title: Perceptual alternations between unbound moving contours and bound shape motion engage a ventral/dorsal interplay.
abstract: Visual shape and motion information, processed in distinct brain regions, should be combined to elicit a unitary coherent percept of an object in motion. In an fMRI study, we identified brain regions underlying the perceptual binding of motion and shape independently of the features-contrast, motion, and shape-used to design the moving displays. These displays alternately elicited a bound (moving diamond) or an unbound (disconnected moving segments) percept, and were either physically unchanging yet perceptually bistable or physically changing over time. The joint analysis of the blood-oxygen-level-dependent (BOLD) signals recorded during bound or unbound perception with these different stimuli revealed a network comprising the occipital lobe and ventral and dorsal visual regions. Bound percepts correlated with in-phase BOLD increases within the occipital lobe and a ventral area and decreased activity in a dorsal area, while unbound percepts elicited moderate BOLD modulations in these regions. This network was similarly activated by bistable unchanging displays and by displays periodically changing over time. The uncovered interplay between the two regions is proposed to reflect a generic binding process that dynamically weights the perceptual evidence supporting the different shape and motion interpretations according to the reliability of the neural activity in these regions.
authors: Université Pierre et Marie Curie, Centre de Recherche de l'Institut du Cerveau et de la Moelle épinière, UMRS975, Paris, France.
authors: Anne
authors: A
authors: Caclin
authors: Anne-Lise
authors: AL
authors: Paradis
authors: Cédric
authors: C
authors: Lamirel
authors: Bertrand
authors: B
authors: Thirion
authors: Eric
authors: E
authors: Artiges
authors: Jean-Baptiste
authors: JB
authors: Poline
authors: Jean
authors: J
authors: Lorenceau
mesh_terms: D000328:Adult; D001288:Attention / Q000502:physiology; D015350:Contrast Sensitivity / Q000502:physiology*; D005133:Eye Movements / Q000502:physiology; D005260:Female; D005403:Fixation, Ocular / Q000502:physiology; D005556:Form Perception / Q000502:physiology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009039:Motion Perception / Q000502:physiology*; D009778:Occipital Lobe / Q000502:physiology; D010364:Pattern Recognition, Visual / Q000502:physiology; D010775:Photic Stimulation / Q000379:methods*; D013702:Temporal Lobe / Q000502:physiology; D014793:Visual Cortex / Q000502:physiology