Image: Scientist and Buddhist Monk Matthieu Ricard, with psychologist and neuroscientist Richie Davidson
Check out the Buddhist Monk Matthieu Ricard rocking a whole head of EEG electrodes as part of a study investigating brain changes during meditation of experienced participants. EEG stands for electroencephalogram (eh-LEK-tro-en-SEF-a-low-gram), a device which uses electrodes to read brain activity.
When a group of neurons in the brain are active, they ‘fire’ electrochemical impulses along nerve fibres, resulting in tiny changes in voltage, which be detected by electrodes on the scalp near that area. This change in the electrical activity of brain areas is what produces the ‘brain waves’ visible on an EEG screen (below).
EEG has been in use for a long time; the first human EEG was recorded in 1924. Although it’s hard to know precisely where in the brain the signal is coming from, and electrodes placed on the scalp are only able to detect voltage changes from the outer layer of the brain, EEG has been a useful research tool in psychology, and has specifically resulted in some very interesting observations in the field of meditation research.
Eyes Open, Eyes Closed
Different frequencies of brain waves are generally associated with different states of mind. For instance, beta waves (see below) are typically seen when one is awake and acting normally, whereas very slow delta waves are only seen during deep sleep. Slower alpha waves are associated with closed eyes, and in fact were initially believed to only occur with closed eyes due to the reduction in visual processing, until researchers read the EEG signal of meditators and were surprised to find a strong alpha signal even when their eyes were open.
Meditation on the Brain
Experience with meditation seems to be associated with both increased alpha and theta wave strength, and an overall reduction in the frequencies of brain waves. This is especially the case during meditation, although highly experienced meditators also show high levels of alpha wave activity even during normal waking activity. Alpha waves in general have been linked with relaxation and feelings of calm, and theta waves with concentration. Theta waves in experienced meditators have also been correlated with self-reports of bliss and stillness of mind.
It is impossible to make detailed inferences about what effects meditation is having in the brain simply from EEG signals, however a certain pattern of signals does seem to correlate reliably with meditation, and so can be put to use. As EEG technology has become cheaper, a number of commercial EEG devices have been made available, and some which are specifically intended to help meditation. For example, the Muse headset comes with an app which gives you real-time feedback about the quality of your meditation based on your brainwaves, and claims to be able to give immediate feedback if your concentration slips.
Muse, Emotiv, and other meditation headsets are secretive about what their algorithms are actually using to indicate quality of meditation. It may be alpha waves, theta waves, or some relationship between the strengths of these and other frequencies, compared to the baseline measurement that they take. It’s a shame not to know the details of their research, since, aside from being fascinating, would open the way for other start-ups and independent researchers to test and continue developing these technologies.
Due to the variety of meditation techniques used, different levels of meditation experience in participants, inconsistent placement of electrodes between studies, and varying research methods, many questions remain unanswered about the relationship between EEG output and meditation. Furthermore, the question of whether EEG-based meditation feedback will be useful for learning meditation at all remains open. Will it act like a cyborg brain extension and artificially improve concentration, or will it simply make users’ concentration dependent on the feedback?
The algorithms used by these headsets may also be measuring only a proxy of actual meditative progress, such as relaxation or, if the research process has used inexperienced meditators or misinterpreted the relationship between EEG output and mind state, even drowsiness. Theta brainwaves are also present during light sleep, yet this is, of course, a completely different state from the precise, alert engagement of deep meditation.
As meditation continues to grow in popularity, and as EEG tech becomes cheaper and more accessible (see this video of somebody controlling a robot with their brainwaves), doubtless these tools will become better and more reliable, and a fascinating and fruitful union of ancient techniques and modern technology may await along this path.