Collier Elizabeth S, Lawson Rebecca
Department of Experimental Psychology, University of Liverpool, Eleanor Rathbone Building, Bedford Street South, Liverpool, L69 7ZA, UK.
Exp Brain Res. 2016 Sep;234(9):2697-708. doi: 10.1007/s00221-016-4673-x. Epub 2016 May 27.
In the filled space illusion, an extent filled with gratings is estimated as longer than an equivalent extent that is apparently empty. However, researchers do not seem to have carefully considered the terms filled and empty when describing this illusion. Specifically, for active touch, smooth, solid surfaces have typically been used to represent empty space. Thus, it is not known whether comparing gratings to truly empty space (air) during active exploration by touch elicits the same illusionary effect. In Experiments 1 and 2, gratings were estimated as longer if they were compared to smooth, solid surfaces rather than being compared to truly empty space. Consistent with this, Experiment 3 showed that empty space was perceived as longer than solid surfaces when the two were compared directly. Together these results are consistent with the hypothesis that, for touch, the standard filled space illusion only occurs if gratings are compared to smooth, solid surfaces and that it may reverse if gratings are compared to empty space. Finally, Experiment 4 showed that gratings were estimated as longer than both solid and empty extents in vision, so the direction of the filled space illusion in vision was not affected by the nature of the comparator. These results are discussed in relation to the dual nature of active touch.
在填充空间错觉中，一个充满光栅的范围被估计为比一个明显为空的同等范围更长。然而，研究人员在描述这种错觉时似乎没有仔细考虑“填充”和“空”这两个术语。具体而言，对于主动触摸，光滑、坚实的表面通常被用来代表空的空间。因此，在通过触摸进行主动探索时，将光栅与真正的空空间（空气）进行比较是否会产生相同的错觉效果尚不清楚。在实验1和实验2中，如果将光栅与光滑、坚实的表面进行比较，而不是与真正的空空间进行比较，光栅会被估计为更长。与此一致的是，实验3表明，当直接比较空空间和坚实表面时，空空间被感知为比坚实表面更长。这些结果共同与以下假设一致：对于触摸来说，只有当光栅与光滑、坚实的表面进行比较时，标准的填充空间错觉才会出现，如果将光栅与空空间进行比较，错觉可能会反转。最后，实验4表明，在视觉中，光栅被估计为比坚实和空的范围都更长，因此视觉中填充空间错觉的方向不受比较对象性质的影响。将结合主动触摸的双重性质对这些结果进行讨论。
