Visual Word Recognition: Are the Processing Dynamics Fixed?

The joint effects of word frequency and stimulus quality were additive on RT when participants read aloud high and low frequency words randomly mixed with nonwords at two levels of stimulus quality within a single block of trials. This directly contrasts with the interaction between word frequency and stimulus quality previously reported for the same word set when nonwords were excluded. This finding suggests that early processing dynamics underlying visual word recognition are variable rather than fixed. One way to explain these and other data appeals to the distinction between cascaded and thresholded modes of processing, with contextual factors determining which mode dominates.