A COHORT MODEL OF VISUAL WORD RECOGNITION

A model of word recognition is proposed which assumes that when a word is encountered, the first available orthographic code activates all l exical entries that are positionally consistent with that information (i.e., the word's cohort). As subsequently encoded orthographic inform ation becomes available, activation is withdrawn from lexical entries with which it is inconsistent, and the cohort is resolved when only a single candidate remains. The model is intended to characterize: (1) T he initial encoding of the graphic information; (2) the recoding of th at information into an abstract orthographic form; (3) the manner in w hich the appropriate lexical entries are then activated; (4) the proce ss whereby subsequent orthographic encoding resolves those activated e ntries to a single candidate; and finally (5) the way in which subject s use information for making decisions as it emerges during this proce ssing. The model includes two critical points. The first is that lette r identity information is encoded in the form of a complex orthographi c unit termed a wickelgraph. A wickelgraph includes an encoding of the target letter's identiy information as its core, plus, as a context, the identity of its two immediately adjacent letters. The set of possi ble wickelgraphs is assumed to instantiate the rules of orthography. T he second point is that once a cohort is established, the perceiver ca n sample its status at any point during resolution and base a decision on the outcome of that sample. Some tasks (e.g., naming) may allow fo r a decision based on the initial status of the cohort, while others ( e.g., lexical decision) can require its complete resolution. Six exper iments are reported that illustrate some of these cohort effects in le xical access. (C) 1994 Academic Press, Inc.