Electrophysiological decoding captures the temporal trajectory of face categorization in infants

Area of Science:

• Developmental neuroscience
• Cognitive psychology
• Human and comparative psychology

Background:

• Adults rapidly discriminate faces (~170ms).
• Infant face discrimination was previously thought to require significantly longer processing times.
• This study re-examines the timeline of face processing in early development.

Purpose of the Study:

• To investigate the temporal dynamics of face categorization in preverbal infants.
• To determine if infants can rapidly distinguish between human and nonhuman faces.
• To challenge the assumption that infant face discrimination is significantly slower than in adults.

Main Methods:

• Event-related electroencephalography (EEG) experiment with 5-13-month-old infants.
• Presentation of human and nonhuman primate faces.
• Time-resolved decoding analysis using logistic regression.

Main Results:

• Above-chance discrimination of human vs. nonhuman faces detected around 200ms post-stimulus onset.
• Discrimination signals originated from occipito-temporal electrodes.
• No above-chance discrimination of individual human or nonhuman faces was found.

Conclusions:

• Rapid face categorization emerges early in human development, even before language acquisition.
• Infants can quickly categorize faces, similar to adults, though individual face recognition may develop later.
• Findings suggest a faster timeline for early face processing than previously assumed.