SOMATOSENSORY EVOKED-POTENTIAL CORRELATES OF PSYCHOPHYSICAL MAGNITUDE ESTIMATIONS FOR TACTILE AIR-PUFF STIMULATION IN MAN
SOMATOSENSORY EVOKED-POTENTIAL CORRELATES OF PSYCHOPHYSICAL MAGNITUDE ESTIMATIONS FOR TACTILE AIR-PUFF STIMULATION IN MAN
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DOI：
10.1007/bf00406602
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发表时间：
1988-01-01
影响因子：
2
通讯作者：
SASAKI, M
中科院分区：
文献类型：
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作者：
HASHIMOTO, I;YOSHIKAWA, K;SASAKI, M
短暂的充气刺激应用于右手掌面，以获得心理物理和神经生理反应。首先确定了检测阈值（So）为0.56 kg .cntdot。cm-2。+ -。0.20 kg .cntdot。Cm-2，平均值+-。SD)和六个级别的刺激强度(So + 0.25 kg .cntdot。cm-2，所以+ 1.24 kg。厘米-2，所以+ 2.50公斤。厘米-2，所以+ 3.75千克。cm-2，所以+ 5.00 kg。所以+ 6.25 kg。cntdot。利用So + 2.50 kg .cntdot的刺激水平，采用cm-2)进行震级估计。Cm-2作为标准刺激。受试者被要求对随机呈现的一系列刺激强度进行数值估计。对120次相同强度的充气反应，记录手部感觉区皮层sep。因此，从每个被试中获得了随机顺序给出的六组刺激强度的sep。刺激后100 ms内记录6种成分（N20、P27、N35、P45、N60和P75）。由此可见，一个指数为0.81的简单幂函数可以很好地描述震级估计的刺激-响应函数，高相关系数（r - 0.98）也揭示了这一点。同样，在双对数图中，不同SEP分量的刺激振幅函数用直线很好地表示。早期P27-N35的指数最高（0.56），相关系数也最高（r = 0.91）。在横坐标上绘制主观幅度会产生类似于刺激幅度函数的幂函数。然而，后期成分的相关性较高。去除主观强度的影响后，前四个分量的振幅与刺激强度相关。而在刺激强度保持不变的情况下，后三个分量的振幅与主观幅度呈显著正相关。这些结果可能表明，早期的SEP成分代表了物理强度的神经编码，而后期的SEP成分与刺激的主观判断更密切相关。
Brief air-puff stimuli were applied to the volar surface of the right hand to obtain both psychophysical and neurophysiological responses. The detection threshold (So) was first determined (0.56 kg .cntdot. cm-2 .+-. 0.20 kg .cntdot. cm-2, mean .+-. SD) and six levels of the stimulus intensities (So + 0.25 kg .cntdot. cm-2, So + 1.24 kg .cntdot. cm-2, So + 2.50 kg .cntdot. cm-2, So + 3.75 kg .cntdot. cm-2, So + 5.00 kg .cntdot. cm-2, and So + 6.25 kg .cntdot. cm-2) were employed for magnitude estimation using the stimulus level of So + 2.50 kg .cntdot. cm-2 as the standard stimulus. The subject was asked to estimate numerically the series of stimulus intensities randomly presented. Cortical SEPs were recorded over the hand sensory area in response to a set of 120 air-puffs at the identical intensity level. Thus SEPs for six sets of stimulus intensities given in a random order were obtained from each subject. Six components (N20, P27, N35, P45, N60, and P75) were recorded within 100 ms following stimulation. It was seen that a simple power function with an exponent of 0.81 could be an adequate description of the stimulus-response function for magnitude estimation, as was also revealed by the high correlation coefficient (r - 0.98). Similarly, stimulus-amplitude functions of different SEP components were well represented by straight lines in double logarithmic plots. The function of the early P27-N35 had the highest exponent (0.56) and also the highest correlation coefficient (r = 0.91). Plotting subjective magnitude on the abscissa produced power functions similar to the stimulus-amplitude functions. However, higher correlations were observed for later components. The amplitudes of the four earlier components correlated with stimulus intensity when the effect of subjective magnitudes was removed. In contrast, the correlation between amplitudes and subjective magnitudes with stimulus intensity held constant was positive and significant for the latter three components. These results may indicate that early SEP components represent neural coding of physical intensity while later components are more closely related to the subjective judgment of the stimulus.