Differences in EEG Brain Activity for Black/White Versus RGB Stimuli

Background: Color perception is vital in many aspects of human behavior. It is tremendously engaged in the early stage of information processing to accelerate attention. Several studies focused on different aspects of the psychological effect of colors, which showed that color designs induce positive emotion, increased cognitive effort, and better learning outcomes compared to achromatic stimuli. Considering the importance of our daily encounters with colored stimuli, especially the RGB, black and white, studying the effect of these stimuli on brain activities is essential. Method: We investigated the significant differences in spatiotemporal brain activity of black, white, and RGB information. We used a task in which 12 participants were presented with random black-and-white and RGB-colored stimuli in a dark room. Each stimulus was displayed on the whole screen of a CRT calibrated monitor for 10 seconds. A 64-channel EEG device was used to acquire the EEG data. Results: Our results show that for RGB-colored stimuli, the beta power of the occipito-parietal region in early period (85 - 120 ms after stimulus onset) for RGB is higher than that of black ( $p < 0.05$ ), while in late period (800 - 855 ms after stimulus onset), for RGB it is higher than that of both black and white ( $p < 0.05$ ). Moreover, the alpha power of the centro-parietal region in late period (930 - 1360 ms after stimulus onset) for RGB is higher than that of black ( $p < 0.01$ ). Finally, ITPC of alpha band in occipariatal region in the late period (840 - 920 ms after stimulus onset) for white is higher than black ( $p < 0.05$ ) and RGB ( $p < 0.01$ ). Conclusion: The results regarding brain responses to black/white and RGB stimuli, as well as beta and alpha-band differences in centro-pariatal and occipito-parietal regions provide valuable insights that can be interpretted within perception, emotional activities, and visual processes. Practical applications may span psychology, biofeedback, and BCI systems, with implications for cognitive training, rehabilitation, and human-computer interaction.