MCI	Mild cognitive impairment
fNIRS	Functional near-infrared spectroscopy
PW	Prepared walking
SW	Single walking
CT	Computed tomography
HC	Healthy control
ROI	Region of interest
PFC	Prefrontal cortex
GLM	Generalized linear model
MoCA	Montreal Cognitive Assessment
BMI	Body Mass Index
fMRI	Functional magnetic resonance imaging
R-SW	Rest-state of SW
OD	Optical density
CV	Coefficient of variation
HRF	Hemodynamic response function
MRI	Magnetic resonance imaging.