Interhemispheric integration in the neural face perception network: Does stimulus location matter?

Area of Science:

• Neuroscience
• Cognitive Science
• Neuroimaging

Background:

• Hemispheric lateralization research often uses peripheral stimuli, potentially differing from central processing.
• Understanding interhemispheric integration requires models applicable to typical foveal processing.

Purpose of the Study:

• To investigate how stimulus location (peripheral vs. central) affects neural network connectivity during face perception.
• To compare interhemispheric transfer mechanisms for peripheral versus central face stimuli using fMRI and DCM.

Main Methods:

• Functional magnetic resonance imaging (fMRI) on 17 healthy volunteers viewing peripheral or central face and object images.
• Dynamic Causal Modelling (DCM) to analyze neural network connectivity and interhemispheric transfer.
• Bayesian Model Averaging (BMA) to integrate parameters across five connectivity models.

Main Results:

• Bilateral face-sensitive regions (FFA, OFA) and V1 were identified.
• Peripheral face stimuli induced significantly different interhemispheric transfer patterns compared to central stimuli.
• Asymmetrical connectivity patterns were observed for left and right visual field presentations.

Conclusions:

• Stimulus location critically modulates neural network connectivity in face processing.
• Peripheral and central face presentations activate distinct processing pathways.
• Central stimulus processing aligns more closely with typical face perception networks.