Distributional Population Codes and Multiple
Motion Models
Rich Zemel Peter Dayan
NIPS 11.
Abstract
Theoretical and empirical studies of population codes make the
assumption that neuronal activities reflect a unique and unambiguous
value of an encoded quantity. However, population activities can
contain additional information, such as multiple values of the
quantity and uncertainty about it. We have previously suggested a
method to recover the extra information by treating the activities of
the population of cells as coding for a complete distribution over the
coded quantity rather than just a single value. We now show how this
approach bears on psychophysical and neurophysiological studies of
population codes for motion direction. Our model is consistent with
both correct and erroneous human performance on tasks in which
subjects must report the directions of motion in stimuli containing
groups of dots moving in some small number of directions. The model
also suggests a natural explanation for why a monkey's psychophysical
discrimination performance is not substantially better.
compressed postscript pdf