van Beers R J, Sittig A C, Denier van der Gon J J
Faculty of Design, Engineering and Production, Delft University of Technology, The Netherlands.
Exp Brain Res. 1999 Mar;125(1):43-9. doi: 10.1007/s002210050656.
In a previous study we investigated how the CNS combines simultaneous visual and proprioceptive information about the position of the finger. We found that localization of the index finger of a seen hand was more precise (a smaller variance) than could reasonably be expected from the precision of localization on the basis of vision only and proprioception only. This suggests that, in localizing the tip of the index finger of a seen hand, the CNS may make use of more information than proprioceptive information and visual information about the fingertip. In the present study we investigate whether this additional information stems from additional sources of sensory information. In experiment 1 we tested whether seeing an entire arm instead of only the fingertip gives rise to a more precise proprioceptive and/or visual localization of that fingertip. In experiment 2 we checked whether the presence of a structured visual environment leads to a more precise proprioceptive localization of the index finger of an unseen hand. In experiment 3 we investigated whether looking in the direction of the index finger of an unseen hand improves proprioceptive localization of that finger. We found no significant effect in any of the experiments. The results refute the hypothesis that the investigated effects can explain the previously reported very precise localization of a seen hand. This suggests that localization of a seen finger is based exclusively on proprioception and on vision of the finger. The results suggest that these sensory signals may contain more information than is described by the magnitude of their variances.
在之前的一项研究中，我们探究了中枢神经系统（CNS）如何整合关于手指位置的同时性视觉和本体感觉信息。我们发现，对于所看到的手的食指定位比仅基于视觉和仅基于本体感觉的定位精度所能合理预期的更为精确（方差更小）。这表明，在定位所看到的手的食指指尖时，中枢神经系统可能利用了比关于指尖的本体感觉信息和视觉信息更多的信息。在本研究中，我们调查了这种额外信息是否源于额外的感觉信息源。在实验1中，我们测试了看到整条手臂而非仅指尖是否会使该指尖的本体感觉和/或视觉定位更精确。在实验2中，我们检查了结构化视觉环境的存在是否会使未看到的手的食指的本体感觉定位更精确。在实验3中，我们研究了看向未看到的手的食指方向是否会改善该手指的本体感觉定位。我们在任何实验中均未发现显著影响。这些结果反驳了以下假设，即所研究的效应可以解释先前报道的所看到的手的非常精确的定位。这表明所看到的手指的定位仅基于本体感觉和手指的视觉。结果表明，这些感觉信号可能包含比其方差大小所描述的更多信息。
