One or more sensory, auditory and/or visual stimuli are presented to a subject at a specific frequency that is equal to, or a harmonic of, the intrinsic frequency of one or more of the subject's biological signals. The purpose is to indirectly (through the eyes, ears, or touch) provide frequency coupling among different organs (e.g., heart, brain, breathing, and gastrointestinal movement) through rhythmic entrainment. The specific harmonic chosen is the one closest to the interested EEG frequency. The interested frequency is chosen based on the cognitive element or symptom that is targeted. Additionally, games and programs (audio, video, computer) can incorporate Pavlovian cues to facilitate placing the brain in an acceptable state. In one embodiment, the ticking sound of a repetitive transcranial stimulation (rTMS) device is played to subconsciously remind the patient of the rTMS treatment and thereby produce a therapeutic effect. Additionally, physical stimulus such as tapping or low-level electrical stimulation at a predetermined rate will accomplish the same effect.
