While doing the postures, your mind should be in half-consciousn ess, which does not mean sleep. It means silence, emptiness, space, which can then be filled with an acute awareness of the sensations given by the posture. You watch yourself from inside. It is a full silence.
B.K.S. IyengarThat's the beauty of backbends. Emotionally we can never be disturbed, for the emotional centre becomes an extrovert. When you do Viparita Dandasana, your head looks backwards, but your conscious mind stretches everywhere. Study by observing how the mind gets regulated. You not only know the freedom in the spine, but also the freedom in the spirit.
B.K.S. Iyengar