Metacontrast Masking Functions: A Question Of Speed?

Document Type


Publication Date


Published In

Journal Of Experimental Psychology: Human Perception And Performance


When a briefly presented disk is followed by a briefly presented ring, observers may report not seeing the disk, an effect known as "metacontrast." Three experiments showed that the ability of observers to distinguish such a disk–ring pair from a flickering ring depended on how quickly they responded. When responding slowly, observers were least accurate at disk-ring stimulus onset asynchronies (SOAs) of about 40–50 ms. Shorter and longer SOAs resulted in improved performance. When responding quickly, however, performance improved monotonically with SOA. These findings are discussed with reference to a 2-stage model of metacontrast, in which early responses reflect a stage of processing before surface completion is carried out (so only contour information is available). The technique of experimentally controlling response latency may prove useful in tracing the temporal development of other percepts. (PsycINFO Database Record (c) 2013 APA, all rights reserved)(journal abstract)

This document is currently not available here.