Physiological Mental Strain and Performance during Arithmetic Tasks through Tone-Entropy Analysis

The purpose of this study is to measure cardiac autonomic nervous system (CANS) activity through Tone-Entropy (T-E) Analysis during arithmetic tasks. Then, as compared with T-E Analysis, frequency powers with Power Spectral (PS) Analysis, which is ordinary used to measure autonomic nervous system activity, have been evaluated. Young ten subjects were participated in this study. They tried arithmetic task which is two digit number add-up calculations per 5 seconds during 5 minutes. We evaluate CANS activity through T-E Analysis during arithmetic task and resting tasks before and after the arithmetic task. Then, evaluation of CANS activity through T-E Analysis is compared with that of PS Analysis. We classify each five subjects into two groups: Group L and Group H. The groups have significant differences on CANS activity based on entropy severally. In Group L, there is little change among resting tasks and arithmetic task on T-E space. To it, in Group H, T-E plot distribution during arithmetic task shifts left-upper position as compared with those of resting tasks. However, PS Analysis has little significant meanings on CANS activity during arithmetic tasks to resting tasks because of no breathing control in these experiments. In conclusion, T-E Analysis is more suitable for evaluation on CANS activity during arithmetic tasks as compared with PS Analysis. The fact also indicates that mental strain based on CANS activity should be measured through T-E Analysis.