Gescheider G A, Hoffman K E, Harrison M A, Travis M L, Bolanowski S J
Department of Psychology, Hamilton College, Clinton, New York 13323.
J Acoust Soc Am. 1994 Feb;95(2):1006-16. doi: 10.1121/1.408464.
Thresholds for the detection of vibrotactile signals of varied duration applied to the thenar eminence were measured in the absence of and in the presence of a masking stimulus. Signals were 250- and 500-Hz sinusoids and noise bursts with bandwidth limited to 250-1000 Hz. The masking stimulus was either a 250-Hz sinusoid, which was presented in phase with the signal when it was sinusoidal, or noise. Changes in threshold as a function of changes in signal duration were found which were predicted accurately from Zwislocki's theory [J. Acoust. Soc. Am. 32, 1046-1060 (1960)] of temporal summation when the signal was detected by the Pacinian channel, but not when it was detected by a non-Pacinian channel (NP). However, when either the signal or the masking stimulus or both were noise, NP thresholds were affected by changes in signal duration. Only when the signal and masking stimuli were both sinusoids were NP thresholds independent of signal duration. It is concluded that signal duration effects in the NP channel are not due to temporal integration, but rather to increases in information about the signal content provided to the subject as exposure duration is increased.
在有无掩蔽刺激的情况下，测量了施加于鱼际隆起处的不同持续时间的振动触觉信号的检测阈值。信号为250赫兹和500赫兹的正弦波以及带宽限制在250 - 1000赫兹的噪声脉冲串。掩蔽刺激要么是250赫兹的正弦波（当信号为正弦波时与信号同相呈现），要么是噪声。发现阈值随信号持续时间变化而变化，当信号由帕西尼氏通道检测时，根据兹维斯洛茨基关于时间总和的理论[《美国声学学会杂志》32, 1046 - 1060 (1960)]能准确预测这种变化，但当信号由非帕西尼氏通道（NP）检测时则不然。然而，当信号或掩蔽刺激或两者都是噪声时，NP阈值会受到信号持续时间变化的影响。只有当信号和掩蔽刺激都是正弦波时，NP阈值才与信号持续时间无关。得出的结论是，NP通道中的信号持续时间效应不是由于时间整合，而是由于随着暴露持续时间增加，提供给受试者的关于信号内容的信息增加。
