Economists and cognitive psychologists have long
known that prior rewards bias decision making in favor of options with high
expected value. Accordingly, value modulates the activity of sensorimotor neurons
involved in initiating movements towards one of two competing decision
alternatives. However, little is known about how value influences the
acquisition and representation of incoming sensory information, or about the
neural mechanisms that track the relative value of each available stimulus to
guide behavior. Here, fMRI revealed value-related modulations throughout
spatially selective areas of the human visual system in the absence of overt
saccadic responses (including in V1). These modulations are primarily
associated with the reward history of each stimulus and not to self-reported
estimates of stimulus value. Finally, subregions of frontal and parietal cortex
represent the differential value of competing alternatives and may provide
signals to bias spatially-selective visual areas in favor of more valuable
stimuli. To appear in December 26th edition of Neuron. See here for a reprint |
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New paper: Value-based modulations in human visual cortexposted Oct 27, 2008 10:05 PM by Perception Lab [ updated Dec 30, 2008 10:13 PM ] |