Abstract:

Kelly et al. (2007) studied sensorimotor alignment effects in the learning environment and novel environment. It found that sensorimotor alignment effects disappeared in the novel environment. But Xiao and Liu (2014) found that sensorimotor alignment effects always appeared in the novel environment except when participants faced the opposite direction to the learning direction. These two studies’ results were both interpreted by the dual system spatial memory theories, which made a hypothesis that sensorimotor and memory alignment effects need different representations. The reason might be that the different promoting extend of memory and body movement to the spatial updating procedure. The promotion effects of memory to spatial updating were efficient both in online and offline representations. Therefore, it is possible to make a comparative study on the two promotion effects of memory and body movement to the spatial updating. The paradigm used in Kelly et al. (2007) was applied in the present study. After remembering a body-centered spatial layout, participants were asked to finish spatial judgments in imagined perspectives (for example, “imagine that you faced A, point to B.”). The imagined perspectives were memory-aligned (the imagined perspective was aligned with learning perspective), sensorimotor-aligned (the imagined perspective was aligned with the current body direction) and misaligned (the imagined perspective was neither aligned with learning perspective nor aligned with the current body direction. And it was defined as the opposite direction of sensorimotor- aligned perspective while the learned perspective was the axis of symmetry) perspectives. The promotion of memory to spatial updating was defined as the subtraction of misaligned and memory-aligned performances. The promotion of body movement to spatial updating was defined as the subtraction of misaligned and sensorimotor-aligned performances. In Experiment 1, 20 participants (10 men) learned a regular 8-object layout and then they turned 90 degrees to the left or right before they performed spatial judgments from a perspective aligned with the learning direction (memory aligned), aligned with the direction they face (sensorimotor aligned), and the novel direction misaligned with the two directions mentioned above (misaligned). In each imagined perspective, participants pointed to all the 8 objects of the layout (e.g. “Imagine that you are facing the ball, please point to the candle”). Each participant performed 48 trials (8 target objects × 3 imagined perspectives × 2 blocks). Participants in experiment 2 finished the same spatial judgment task in the novel environment. After learning the spatial layout, the participants of Experiment 2a were disoriented before standing at the testing position in the novel environment, facing 180 degrees opposite to the learning direction. And the participants of Experiment 2b walked straight forward to the testing position in the novel environment remaining in their orientation. The participants of Experiment 2c turned to face the direction opposite to learning perspective after walking straightforward to the novel environment. The dependent measures were the latency and the absolute angular error of the pointing response. In Experiment 1, the pointing latency and absolute pointing error were subjected to mixed-model analyses of variance (ANOVAs), with imagined heading (memory aligned, sensorimotor aligned, or misaligned) as the within-subject variable. Participants pointed more accurately and faster from the memory aligned perspective than from the misaligned perspective (a memory alignment effect), and faster from the sensorimotor aligned perspective than from the misaligned perspective (a sensorimotor alignment effect). The same effects appeared in Experiment 2a, 2b, but not 2c. The Pearson correlations between the promotion of memory to spatial updating and promotion of body movement to spatial updating were significantly high in all of the conditions. And these two effects were significantly different only in Experiment 2. In conclusion, results in the present study indicate that the environment dependent effect of body movement exists. The promotion effect of body movement is equally effective in the learning environment but significantly worse in the novel environment than the promotion effect of memory to spatial updating.

Key words: body movement, spatial updating, spatial imagination, dual system processing, environment dependent effect.