Wait for It: Defensive Reactivity and Individual Differences in Contrast Avoidance in the NPU-Reward Task

Area of Science:

• Neuroscience
• Cognitive Psychology
• Affective Science

Background:

• Defensive reactivity, measured by startle responses, heightens during unpredictable threat anticipation.
• Reward anticipation also potentiates startle, but the impact of temporal unpredictability on this effect remains under-explored.
• Individual differences in emotional regulation, such as contrast avoidance, may modulate defensive reactivity to salient events.

Purpose of the Study:

• To investigate the influence of temporal unpredictability and contrast avoidance on startle eyeblink and reward positivity (RewP) during reward anticipation and feedback.
• To examine how predictable versus unpredictable reward schedules affect defensive responses.
• To explore the relationship between individual contrast avoidance tendencies and defensive reactivity in response to rewards.

Main Methods:

• A novel No (N), Predictable (P), and Unpredictable (U) reward task was employed.
• Participants (N=65) underwent EEG and EMG data collection during the task.
• Participants also completed the Contrast Avoidance Questionnaire (Worry version).

Main Results:

• Startle eyeblinks were potentiated for predictable rewards (P vs. N) but not unpredictable rewards (U vs. N).
• The reward positivity (RewP) was significantly larger for both predictable (P) and unpredictable (U) rewards compared to no reward (N).
• Higher contrast avoidance correlated with increased startle eyeblinks during predictable reward anticipation (P vs. U).

Conclusions:

• The timing of reward delivery critically modulates anticipatory defensive reflexes.
• Contrast avoidance may impede the reduction of defensive reactivity following rewarding feedback.
• Findings highlight the interplay between temporal uncertainty, reward anticipation, and individual differences in emotional regulation.