The fundamental difference of the human species from other animals is his ability to think abstractly, plan their activities, reflect on his past and evaluate it, make plans for the future by developing and implementing the program of such plans. All of these listed qualities of a person connected with the sphere of his consciousness. Ideas about consciousness were formed on the basis of the different approaches, both in terms of materialistic and idealistic philosophy. Neither one nor the other positions did not give a definitive answer and did not come to a common definition of what consciousness. Therefore, in the psychology topic of consciousness is one of the most complex. Very many of the major psychologists of both foreign and domestic schools turned to the topic. The difficulty in studying consciousness is that it can only study on this introspection, therefore, impossible to create objective methods for its study. In addition, all mental phenomena appear to man only to the extent to which they are realized.
Many of them may not reach the threshold awareness. Therefore, the data of introspection can be distorted and inaccurate. And finally, the third factor complicating the study of consciousness is the inability to isolate it in separate time intervals, individual units of study, since consciousness, when it works (ie, a person is not sleeping, not in a swoon, etc.), is a continuous stream and is parallel to the flow of the set of mental processes. In A long term study the problem of consciousness psychologists various currents were their own ideas about it. Further details can be found at Vladislav Doronin, an internet resource.