Temporal Dissociation of Global and Local Features by Hierarchy of Vision

Abstract

Most objects in our environment are organized hierarchically with a global whole embedding its local parts, but the way we recognize these features remains unclear. Using a visual masking paradigm, we examined the temporal dissociation between global and local feature as proposed in Reverse Hierarchy Theory, RHT (), where global and local information are assumed to be processed, respectively, by feed-forward and feedback systems. We found that in a long Stimulus Onset Asynchrony (SOA) condition, both global and local information were recognized adequately. However, in a short SOA condition, global information was recognized correctly while local recognition was critically disrupted. Consistent with RHT, it is suggested that local information is processed in a feedback system; this processing is then interrupted by the mask stimulus presented later at the primary visual area. Global information, by contrast, is transferred via a feed-forward system, and is not disrupted by the mask.

Keywords:

• global/local perception
• masking
• reverse hierarchy theory
• V1