Naming the color of a word: Is it responses or task sets that compete?

Subjects named the colors in which high- and low-frequency words and pronou nceable nonwords, otherwise matched, were displayed. Color naming was slowe r for all three item types than for visually equivalent strings of nonalpha numeric symbols but was no slower for words than for nonwords, nor for high -frequency words than for low-frequency words. Unpronounceable letter strin gs had intermediate color-naming latencies. However, frequency and lexical status had large effects on latency for reading the same words and pseudowo rds aloud. Interference is thus predicted not by the strength of associatio n between a letter string and its pronunciation but by the presence of word -like constituents. We argue that the interference from an unprimed noncolo r word is due to, and isolates, one of two components of the classic Stroop effect: competition from the whole task set of reading. The other componen t, response competition, occurs only when lexical access is sufficiently pr imed.