Mäkelä J P
Low Temperature Laboratory, Helsinki University of Technology, Espoo, Finland.
Pflugers Arch. 1988 Jul;412(1-2):12-6. doi: 10.1007/BF00583725.
Auditory evoked magnetic fields were recorded over the right hemisphere of healthy humans. The stimuli were noise bursts presented either to the contra- (C) or ipsilateral (I) ear in different combinations. The largest deflection of the responses, N100m (magnetic counterpart of electric N100), showed a field pattern which suggests activation of the supratemporal auditory cortex. In an oddball paradigm, where the standards (90%) were 400-ms noise bursts presented to the contralateral ear, and the deviants (10%) similar stimuli to the ipsilateral ear, the deviants elicited on the average 130% stronger equivalent dipoles for N100m than standards. Contralateral standards did not substantially decrease the response amplitude of ipsilateral deviants as compared with the response amplitude to ipsilateral stimuli alone presented at the interstimulus interval of the deviants. When two 50 ms noise bursts, separated by 310 ms, were presented once every 2 s, N100m evoked by the second stimulus of the pair was smaller when the stimuli were presented monaurally (C-C or I-I) than to different ears (I-C or C-I). The results suggest that contra- and ipsilateral auditory stimuli are analyzed, at least in part, in different neural networks at the human auditory cortex.
在健康人类的右半球记录听觉诱发磁场。刺激是不同组合呈现给对侧（C）或同侧（I）耳的噪声脉冲。反应的最大偏转，即N100m（电N100的磁对应物），显示出一种场模式，表明颞上听觉皮层被激活。在一个oddball范式中，标准刺激（90%）是呈现给对侧耳的400毫秒噪声脉冲，偏差刺激（10%）是与同侧耳相似的刺激，与标准刺激相比，偏差刺激诱发的N100m等效偶极子平均强130%。与仅在偏差刺激的刺激间隔单独呈现同侧刺激时的反应幅度相比，对侧标准刺激并没有显著降低同侧偏差刺激的反应幅度。当每2秒呈现一对间隔310毫秒的50毫秒噪声脉冲时，当刺激单耳呈现（C-C或I-I）时，该对中的第二个刺激诱发的N100m比刺激双耳呈现（I-C或C-I）时小。结果表明，对侧和同侧听觉刺激至少部分在人类听觉皮层的不同神经网络中进行分析。
