Concentration of various sorts is a part of yogic development generally. In most cases, particular paths recommend very specific forms of concentration, whether it be visualisation, recitation of mantras, or specific devotional exercises. The integral yoga also utilizes concentration, but does not prescribe a very specific fixed regimen for everyone, recognising that each individual has his own starting point, specific issues to address and resolve and different phases in the yogic sadhana. Thus there may be times when concentration may be centred between the eyebrows, and other times when it may be centred behind the heart in the psychic centre. Sri Aurobindo has also included a form of concentration that emphasizes creation of a mood or standpoint of consciousness rather than on a more specific form or mantra. Thus, there can be a generalized will or aspiration not just a specific deity, color, form or fixed object.
Sri Aurobindo notes: “…in this yoga, you do the same, not necessarily at that particular spot between the eyebrows, but anywhere in the head or at the centre of the chest where the physiologists have fixed the cardiac centre. Instead of concentrating on an object, you concentrate in the head in a will, a call for the descent of the peace above or, as some do, an opening of the unseen lid and an ascent of the consciousness above. In the heart centre one concentrates in an aspiration, for an opening, for the presence of the living image of the Divine there or whatever else is the object. There may be Japa of a name but, if so, there must also be a concentration on it and the name must repeat itself there in the heart centre.”
“It may be asked what becomes of the rest of the consciousness when there is this local concentration? Well, it either falls silent as in any concentration or, if it does not, then thoughts or other things may move about, as if outside, but the concentrated part does not attend to them or notice. That is when the concentration is reasonably successful.”
“One has not to fatigue oneself at first by long concentration if one is not accustomed, for then in a jaded mind it loses its power and value. One can relax and meditate instead of concentrating. It is only as the concentration becomes normal that one can go on for a longer and longer time.”
Sri Aurobindo, Integral Yoga: Sri Aurobindo’s Teaching and Method of Practice, Chapter 6, Sadhana Through Work, Meditation and Love and Devotion, Meditation and Concentration in the Integral Yoga, pp. 149-153