Lin Y Y, Forss N
Brain Research Unit, Low Temperature Laboratory, Helsinki University of Technology, P.O. Box 2200, FIN-02015 HUT Espoo, Finland.
Behav Brain Res. 2002 Sep 20;135(1-2):141-5. doi: 10.1016/s0166-4328(02)00143-2.
Magnetoencephalographic (MEG) recordings allow noninvasive monitoring of simultaneously active brain areas with reasonable spatial and excellent temporal resolution. Whole-scalp neuromagnetic recordings show activation of contralateral primary (SI) and bilateral second (SII) somatosensory cortices to unilateral median nerve stimulation. Recent MEG studies on healthy and diseased human subjects have shown some functional characteristics of SII cortex. Besides tactile input, the SII cortex also responds to nociceptive afferents. The SII activation is differentially modulated by isometric muscle contraction of various body parts. Lesions in the SII cortex may disturb the self-perception of body scheme. Moreover, the SI and SII cortices may be sequentially activated within one hemisphere, but the SII cortex may also receive direct peripheral input on the ipsilateral side.
脑磁图（MEG）记录能够以合理的空间分辨率和出色的时间分辨率对同时活跃的脑区进行无创监测。全头皮神经磁记录显示，单侧正中神经刺激会激活对侧初级（SI）和双侧次级（SII）体感皮层。最近针对健康和患病人类受试者的MEG研究揭示了SII皮层的一些功能特征。除了触觉输入外，SII皮层还对伤害性传入信号做出反应。SII激活受到身体各部位等长肌肉收缩的差异调节。SII皮层的损伤可能会扰乱身体图式的自我认知。此外，SI和SII皮层可能在一个半球内依次被激活，但SII皮层也可能在同侧接受直接的外周输入。
