The effect of stimulus probability on the somatosensory mismatch field
The effect of stimulus probability on the somatosensory mismatch field
复制标题
DOI：
10.1007/s00221-007-0958-4
复制
发表时间：
2007-08-01
影响因子：
2
通讯作者：
Kakigi, Ryusuke
中科院分区：
文献类型：
--
作者：
Akatsuka, Kosuke;Wasaka, Toshiaki;Kakigi, Ryusuke
我们使用电两点刺激研究了异常刺激概率对体感磁失配负性（MMNm）的影响。首先，我们确定了两点距离的区分阈值（DT）。我们在一定距离处施加标准刺激，受试者感觉为一个点，在一定距离处施加偏离刺激，受试者绝对感觉为两个点。我们使用了三种偏离刺激概率，10%、30%和50%。在10%条件下，偏离刺激后30-70 ms（第一成分）和150-250 ms（第四成分）的峰值显著大于标准刺激后的峰值，而在30%和50%条件下则无显著差异。等效电流偶极子（ECD）位于对侧初级躯体感觉皮层（cSI）的第一个组件，并在cSI和对侧次级躯体感觉皮层（cSII）的第四个组件。MMNm的峰值幅度随着偏离刺激概率的增加而降低。躯体感觉MMNm受偏离刺激概率的影响，类似于听觉失配负波（MMN）。
We investigated the effect of deviant stimulus probability on the somatosensory magnetic mismatch negativity (MMNm) using an electrical two-point stimulation. First, we determined the discrimination threshold (DT) of the two-point distance. We applied standard stimuli at a distance that subjects felt as one point and deviant stimuli at a distance that subjects definitely felt as two points. We used three deviant stimulus probabilities, 10, 30, and 50%. The components peaking around 30-70 ms (first component) and 150-250 ms (fourth component) following deviant stimuli were significantly larger than those following standard stimuli in 10% condition, but not in 30 or 50% condition. The equivalent current dipole (ECD) was located in the contralateral primary somatosensory cortex (cSI) for the first component, and in the cSI and in the contralateral secondary somatosensory cortex (cSII) for the fourth component. The peak amplitude of the MMNm decreased as the probability of the deviant stimulus increased. The Somatosensory MMNm was affected by deviant stimulus probability similar to an auditory mismatch negativity (MMN).