WHAT CAN A PRECUE ENHANCE - AN ANALYSIS OF THE EXPERIMENTS OF PROCTOR, LU AND VAN ZANDT (1992)

Contrary to traditional conceptions, Stoffels, Van der Molen and Keuss (1989) and Hasbroucq and Guiard (1998) have proposed that the Simon e ffect reflects the processes of stimulus identification rather than th ose of response selection. In a recent issue of the journal, this new hypothesis was challenged by Proctor, Lu and Van Zandt (1992) on the b asis of results showing that the Simon effect can be enhanced by precu ing procedures. In the present paper, the evidence gathered by Proctor et al. is closely examined and a new analysis reveals that the data p resented support rather than invalidate an explanation of the Simon ef fect in terms of stimulus identification mechanisms.