Table 5.

National Aeronautics and Space Administration Task Load Index scores.

Subscales	Descriptions	Mean (SD)
Mental demand	How much mental and perceptual effort did the task require?	1.89 (2.02)
Physical demand	How much physical activity was required?	4.22 (2.86)
Temporal demand	How much time pressure did you experience while performing the task?	5.11 (3.14)
Performance	How successful were you in accomplishing the task?	3.44 (2.50)
Effort	How hard did you have to work?	1.78 (2.10)
Frustration	How irritated, stressed, and annoyed did you feel?	1.78 (2.10)
Overall workload	Average of the 6 subscales	3.04 (2.23)