Gescheider G A, Bolanowski S J, Zwislocki J J, Hall K L, Mascia C
Department of Psychology, Hamilton College, Clinton, New York 13323.
J Acoust Soc Am. 1994 Sep;96(3):1479-88. doi: 10.1121/1.410290.
In this study, the hypothesis that the difference limen (DL) for the detection of differences in amplitude of vibrotactile stimuli is independent of the slope of the sensation magnitude function was tested. The slope of the sensation magnitude function was varied by presenting test stimuli in the presence of or in the absence of vibrotactile noise. The slopes of the sensation magnitude functions were determined through a matching technique in which the subject adjusted stimulus amplitudes of a 250-Hz stimulus presented alone and a 250-Hz stimulus presented simultaneously with a masking noise, so that their sensation magnitudes were equated. The slope of the matching function was found to increase as a function of the intensity of the masking noise. In the second phase of the experiment, the amplitude DL was measured by the gated-pedestal method for test stimuli presented under the same stimulus conditions as used in the matching procedure. At all levels of stimulus intensity, the DL was found to be independent of the masking condition provided the sensation magnitudes of the stimuli were the same. This finding supports the hypothesis that the size of the DL is independent of the slope of the sensation magnitude function, provided the sensation magnitudes of stimuli are the same. The generality of this principle, first discovered in hearing, is thus extended to another sense modality.
在本研究中，对振动触觉刺激幅度差异检测的差别阈（DL）与感觉强度函数斜率无关这一假设进行了测试。通过在存在或不存在振动触觉噪声的情况下呈现测试刺激来改变感觉强度函数的斜率。感觉强度函数的斜率通过一种匹配技术来确定，在该技术中，受试者调整单独呈现的250赫兹刺激以及与掩蔽噪声同时呈现的250赫兹刺激的幅度，以使它们的感觉强度相等。发现匹配函数的斜率随着掩蔽噪声强度的增加而增大。在实验的第二阶段，通过门控基线法测量在与匹配程序相同的刺激条件下呈现的测试刺激的幅度DL。在所有刺激强度水平下，只要刺激的感觉强度相同，DL就与掩蔽条件无关。这一发现支持了这样的假设：只要刺激的感觉强度相同，DL的大小就与感觉强度函数的斜率无关。因此，这一最初在听觉中发现的原理的普遍性被扩展到了另一种感觉模态。
