In the Upadesha Sahasri (18:36) Shankara disagrees with the Buddhist theory of the temporal gap – that what we call the individual soul is only a momentary consciousness of the present moment, and there is no separate witnessing consciousness that persists from the beginning to the end of momentary phenomena (and beyond).
This is a very interesting point on the nature of consciousness. By claiming that consciousness can transcend the brain and personality, Vedanta foreshadows the discoveries of Oliver Sacks, a leading scientist in the field of neuropsychology. His researches into degenerative brain diseases such as Parkinson's indicate that there is a 'witness' to the breakdown of brain function which can stay intact throughout the process. Sacks writes that while he was studying how the nervous system is organized at the level of primitive, subcortical behaviours and controls, he was overwhelmingly confronted by the responses of his patients to the ongoing breakdown of their mental processes. He speaks of their heroic struggle to adapt and survive as their external and internal worlds collapsed. For him, this became the real focus of his work and the study – how they struggled to maintain their identity while different levels of 'reality' collapsed around them:
. . . it was, by virtue of the enormous range of disturbances occurring at every level of the nervous system, a disorder that could show, far better than any other, how the nervous system was organized, how brain and behaviour, at their more primitive levels, worked . . . But then, over and above the disorder and its direct effects, were all the responses of the patients to their sickness – so what confronted one, what one studied, was not just disease or physiology, but people, struggling to adapt and survive . . . Through them I would explore what it was like to be human, to stay human, in the face of unimaginable adversities and threats. Thus, while continually monitoring their organic nature – their complex, ever-changing pathophysiologies and biologies – my central study and concern became identity – their struggle to maintain identity.*1
Like Sacks with his patients, Shankara is totally absorbed in the effort his disciples must make to regain and maintain their identity – which for him implies realization of Brahman, the ever-expanding consciousness. It is a one-pointed fight through the matrix of different levels of consciousness by constantly identifying with the Witness. In Upadesha Sahasri (18:83) he writes:
The non-conscious intellect appears to be conscious, and its modifications also, like sparks of red-hot iron. But one's knowledge of the appearance and disappearance of the mental modifications is only possible because of the (continuous) witness – and it is through this refection of the witness that the intellect may know itself to be Brahman.
The new concept of neuroplasticity helps one recognize the aptness of Shankara's description of the relationship between brain, awareness and consciousness. Although for some years science argued that mind was a result of the brain, experiments on animals and humans have now shown the brain as being a tool of consciousness. The brain can actually be shaped by how we direct our awareness; it is not only shaped by genetics.
Neuroplasticity means the brain is not totally 'hardwired' from birth. We can, ourselves, affect the conditioning of the brain and nervous system at a molecular level because new areas of the brain can be assigned to new perceptual or motor tasks by repeating an activity for a long time. For this neuroplasticity to happen in experimental situations, however, sustained awareness or attention is indispensable. And we should note that for yoga sadhana or for meditation to 'happen', sustained awareness or attention is also indispensable.
Sharon Begley refers to Mike Merzenich's experiments in 1996 with monkeys who received repeated stimulation of their fingertips while music was played.*2 Some monkeys were taught to pay attention to music, some to the tactile sensation. As a result, different parts of the brain developed, with an expansion up to three times, either in the auditory cortex or in the somatosensory cortex, according to where attention was trained. Such experiments prove that one's attention directly affects the activities of the neurons in the brain, resulting in physical changes in the structure and capability of the nervous system. Her assertion that we therefore 'choose' from moment to moment what the ongoing form of our own mind will be is an interesting scientific validation of the teaching of Buddha, Shankara, and the living gurus of today.
It gives new insight into why Patanjali stressed abhyasa, extended unbroken practice for a long time, with respect (attention), and why Shankara placed such emphasis on the need for nididhyasana, the relentless repetition of the practice of meditation.
The recognition of neuroplasticity focuses attention on the need to leave the once-accepted hypothesis that the brain creates consciousness or mind, and demonstrates that it is a reciprocal process, or even the other way round. If the brain is like a laptop, consciousness is like the internet. The brain is controlled by physical-electrical circuits, enclosed by DNA and conditioning, but the number of dendrites, and the myelin sheathing which speeds up some neuronal channels and affects our habit patterns, moods, perceptions and responses is shaped by life experiences. So, new software and motherboards can be added, and one can download from an ever-expanding source: consciousness.
The 'discovery' of neuronal plasticity can be used to argue that the personality is mechanical, but the core identity can witness the personality inherited, the conditioning received, the breakdown of it and its evolution – even, it is claimed by adepts – through death and rebirth.
1. Oliver Sacks, Awakenings, Picador, Pan, London, UK, rev ed 1991, p. xxviii–xxvix
2. Sharon Begley, Train Your Mind, Change Your Brain, Ballentine Books, New York, USA, 2007, pp. 158 & 159