RT Journal Article
SR Electronic
T1 Cortical Correlates of Human Motion Perception Biases
JF The Journal of Neuroscience
JO J. Neurosci.
FD Society for Neuroscience
SP 2592
OP 2604
DO 10.1523/JNEUROSCI.2809-13.2014
VO 34
IS 7
A1 Brett Vintch
A1 Justin L. Gardner
YR 2014
UL http://www.jneurosci.org/content/34/7/2592.abstract
AB Human sensory perception is not a faithful reproduction of the sensory environment. For example, at low contrast, objects appear to move slower and flicker faster than veridical. Although these biases have been observed robustly, their neural underpinning is unknown, thus suggesting a possible disconnect of the well established link between motion perception and cortical responses. We used functional imaging to examine the encoding of speed in the human cortex at the scale of neuronal populations and asked where and how these biases are encoded. Decoding, voxel population, and forward-encoding analyses revealed biases toward slow speeds and high temporal frequencies at low contrast in the earliest visual cortical regions, matching perception. These findings thus offer a resolution to the disconnect between cortical responses and motion perception in humans. Moreover, biases in speed perception are considered a leading example of Bayesian inference because they can be interpreted as a prior for slow speeds. Therefore, our data suggest that perceptual priors of this sort can be encoded by neural populations in the same early cortical areas that provide sensory evidence.