Improvement of neural activity in brain EEG network using somatosensory electrical stimulation

Abstract

Objective To investigate the characteristics of brain network based on brain electrical activity induced by somatosensory electrical stimulation, and to provide a theoretical basis for further understanding the mechanism of brain neural plasticity induced by somatosensory electrical stimulation. Methods Ten healthy subjects were selected and a somatosensory electrical stimulation experiment was constructed based on the directed transfer function (DTF). In the experiment, the DTF causal connection matrixes of the 32-channel EEG data of Delta, Theta, Alpha and Beta bands were obtained under the somatosensory electrical target and non-target stimulation, and the differences of clustering coefficient and global efficiency between two stimulation states were contrasted based on graph theory. Results Under the target stimulation and non-target stimulation states, the regions with stronger DTA causal connections were mainly concentrated in FCz, Cz, CPz and Pz channels. The causal connection intensity under target stimulation state was greater than that of non-target stimulation. Also, in the Delta, Theta, and Alpha bands, the clustering coefficient under the target stimulation state was significantly higher than that in the non-target stimulation state (P<0.05). In the Delta and Theta bands, the global efficiency of the target stimulation state was significantly higher than that of the non-target stimulation state (P<0.05). Conclusions Somatosensory electrical stimulation can activate and induce EEG brain networks. In the target stimulation state, the role of the parietal lobe in the EEG causal network is enhanced, which helps to induce attention to specific brain region plasticity, and thus realizing the nerve rehabilitation in the brain regions of interest. While in the non-target stimulation state, the synergistic interactions between brain regions were enhanced, which helps to activate and induce a wide range of associations in the whole brain network, so as to promote the global neural activity in the brain. Key words: Somatosensory electrical stimulation; Target stimulation; Non-target stimulation; Directed transform function; Brain network