Effect of display resolution on brain activity and physical and mental stress when using a tablet

We experimentally investigated the effect of the use of a high-resolution 4K tablet on brain activity and physical and mental stress while engaged in searching tasks. The results showed NIRS, an index of nervous system activity, to be significantly higher during searching tasks with 4K content than with 2K content, whereas LF/HF (level of sympathetic nerve activity) and blinking rates during the first half of the rest time after a set of tasks showed a tendency to be lower for 4K content than for 2K content. Moreover, the score for “visual fatigue” in subjective assessments tended to be lower for 4K content than for 2K content. Our results suggest that searching tasks in 4K can cause a surge in brain activity but a lower task workload, such as physical and mental stress and visual fatigue.