Task influences pattern discriminability for faces and bodies in ventral occipitotemporal cortex

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Visual Perception

Background:

• Prior research indicates overlapping activation in the ventral occipitotemporal cortex (VOTC) for faces and bodies.
• Multivoxel pattern analysis (MVPA) previously demonstrated discriminability of faces and bodies within these overlapping VOTC regions based on spatial activity patterns.

Purpose of the Study:

• To investigate if spatial patterns and their temporal courses in the VOTC are modulated by different categorization tasks.
• To determine how behavioral goals (object vs. emotion categorization) affect neural representations of faces and bodies.

Main Methods:

• Participants performed two tasks: categorizing images as faces or bodies, and categorizing emotions (happy/fearful) depicted by faces or bodies.
• Multivoxel pattern analysis (MVPA) was employed using a classifier trained on independent data to assess classification accuracy over time.
• The temporal course of classification accuracy was analyzed for both tasks to understand the dynamics of neural pattern differences.

Main Results:

• Higher face-body classification accuracy was achieved when participants categorized emotions compared to when they categorized objects.
• Neural classification accuracy rose above chance for both tasks initially but sustained a longer increase during emotion categorization.
• The temporal dynamics of pattern differences between faces and bodies in the VOTC were significantly modulated by the behavioral task.

Conclusions:

• The behavioral goal of the observer modulates the temporal course of category-selective activity in the VOTC.
• Task context exerts a top-down modulatory effect on neural representations, influencing how the brain distinguishes between faces and bodies.
• This suggests that visual perception is not solely data-driven but is actively shaped by cognitive and task demands.