Abstract

The study of mental stress is essential to elevate our understanding of the designer's cognitive approach during a creative design process. As the first step in this effort, this thesis focuses on the analysis of the electroencephalogram (EEG) signals of the subject during the stroop test. Computer based stroop test, consisting of six difficulty levels, was developed and used as a stressor. The EEG data was recorded on Fz, Cz, Pz and Oz channel locations. Average absolute power of alpha, beta, delta and theta bands at all the channel locations was calculated. The subject's average performance on the Stroop test was calculated based on his/her reaction time and incorrectness. It was observed that the power of theta band is more dominant in the Fz channel. Since the theta band corresponds to the subject's mental/emotional stress, the present study suggests using the theta band in Fz location for further analysis during the design process. It was also observed that Alpha and beta powers, corresponding to the subject's vision, are more dominant in the Oz channel. A simultaneous comparison of the performances and of the theta power of different subjects suggested a direct relationship between the performance and the theta power. The present study demonstrates the potential use of theta power, after being quantified in terms of mental/emotional stress, in obtaining a correlation between the subject's performance and mental/emotional stress. The present thesis laid a foundation for on-going analysis of designer's mental stresses during design related tasks, in Dr. Zeng's research group.