Sherrick C E, Cholewiak R W, Collins A A
Department of Psychology, Princeton University, New Jersey 08544-1010.
J Acoust Soc Am. 1990 Jul;88(1):169-79. doi: 10.1121/1.399937.
Four experiments were conducted to determine whether spatial localization on the skin varied in acuity as a function of frequency of vibratory stimulation. The glabrous skin of the palm over the hypothenar eminence was selected as the site for stimulation by two frequencies, one at 25 Hz to stimulate non-Pacinian receptors, and one at 250 Hz to excite Pacinian receptors. Because the Pacinian receptors have larger receptive fields than the non-Pacinians, it was thought that the subjects' ability to localize would be poorer when the Pacinians were the class of receptor stimulated. In addition to frequency of vibration, the presence of a surround, the site of stimulation, the separation of the stimulator pair used in the 2AFC method, and the use of an impulse stimulus were all conditions varied to determine whether a simple direct correlation exists between receptor category and spatial acuity for vibratory stimuli. A significant difference in acuity was found as a function of vibration frequency at a proximal locus on the palm, but this vanished at a distal locus. The results have been interpreted to suggest that receptor density and its gradient across the skin areas involved may be as important as receptor type in the determination of spatial acuity.
进行了四项实验，以确定皮肤上的空间定位敏锐度是否会随着振动刺激频率的变化而变化。选择小鱼际隆起上方手掌的无毛皮肤作为刺激部位，采用两种频率进行刺激，一种是25赫兹，用于刺激非帕西尼小体感受器，另一种是250赫兹，用于激发帕西尼小体感受器。由于帕西尼小体感受器的感受野比非帕西尼小体感受器的大，因此人们认为当刺激的感受器类型为帕西尼小体感受器时，受试者的定位能力会较差。除了振动频率外，还改变了周围环境的存在、刺激部位、用于二项迫选法的刺激器对之间的间距以及使用脉冲刺激等条件，以确定对于振动刺激而言，感受器类型与空间敏锐度之间是否存在简单的直接关联。在手掌近端部位发现敏锐度随振动频率存在显著差异，但在远端部位这种差异消失了。这些结果被解释为表明，在所涉及的皮肤区域上，感受器密度及其梯度可能与感受器类型在确定空间敏锐度方面同样重要。
