Optical Imaging of Brain Motor Cortex Activation During Wrist Movement Using Functional Near-Infrared Spectroscopy (fNIRS)

Abstract

Background: Optical imaging has attracted the researcher’s attention in recent years as an uncompromising and efficient method to measure the changes in brain cortex activity. Functional Near-Infrared Spectroscopy (fNIRS) is a method that measures hemodynamic changes in the brain cerebral cortex based on optical principles. Objectives: The current study aimed to evaluate the activities of the brain cortex during wrist movement using fNIRS. Methods: In this study, the activity of the brain motor cortex was investigated during right wrist movement in 10 young right-handed volunteers. Data were collected using a 48-channel fNIRS device with two wavelengths of 855 nm and 765 nm. For this experiment, 20 channels were used and the sampling frequency was set at 10 Hz. Results: Signal intensity in the motor cortex was significantly higher during movement than in the rest (P ≤ 0.05). The activation map of wrist movements was separated spatially in the motor cortex. The highest activity was recorded in the primary motor cortex (M1). There was a significant difference in the focus of the maximum activation of the brain between the four main directions. Conclusions: It is possible to differentiate between different directions of movement using near-infrared signals. The presence of directional activation in the cerebral cortex helps confirm the notion that this part of the brain participates in the processing of complex information besides controlling the movement of different parts of the body.