Posted 10.30.2015 | by AMRA

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The basic mindfulness instruction to “attend to the present moment without judgment” seems straightforward, but novices are often unsure whether they are practicing mindfulness “correctly.” There are no existing objective behavioral markers of mindfulness, and descriptions of what mindfulness “feels like” are often metaphorical (e.g., “spacious” or “intimate”) and hard to interpret.

This lends a hit-or-miss quality to training, and has led some to wonder whether neurofeedback (a form of biofeedback that uses electro-encephalogram (EEG) data to alter brain rhythms) might be a useful way to support mindfulness practice. Previous research has identified a group of EEG parameters (e.g., the appearance of alpha frequencies, increasing alpha amplitude, and a gradual shift towards lower alpha and theta frequencies) that accompany the meditative state. Neuro-feedback devices that help meditators achieve these EEG patterns may help assist in cultivating mindfulness.

Sas & Chopra [Personal and Ubiquitous Computing] developed a wearable mindfulness neurofeedback device (MeditAid) and tested it with novice and experienced meditators. The MeditAid prototype includes a wearable, wireless headset to record scalp EEGs and software to translate EEG patterns into auditory feedback. The auditory feedback is delivered as either monaural beats (sounds of differing frequencies presented to both ears simultaneously) or binaural beats (sounds of differing frequencies presented to each ear separately) through headphones. Each method produces a rhythmic pattern of beats that corresponds to the user’s EEG frequency.

The difference between monaural and binaural beats is that monaural beat perception is a function of the mechanics of the inner ear, whereas binaural beat perception is a function of the integrative activity of the brain. Listeners hear lower monaural and binaural beat frequencies as having a lower pitch. MeditAid users move their EEGs toward slower, more “mindful” brain rhythms by attempting to lower the pitch of the beats. The beats do more than just provide, feedback, however. They also stimulate the brain to match and echo their frequencies, a phenomenon known as “entrainment.”

The researchers recruited 16 participants (62% female, average age = 41) with a range of from 1 month to 40 years of meditation experience. Those with over 8 years of experience were designated “experienced;” those with less were deemed “novices.” Participants used the MeditAid device under three different conditions: without auditory feedback, with monaural beats, and with binaural beats. The deepest meditative level attained under each condition was assessed by EEG, and participants were interviewed and asked to rate how “still” their minds were under each condition.

All of the participants achieved significantly “deeper” EEG levels with binaural feedback than with either no feedback or monaural feedback (η2=0.80). Experienced meditators achieved significantly “deeper” EEG levels than novices (η2=0.44), but binaural feedback was of significantly more benefit to novices (η2=0.26). EEG levels were significantly associated (correlations ranged from 0.51 to 0.55) with subjective judgments of the percentage of time participants experienced their minds as being “still.” Participants reported significantly greater “stillness” with binaural beats than either monaural or no beats (η2=0.38). While participants rated the prototype as “useful,” some complained of physical discomfort or found the beats distracting.

This study demonstrates neurofeedback’s potential value in cultivating mindfulness. Neurofeeback increases lower alpha and theta rhythms, and binaural beat feedback is more effective for novices. More research is needed, however, to determine the degree to which lower alpha and theta rhythms mirror the subjective experience of mindfulness.

Reference:

Sas, C., & Chopra, R. (2015). MeditAid: A wearable adaptive neurofeedback-based system for training mindfulness state. Personal and Ubiquitous Computing, 19(7), 1169-1182.

[Link to abstract]