samādhi.eeg

Mind, Brain, Consciousness


The nimitta and neurofeedback

There is a remarkable parallel between the role of the nimitta in Samatha meditation, and the modern scientific technique of neuro-feedback6. An example is the use of neurofeedback to help a child suffering from ADHD (Attention Deficit Hyperactivity Disorder) to re-train their brain into a more healthy functioning. First a full brain EEG is recorded measuring the electrical activity at typically 19 or 32 positions on the child’s head. The results are then compared to a “normative database” of many thousands of “normal” subjects to identify any abnormalities. Typically, an overexcited region is found, as well as an underactive region, compared to the norm.


Neurofeedback consists in then placing just two electrodes at the two key sites on the child’s head, to monitor the electrical activity. These electrical signals are fed to a computer and a neurofeedback software program. In one well-known software approach, the child is invited to bring in a favourite video, that is played on the computer. The EEG software adds noise to the picture to make it blurred, and the child is asked to “will” the picture to become clearer, and therefore more enjoyable to see.


The software will only allow this if the overactive region is slightly quietened, and at the same time the underactive region is made just a little more active. Remarkably, usually within a few sessions of maybe 30 mins each, the child “learns” how to do this, and gradually over many repeated sessions the symptoms of ADHD may be reduced as the child, in effect, reprograms their own brain, and becomes familiar with the “feel” of a more balanced and enjoyable attention.


The parallel in meditation, is that the nimitta acts as a feedback link similar to the child’s film, allowing the meditator to “tune in” to a progressively more peaceful and absorbed mental state. The nimitta arises when the meditator has withdrawn attention from external sensory stimulation, towards a more internal “mind-door” process. It is as though the mind seeks to be aware of itself (its mirror image in the sketch), with the nimitta the sign of that awareness.


There has long been a controversy in Buddhist philosophy as to whether the mind can be aware of itself, and attempts to conceptualise whether it can, usually lead to multiple splits in consciousness, or nāma-rūpa  (subject-object) pairs, as an infinite regress. What the nimitta appears to be, is our ability to sense the mind’s awareness directly, rather than being drawn into an attempt to be aware of the mind as an “object”, which is in any case refuted in Buddhism.


What is particularly remarkable in this view, is that developing and using the nimitta as a “guide” in Samatha meditation, appears to be a completely natural form of neurofeedback, that predates any modern “scientific” experiments in neurofeedback by over two and a half millennia. There are also other implications for the mind-brain interface that I will return to in the section on Quantum Mind.


It should be added that, the use of words like “mind” and “consciousness” in Buddhism, or in any other context for that matter, is not unlike concepts in Physics such as “gravitation”, or “the electromagnetic field”, which tend to be taken as givens. Such words or concepts can easily be assumed to be fundamental properties of nature, whereas in fact we do not really know what they are. The words themselves act as “signs”, pointing towards something, a property or a reality, that we are attempting to grasp.  


© 2012, samadhieeg.org.uk