INVESTIGATING VISUAL DEGRADATION COSTS IN WORD RECOGNITION
Skilled reading is an outcome of perceptual expertise. Years of practice shift perceptual processing from a serial to a parallel analysis of a word's components (e.g., letters). Degrading a word by letter spacing or word inversion (i.e., 180Â° rotation) impairs recognition, possibly because a fast parallel-process fails and the reader resorts to a slow serial-process (Cohen et al., 2008). To examine this proposal we manipulated the mode of visual degradation (inversion, spacing, or both), word length (3-6 letters) and stimulus duration (limited, unlimited) in a semantic decision task. The main finding was that a word length effect (WLE), marking the transition from parallel-to-serial analysis, emerged in response times for words degraded by inversion that were presented for an unlimited duration, but was absent for inverted words presented for a limited duration (174 ms).This finding supports the view of two successive perceptual processing stages â€“ parallel and serial - during word recognition (e.g., Ans et al., 1998). However, an unexpected difference between 5- and 6-letter standard words in the unlimited duration warrants modification of such a "2- stage" model. We discuss the addition of a "verification" process to resolve these seemingly contradictory findings.