Table 2.

Summary of the three experiments in our study.

	Auditory stimulus	Stroop stimulus	MAT stimulus
Participants	10 (1 female)	11 (0 females)	11 (7 females)
Age ranges	22–43 years	22–30 years	18–30 years
Stimulus/task	Pure-tone sound at 1 kHz for 140 s	Stroop task with words at a rate of 1.5 s for 6 min	Subtracting 7 from 4000 repetitively for 2 min
Region of interest	Hand	Finger	Face
Camera	4-bit RGB CCD camera (DMK-21BF04, Imaging Source LLC, USA) with a camera lens (Pentax/Cosmica, Japan; f 16 mm, 1:1.4)	4-bit RGB CCD camera (DMK-21BF04, Imaging Source LLC, USA) with a camera lens (Pentax/Cosmica, Japan; f 16 mm, 1:1.4)	Olympus DSLR with a standard Zuiko 50 mm lens
Resolution/frame rate	640 × 480, 15 FP	640 × 480, 15 FPS	960 × 720, 30 FPS
Protocol	140-s rest period followed by 140-s task.	6-min rest period followed by 6-min task	120-s rest period followed by 120-s arithmetic task

We used three different stimuli to induce cognitive and psychological stress and recorded videos of the face or hand before and during these stimuli.