The Human Posterior Superior Temporal Sulcus Samples Visual Space Differently From Other Face-Selective Regions

Area of Science:

• Cognitive Neuroscience
• Neuroimaging
• Visual Perception

Background:

• Ventral face-selective regions like the fusiform face area (FFA) and occipital face area (OFA) show a contralateral visual field (VF) bias.
• The visual field response of the face-selective posterior superior temporal sulcus (pSTS) remains less understood.

Purpose of the Study:

• To investigate the visual field (VF) response of the face-selective posterior superior temporal sulcus (pSTS).
• To compare the VF bias of pSTS with known ventral face areas (FFA, OFA) and motion-selective area MT+.

Main Methods:

• Three functional magnetic resonance imaging (fMRI) experiments presenting faces in different VFs.
• Transcranial magnetic stimulation (TMS) applied over right pSTS (rpSTS) and right OFA (rOFA) during facial expression matching tasks.

Main Results:

• A contralateral VF bias was confirmed in bilateral FFA, right OFA (rOFA), and bilateral human motion-selective area MT+.
• The bilateral pSTS demonstrated an absence of this contralateral VF bias.
• TMS over rpSTS disrupted performance in both hemifields, while TMS over rOFA only affected the contralateral hemifield.

Conclusions:

• The pSTS exhibits a unique lack of contralateral visual field bias for face processing compared to ventral face areas.
• This finding supports models of face processing involving distinct functional pathways.
• Differences in interhemispheric connections between face-selective areas across these pathways should be considered.