Johansson Roland S, Birznieks Ingvars
Department of Integrative Medical Biology, Physiology Section, Umeå University, SE-901 87 Umeå, Sweden.
Nat Neurosci. 2004 Feb;7(2):170-7. doi: 10.1038/nn1177. Epub 2004 Jan 18.
It is generally assumed that primary sensory neurons transmit information by their firing rates. However, during natural object manipulations, tactile information from the fingertips is used faster than can be readily explained by rate codes. Here we show that the relative timing of the first impulses elicited in individual units of ensembles of afferents reliably conveys information about the direction of fingertip force and the shape of the surface contacting the fingertip. The sequence in which different afferents initially discharge in response to mechanical fingertip events provides information about these events faster than the fastest possible rate code and fast enough to account for the use of tactile signals in natural manipulation.
一般认为，初级感觉神经元通过其放电频率来传递信息。然而，在自然物体操作过程中，来自指尖的触觉信息的使用速度比速率编码能够轻易解释的速度要快。在这里，我们表明，传入神经群中各个单元引发的第一个冲动的相对时间可靠地传达了有关指尖力方向和接触指尖表面形状的信息。不同传入神经最初响应指尖机械事件而放电的顺序，比最快的速率编码更快地提供有关这些事件的信息，并且快到足以解释自然操作中触觉信号的使用情况。
