Guidelines for Visual Mental Stressors Design

All jobs that are carried out by humans contain either mental and/or physical stresses. Therefore, quantifying these stresses to certain levels is an essential task to ensure not reaching the breakdown state. This state can lead to failure in maintaining the correct outcome of the job. All research work which are focused on studying the effect of mental stress on humans, require the use of mental stressor that is able to correctly quantify the stress level without adding any extra loads on human. The most common mental stressor that was heavily used in research, according to literature, is the Stroop color stressor. Therefore, some guidelines are required that will be helpful in designing such stressor. Moreover, the proposed guidelines can be applied to the Stroop color test which are believed to restrict the mental stress level to the matching task only with no extra stress load. MATLABO was used as the programming platform that was used to implement a graphical user interface (GUI) for the Stroop color stressor. The proposed guidelines examine the effect of changing the buttons’ sizes and locations in the stressor GUI to detect their influence on the applied mental stress. The validity of the guidelines were verified using the one-way ANOVA test. The proposed guidelines showed that the sizes and locations of the buttons, which are used by the user to respond to the visual matching tasks have very high impact on the applied mental stress level. Therefore, designing the Stroop color stressor GUI with buttons having the same buttons’ sizes and locations apart from the center of the displayed image will correctly apply quantified mental stress levels. Changing the Stroop color stressor’s buttons sizes and locations were found to have some extra mental stress on the human under test. Some guidelines for designing any Stroop color-based mental stressor are proposed based on the results of this study. It is believed that applying such guidelines will ensure diminishing any measurement errors due to the unequal sizes and locations of the stressor’s buttons.