Churan Jan, Paul Johannes, Klingenhoefer Steffen, Bremmer Frank
Department of Neurophysics, Marburg University, Marburg, Germany; and
Department of Neurophysics, Marburg University, Marburg, Germany; and.
J Neurophysiol. 2017 Sep 1;118(3):1650-1663. doi: 10.1152/jn.00342.2017. Epub 2017 Jun 28.
In the natural world, self-motion always stimulates several different sensory modalities. Here we investigated the interplay between a visual optic flow stimulus simulating self-motion and a tactile stimulus (air flow resulting from self-motion) while human observers were engaged in a distance reproduction task. We found that adding congruent tactile information (i.e., speed of the air flow and speed of visual motion are directly proportional) to the visual information significantly improves the precision of the actively reproduced distances. This improvement, however, was smaller than predicted for an optimal integration of visual and tactile information. In contrast, incongruent tactile information (i.e., speed of the air flow and speed of visual motion are inversely proportional) did not improve subjects' precision indicating that incongruent tactile information and visual information were not integrated. One possible interpretation of the results is a link to properties of neurons in the ventral intraparietal area that have been shown to have spatially and action-congruent receptive fields for visual and tactile stimuli. This study shows that tactile and visual information can be integrated to improve the estimates of the parameters of self-motion. This, however, happens only if the two sources of information are congruent-as they are in a natural environment. In contrast, an incongruent tactile stimulus is still used as a source of information about self-motion but it is not integrated with visual information.
在自然界中，自我运动总会刺激多种不同的感觉模态。在此，我们研究了在人类观察者进行距离再现任务时，模拟自我运动的视觉光流刺激与触觉刺激（自我运动产生的气流）之间的相互作用。我们发现，向视觉信息中添加一致的触觉信息（即气流速度与视觉运动速度成正比）能显著提高主动再现距离的精度。然而，这种提高比视觉和触觉信息的最优整合所预测的要小。相比之下，不一致的触觉信息（即气流速度与视觉运动速度成反比）并不能提高受试者的精度，这表明不一致的触觉信息和视觉信息没有被整合。对这些结果的一种可能解释是，这与腹侧顶内区神经元的特性有关，这些神经元已被证明对视觉和触觉刺激具有空间和动作一致的感受野。这项研究表明，触觉和视觉信息可以整合起来以改善对自我运动参数的估计。然而，只有当这两种信息源一致时才会发生这种情况——就像在自然环境中那样。相比之下，不一致的触觉刺激仍被用作关于自我运动的信息源，但它不会与视觉信息整合。
