This can be seen 
To approach experience, we will use David Chalmers division of consciousness into two part. The first part is the "easy problems of consciousness" which we may eventually be able to explain including the following phenomena: the ability to discriminate, categorize, and react to environmental stimuli; the integration of information by a cognitive system; the reportability of mental states; the ability of a system to access its own internal states; the focus of attention; the deliberate control of behaviour; and the difference between wakefulness and sleep \cite{Chalmers_1998}. On the contrary, the hard problem refers then to the problem of explaining why and how  sentient organisms have qualia \cite{Frankish_2012} or phenomenal experience.