This center would have to be considered a zero center in human energy structure. We call it the fourth, given the description of the centers in yoga, starting with the first located in the perineum.
As the center opens, the sensation of energy extends beyond the physical body. If you can see the energies of the center - good, no - that is also fine. Body sensations are much more significant. To do this, you need to direct relaxed attention inside the chest. You should not "imagine" any energy processes; it is better to look for sensations of warmth or rapid movement in this area.
At the beginning of the practice, sensations can be very individual. These are sensations not of the center but of what "closes" it. It is advisable not to focus on one spot but to listen to the energies of the center widely throughout the entire chest.
Listening to the fourth center is the traditional start of practice that leads to self-realization, or "ahamkara." Its manifestation gives a sense of one's "I" value. Love for yourself as a self-awarebeing. Striving for internal growth and change. These energies create a great thirst for life and a desire to know yourself and the world around you.
The fire of the fourth center makes a person harmonious and open. People with a manifested fourth center are pleasant in communication, and the world around them becomes cozy and filled. If you speak from the fourth center, that will give depth to your speech and arouse the sincere interest of the listener.
In the fourth center projection area, there are such energy process as "Life Inception," the Heart (Love), Ishta-Deva, and the fifth gate. Without awareness of the fourth center, all these practices are impossible. With its energies flowing ourside, it gradually manifests all of the above, melting the frozen consciousness and activating the primary connections between the physical body and the person's energies.