An interactive activation model of context effects in letter perception: I. An account of basic findings.

Describes a model in which perception results from excitatory and inhibitory interactions of detectors for visual features, letters, and words. A visual input excites detectors for visual features in the display and for letters consistent with the active features. Letter detectors in turn excite detectors for consistent words. It is suggested that active word detectors mutually inhibit each other and send feedback to the letter level, strengthening activation and hence perceptibility of their constituent letters. Computer simulation of the model exhibits the perceptual advantage for letters in words over unrelated contexts and is considered consistent with basic facts about word advantage. Most important, the model produces facilitation for letters in pronounceable pseudowords as well as words. Pseudowords activate detectors for words that are consistent with most active letters, and feedback from the activated words strengthens activations of the letters in the pseudoword. The model thus accounts for apparently rule-governed performance without any actual rules. (50 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)