McEvoy L, Mäkelä J P, Hämäläinen M, Hari R
Low Temperature Laboratory, Helsinki University of Technology, Espoo, Finland.
Hear Res. 1994 Aug;78(2):249-57. doi: 10.1016/0378-5955(94)90031-0.
To determine if interaural time differences (ITDs) in binaural stimuli affect the middle-latency auditory evoked fields (AEFs) in the same manner as they affect the N100m deflection, neuromagnetic responses were recorded over the whole head using a 122-channel SQUID magnetometer. Binaural stimuli were lateralized to three positions, left, midline, and right, on the basis of ITDs. The N100m was significantly larger to stimuli with contralaterally-leading ITDs than to stimuli with no, or with ipsilaterally-leading ITDs. Neither the P30m nor the P50m deflections of the middle-latency response were significantly affected by ITD, although the P30m showed a tendency, similar to but smaller than that of N100m, to be larger to stimuli with contralaterally-leading ITDs. In some subjects, the source location of the P50m was anterior and inferior to the sources of the P30m and N100m, which are generated in the superior surface of the temporal lobe. Sound-related muscular artifacts were seen in the posterior recording channels of one subject, and the contribution of this activity to the signals over the temporal area was determined.
为了确定双耳刺激中的双耳时间差（ITD）是否以与影响N100m偏转相同的方式影响中潜伏期听觉诱发电场（AEF），使用122通道超导量子干涉仪磁力计在整个头部记录神经磁反应。基于ITD，将双耳刺激定位到三个位置：左、中线和右。与无ITD或同侧领先ITD的刺激相比，对侧领先ITD的刺激所诱发的N100m明显更大。尽管P30m显示出与N100m相似但较小的趋势，即对侧领先ITD的刺激所诱发的P30m更大，但中潜伏期反应的P30m和P50m偏转均未受到ITD的显著影响。在一些受试者中，P50m的源位置位于颞叶上表面产生的P30m和N100m源的前方和下方。在一名受试者的后部记录通道中观察到与声音相关的肌肉伪迹，并确定了该活动对颞区信号的贡献。
