Amygdala responsivity to high-level social information from unseen faces

Area of Science:

• Neuroscience
• Social Cognitive Neuroscience
• Perception Psychology

Background:

• The amygdala automatically responds to facial trustworthiness when faces are clearly visible.
• It remains unclear if the amygdala can evaluate high-level facial information without conscious perception.

Purpose of the Study:

• To investigate if the amygdala processes facial trustworthiness subliminally.
• To determine if the amygdala tracks trustworthiness variations without conscious awareness.

Main Methods:

• Two functional neuroimaging experiments were conducted.
• A backward masking paradigm was used to present faces subliminally.
• Amygdala responses were analyzed for sensitivity to trustworthiness variations.

Main Results:

• The human amygdala is sensitive to subliminal variations in facial trustworthiness.
• Amygdala regions tracked untrustworthy facial appearances (negative-linear responses).
• The amygdala also tracked the overall strength of trustworthiness signals (nonlinear responses) for unseen faces.

Conclusions:

• The amygdala processes high-level facial information, such as trustworthiness, before conscious perception.
• Amygdala's processing of social cues can occur extensively in the absence of awareness.
• Findings suggest a more profound role for the amygdala in rapid, unconscious social evaluation.