Acute threat enhances perceptual sensitivity without affecting the decision criterion

Area of Science:

• Cognitive Neuroscience
• Psychophysiology

Background:

• Threat perception requires quick decisions.
• Bradycardia (slow heart rate) during threat anticipation may improve perception.
• It's debated whether this involves better sensory input or reliance on expectations.

Purpose of the Study:

• To investigate if threat-induced bradycardia enhances perception through bottom-up processing or prior expectations.
• To examine how threat of shock influences perceptual decision-making.

Main Methods:

• Participants completed a visual target-detection task under threat-of-shock or safe conditions.
• Decision criteria were manipulated using varying target presence rates.
• Heart rate was monitored to assess psychophysiological responses.

Main Results:

• Threat-of-shock increased heart rate deceleration (bradycardia) and enhanced perceptual sensitivity.
• Prior expectations did not influence decisions differently under threat.
• Increased bradycardia magnitude correlated with better target detection under threat.

Conclusions:

• Acute threat enhances perception, possibly by prioritizing bottom-up sensory information over prior expectations.
• Threat-induced bradycardia may be a key mechanism for improved perceptual sensitivity during threatening situations.