National Research Centre "Kurchatov Institute", Moscow, Russia; Z1315@mail.ru
The work presents the theoretical research in the field of ultrafast methods of functional magnetic resonance imaging (fMRI), to form the functional systems of the human brain, shown the existing standard fMRI methods and the new ultrafast sequence. The experimental data on the ultrafast fMRI sequences obtained. The ultrafast fMRI method, which was developed in our lab, represents an interest in increasing the accuracy in the localization areas of the brain neuronal activity and studying the time dependence of the signal increasing the oxygenation of blood in cognitive processes. At the same time, using this method the spatial resolution is not decreases, but the time resolution increases from 2-3 seconds to 500 ms. The result of the use of this method is the possibility of constructing a functional networks of neural activity of the human brain in tasks of the real motor movement and its mental representation. 15 subjects from 21 to 35years took part in experiments, all are right-handed. Two modes were used for studying functional brain systems: standard echo-planar imaging (TR=3000ms, TE=30 ms, 36 slices) and ultrafast (TR=525ms, TE=30 ms, 11 slices); DTI data were recorded in RI UCS and T. The bloc paradigm was used for each study, which consists of three sequential blocks (the duration of the one block - 1 minute (standard echo-planar. imaging) 21 sec - (ultra)). Each block consists of two parts: active (the subject shuffled with his fingers of the right hand, or visualized any movement) and passive (the subject is in a passive state). The obtained data were used for constructing of the human brain deployed maps with applied areas of neuronal activity. Functional and anatomical MRI data were processed using next software: SPM8, Caret 5.62, GIFT, Statistica8. As a result of data processing areas of the brain activity of the subject correspond to zones, which are responsible for motor function (that is a positive result, because the experiment was based on plucking fingers), was shown. The statistical analysis of the main activated areas for mental representation and real shuffling fingers with in confidence probability did not reveal significant differences. Thus the theory about presence systems of "mirror" neurons in the sensorimotor cortex is confirmed. This work was supported by RFBR grant 13-04-02036.