The normal human individual lives primarily in a state of consciousness that is immersed in the outer life, including the inner reactions to that life, and the functions of the body, life-energy and mind. This is true whether the person considers himself to be an extrovert or an introvert. The introvert simply focuses more on the inner reactive states of the being in relation to that external reality, but the focus remains essentially the same as the extrovert.
When an individual takes up the practice of yoga, one of the first recommended steps is stepping back from this external personality to achieve the standpoint of the witness-consciousness, the Purusha, observing the action of the nature, Prakriti. This leads to a dual status of consciousness as the Purusha awareness takes hold, while the ego-consciousness is still active.
Sri Aurobindo notes: “What you have noticed about the disturbance is true. There are now two consciousnesses in you, the new one that is growing and what is left of the old. The old has something in it which is a habit of the human vital, — the tendency to keep any touch of grief, anger, vexation etc. or any kind of emotional, vital or mental disturbance, to make much of it, to prolong it, not to wish to let it go, to return to it even when the cause of disturbance is past and could be forgotten, always to remember and bring it up when it can. This is a common trait of human nature and a quite customary movement. The new consciousness on the contrary does not want these things and when they happen throws them off as quickly as possible. When the new consciousness is fully grown and established, then the disturbances will be altogether rejected. Even if the causes of them happen, there will be no response of grief, anger, vexation etc. in the nature.”
Sri Aurobindo and The Mother, Living Within: The Yoga Approach to Psychological Health and Growth, Disturbances of the Vital, Transforming the Vital, pp. 69-85