Hari R, Pelizzone M, Mäkelä J P, Hällström J, Leinonen L, Lounasmaa O V
Audiology. 1987;26(1):31-43. doi: 10.3109/00206098709078405.
Cortical sources of neuromagnetic responses to noise bursts were compared in 7 healthy humans. The earliest response, P40m, peaking about 40 ms after the stimulus onset, was followed by a prominent deflection in the opposite direction at about 100 ms (N100m) and by another peak at 200 ms (P200m). A sustained field, seen near the end of the 400- to 550-ms stimuli, ended with an off-response of the same polarity as N100m. All deflections could be explained by cortical activity within the Sylvian fissure. The source of P200m was anterior to other sources of the on-response, except P40m. When noise bursts, or pauses of equal duration in a continuous noise were presented to the subject, striking similarities were found between the 100-ms deflections of the on- and off-responses: both peaked at about the same latency; their estimated sources were closed to each other in the supratemporal plane and their amplitudes depended in a similar way on the interstimulus interval (1.1-8.8 s). However, only the on-response was preceded by P40m, suggesting that P40m and N100m are not causally linked. N100m seems to reflect cortical activity related to any abrupt change in the auditory environment.
在7名健康受试者中比较了对噪声猝发的神经磁反应的皮层来源。最早的反应，即P40m，在刺激开始后约40毫秒达到峰值，随后在约100毫秒时出现相反方向的明显偏转（N100m），并在200毫秒时出现另一个峰值（P200m）。在400至550毫秒刺激接近结束时出现一个持续场，以与N100m相同极性的离场反应结束。所有偏转都可以用颞叶沟内的皮层活动来解释。P200m的来源位于起始反应的其他来源（P40m除外）之前。当向受试者呈现噪声猝发或连续噪声中持续时间相等的停顿，在起始反应和离场反应的100毫秒偏转之间发现了惊人的相似之处：两者在大致相同的潜伏期达到峰值；它们估计的来源在颞上平面彼此接近，并且它们的振幅以类似的方式取决于刺激间隔（1.1 - 8.8秒）。然而，只有起始反应之前有P40m，这表明P40m和N100m没有因果联系。N100m似乎反映了与听觉环境中任何突然变化相关的皮层活动。
