Experience-dependent coding of facial expression in superior temporal sulcus.

Area of Science:

• Neuroscience
• Cognitive Science
• Visual Perception

Background:

• Sensory input is ambiguous, requiring prior experience for accurate perception.
• Facial expression adaptation shifts perception towards categories different from the adapted one.

Purpose of the Study:

• Investigate the neural dynamics of experience-dependent visual coding.
• Examine the timing of neural responses to facial morphs after adaptation.

Main Methods:

• Magnetoencephalography (MEG) was used to record brain activity.
• Studied neural responses to ambiguous facial morphs following facial expression adaptation.

Main Results:

• Evoked fields from the superior temporal sulcus (STS) correlated with deviations between morphs and adapted expressions.
• STS adaptation effects predicted the magnitude of behavioral aftereffects.

Conclusions:

• The STS codes facial expressions relative to recent experience, not in absolute terms.
• This relative coding mechanism may bias perception of facial expressions, potentially involving predictive coding via feedback connections.