Higashiyama A, Tashiro T
Percept Psychophys. 1989 Jun;45(6):537-49. doi: 10.3758/bf03208061.
The hypothesis that there are two neural mechanisms for electrocutaneous stimulation--one that is sensitive to low current and is adaptive to repeated stimulation and another that is responsive to high current and is less adaptive--was tested in a control and four main experiments. In the main experiments, magnitude estimates obtained for single electrical pulses (of 2-msec duration) were described by a simple power function for each combination of high- and low-current levels and 10 trial blocks. The results were: (1) The slope of the power function for low current was steeper than was that for high current; (2) for low current, the intercept of the power function decreased with increasing block, whereas for high current, it remained constant over blocks; (3) this decrease of the intercept for low current disappeared when judgmental blocks were separated by a rest period of 8 min; (4) the modulus did not affect the slope; (5) for a large modulus combined with low current, the intercept decreased rapidly over trial blocks, whereas for a small modulus combined with high current, the intercept increased over trial blocks. The first four findings support the two-mechanism hypothesis, but the last one may also be interpretable in terms of the regression to absolute scale values.
关于存在两种用于电皮肤刺激的神经机制的假说——一种对低电流敏感且对重复刺激具有适应性，另一种对高电流有反应且适应性较差——在一个对照实验和四个主要实验中进行了检验。在主要实验中，对于每个高电流和低电流水平的组合以及10个试验组块，通过一个简单的幂函数描述了对单个（持续时间为2毫秒的）电脉冲获得的量级估计。结果如下：(1) 低电流时幂函数的斜率比高电流时更陡；(2) 对于低电流，幂函数的截距随组块增加而减小，而对于高电流，它在各块中保持恒定；(3) 当判断组块被8分钟的休息时间隔开时，低电流截距的这种减小消失了；(4) 模量不影响斜率；(5) 对于大模量与低电流的组合，截距在试验组块中迅速减小，而对于小模量与高电流的组合，截距在试验组块中增加。前四个发现支持双机制假说，但最后一个发现也可以根据向绝对标度值的回归来解释。
