A Causal Role of Area hMST for Self-Motion Perception in Humans

Constanze Schmitt; Bianca R Baltaretu; J Douglas Crawford; Frank Bremmer

doi:10.1093/texcom/tgaa042

A Causal Role of Area hMST for Self-Motion Perception in Humans

Cereb Cortex Commun. 2020 Jul 30;1(1):tgaa042. doi: 10.1093/texcom/tgaa042. eCollection 2020.

Authors

Constanze Schmitt^{1

2

3}, Bianca R Baltaretu^{3

4

5}, J Douglas Crawford^{3

4

6}, Frank Bremmer^{1

2

3}

Affiliations

¹ Department of Neurophysics, University of Marburg, Marburg, Germany.
² Center for Mind, Brain and Behavior-CMBB, University of Marburg and Justus-Liebig-University Giessen, Germany.
³ International Research Training Group 1901: The Brain in Action.
⁴ Centre for Vision Research and Vision: Science to Applications (VISTA) Program, York University, Toronto, Ontario, Canada.
⁵ Department of Biology, York University, Toronto, Ontario, Canada.
⁶ Departments of Psychology, Biology, Kinesiology and Health Science, York University, Toronto, Ontario, Canada.

Abstract

Previous studies in the macaque monkey have provided clear causal evidence for an involvement of the medial-superior-temporal area (MST) in the perception of self-motion. These studies also revealed an overrepresentation of contraversive heading. Human imaging studies have identified a functional equivalent (hMST) of macaque area MST. Yet, causal evidence of hMST in heading perception is lacking. We employed neuronavigated transcranial magnetic stimulation (TMS) to test for such a causal relationship. We expected TMS over hMST to induce increased perceptual variance (i.e., impaired precision), while leaving mean heading perception (accuracy) unaffected. We presented 8 human participants with an optic flow stimulus simulating forward self-motion across a ground plane in one of 3 directions. Participants indicated perceived heading. In 57% of the trials, TMS pulses were applied, temporally centered on self-motion onset. TMS stimulation site was either right-hemisphere hMST, identified by a functional magnetic resonance imaging (fMRI) localizer, or a control-area, just outside the fMRI localizer activation. As predicted, TMS over area hMST, but not over the control-area, increased response variance of perceived heading as compared with noTMS stimulation trials. As hypothesized, this effect was strongest for contraversive self-motion. These data provide a first causal evidence for a critical role of hMST in visually guided navigation.

Keywords: heading; medial-superior-temporal area; self-motion; transcranial magnetic stimulation; visually guided navigation.