PDF(Pubmed)
Abstract：
Functional magnetic resonance imaging (fMRI) was used to estimate neuronal activity in the primary somatosensory cortex of six participants undergoing cutaneous tactile stimulation on skin areas spread across the entire body. Differences between the accepted somatotopic maps derived from Penfield\'s work and those generated by this fMRI study were sought, including representational transpositions or replications across the cortex. MR-safe pneumatic devices mimicking the action of a Wartenberg wheel supplied touch stimuli in eight areas. Seven were on the left side of the body: foot, lower, and upper leg, trunk beneath ribcage, anterior forearm, middle fingertip, and neck above the collarbone. The eighth area was the glabella. Activation magnitude was estimated as the maximum cross-correlation coefficient at a certain phase shift between ideal time series and measured blood oxygen level dependent (BOLD) time courses on the cortical surface. Maximally correlated clusters associated with each cutaneous area were calculated, and cortical magnification factors were estimated. Activity correlated to lower limb stimulation was observed in the paracentral lobule and superomedial postcentral region. Correlations to upper extremity stimulation were observed in the postcentral area adjacent to the motor hand knob. Activity correlated to trunk, face and neck stimulation was localized in the superomedial one-third of the postcentral region, which differed from Penfield\'s cortical homunculus.
摘要：
功能磁共振成像（fMRI）用于估计六名参与者的初级体感皮层中的神经元活动，这些参与者对遍布全身的皮肤区域进行皮肤触觉刺激。寻求从Penfield的工作中得出的公认的体位图与本功能磁共振成像研究中得出的差异，包括跨皮质的代表性移位或复制。模拟Wartenberg车轮动作的MR安全气动设备在八个区域提供了触摸刺激。七个在身体的左侧:脚，较低,和大腿，胸腔下面的树干，前臂前,中指,脖子在锁骨上方.第八个区域是glabella。激活幅度估计为理想时间序列与皮质表面上测得的血氧水平依赖性（BOLD）时间过程之间的某个相移处的最大互相关系数。计算与每个皮肤面积相关的最大相关簇，和皮质放大倍数的估计。在中央旁小叶和中央后中部区域观察到与下肢刺激相关的活动。在靠近运动手旋钮的中央后区域观察到与上肢刺激的相关性。与躯干相关的活动，面部和颈部刺激位于中央后区域的上中部三分之一，这与彭菲尔德的大脑皮层同质不同。
