|其他题名||Event-related Ir uinctionat Magnetic Resonance Lmaging of Simple and Sequential Movements
Although neural substrates for sequential movements have been intensively
investigated, a series of issues remain contraversial. Event-related functional magnetic resonance imaging, a single-trial based non-invasive brain imaging technique, has provided an effective tool for exploring the neural mechanisms underlying simple and sequential movements.
Methods: Event-related fMRI was used to investigate the activation of cerebral cortex during movements in 15 normal right-handed volunteers. The movement task included delayed (moving during cue presentation) and non-delayed (not moving until the end of cue presentation) "simple" (repetitively moving index finger) and "sequential" (sequentially moving all fingers according to the cue singal) movements. Multiple linear regression and deconvolution procedure was used to}detect the active ,brain region. Quantitative analysis was further implemented for comparison of the activation volume and intensity in each ROI between different movement tasks.
Results: While the supplementary motor area (SMA) and contralateral sensorimotor cortex (SMC) were activated in all subjects during simple movements,only 60% subjects showed activation in bilateral premotor cortex (PMC), and bilateral posterior parietal cortex (PPC) during } sequential movements. All activated regions during simple movements were also activated during sequential movements, and the activated volume is larger than that of simple movements. The signal intensity in the contralateral SMC, bilateral PMC and PPC during sequential finger movement was significantly stronger than that during simple finger movements; the signal change in ipsilateral PMC and contralateral PPC during delayed sequential movements was stronger than that during non-delayed sequential movements.
Conclusion: Almost all studied brain areas are enganged during all four movement tasks in the present study. SMA and contralateral Ml play a critical role in motor control, involved in motor preparation and exectution respectively. When in tasks with higher spatio-temporal coordination and working memory demanding, PMC and PPC become more active. The present study revealed a distributed cortical network, areas within this network play complemental roles for coordination and execution of movements.
贾富仓. 简单与序列运动的事件相关功能磁共振成像研究[D]. 北京. 中国科学院研究生院,2001.