Electrocortical Effects of Acetaminophen during Emotional Picture Viewing, Cognitive Control, and Negative Feedback.

Acetaminophen, the active ingredient in Tylenol, may have psychological effects, such as reducing social and emotional pain. The current study (N = 173) used electroencephalography (EEG) to extend past research on acetaminophen. Healthy undergraduate students (64.7% women, age M = 18.15, SD = 3.33) were randomly assigned to ingest 1,000 mg of acetaminophen or placebo before completing emotional picture viewing (n = 143), a flanker task (n = 69), and a probabilistic learning task (n = 143) while EEG was recorded. (Sample sizes used for the analyses of each task differ from the total N due to data loss.) We observed standard event-related potentials (ERPs), including emotion-modulated late positive potentials during picture viewing and feedback-related negativity during feedback on the probabilistic learning task. We also observed standard error-related and conflict-related ERPs in the flanker task but could not adequately assess acetaminophen's effect on flanker ERPs due to excessive data loss. Acetaminophen did not alter any of the ERPs, in contrast to predictions based on prior research. Exploratory analyses revealed that acetaminophen reduced the relationship between trait behavioral inhibition system sensitivity and emotion-modulated late positive potentials. Together these findings suggest that a standard dose of acetaminophen did not reliably alter neural indicators of emotional or feedback processing. Instead, preliminary findings from our study suggested that a more nuanced relationship may exist between acetaminophen and individual differences in emotional processing, although this latter finding calls for further replication.

Self-affirmation enhances processing of negative stimuli among threat-prone individuals.

Self-affirmation reduces defensive responding to self-threats. The present study extended beyond self-threats to assess affirmation's influence on responses to negative emotional pictures as measured by the late positive potential (LPP), an event-related potential in the encephalogram that reflects motivational significance. Participants completed a trait measure of behavioral inhibition system (BIS) sensitivity. Then they affirmed (or did not affirm) a core personal value before viewing a series of emotionally evocative pictures. Affirming a core value increased LPP responses to negative emotional pictures among individuals higher in BIS. Self-affirmation thus appeared to alter the motivational significance of negative pictures among threat-prone individuals, consistent with a reduction in the defensive avoidance of aversive stimuli. These findings suggest that affirming values may influence responses associated with basic (non-self) motivational systems among individuals sensitive to threat.

Effects of prior mental effort on picture processing: An ERP investigation.

The current study examined the aftereffects of mental effort on the processing of picture stimuli using neural measures. Ninety-seven healthy young adults were randomly assigned to exercise more versus less mental effort on a writing task. Then participants viewed positive, negative, and neutral affective images while P1, N1, P2, N2, P3, and late positive potential (LPP) magnitudes to the images were assessed. We found that performing the more (versus less) effortful writing task caused more negative N2 amplitudes to all images. In addition, and consistent with past research, emotional (versus neutral) images elicited more positive amplitudes on the N2, P3, and LPP components. Thus, prior mental effort appeared to reduce early attentional engagement with visual stimuli but did not diminish later attention modulation by emotional content. These findings suggest novel implications for understanding the behavioral aftereffects of mental effort and self-control.

The Influence of Agreeableness and Ego Depletion on Emotional Responding.

OBJECTIVE: Agreeable individuals report more intense withdrawal-oriented negative emotions across aversive situations. Two studies tested the hypothesis that self-regulatory depletion (i.e., ego depletion) moderates the relationship between trait Agreeableness and negative emotional responding. METHOD: Ego depletion was manipulated using a writing task. Emotional responding was measured with startle eye-blink responses (Study 1, N = 71) and self-reported valence, arousal, and empathic concern (Study 2, N = 256) during emotional picture viewing. Trait Agreeableness was measured using a questionnaire. RESULTS: In Study 1, Agreeableness predicted especially large startle responses during aversive images and especially small startles during appetitive images. After exercising self-control, the relationship between startle magnitudes and Agreeableness decreased. In Study 2, Agreeableness predicted more empathic concern for aversive images, which in turn predicted heightened self-reported negative emotions. After exercising self-control, the relationship between Agreeableness and empathic concern decreased. CONCLUSIONS: Agreeable individuals exhibit heightened negative emotional responding. Ego depletion reduced the link between Agreeableness and negative emotional responding in Study 1 and moderated the indirect effect of Agreeableness on negative emotional responding via empathic concern in Study 2. Empathic concern appears to be a resource-intensive process underlying heightened responding to aversive stimuli among agreeable persons.

Disgust sensitivity predicts defensive responding to mortality salience.

Disgust protects the physical self. The present authors suggest that disgust also contributes to the protection of the psychological self by fostering stronger defensive reactions to existential concerns. To test this idea, 3 studies examined the link between disgust sensitivity and defensive responses to mortality salience or "terror management" processes (Greenberg, Solomon, & Pyszczynski, 1997). Each study included an individual difference measure of disgust sensitivity, a manipulation of mortality salience, and a dependent measure of defensive responding. In Study 1, disgust sensitivity predicted increases in worldview defense in the mortality salience condition but not in the control condition. In Study 2, disgust sensitivity predicted increases in optimistic perceptions of the future in the mortality salience condition but not in the control condition. In Study 3, disgust sensitivity predicted reductions in delay discounting for those in the mortality salience condition such that those higher in disgust sensitivity discounted the future less. This pattern did not occur in the control condition. These findings highlight disgust sensitivity as a key to understanding reactions to mortality salience, and they support the view that disgust-related responses protect against both physical (e.g., noxious substances) and psychological threats.