Estrangement and Cognition and The FILM E.T.

Hi, I was wondering if you guys could help me! I am a Sociology student at University. Because of a mix up with time tables etc. I have been put in for a Media module for the first time. This is ‘Science Fiction’ module. I’m not very into media and therefore, do not know a lot about science fiction (Don’t shoot me!). Basically, I am trying to grasp the theme ‘Estrangement and Cognition’. The only Science Fiction film I know pretty well is E.T. (One of the most mainstream I guess). I was wondering if someone would be able to roughly describe ‘Estrangement and Cognition’ in relation to E.T so I could grasp this a little more?
Thanks so much!