Ahamkara gives way to manas, which is the mind bound by time, space, name and form.
It operates completely through the world of the senses.
The senses receive numerous impressions from the external world. the mind then agrees with the senses, and the impressions are perceived and formulated into concepts.
The mind thinks, the intellect determines and the ego becomes conscious and projects itself back into the world.
The mind makes a horrible master but an excellent servant.