Test-retest reliability of brain activation induced by robotic passive hand movement synchronized with a Video game: A randomized crossover functional NIRS study

Test-retest reliability (TRR) of brain activation, the likelihood that a certain brain area is repeatedly activated, is deeply related to brain plasticity, the basic paradigm of rehabilitation. In this study, we opted for a video game (VG) to promote TRR of robotic passive hand movement (RPHM), since our previous study has shown that RPHM has a low TRR. The two elements of VG, proprioception and real-time reaction, which we believe contribute to the interesting and immersive nature of VG, thereby enhancing the user engagement, a potent cause of contrasting TRR between the active and passive movements. To combine the VG with the RPHM, the pre-recorded video of VG is synchronized with the RPHM. The 40 subjects are being offered both RPHM and RPHM+VG, according to the crossover design, corresponding brain activations are measured by using fNIRS. Subsequently, TRR indices and the results of statistical analysis of crossover design are used to evaluate TRR. As a result, the introduction of VG to RPHM has shown enhanced activation in the primary sensorimotor area and premotor cortex as well as increasing TRR in those regions compared to RPHM. Current results suggest that RPHM with VG surpasses passive movement and is similar to active movement in terms of functional elements and the region of activation. Also, it can be inferred that VG is an appropriate modality of increasing TRR by enhancing user engagement when combined with passive movement. The 40 subjects were equally divided into and randomly assigned to two groups, Group A and Group B. The overall experiments take three months: one month for Period 1, followed by another month as a washout period, and still another month for Period 2. At the beginning and end of each period, a respective session of the experiment is conducted to determine the activation, and TRR is evaluated after the end-period session. The one month period was selected out of our previous research on TRR of brain activity. It is a part of the crossover design for one group to experiment RPHM and RPHM+VG in an order reverse to the other group does: While Group A carried out RPHM+VG in Period 1 (session1 and session2) before RPHM in Period 2 (session3 and session4), Group B RPHM in Period 1 before RPHM + VG in Period 2. There are two types of uploaded data as follows: first the relative changes in concentration of oxygenated hemoglobin, deoxygenated hemoglobin, and total hemoglobin; second, 3d coordinates of anatomical landmark and the p