Connectionists: Preprint: Bayesian inference and attention in the visual cortex

[Rajesh Rao]

The following paper is available for download:

http://www.cs.washington.edu/homes/rao/nreport_bayes_atten05.pdf

Bayesian Inference and Attentional Modulation in the Visual Cortex
Neuroreport 16(16), 1843-1848, 2005

The responses of neurons in cortical areas V2 and V4 can be 
significantly modulated by attention to particular locations within an 
input image. We show that such effects emerge naturally when perception 
is viewed as a probabilistic inference process governed by Bayesian 
principles and implemented in hierarchical cortical networks. We show 
that the proposed model can explain a rich variety of attention-related 
responses in cortical area V4 including multiplicative modulation of 
tuning curves, restoration of neural responses in the presence of 
distracting stimuli, and influence of attention on neighboring 
unattended locations. Our results suggest a new interpretation of 
attention as a cortical mechanism for reducing perceptual uncertainty by 
combining top-down task-relevant information with bottom-up sensory 
inputs in a probabilistic manner.

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Rajesh P. N. Rao                     
Dept of Computer Science and Engineering
Univ of Washington  
Seattle, WA 98195-2350  
http://cs.washington.edu/homes/rao/   
Lab Website: http://neural.cs.washington.edu