Emotionally-loaded Visual Stimuli to Alter Brain Arousal: A Flicker Fusion Study

Background: Human brain performance and arousal are still challenging and critical, especially in environments such as power plants. Since different emotions are common in daily work life and have inevitable effects on cognitive performance, it is important to evaluate whether or not emotional interventions can, in any way, alter brain arousal, leading to mental fatigue in control room operators (CROs) and affecting their cognitive emotion regulation. To address this issue, flicker fusion frequency (FFF) was employed as a simple and reproducible surrogate index for mental fatigue. Objectives: This study aimed to investigate whether or not emotionally loaded visual stimuli can alter brain arousal (brain fatigue) or is associated with cognitive emotion regulation (CER) ability. Methods: Flicker fusion frequency was assessed by RT-961, and the International Affective Picture System (IAPS) was adopted as the picture database of stimuli. Additionally, the Cognitive Emotion Regulation Questionnaire (CERQ) was used to determine the participants’ cognitive emotion CER ability. Twenty volunteer CROs from Fars Combined Cycle Power Plant participated in this study. They completed CERQ and then were assessed at two different time points, i.e., before and after presenting emotional stimuli. At each round, FFF was assessed 20 times, and the average frequency was recorded. Emotionally-loaded images were considered as stimuli. The stimuli sets were classified based on their arousal level and valence, yet they were presented in a random order. Subjects were exposed to each image for five seconds (30 minutes in total). Results: The participants’ mean age was 39.55 ± 7.02 years. The first and second FFFs were 42.15 ± 3.90 and 41.96 ± 3.98 in the appropriate group and 42.82 ± 3.59 and 42.26 ± 4.07 in the inappropriate group, respectively. Based on the statistical tests, there were no significant relationships between the measurements (P > 0.05). Conclusions: Our findings suggest that CROs may positively maintain their brain arousal during specific emotional stimuli when the intervention lasts less than 30 minutes. Considering the prolonged working hours in such industries (roughly over eight hours a day) and the importance of cognitive aptitude in preventing work-related errors, we propose this line of research to gain momentum.