Table 1.

Physiological parameters of each device in all three cognitive tasks

Cognitive task	Physiological measurement device	Main parameters
Stroop (congruent and incongruent)	ECG	RMSSD, pNN50, HF (absolute and nu), non-linear parameters (SD1, SD2, ApEn, SampEn, DFA, D2, RPA, MSE)
	fNIRS	oxyHb, deoxyHb, totHb
	EEG	ERPs, PSD, connectivity and source localisation
N-back (0-, 1- and 2-back)	ECG	RMSSD, pNN50, HF (absolute and nu), non-linear parameters (SD1, SD2, ApEn, SampEn, DFA, D2, RPA, MSE)
	fNIRS	oxyHb, deoxyHb, totHb
	EEG	ERPs, PSD, connectivity and source localisation
VFT (semantic and phonological)	ECG	RMSSD, pNN50, HF (absolute and nu), non-linear parameters (SD1, SD2, ApEn, SampEn, DFA, D2, RPAn, MSE)
	fNIRS	oxyHb, deoxyHb, totHb
	EEG	PSD

ApEn, approximate entropy; D2, correlation dimension; deoxyHb, deoxygenated haemoglobin; DFA, detrended fluctuation analysis; ERPs, event related potentials; HF, high frequency power in absolute and normalised units (nu) [0.15–0.4 Hz]; MSE, mutliscale entropy; oxyHb, oxygenated haemoglobin; pNN50, NN50 divided by the total number of NN intervals; PSD, power spectral density; RMSSD, root mean square of the successive differences between adjacent normal RR intervals; RPAn, recurrence plot analysis; SampEn, sample entropy; SD1, in Poincaré plot, the standard deviation perpendicular to the line-of-identity; SD2, in Poincaré plot, the standard deviation along the line-of-identity; totHb, total haemoglobin.