Orientation-dependent priming effects in the perception of biological motion.

In a serial 2-choice reaction time task, subjects discriminated between a biological motion walker and a similar distractor. The point-light walker appeared in 1 of 2 possible in-depth orientations: The figure was walking either to the right or to the left in the sagittal plane. Reliable priming effects were established in consecutive trials but only when priming and primed walkers had the same in-depth orientation. This orientation-dependent priming effect was not tempered when priming and primed figures had different directions of articulatory motion (Experiments 1 to 6), different starting positions in the step cycle (Experiment 2), and different point-light localizations (Experiment 3) or when the figures were translating (Experiments 4 to 6). The data converge with neurophysiological findings that suggest that object recognition is accomplished by accessing high-level, orientation-dependent representations.