Exploring neural responses in the human brain to real-world face size and distance

In natural binocular vision, three-dimensional (3D) geometry provides information about physical facial size and egocentric distance that can inform social behaviours. Yet most neuroimaging studies present two-dimensional stimuli at fixed distances and overlook 3D spatial cues. In this fMRI study, we stereoscopically presented realistic 3D avatar faces rendered at three sizes and three distances, with some combinations matched for retinal angle, to test whether the brain encodes face size or distance beyond retinal geometry. After partialling out the contribution of retinal size, activation in right pSTS and FFA showed some sensitivity to face size and distance, respectively. Conversely, depth-selective regions did not show robust sensitivity to real-world geometry. Taken together, these results suggest that face processing regions are sensitive to real-world 3D geometry, possibly to support social behaviours that depend on the spatial location of others.

Name thesis:degree_name

M Sc

Discipline thesis:degree_discipline

Neuroscience

Grantor dc:publisher

The University of Western Ontario

Year dc:date.issued

2025

Author dc:creator

• Deligiannis, Eva

Advisor dc:contributor.advisor

• Culham, Jody C.

• 3D vision
• face processing
• functional magnetic resonance imaging
• stereopsis
• real-world geometry

Statement dc:rights

• Attribution-NonCommercial-NoDerivatives 4.0 International

Language dc:language.iso

en

Handle dc:identifier.uri

https://hdl.handle.net/20.500.14721/39114

OAI identifier oai:identifier

oai:uwo.scholaris.ca:20.500.14721/39114