak 4–5 seconds after stimulus onset; and 3) it decreases in amplitude after a few trials (habituation). Objective: To determine whether the late positive potential (LPP) in ERP recordings could provide an alternative method for assessing fear conditioning. Methods: SCR and EEG signals were measured in seventy volunteers who participated in a fear conditioning paradigm consisting of three blocks in which colored circles (blue, green and yellow) were either paired (CS+) or not paired (CS-) with a loud noise (100 dB). Participants also reported the perceived likelihood of being exposed to the noise for each color. Results: Both SCR and LPP showed significant differences between CS+ and CS- trials. However, SCR decreased steeply after the first conditioning block whereas LPP and self-reports were stable over time. Conclusion: The LPP has various advantages over the SCR for assessing fear conditioning in humans: 1) it is fast, peaking approximately 500 ms post-stimulus onset; 2) it is a direct response of the CNS; 3) it does not habituate over time; 4) it is more closely related to the participants’ subjective experience.
Topic Area: EMOTION & SOCIAL: Emotional responding