title: Stimulus context alters neural representations of faces in inferotemporal cortex.
abstract: One goal of our nervous system is to form predictions about the world around us to facilitate our responses to upcoming events. One basis for such predictions could be the recently encountered visual stimuli, or the recent statistics of the visual environment. We examined the effect of recently experienced stimulus statistics on the visual representation of face stimuli by recording the responses of face-responsive neurons in the final stage of visual object recognition, the inferotemporal (IT) cortex, during blocks in which the probability of seeing a particular face was either 100% or only 12%. During the block with only face images, ∼30% of IT neurons exhibit enhanced anticipatory activity before the evoked visual response. This anticipatory modulation is followed by greater activity, broader view tuning, more distributed processing, and more reliable responses of IT neurons to the face stimuli. These changes in the visual response were sufficient to improve the ability of IT neurons to represent a variable property of the predictable face images (viewing angle), as measured by the performance of a simple linear classifier. These results demonstrate that the recent statistics of the visual environment can facilitate processing of stimulus information in the population neuronal representation.
  
  
  
  Neurons in inferotemporal (IT) cortex anticipate the arrival of a predictable stimulus, and visual responses to an expected stimulus are more distributed throughout the population of IT neurons, providing an enhanced representation of second-order stimulus information (in this case, viewing angle). The findings reveal a potential neural basis for the behavioral benefits of contextual expectation.
authors: Department of Cell Biology and Neuroscience, Montana State University, Bozeman, Montana; bnoudoost@montana.edu.
authors: Behrad
authors: B
authors: Noudoost
authors: Department of Electrical and Computer Engineering, Montana State University, Bozeman, Montana.
authors: Neda
authors: N
authors: Nategh
authors: Department of Cell Biology and Neuroscience, Montana State University, Bozeman, Montana.
authors: Kelsey
authors: K
authors: Clark
authors: School of Cognitive Sciences, Institute for Research in Fundamental Sciences, Tehran, Iran; and.|Research Center for Brain and Cognitive Sciences, Shaheed Beheshti University of Medical Sciences, Tehran, Iran.
authors: Hossein
authors: H
authors: Esteky
mesh_terms: D000818:Animals; D001931:Brain Mapping; D005074:Evoked Potentials, Visual / Q000502:physiology*; D005145:Face; D008253:Macaca mulatta; D008297:Male; D009474:Neurons / Q000502:physiology*; D010364:Pattern Recognition, Visual / Q000502:physiology*; D010775:Photic Stimulation; D011237:Predictive Value of Tests; D013702:Temporal Lobe / Q000166:cytology* / Q000502:physiology*
keywords: contextual effect; face perception; object recognition; view representation