The `CHAKRA's, which is a sanskrit word transliterated into english means circles, is usually referred to the nodal points of energy or awareness in the human body. In spite of the extensive literature available on this subject, it is still steeped in myth and suspect in the eyes of modern science. In this presentation an attempt is made to outline the neurological and physiological significance of chakras on a rational basis so that it can be acceptable to medical practitioners. Proper understanding of the significance of chakras can possibly help modern psychiatrists in dealing with human beings having psychological problems. In the present investigations the results obtained on the activation of `Chakra's as monitored with the help of optical sensors are presented. A suitable subject who is familiar with `Chakra's has been chosen for the present study. Data is also obtained simultaneously with the help of other sensing elements like temperature sensors which help in monitoring the differential breathing through the two nostrils of the subject. The emergence of approximately 8 cycles per minute (0.13 Hz) rhythm has been noticed in PPG signals from the Ajna chakra located on the forehead. An attempt is made to understand the neurological and physiological significance of these rhythms and other associated phenomena seemingly originating from the activation of `Chakra's.