The human visual system is extremely sensitive to biological signals around us. In the current study, we demonstrate that biological motion walking direction can induce robust reflexive attentional orienting. Following a brief presentation of a central point-light walker walking towards either the left or right direction, observers' performance was significantly better on a target in the walking direction compared with that in the opposite direction even when participants were explicitly told that walking direction was not predictive of target location. Interestingly, the effect disappeared when the walker was shown upside-down. Moreover, the reflexive attentional orienting could be extended to motions of other biological entities but not inanimate objects, and was not due to the viewpoint effect of the point-light figure. Our findings provide strong evidence that biological motion cues can trigger reflexive attentional orienting, and highlight the intrinsic sensitivity of the human visual attention system to biological signals.
Bibliographical noteFunding Information:
This research was supported by the Knowledge Innovation Program of Chinese Academy of Sciences (KSCX2-YW-R-248 and 09CX202020), Chinese Ministry of Science and Technology (2007CB512300), and the US National Science Foundation (BCS-0818588) and National Institutes of Health (EY015261). We thank Nikolaus Troje for kindly providing us the point-light biological motion stimuli, and Robert Shannon and Patricia Costello for their help with English proof.
- Biological motion
- Reflexive orienting
- Walking direction