Processing of Individual Items during Ensemble Coding of Facial Expressions

Area of Science:

• Cognitive Psychology
• Social Neuroscience
• Visual Perception

Background:

• Human observers can perceive collective emotional information from sets of faces.
• This collective perception often occurs even when individual faces are not consciously recognized.
• Previous studies primarily used limited processing resources, potentially influencing these findings.

Purpose of the Study:

• To investigate how exposure time influences the extraction of mean versus individual facial emotion representations.
• To explore the relationship between processing time and the accuracy of both mean and individual face perception.
• To determine if different processing mechanisms underlie the perception of single faces versus crowds of faces.

Main Methods:

• Participants viewed sets of faces with varying exposure durations.
• Judgments of mean emotion and individual face recognition were recorded.
• Diffusion model analysis was employed to examine decision-making processes.

Main Results:

• At short exposure times (50 ms), observers prioritized mean emotion extraction over individual face representation.
• With increased exposure time, observers accurately extracted both mean and individual facial representations.
• Diffusion modeling indicated mean representations are susceptible to noise, leading to conservative bias, while individual representations are more robust.

Conclusions:

• Facial emotion encoding from multiple faces involves distinct processes: single face processing and crowd face processing.
• Exposure duration is a critical factor modulating the balance between perceiving collective and individual facial information.
• Understanding these dual processing modes offers insights into social perception and information extraction from complex visual scenes.