[Evaluation of time resolution of the primary motor cortex by a single paradigm using a stimulation system]

Many researchers are investigating brain function by using a block paradigm in fMRI measurement. However, time resolution has been limited because the block paradigm employed data collection by consecutive image acquisition after stimulation began. Because of this problem, the evaluation of early brain activity was not adequate. Therefore, a system that was able to take imaging from a high time dependence to stimulation in real time was necessary to evaluate early brain activity. It is necessary to obtain controlled image taking by an MRI device with an external trigger by creating a sequence design in the system controlling stimulation and a sequence designed to achieve the above. The execution of a single paradigm by the originally designed sequence thus becomes possible, and arbitrarily setting all processes from stimulation to image taking is possible. It is thought that the practical use of the single paradigm designed by the control system of stimulation enables real-time imaging for stimulation and provides time-dependent data. From this, evaluation of brain activity of the primary motor cortex is possible in the early stage by event-related data collection. In addition, "sank," a relative decrement in PO(2) was also an initial stage of BOLD, that is, an initial dip occurs as a transitory signal change by using a single paradigm that synchronizes with the control system of stimulation for the evaluation of early brain activity. Moreover, it is thought that taking images by a single paradigm that is synchronized with the control system of stimulation is indispensable for time and spatial elucidation of detailed brain activity, to evaluate hyper brain function. Therefore, the brain activity in the primary visual cortex at the early stage was clarified in this study by using a single paradigm designed to synchronize with the control system of stimulation by single-shot EPI.