Porro C A, Francescato M P, Cettolo V, Diamond M E, Baraldi P, Zuiani C, Bazzocchi M, di Prampero P E
Dipartimento di Scienze Tecnologie Biomediche, Università di Udine, Italy.
J Neurosci. 1996 Dec 1;16(23):7688-98. doi: 10.1523/JNEUROSCI.16-23-07688.1996.
The intensity and spatial distribution of functional activation in the left precentral and postcentral gyri during actual motor performance (MP) and mental representation [motor imagery (MI)] of self-paced finger-to-thumb opposition movements of the dominant hand were investigated in fourteen right-handed volunteers by functional magnetic resonance imaging (fMRI) techniques. Significant increases in mean normalized fMRI signal intensities over values obtained during the control (visual imagery) tasks were found in a region including the anterior bank and crown of the central sulcus, the presumed site of the primary motor cortex, during both MP (mean percentage increase, 2.1%) and MI (0.8%). In the anterior portion of the precentral gyrus and the postcentral gyrus, mean functional activity levels were also increased during both conditions (MP, 1.7 and 1.2%; MI, 0.6 and 0.4%, respectively). To locate activated foci during MI, MP, or both conditions, the time course of the signal intensities of pixels lying in the precentral or postcentral gyrus was plotted against single-step or double-step waveforms, where the steps of the waveform corresponded to different tasks. Pixels significantly (r > 0.7) activated during both MP and MI were identified in each region in the majority of subjects; percentage increases in signal intensity during MI were on average 30% as great as increases during MP. The pixels activated during both MP and MI appear to represent a large fraction of the whole population activated during MP. These results support the hypothesis that MI and MP involve overlapping neural networks in perirolandic cortical areas.
通过功能磁共振成像（fMRI）技术，在14名右利手志愿者中研究了优势手自定节奏的拇指对掌运动的实际运动表现（MP）和心理表象[运动想象（MI）]过程中，左侧中央前回和中央后回功能激活的强度及空间分布。在包括中央沟前壁和顶部（推测为初级运动皮层所在部位）的区域，发现在MP（平均增加百分比为2.1%）和MI（0.8%）过程中，平均标准化fMRI信号强度比在对照（视觉想象）任务期间获得的值有显著增加。在中央前回和中央后回的前部，在两种情况下平均功能活动水平也都增加（MP时分别为1.7%和1.2%；MI时分别为0.6%和0.4%）。为了定位MI、MP或两种情况下的激活焦点，将位于中央前回或中央后回的像素信号强度随时间变化的过程与单步或双步波形绘制在一起，其中波形的步长对应不同任务。在大多数受试者的每个区域中，都识别出在MP和MI期间均显著激活（r>0.7）的像素；MI期间信号强度的增加百分比平均为MP期间增加量的30%。在MP和MI期间均被激活的像素似乎占MP期间激活的整个群体的很大一部分。这些结果支持了MI和MP在中央旁小叶皮质区域涉及重叠神经网络的假说。
