Faces and emotions: brain electric field sources during covert emotional processing

Area of Science:

• Neuroscience
• Cognitive Psychology
• Social Neuroscience

Background:

• Emotional processing of visual stimuli is crucial for social interaction.
• Previous research often involves directed tasks, limiting understanding of spontaneous affective responses.
• Event-related potentials (ERPs) offer insights into the temporal dynamics of brain activity.

Purpose of the Study:

• To investigate covert brain activity during spontaneous emotional evaluation of human faces.
• To determine if affective evaluation (liked vs. disliked) and attitude (philanthropist vs. misanthropist) influence neural processing.
• To explore the spatial distribution of brain activity related to these affective responses.

Main Methods:

• Recorded 27-channel averaged event-related potential (ERP) maps from 18 healthy subjects viewing face images.
• Subjects self-rated faces as 'liked' or 'disliked' post-recording.
• Analyzed the spatial configuration of electric field maps using the electric gravity center to identify differences in neuronal population activity.

Main Results:

• The electric gravity center for disliked faces was significantly more to the right and posterior than for liked faces.
• Similar spatial differences were observed between 'misanthropists' and 'philanthropists'.
• These findings indicate that visual emotional processing is modulated by affective evaluation and attitude, even without a directed task.

Conclusions:

• Spontaneous affective evaluation of faces engages distinct neural populations.
• The brain's spatial electrical activity patterns reflect subjective emotional valence and individual affective attitudes.
• This research extends our understanding of visual emotional processing to unrequested, task-free contexts.