How are individual and collective human experiences presented in George Orwell's novel 1984? The answer needs to be supported by textual evidence and analysis of literary techniques used in quotations from the book.

One could argue that the chief factors governing both individual and collective experience in 1984 are the emotions of uncertainty, terror, and hopeless isolation. When Winston begins his diary, his realization is that "the thing he was about to do was not illegal . . . nothing was illegal, for there were no longer any laws." The reader's reaction to this is often one of surprise, because our assumptions might be that the obvious feature of a totalitarian world is that activities we take for granted are forbidden and therefore against the law. But in Oceania, "law" is a concept made obsolete. If nothing is explicitly defined as right or wrong, then everything is suspect and everything is dangerous. The power of a totalitarian regime is completely arbitrary, so one is kept in a state of uncertainty and terror about one's actions. The individual is isolated totally, unable to communicate a sense of this terror to anyone else.
But what in the text describes Winston's reactions to this fact? From all the interior monologues of Winston's thoughts, if I had to select one excerpt, it would be his crucial observation about Syme. Winston, perhaps ironically, likes Syme and enjoys his company, though Syme's thinking is completely "orthodox" with respect to the Party line. "Unquestionably," Winston tells himself, "Syme will be vaporized." Syme is too intelligent; he sees things too clearly, and the Party gets rid of such people. On the other hand, Parsons is also orthodox, but in an unintelligent way. "That bloody fool," Winston senses as the subtext of Syme's observation in the canteen: "Here comes Parsons." When Parsons is arrested, Winston is astonished, and in Parsons's blurting out "Thoughtcrime!" as the reason the police have picked him up (Parsons is "almost blubbering" as he speaks), Winston realizes that no one is safe in this world, even a simple, harmless, and dimwitted man like Parsons.
Each of the above quotes and episodes illustrates the terror that is exercised by the Party and forms the core of the individual's life. And in Orwell's prose there is a uniformly quiet, matter-of-fact tone that is sustained throughout. Orwell's description of Arthur Koestler's Darkness at Noon as a novel with a "grownup" quality, lacking "surprise or denunciation," is true of much of his own writing. Winston knows from the beginning that he is doomed, that he, and then Julia as well, will ultimately be destroyed by their defiance of the Party. The narrative style corresponds to the hopelessness of their circumstances.
And yet, the "collective" experience of people, as Winston observes it, is described as if "the masses" are completely subservient and have not the slightest sense of how appalling their world has become. When Winston is attending a rally and the speaker suddenly declares that Eastasia is the enemy and Eurasia the ally—and that this has always been so, contrary to what Winston knows to be the facts—the crowd does not even react, does not seem to notice that anything is wrong or has changed. And what is curious, Winston observes, is that the speaker makes this shift in his announcement without any interruption, without blinking an eye. Winston himself does not react overtly either, of course. We are told at the start of the scene that Winston "was participating in a demonstration." He plays his role as part of the herd in the same way everyone else does. Yet, with the exception of Julia, Winston is mentally cut off from every person in the world. In spite of his awareness that he's doomed, his heart still leaps at the meeting with O'Brien in his flat: His excited "They had done it!" then becomes more pathetic in retrospect when the truth about O'Brien is revealed. In the holding cell after he is arrested, when O'Brien appears, Winston cries, "They got you too!" to which O'Brien responds, "They got me a long time ago, Winston." To me this has always seemed one of the most horrifying and yet poignant moments in the story. The bottom has dropped out, and Winston's position is emblematic of the individual's complete powerlessness in that one instant. But it is almost as if O'Brien is a victim too, as the ironic but seemingly rueful description he gives of himself reveals.