Effects of stress and effort on self-rated reports in experimental study of design activities

This paper investigates the relationships between subjective rating measure and physiological measure of mental stress and mental effort during design activities. mental stress and mental effort were captured by skin conductance and eeg beta2 power (20–30 hz) whereas self-rated mental stress and self-rated mental effort were obtained using the nasa task load index. a strong association between self-rated effort and eeg beta2 power was found in several design tasks. the analysis shows that self-rating is by itself a mental activity which be affected by psychological stress and be influenced by the amount of cognitive effort allocated. researchers who rely on subjective rating should take into account the stress and effort of respondents during the rating activities to ensure the validity of the self-report measures. the study also demonstrated that design tasks induced mental stress that continued to stay above the baseline even after the tasks were completed.