Abstract:
When moving around in the world, the human visual system uses both form and motion information to estimate the direction of self-motion (i.e., heading). However, the neural mechanism responsible for integrating motion and form cues for heading perception remains unknown. In this study, we explored the brain areas that process form cues for heading perception and examined whether they overlap with the known brain areas that process motion cues for heading perception. We further investigated brain areas responsible for integrating motion and form cues for heading perception. Specifically, we used integrated glass patterns that had dot pairs oriented toward a locus on a screen (the form-defined focus of expansion (FOE)) but moved away from a different locus (the motion-defined FOE). The form- and the motion-defined FOEs were congruent or incongruent. In the congruent condition, the form- and the motion-defined FOEs were centered on the same location on the screen. In the incongruent condition, the form- and the motion-defined FOEs were on the opposite side relative to the center of the screen. Different stimulus conditions were presented in separate blocks in fMRI scans. Participants made a task-irrelevant (luminance discrimination) judgment during scanning. We compared BOLD response patterns across stimulus conditions using multiple voxel pattern analysis. We selected the 200 most active voxels in each ROI, trained a linear SVM to discriminate stimulus types, and then tested the classifier’s prediction for each stimulus block. We found that early visual areas (V1 and V2) decoded both the form- and the motion-defined FOEs but could not discriminate the congruent and incongruent conditions, suggesting that these areas do not integrate form and motion cues for heading perception. The higher ventral areas (V4 and LO) decoded the form- but not the motion-defined FOE while the dorsal areas (MT and MST) decoded the motion- but not the form-defined FOE. In contrast, the higher dorsal areas (V3a, V3B and V7) and the parietal lobe (VIP, CSV) not only decoded both the form- and the motion-defined FOEs but also dissociated the congruent and incongruent conditions, suggesting that they contribute to the integration of form and motion cues for heading perception. Our findings show that form and motion information are first processed along separate pathways and then integrated in the higher dorsal areas for the final estimation of heading during self-motion.
*Please note that tea and coffee reception will start at 4:00 PM.
NYU Shanghai STEM Seminar Series - Spring 2018
4:30-5:30 PM, Every Wednesday | Room 204, NYU Shanghai
- March 21: Jeffrey Erlich, Assistant Professor of Neural and Cognitive Sciences
- March 28: Gang Fang, Assistant Professor of Biology
- April 11: Tao Huang, Visiting Assistant Professor of Mathematics
- April 18: Li Li, Associate Professor of Neural Science and Psychology
- April 25: Leonardo T. Rolla, Visiting Assistant Professor of Mathematics
- May 02: Xinying Cai, Assistant Professor of Neural and Cognitive Sciences
- May 09: Hanghui Chen, Assistant Professor of Physics
This event is for NYU Shanghai community. External attendees please RSVP HERE.