Single-unit responses selective for whole faces in the human amygdala.

Area of Science:

• Neuroscience
• Cognitive Science
• Social Cognition

Background:

• The human amygdala is vital for processing facial information and social cognition.
• Previous research in primates shows amygdala neurons respond to faces, but human representation remains unclear.
• Key question: does the amygdala encode facial features or the whole face?

Purpose of the Study:

• To investigate how the human amygdala represents face information.
• To determine if the amygdala encodes specific facial features or holistic face representations.

Main Methods:

• Recorded single-unit activity from over 200 neurons in the amygdalae of seven neurosurgical patients.
• Presented patients with whole faces and parts of faces during recordings.

Main Results:

• Around 50% of recorded amygdala neurons responded to faces or facial parts.
• Approximately 20% of neurons responded selectively to whole faces.
• Neurons responding to whole faces showed increased activity with partial face stimuli, suggesting global processing.

Conclusions:

• The human amygdala predominantly represents global information about faces.
• This global representation may involve inhibitory mechanisms between facial features.
• Findings advance understanding of the neural basis of social cognition and face perception.