PROCESSING SPATIAL INFORMATION AND SELECTIVE-MASKING EFFECT

When a mask follows tachistoscopic presentation of a letter string, the performance on the middle letters is reduced more than at the ends, the selective-masking effect. The ends-first explanation for selective masking holds that the letter string is identified from the ends to the middle. As a result, the end items escape the effects of the mask. Using a bar-probe task, we present three kinds of evidence both questioning the ends-first account and offering an alternate based on spatial-localization processes. The first experiment exposed the role of spatial localization by using words to minimize identification factors. The second obtained a comparable selective-masking effect with pseudowords; again, the pattern of errors favored the localization account. A final experiment tested predictions derived from the localization view in response to inconsistencies posed by the sequential-identification idea. © 1978 Psychonomic Society, Inc.