Table 1.

Digital biomarker variables used in analyses.

Digital Biomarkers	Features	Description
Heart Rate Variability	HF	Absolute power of the high-frequency band (0.15–0.4 Hz)
	LF	Absolute power of the low-frequency band (0.04–0.15 Hz)
	LF/HF	Ratio of LF-to-HF power
	RMSSD	Square root of the mean squared differences of successive heart periods
	SDNN	Standard deviation of NN intervals
	pNN50	Percentage of successive RR intervals that differ by more than 50milliseconds
Eye-tracking	Total Fixation Time	Total duration of gaze on the stimuli
Voice	Pitch	Relative highness or lowness of a tone as perceived by the ear, which depends on the number of vibrations per second produced by the vocal cords
	Jitter	Variation of the phase of a timing signal from its ideal positions in time
	Shimmer	Measure of the high-frequency amplitude perturbations in a speech signal
	Loudness	Subjective perception of the intensity or volume of a sound as perceived by the human auditory system