Neural Latency Correlates Within and Between Cortical Areas

The intensity and timing of the brain’s representation of sensory stimuli varies, even in response to repetitions of an identical stimulus. This variation ultimately impacts behavioural responses and reaction times. To understand how the timing of neural responses covary within and between brain areas, we simultaneously recorded from populations of visually responsive neurons in pairs of brain areas in anaesthetized marmosets. We found stimulus-independent latency correlations in all neural populations, which were higher within than between areas. We argue that population analysis of single-trial latency covariations provides unique insight into the structure of feedforward sensory processing networks within the brain.