Substituting objects from consciousness: A review of object substitution masking

Abstract

Object substitution masking (OSM) occurs when a sparse (e.g., four dot), temporally-trailing mask obscures the visibility of a briefly-presented target. Here, we review theories of OSM: Those which propose that OSM reflects the interplay between feedforward and feedback/reentrant neural processes, those which predict that feedforward processing alone gives rise to the phenomenon and theories that focus on cognitive explanations, such as object updating. We discuss how each of these theories accommodates key findings from the OSM literature. In addition, we examine the relationship between OSM and other visual-cognitive phenomena, including object correspondence through occlusion, change blindness, metacontrast masking, backward masking, and visual short-term memory. Finally, we will examine the level of processing at which OSM impairs target perception. Collectively, OSM appears to reflect the conditions under which the brain confuses two visual events for one when they are encoded with low spatiotemporal resolution, due to processing resources being otherwise occupied.