Abstract
It is well known that one's preference is facilitated or impeded due to misattribution of a prior cognitive event as shown in priming, framing, or orienting behavior. Here we report the initial finding that misattribution occurs even due to a visuo-motor conflict. Twenty subjects were asked to choose a preferred face out of the two faces, presented on the left and right sides of a central fixation point, by moving a joystick leftward or rightward. In the background, task-irrelevant random dot motion (moving leftward, rightward, or vertically) was presented at one of six coherence levels (0, 5, 10, 20, 50, 100%). According to subjects' choice, trials were classified into the three types: a congruent trial (the direction from the fixation point to the chosen face matched the direction of task-irrelevant motion), an incongruent trial (the two directions were opposite), and a baseline trial (the two directions were perpendicular). Results indicate that only when task-irrelevant motion was subliminal (5% coherence), the number of the congruent trials was significantly larger than that of the incongruent trials. Following each choice, the subjects were asked to rate their relative preference for the chosen face on a five-point scale. The relative preference was significantly higher in congruent trials than in incongruent trials only when subliminal motion was presented. In addition, the relative preference was significantly impeded when a subliminal motion direction was opposite to a response direction but was not facilitated when these directions were the same. Taken together with results of further experiments, we conclude that when a conflict between directions of motor response and task-irrelevant motion is not consciously noticed, it can be misattributed to preferential decision. Moreover, unlike the misattribution of a prior cognitive event that can facilitate or impede preference, visuo-motor misattribution only impedes preference but do not facilitate it.
This study is funded by grants from NFS (BCS-0549036) and NIH (R01 EY 015980, R01 EY019466, R01 AG031941, R01 MH091801) to T.W. K. S. was supported by the Uehara Memorial Foundation. Portions of the research in this paper use the FERET database of facial images collected under the FERET program, sponsored by the DOD Countergrug Technology Development Program Office. We thank CVL and CV, PTER, Velenje for granting permission to use their face database and Kou Murayama and Hisato Imai for their comments on the earlier version of our study.