Similar neural and perceptual masking effects of low-power optogenetic stimulation in primate V1

Can direct stimulation of primate V1 substitute for a visual stimulus and mimic its perceptual effect? To address this question, we developed an optical-genetic toolkit to 'read' neural population responses using widefield calcium imaging, while simultaneously using optogenetics to 'write' neural responses into V1 of behaving macaques. We focused on the phenomenon of visual masking, where detection of a dim target is significantly reduced by a co-localized medium-brightness mask (Cornsweet and Pinsker, 1965; Whittle and Swanston, 1974). Using our toolkit, we tested whether V1 optogenetic stimulation can recapitulate the perceptual masking effect of a visual mask. We find that, similar to a visual mask, low-power optostimulation can significantly reduce visual detection sensitivity, that a sublinear interaction between visual- and optogenetic-evoked V1 responses could account for this perceptual effect, and that these neural and behavioral effects are spatially selective. Our toolkit and results open the door for further exploration of perceptual substitutions by direct stimulation of sensory cortex.

Automated summary

The study investigates whether direct stimulation of primate V1 can substitute for a visual stimulus and mimic its perceptual effect. The researchers developed an optical-genetic toolkit to 'read' and 'write' neural population responses in behaving macaques. The results show that low-power optogenetic stimulation in V1 can mimic the visual masking effect, and there is a sublinear interaction between visual and optogenetic-evoked V1 responses that accounts for this effect. These findings provide further insights into perceptual substitutions by direct stimulation of sensory cortex.