title: Networks extending across dorsal and ventral visual pathways correlate with trajectory perception.
abstract: Despite its apparent importance in understanding the visual environment, neural mechanisms underlying perception of motion trajectories have been investigated less thoroughly compared with those of various other aspects of visual motion. In the present functional magnetic resonance imaging (fMRI) experiment, we focused on a recently reported visual illusion called the wriggling motion trajectory illusion (WMTI), which consists of dots that are actually moving straight and yet at the same time induce perception of curved trajectories. The use of this illusion enabled us to bypass confounding associations between trajectories and various other local motion features. Thus, the aim of the present study was to locate the brain areas that allow for differentiation between qualitatively distinct motion trajectories, such as straight or curved. At the same time, we also aimed to obtain further insights into the mechanisms of the illusion. Areas whose activation correlated with perceived wriggling trajectories were scattered across the dorsal and ventral visual pathways, including the superior parietal lobule (SPL) and fusiform. These patterns of activity indicate that motion information is integrated into trajectories in the ventral visual pathway in a similar manner to the integration of spatially continuous orientations into static contours. The present result is also in line with a previously suggested hypothetical mechanism of the illusion, which involves visual grouping.
authors.forename: Ryosuke
authors.initials: R
authors.lastname: Tanaka
authors.forename: Yuko
authors.initials: Y
authors.lastname: Yotsumoto
mesh_terms: D000328:Adult; D001921:Brain / Q000502:physiology; D001931:Brain Mapping; D005260:Female; D005556:Form Perception / Q000502:physiology; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D009039:Motion Perception / Q000502:physiology*; D010296:Parietal Lobe / Q000502:physiology*; D014795:Visual Pathways / Q000502:physiology*; D055815:Young Adult