Running modulates primate and rodent visual cortex differently

Abstract

When mice run, activity in their primary visual cortex (V1) is strongly modulated. This observation has altered conception of a brain region assumed to be a passive image processor. Extensive work has followed to dissect the circuits and functions of running-correlated modulation. However, it remains unclear whether visual processing in primates might similarly change during locomotion. We measured V1 activity in marmosets while they viewed stimuli on a treadmill. In contrast to mouse V1, marmoset V1 was slightly but reliably suppressed during running. Population-level analyses revealed trial-to-trial fluctuations of shared gain across V1 in both species, but these gain modulations were smaller and more often negatively correlated with running in marmosets. Thus, population-scale gain fluctuations of V1 reflect a common feature of mammalian visual cortical function, but important quantitative differences yield distinct consequences for the relation between vision and action in primates versus rodents.

Top-down modulation of visual cortical stimulus encoding and gamma independent of firing rates

“…Humans, non-human primates and cats show particularly strong gamma-band synchronization in primary visual cortex. At the same time, effects of behavioral and cognitive state on firing rates in the visual system typically decrease with decreasing hierarchical level of the investigated area and are smallest in primate area V1 [92][93][94] . While an inter-species comparison is difficult due to differences in tasks and other factors, effect sizes found in mid-to high-level primate visual areas might be most comparable to those found in rodent V1, where firing rates can be strongly affected by top-down signals such as arousal and motor activity 20,95,96 .…”

Physical activity modulates early visual response and improves target detection in humans

“…Studies in mice demonstrated a doubling of visual neuronal response amplitudes without affecting firing rate or tuning properties 4 . However, findings in marmosets suggest that movement tends to decrease V1 responses 25 . The impact of PA on early visual activity in humans, reflected by a reduction in BHA, may parallel the effect observed in marmosets.…”