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bioRxiv · 10.1101/773689

Delayed suppression normalizes face identity responses in the primate brain

Koyano, K. W.·Jones, A. P.·McMahon, D. B.·Waidmann, E. N.·Russ, B. E.·Leopold, D. A.
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Abstract

SummaryThe primate brain is specialized for social visual perception. Previous work indicates that recognition draws upon an internal comparison between a viewed face and an internally stored average face. Here we demonstrate that this comparison takes the form of a delayed, dynamic suppression of face averageness among single neurons. In three macaque face patches, spiking responses to low-identity morphed faces met with a synchronous attenuation starting approximately 200 ms after onset. Analysis showed that a late-emerging V-shaped identity tuning was sometimes superimposed on linear ramp tuning. This pattern could not be ascribed to repetition suppression within a given session. The results indicate that the brains analysis of faces is enhanced through predictive normalization of identity, which increases sensitivity among face-selective neurons to distinctive facial features known to drive recognition.

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Koyano, K. W., Jones, A. P., McMahon, D. B., Waidmann, E. N., Russ, B. E., Leopold, D. A.. 2019-09-19. Delayed suppression normalizes face identity responses in the primate brain. https://doi.org/10.1101/773689

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