Physiological Characteristics and Nonparametric Test for Master-Slave Driving Task’s Mental Workload Evaluation in Mountain Area Highway at Night

Table 2

Average of ECG index (day).

Physiological index	Single driving	Master-slave task one	Master-slave task two
MHR (mean heart rate)	75.34	83.17	84.22
RR (interval standard deviation)	0.057	0.049	0.046
LF (NU) (low frequency)	0.769	0.711	0.558
HF (NU) (high frequency)	0.153	0.22	0.249
LF/HF	4.02	2.62	1.76