Movie showing the correlation between the neural population
response
to different images
The
movie below shows the correlation of the population response using
all neurons in ITC (left) and PFC (right) to each of the 42 cat/dog
images, through different time periods. Each square
in the image corresponds to the correlation between the population
response to two images, with lighter values indicating positive
correlations and darker values indicating negative correlations (note
that all correlations between the same images have been set to the
average correlation value so that they do not appear too bright in the
movie). The responses to each image are arranged in blocks
based on the prototype images (e.g., c1 100%, c1 80%, ..., c2 100%,
etc.). At each time point the firing rates in 150ms bins
are used, and each neuron has been z-score normalized across the 42
images, so that all neurons contribute equally to the correlation.
When there are 6 blocks of lighter color displayed diagonally
across the image (spanning the images derived from the 6 prototypes)
this indicates that the dominant form of information
is visual, and when there are 2 larger light blocks
(spanning the two cat/dog categories), this indicates that the dominant
form of information is more categorical. From looking at the
movie for ITC, one see that during the sample period the dominant form
of information in visually based, and that during the response period,
the dominant form of information is category based. From
looking the the PFC movie, one sees that the dominant form of
information during the sample period is mixed between visual and
category based, and that during the response period, that the dominated
form of information is strongly category based.