Activation During Upper Limb Movements Measured with Functional Near-Infrared Spectroscopy in Healthy Elderly Subjects

Objective: Understanding the cortical activation patters can play an important role in exploring the motor control mechanisms in elderly subjects. This study investigates the hemodynamic responses in elderly subjects during the upper-limb movements using functional near-infrared spectroscopy (fNIRS). Methods: The multi-channel fNIRS signals were continuously recorded from the bilateral prefrontal cortex (PFC) and motor cortex (MC) in eight healthy elderly subjects during the resting state (RS), right and left upper-limb movements (RM and LM). In this study, we applied the generalized linear model (GLM) informed in the NIRS-SPM software to compute the changes of hemoglobin concentrations and describe the brain activations during motor tasks. Results: The results showed that the changes of oxyhemoglobin concentrations were more concentrated in the left motor cortex of subjects during the RM task, and in the right hemisphere including prefrontal cortex and motor cortex during the LM task. Further analysis also showed that there was a significant difference between two hemispheres in the RM and LM tasks, while no difference in the RS task. Conclusions: These findings suggested that the fNIRS signals could reliably quantify the neuronal activity during limb movements. This study may provide a new insight into the motor mechanism of the upper-limb movements and is significant for monitoring brain function.