DOES MOTION-INDUCED GROUPING MODULATE THE FLANKER COMPATIBILITY EFFECT - A FAILURE TO REPLICATE DRIVER AND BAYLIS

Several experiments explored the possibility that motion-induced group ing would modulate the spatial distribution of the flanker compatibili ty effect (FCE). Subjects were required to make a speeded decision abo ut a central target letter embedded in a five letter string. On each t rial the identity of the near or far letters was either compatible or incompatible with the correct response while the remaining letters wer e neutral. In contrast to the findings of Driver & Baylis (1989), when the far distracters and the target moved together while the near dist racters remained stationary, we did NOT find that the FCE for the far distracters was greater than the FCE for the stationary near distracte rs. Moreover, the pattern of response latencies in this moving conditi on were not different from what we observed when all letters remained stationary. Accuracy was affected, but not in the direction predicted by the view that attention is directed to perceptual groups. Modulatio n of the distribution of attention in response to motion-induced group ing is not a robust phenomenon. Nevertheless, a simple spotlight model of attention is challenged by demonstrations in the literature that p erceptual grouping mediated by static properties such as closure, colo ur and good continuation strongly influence the spatial distribution o f the FCE and that the allocation of attention in search is strongly i nfluenced by stimulus motion.