Table 4.

Relation of fNIRS and cortical excitability as measured by TMS: motor mapping, functional MEPs, and central fatigue.

	References	Population	Task	Stimulation Parameters	Stimulation Area	Measurement Area	No. of Subjects	Finding
Motor Mapping	Park et al., 2004	Stroke-Paresis	Key Turning	110%RMT for Motor Mapping	L/R-M1	Bilateral-M1	Case Study (Stroke)	Decreased [HbO], increased lateralization during task over therapy. Enlarged motor region after therapy.
	Akiyama et al., 2006	Healthy	Hand Grasping	120%RMT for Motor Mapping	L-M1	L-M1	10 HC	Biphasic [HbO] changes observed over MEP COG
	Koenraadt et al., 2011	Healthy	Thumb abduction	120%RMT for Motor Mapping	L-M1	L-M1	11 HC	No difference in [HbO] changes at MEP COG vs C3
MEP during Task	Lo et al., 2009	Healthy	Reading aloud, Singing	110%RMT, random MEP evaluation during task	L-M1	L-M1	5 HC	Changes in evoked MEP amplitude during vocalization at MEP COG, MEP changes not correlated with [HbO]
	Derosière et al., 2015	Healthy	Sustained Attention	MEP evaluated at 5min intervals	L-M1	PFC, L-M1, R-Parietal	15 TMS, 13 fNIRS, 4 Control	Increase in lateral PFC and right parietal [HbO], MEP amplitude increase over TOT
	Corp et al., 2018	Elderly	Dual Task [Tapping, N-Back]	MEP evaluated at 12.5s intervals	L-M1	Exp1: PFC (Online), Exp2: PFC, PM, M1	Exp1: 15 Young, 15 Eld. Exp2: 15 Eld.	Increased CSP during dual-tasks in elderly correlated with worse performance. fNIRS uncorrelated with dual-task performance
Exercise & Fatigue	Millet et al., 2012	Healthy	Isometric elbow contraction	MEP and CSP evaluation every 4th contraction	R-M1	L-DLPFC	Exp1: 12 HC, Exp2: 10 HC	Reduced performance and prefrontal oxygenation in hypoxia despite normoxia in muscle. Similar CSP and MEP responses
	Goodall et al., 2012	Healthy	Cycling	MEP, CSP, VA evaluation at 130%RMT before and after exercise	L-M1	L-DLPFC	9 HC	Reduced performance and prefrontal oxygenation in hypoxia and larger decrease in VA TMS after exercise
	Goodall et al., 2014	Healthy	Cycling	MEP, CSP, VA evaluation at 130%RMT before and after exercise	L-M1	L-DLPFC	7 HC	Greater decrease in prefrontal oxygenation in acute hypoxia, decrease in voluntary and potentiated force in both chronic and acute hypoxia. Doubled MEP size in chronic hypoxia.
	Rupp et al., 2015	Healthy	Isometric knee contraction	MEP, VA, CSP evaluated before and during contractions	L-M1	L-DLPFC	15 HC	Reduced performance in hypoxia, increased prefrontal oxygenation in hypoxia with CO2 clamping vs. w/o, VA TMS decrease greater in hypoxia w/o CO2 clamping
	Jubeau et al., 2017	Healthy	Cycling	MEP, VA, CSP evaluated before and 1,2,3 hours after exercise	L-M1	L-DLPFC, L-M1	10 HC	No performance difference, VA TMS or CSP after prolonged exercise in hypoxia conditions, reduced prefrontal oxygenation in hypoxia
	Marillier et al., 2017	Healthy	Isometric elbow contraction	MEP, VA, CSP evaluated before and during contractions	L-M1	L-DLPFC	11 HC	No performance differences between acute, chronic, or normoxia conditions or in VA TMS decline. Longer CSP in hypoxia conditions. No difference in prefrontal or muscle oxygenation
	Laurent et al., 2018	Healthy	Isometric knee extension	MEP, VA evaluated at 140% 'optimal' power, before and during extension, and after task failure	L-M1	L-DLPFC	14 Trained Athletes	No effect of salbutamol intake on VA TMS, prefrontal oxygenation, or task performance
	Solianik et al., 2018	Healthy	2 Hr Speed-Accuracy Motor task	MEP evaluation at 130%RMT before and after task	L-M1	DLPFC	10 HC	Increased MEP amplitude after prolonged activity, decrease in evoked left-prefrontal [Hb] in Stroop task vs. pre-task Stroop, no change for control activity