Dr. singh, who is concerned with how vision is processed consciously and unconsciously, is studying:

I believe the answer is: dual processing

dual processing refers to a theory that view every information that come into our head would be processed by two different methods The conscious and the unconscious.  This theory was first introduced by William James. He believed that  conscious process would involve a person's associative thinking while the unconscious would involves the true reasoning.

answer; ancient times;

answerstructuralism; functionalism;