Avant, Thieman, Brewer, and Woodman (1986) reported that sign message (Stop, Left, Right, Slow) and sign format (word vs. symbol) influenced detection accuracy with exposures at which overall sign presence/absence detection was at chance level (24 msec). Also, a duration judgment task showed that the brain had begun to extract sign message end format information with an exposure duration two standard deviations below that required for chance-level presence/absence detection (8 msec). The present research controlled a previously unsuspected luminance factor in testing (a) effects of sign message and format with 16, 8, 6, 4, and 2 msec exposures and (b) separable effects of sign shape, colour, and words. Sign message and format information was processed with exposures as brief as 4 mec and was apparently not mediated by prior separate processing of sign shape, colour, or words. (Author/publisher)
Samenvatting