eLife Assessment
This study investigates trial-by-trial inter-areal interactions in the visual cortex of the mouse and the monkey by analyzing two previously published datasets. The authors find that activity in one layer (in mice) or one area (in monkeys) can partially predict neural activity in another layer or area on the single-trial level in different experimental contexts. This valuable finding expands previously known contributions of stimulus-independent downstream activity to neural responses in the visual cortex by demonstrating how these change under varying visual stimuli as well as in the absence of visual stimulation. While the methodology is solid, the analysis for the monkey data is incomplete and would benefit from including a second animal.