How the Quantity and Hue Contrast of Interface Color Coding Affect Human Perception: Evidence from Two EEG Studies

Background: Color has considerable effects on physiological and psychological perception in human-machine interaction, but it is unclear how the coding methods of interface color affect users’ perception. The present study investigated the impacts of two dimensions of color coding, quantity and hue contrast, on visual perception from three aspects: brain activity, emotional experience, and visual comfort. Methods: Based on the HSV color space, two sets of experiments were designed with three quantity levels of colors and four quantity levels of hues (8, 16, 36 X 1, 2, 4, Random) as well as five combinations of two hue contrasts (30º, 60º, 120º, 180º, 240º in the HSV hue wheel). Participants’ brain activities were monitored within 2000ms of viewing the color stimuli, and subjective evaluations of their emotional and visual experiences were collected. Significant differences were observed in the synchronization of delta (0-4 Hz) and theta (4–8 Hz) bands in the 0-500ms time window and gamma (30-100Hz) oscillation throughout the presentation by using event-related spectral perturbations (ERSPs). Results: Expanded color elicited significantly higher arousal of emotion, along with stronger delta and theta band synchronization in the parietal and occipital lobes and enhanced gamma power in the posterior cortex, indicating increased visual processing workload and attention input. Grouping on identical hue significantly weakened the activation of delta and theta bands and did not enhance gamma oscillation as shape Gestalt as the number of groups rose, suggesting that color grouping capably lessens the perceptual load of visual processing. In addition, sharper hue contrasts significantly boosted delta and theta band activity and enhanced low gamma (30-50Hz) activation, and undermined visual experience compared with softer combinations, which might relate to the concentric antagonistic receptive fields of visual cells. Conclusion: This paper gives the first elucidation of the effects of color coding on neural activity and subjective perceptions, contributing to the neuroergonomic study of interface color design. These findings bridge the gap between the neural activity of color vision and mental experience during color perception.