In George Orwell's 1984 he brings up the idea of brainwashing. In his dystopia the outer party members like Winston are constantly fed a flow of false or modified information and facts. This is done so much that it is impossible to tell the truth from lies. The party has the information changed and the history destroyed mainly for the reason that they want to control the masses.
This is a form of brainwashing and it is done constantly. The people are told certain pieces of information every day, for example in the 2 minutes hate with Goldstein and the soldiers of which ever place they are currently at war with, and by doing this the people start to believe what they are hearing.
The party uses brain washing so much to get the public to be completely loyal to them that the public will automatically believe what ever they are told. For example during hate week a speaker is talking about how terrible Eurasia is and how well the war is going for Oceania, and then the speaker is handed a piece of paper and he suddenly changes what he is saying and instead of being at war with Eurasia they are at war with Eastasia and Eurasia is the enemy and that's the way it has always been. The people whom he is talking to start to believe it right away without question, some without realizing that it had changed at all.
Another example of how complete the brainwashing the party has done is Parsons. Parsons is so brainwashed by the party that he is actually proud of his children's actions for the spies. His daughter followed a man that she thought was strange and handed him over to the patrols because she saw that he was wearing "funny" shoes that she had never seen before so she thought that he was a foreigner. Parsons supports the party no matter what happens and he would even be proud if his children handed his wife, or even himself over to the patrols.