Case alternation effect: two types of word recognition?

Two experiments were conducted to test Besner’s (1983) claim that the lexical decision task involves a type of recognition mechanism that simply monitors the visual familiarity of the target without uniquely specifying the word. The experiments tested the combined effects of case alternation and decision type, and case alternation and word frequency in a lexical decision task and in a task requiring speeded decisions about the syntactic usage of target words. Contrary to Besner’s proposal, case alternation did not affect word decisions more than nonword decisions in the lexical decision task. Further, the finding of additive effects of case alternation and word frequency in the two tasks was also at odds with the prediction derived from Besner’s account. The discrepancy between the results obtained by Besner and the present lexical decision task was discussed in terms of different decision strategies, and it was suggested that under conditions of difficult word-nonword discrimination, the global visual familiarity of the target is not involved in making lexical decisions.