Neural manifolds in V1 change with top-down signals from V4 targeting the foveal region

Morales-Gregorio, A.; Kurth, A. C.; Ito, J.; Kleinjohann, A.; Barthelemy, F. V.; Brochier, T.; Grün, S.; van Albada, S. J.

doi:10.1101/2023.06.14.544966

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bioRxiv · 10.1101/2023.06.14.544966

Neural manifolds in V1 change with top-down signals from V4 targeting the foveal region

Morales-Gregorio, A.·Kurth, A. C.·Ito, J.·Kleinjohann, A.·Barthelemy, F. V.·Brochier, T.·Grün, S.·van Albada, S. J.

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Abstract

High-dimensional brain activity is often organized into lower-dimensional neural manifolds. However, the neural manifolds of the visual cortex remain understudied. Here, we study large-scale multielectrode electrophysiological recordings of macaque (Macaca mulatta) areas V1, V4 and DP with a high spatio-temporal resolution. We find, for the first time, that the population activity of V1 contains two separate neural manifolds, which correlate strongly with eye closure (eyes open/closed) and have distinct dimensionalities. Moreover, we find strong top-down signals from V4 to V1, particularly to the foveal region of V1, which are significantly stronger during the eyes-open periods, a previously unknown effect. Finally, in silico simulations of a balanced spiking neuron network qualitatively reproduce the experimental findings. Taken together, our analyses and simulations suggest that top-down signals modulate the population activity of V1, causing two distinct neural manifolds. We postulate that the top-down modulation during the eyes-open periods prepares V1 for fast and efficient visual responses, resulting in a type of visual stand-by state.

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Morales-Gregorio, A., Kurth, A. C., Ito, J., Kleinjohann, A., Barthelemy, F. V., Brochier, T., Grün, S., van Albada, S. J.. 2023-06-15. Neural manifolds in V1 change with top-down signals from V4 targeting the foveal region. https://doi.org/10.1101/2023.06.14.544966

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