Higher-order visual areas broaden stimulus responsiveness in mouse primary visual cortex

Abstract

Over the past few years, the various areas that surround the primary visual cortex in the mouse have been associated with many functions, ranging from higher-order visual processing to decision making. Recently, some studies have shown that higher-order visual areas influence the activity of the primary visual cortex, refining its processing capabilities. Here we studied how in vivo optogenetic inactivation of two higher-order visual areas with different functional properties affects responses evoked by moving bars in the primary visual cortex. In contrast with the prevailing view, our results demonstrate that distinct higher-order visual areas similarly modulate early visual processing. In particular, these areas broaden stimulus responsiveness in the primary visual cortex, by amplifying sensory-evoked responses for stimuli not moving along the orientation preferred by individual neurons. Thus, feedback from higher-order visual areas amplifies V1 responses to non-preferred stimuli, which may aid their detection.

Task complexity temporally extends the causal requirement for visual cortex in perception

“…First, we computed the power in the 500-5000 Hz range to localize layer 5 with the highest MUA spiking power 76 . Second, we showed contrast-reversing checkerboards before each recording session and computed the current source density profile to estimate layer 4 with the earliest current sink, as previously described 77 . Lastly, this was aligned with the depth registered when the silicon probes were lowered from the dura.…”