Coordinated transformation of object representations across human visual cortex

Abstract

Our brain constructs increasingly sophisticated representations along the ventral visual pathway to support object recognition. To understand how these representations unfold over time, we recorded human intracranial electroencephalography responses to 120 object images at five consecutive stages of the ventral pathway from V1 to occipitotemporal areas. Using representational similarity analysis, we confirmed that response patterns were more strongly driven by low-order stimulus properties at early stages and high-order category information at late stages, respectively. Interestingly, response patterns also became less stimulus-driven and more categorical at all stages over time, from [~]100 to 200 ms post-stimulus. During this period, we found significant noise correlation between single-trial response patterns across stages, indicating tight inter-areal coupling. Thus, multi-areal recurrent processes may be essential in building high-order object representations.