title: Neuronal synchrony does not correlate with motion coherence in cortical area MT.
abstract: Natural visual scenes are cluttered with multiple objects whose individual features must somehow be selectively linked (or 'bound') if perception is to coincide with reality. Recent neurophysiological evidence supports a 'binding-by-synchrony' hypothesis: neurons excited by features of the same object fire synchronously, while neurons excited by features of different objects do not. Moving plaid patterns offer a straightforward means to test this idea. By appropriate manipulations of apparent transparency, the component gratings of a plaid pattern can be seen as parts of a single coherently moving surface or as two non-coherently moving surfaces. We examined directional tuning and synchrony of area-MT neurons in awake, fixating primates in response to perceptually coherent and non-coherent plaid patterns. Here we show that directional tuning correlated highly with perceptual coherence, which is consistent with an earlier study. Although we found stimulus-dependent synchrony, coherent plaids elicited significantly less synchrony than did non-coherent plaids. Our data therefore do not support the binding-by-synchrony hypothesis as applied to this class of motion stimuli in area MT.
authors.affiliation: Salk Institute for Biological Studies, La Jolla, California 92037, USA.
authors.forename: Alexander
authors.initials: A
authors.lastname: Thiele
authors.forename: Gene
authors.initials: G
authors.lastname: Stoner
mesh_terms: D000200:Action Potentials; D000818:Animals; D002540:Cerebral Cortex / Q000166:cytology / Q000502:physiology*; D003867:Depth Perception / Q000502:physiology; D005133:Eye Movements; D005403:Fixation, Ocular; D008253:Macaca mulatta / Q000502:physiology*; D009038:Motion; D009039:Motion Perception / Q000502:physiology*; D009474:Neurons / Q000502:physiology*; D010775:Photic Stimulation; D014851:Wakefulness