Crommett Lexi E, Pérez-Bellido Alexis, Yau Jeffrey M
Department of Neuroscience, Baylor College of Medicine, Houston, Texas.
Department of Neuroscience, Baylor College of Medicine, Houston, Texas
J Neurophysiol. 2017 Mar 1;117(3):1352-1362. doi: 10.1152/jn.00783.2016. Epub 2017 Jan 11.
Our ability to process temporal frequency information by touch underlies our capacity to perceive and discriminate surface textures. Auditory signals, which also provide extensive temporal frequency information, can systematically alter the perception of vibrations on the hand. How auditory signals shape tactile processing is unclear; perceptual interactions between contemporaneous sounds and vibrations are consistent with multiple neural mechanisms. Here we used a crossmodal adaptation paradigm, which separated auditory and tactile stimulation in time, to test the hypothesis that tactile frequency perception depends on neural circuits that also process auditory frequency. We reasoned that auditory adaptation effects would transfer to touch only if signals from both senses converge on common representations. We found that auditory adaptation can improve tactile frequency discrimination thresholds. This occurred only when adaptor and test frequencies overlapped. In contrast, auditory adaptation did not influence tactile intensity judgments. Thus auditory adaptation enhances touch in a frequency- and feature-specific manner. A simple network model in which tactile frequency information is decoded from sensory neurons that are susceptible to auditory adaptation recapitulates these behavioral results. Our results imply that the neural circuits supporting tactile frequency perception also process auditory signals. This finding is consistent with the notion of supramodal operators performing canonical operations, like temporal frequency processing, regardless of input modality. Auditory signals can influence the tactile perception of temporal frequency. Multiple neural mechanisms could account for the perceptual interactions between contemporaneous auditory and tactile signals. Using a crossmodal adaptation paradigm, we found that auditory adaptation causes frequency- and feature-specific improvements in tactile perception. This crossmodal transfer of aftereffects between audition and touch implies that tactile frequency perception relies on neural circuits that also process auditory frequency.
我们通过触觉处理时间频率信息的能力是我们感知和辨别表面纹理的基础。听觉信号同样提供丰富的时间频率信息，它能够系统地改变对手部振动的感知。听觉信号如何塑造触觉处理尚不清楚；同时出现的声音和振动之间的感知交互符合多种神经机制。在这里，我们使用了一种跨模态适应范式，该范式在时间上分离了听觉和触觉刺激，以检验触觉频率感知依赖于也处理听觉频率的神经回路这一假设。我们推断，只有当来自两种感官的信号汇聚到共同的表征上时，听觉适应效应才会转移到触觉上。我们发现听觉适应可以提高触觉频率辨别阈值。这种情况仅在适应刺激频率和测试频率重叠时才会发生。相比之下，听觉适应并不影响触觉强度判断。因此，听觉适应以频率和特征特异性的方式增强触觉。一个简单的网络模型，其中触觉频率信息从易受听觉适应影响的感觉神经元中解码出来，概括了这些行为结果。我们的结果表明，支持触觉频率感知的神经回路也处理听觉信号。这一发现与超模态算子执行规范操作（如时间频率处理）的概念一致，而与输入模态无关。听觉信号可以影响对时间频率的触觉感知。多种神经机制可以解释同时出现的听觉和触觉信号之间的感知交互。使用跨模态适应范式，我们发现听觉适应会导致触觉感知在频率和特征方面的特异性改善。听觉和触觉之间这种后效的跨模态转移意味着触觉频率感知依赖于也处理听觉频率的神经回路。
