People think that by walking the spiritual path, our consciousness evolves. But is that true? Let us investigate it. If an adult who was functioning normally in the world suffers from a brain injury which affects the frontal part of the brain, what will happen? The consciousness and personality of the person will change, because after a brain injury the person can’t access the same level of consciousness. The same happens in cases of Alzheimer & disease, where the brain decays rapidly and changes the person’s consciousness. If an adult is using hallucinogens, many higher or lower levels of consciousness can be experienced. Changes in the adult brain after drug use again relate to the brain’s neuro-chemical composition.
Consider the lizard, monkey and human – each perceives and behaves differently. The monkey’s behaviour is more complex than the lizard's, and human behaviour is more complex than the monkey & s. The monkey’s brain is more evolved than the lizard and the human brain has a higher capacity than the monkey More evolution of the brain means more consciousness, complexity and creativity which are the hallmarks of spiritual growth.
Spiritual progress in Yoga is the result of changes in the biology of the brain and nervous system. In Yoga, changes occur in brain biology, not in consciousness. At any point, all possible modes of consciousness are available to any living organism. But the state of the brain and body determines if an individual will be able to tune into different dimensions of consciousness or not.
Reptiles have a primitive nervous system, which has helped them survive. The reptilian complex in the human brain is representative of the brain of reptiles and is a mirror for reptilian consciousness. In advanced animals, the brain is responsible for emotions. In humans it has brought the wonders of self-awareness, through which we are able to experience feelings and emotions. It also gives us the ability to reflect on the past and contemplate the future. We are capable of logical thinking, which has unleashed endless creativity and has led to the emergence of science, art, ethics, religion and culture. But above all of this, is the incredible ability we possess to feel the presence of the infinite and eternal, the source of the universe itself. The infinite is not an empty void but contains all that is possible, was possible and will be possible. People have given this feeling of boundless and timeless existence many names including God, Braham and so on.
As our brain develops and vibrates at a particular frequency, we experience a specific level of consciousness. The animal brain vibrates at a different frequency than in humans, and so their perception is different. Because we are self-aware, we can change the structure and physiology of our brain and become conscious of those experiences that are not available to other living beings. This is conscious evolution. Yoga is the science of conscious evolution. Evolution is essentially the evolution of the brain, which vibrates at different frequencies at various stages
Comparing the brain with a TV set will explain the point. Although all possible channels in the form of electromagnetic waves (consciousness) are available in space, but it depends on our TV set (brain) of how many of them we can receive and watch. TV with different capacity (local stations, cable or satellite dish) will receive different number of channels.
All creative and spiritual practices including Yoga are about changing the structure and physiology of the brain, in order to tune into more conscious experience. We have the potential to become conscious of every evolutionary frequency, eventually arriving at a point where the frequency becomes almost infinite or zero. Here we tune into a primal consciousness. This gives us the experience of pure consciousness of Samadhi.
A normal brain, although fully active physiologically, is not functioning to its optimal capacity; the reason being that various parts of the brain remain unconnected. But in Yogic awakening not only some of the physiologically less active parts become more active, but more and more parts connect to each other making the brain and nervous system function as one unit, as one whole. That is the evolution and transformation of the brain and nervous system.
In summary, brain evolves and not the consciousness. All Yogic practices are for the evolution of the brain so that we could become receptive to higher levels of consciousness which are available all the time to us.