Distributed feedback-circuitry uses operant conditioning to train a subject to achieve a target state of consciousness. The distributed feedback-circuitry includes remote circuitry having both a feature-extraction circuit and a controller. The former receives a real-time electroencephalogram and information indicative of a target state from the subject and generates a measured feature-set and a target feature-set therefrom. The latter causes transmission of a conditioning stimulus to be listened to by the subject. The conditioning stimulus causes the measured feature-set to be driven towards the target feature-set. The controller also causes the conditioning stimulus to comprise a conditioning-audio stimulus that transitions between being a base-audio stimulus with no reward stimulus and being a base-audio stimulus that has been operated on to incorporate a reward stimulus. The controller causes this transition based on progress made in causing the measured feature-set to conform to the target feature-set.