On the word-superiority effect

Summary Four experiments tested Johnston's (1981) hierarchical-activation account and McClelland and Rumelhart's (1981) interactive-activation account of the word-superiority effect. The hierarchical-activation account claims that the effect depends on masking. Using both a luminance manipulation and direct feature removal, however, we showed that the word-superiority effect can be obtained without a mask. Moreover, when words were made hard to read by displaying them in a column, the context advantage with both the luminance and the feature-removal techniques was reduced to zero. With masking, in contrast, a context effect remained because of lower accuracy in the no-context (control) condition. Thus, masking confounds enhancement on context trials with inhibition on no-context trials and is neither a necessary nor a desirable procedure with which to demonstrate a context advantage.The advantage of word context is reduced when words are printed with extra space between the letters. The amount of space needed depends on the size of the letters — the reduction requires a manipulation about the size of a blank character. Although both define visual features spatially, neither model includes an internal representation of space. Thus, neither model can represent the configural manipulations, and neither can explain why column orientation and blank characters reduce the word-superiority effect.The research is based on a Ph.D thesis (Marchetti, 1983) supervised by the second author. The work was supported by post-graduate awards from the Natural Sciences and Engineering Research Council of Canada (NSERC) and from the Ontario Graduate Scholarship Fund to the first author. Laboratory facilities were made possible by grants from NSERC to the second author.Preliminary reports of the data were presented at the meeting of the Psychonomic Society in San Diego, November 1983 and at a conference, Common processes in speaking, listening, reading, and writing, held at the Centre for Interdisciplinary Research. University of Bielefeld, July, 1985