| dc.description.abstract | Acetaminophen, the active ingredient in Tylenol, is a popular over-the-counter pain reliever. Recent studies suggest that acetaminophen blunts not only physical pain but also emotional pain (DeWall et al., 2010; Durso, Luttrell, & Way, 2015). The current experiment expands previous research beyond self-report measures to study the effects of acetaminophen administration on emotional responding at the neural level. This study was conducted with a sample of undergraduates from Texas A&M University (n = 97). Participants viewed positive, negative and neutral images on a computer screen while their brain activity was monitored using electroencephalography (EEG). Participants were randomly assigned to either the acetaminophen condition or the control (placebo) condition. On the basis of previous research, we predicted that participants who ingested acetaminophen would have less intense emotional reactions to the negative stimuli as revealed by the late positive potential (LPP, an event-related potential derived from EEG), compared to those who ingested placebo. Personality questionnaires, including the behavioral inhibition and behavioral activation scales (BIS/ BAS; Carver & White, 1994), were included to explore moderating effects. We quantified the LPP as the mean EEG activity in the time window 500-1000 ms after picture onset, separately for each picture type. Results revealed a main effect of picture type, such that positive and negative images elicited larger LPPs than neutral images. However, there was no effect of pill condition and no interaction between pill condition and picture type. This finding is not consistent with our hypothesis or Durso et al.’s self-reported emotion results. We explored moderating effects of BIS on the LPP. A regression analysis found that BIS predicted LPP magnitudes in the placebo condition, but this relationship disappeared in the acetaminophen condition. Within-cell correlations revealed that acetaminophen disrupts the relationship between BIS and LPP for both positive and negative images. These results suggest that trait BIS moderates the effects of acetaminophen on a neural measure of emotional responding. | en |
