Ayumi Muramatsu

This study investigated the effects of movement imitation in a virtual reality (VR) environment on autonomic nervous activity among healthy participants through electrocardiography and finger photoplethysmography. We compared autonomic nervous system activity under two conditions: movement imitation and movement execution. For movement imitation, participants used a head mounted display (HMD) or tablet display (TD), while for movement execution, they referred to text. The results showed that movement imitation via an HMD significantly decreased pulse wavelength, suggesting increased cardiac sympathetic nerve activity compared to movement execution with text (TXT). These findings suggest that movement imitation in a VR environment may benefit rehabilitation settings.

This research aimed to reveal the information process in the brain of the patients who suffered from mild cognitive impairment (MCI) using the power spectra and timelag analysis in electroencephalogram (EEG). The patients with MCI have memory or thinking problems, and are at a great risk of developing Alzheimer's disease or a related dementia. Ten patients with MCI and 13 healthy adults (non-MCI) were examined. The EEGs (122.88 seconds/subject) during a state of relaxation with the eyes closed, were analyzed using the Fourier analysis (power spectrum) and the timelag analysis. The results showed that the mean value of the power spectra in MCI was significantly higher than the mean value in non-MCI in the theta band. The mean value of the absolute timelag values (ATL) in MCI was significantly lower than the mean value in non-MCI in the frontal and left temporal areas. Our findings suggest that the features from EEG of MCI were abstracted in the theta band, and the propagation of information related to memory in brain would becoming fast in MCI.

This study aimed to elucidate the brain changes during motor learning progression and to identify the differences in brain changes between people with early and late motor learning progression. A total of 20 healthy individuals underwent near-infrared spectroscopy measurements during a serial reaction time task before and after motor learning, and the amount of activation and betweenness centrality in brain regions were compared before and after the task by two-way ANOVA with a generalized linear mixed model. The results showed that activation in the right dorsolateral prefrontal cortex, left orbitofrontal cortex, and left and right frontal poles decreased after motor learning, while the betweenness centrality of the left dorsolateral prefrontal cortex increased after motor learning. The difference in motor learning between fast and slow learners was characterized by a reduction in the betweenness centrality of the right dorsolateral prefrontal cortex in the fast learners and its increase in slow learners. Monitoring these areas may provide basic data to assist occupational therapists in selecting the optimal method of motor learning for each subject from the perspective of brain function practice that has been tailored to the subjects.