Task-dependent enhancement of facial expression and identity representations in human cortex

Area of Science:

• Neuroscience
• Cognitive Psychology
• Visual Perception

Background:

• Understanding how the human brain processes complex visual information, such as faces, is crucial.
• Previous research suggests distinct neural pathways for processing facial identity and expression.

Purpose of the Study:

• To investigate the cortical mechanisms underlying the discrimination of facial expression and identity.
• To determine how attention modulates neural responses in the visual hierarchy during face perception.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was used to measure blood-oxygen-level-dependent (BOLD) responses in visual areas.
• Participants performed tasks requiring detection of changes in facial expression or identity presented dynamically.
• Neural decoding was employed to assess the representation of attended facial aspects.

Main Results:

• Dorsal visual areas showed increased activity during expression tasks, while ventral areas were more active during identity tasks.
• Early visual and ventral areas showed increased activity during identity detection.
• Attending to expression enhanced the decoding of expression exemplars in early visual and dorsal areas.
• Attending to identity improved the decoding of identity exemplars in dorsal and ventral areas.

Conclusions:

• Attentional modulation of face perception involves enhanced neural selectivity in specific visual processing streams.
• These findings support a sensitivity enhancement mechanism, where attention sharpens neural representations of task-relevant facial features.