Changes in posterior auricular muscle response and middle-latency brain potential evoked by auditory stimuli according to neck flexion

抄録

  The posterior auricular muscle response（PAMR）and middle-latency auditory response（MLR）evoked by auditory stimuli were examined to know the changes in activation degree of auditory neural circuit while maintaining neck flexion. Fourteen healthy subjects heard click sounds via headphones. The click frequency was 8 Hz and the intensity was 50 dB above hearing threshold. Measurement was carried out with the neck flexed at 0°, 10°and 20°. The PAMR and MLR were simultaneously measured in the neck flexion condition. One trial was 30 seconds, it repeated 5 times with a 30 seconds rest and total of click stimulations in each session was 1000. In the PAMR, the amplitude increased according to the neck flexion, and the latency shortened. In the MLR, the components（Po, Na）with latencies that were almost corresponding to the PAMR（p1, n2）existed. However, the changes in the both responses according to the neck flexion were not so similar as to be able to say that they were influenced by quite the same factor. The change in the latter component of the MLR according to the neck flexion showed the lower similarity to the PAMR.