Unconscious operant conditioning in the paradigm of brain-computer interface based on color perception.

This study investigate the mutual fine-tuning of ongoing EEG rhythmic features with RGB values controlling color shades of computer screen during neuro-feedback training. Fifteen participants had not been informed about the existence of neurofeedback loop (NF), but were guided only to look at the computer screen. It was found that during such unconscious NF training, a variety of color shades on the screen gradually changed from rather various types to the main one within the framework of color palette specified for each individual.