In "1984", what sort of treatment does Winston receive shortly after his arrest?

In Part 3 Ch.1 Orwell describes very graphically, the miserabe and wretched state of Winston after he is arrested and locked up in a cell.

To begin with he is very hungry and there is a constant gnawing pain in his belly because "since he was arrested he had not been fed."

He was forced to sit still on a narrow bench and even if he moved a little a voice on the telescreen yelled at him. When he put his hands into his pocket to look for some food in his pocket, the voice shouted out from the telescreen

'6079 Smith W! Hands out of pockets in the cells!"

Before, being brought here he was kept temporarily in another cell which was "filthily dirty and at all times crowded by ten or fifteen people." There were all sorts of prisoners here and they were constantly on the move. Hardly anyone spoke to him but now and then they whispered the dreaded word "room one-oh-one," which was the torture chamber where all prisoners were mercilessly tortured.

Worse than the hunger was the psychological fear of what would happen to him in the future:

"There were moments when he foresaw the things that would happen to him with such actuality that his heart galloped and his breath stopped. He felt the smash of truncheons on his elbows and iron-shod boots on his shins; he saw himself grovelling on the floor, screaming for mercy through broken teeth."

The first prisoner whom he met was Ampleforth who had been arrested because,

"We were producing a definitive edition of the poems of Kipling. I allowed the word "God" to remain at the end of a line."

After Ampleforth is despatched to "Room 101,"  Parsons arrives. He has been arrested for a 'thought crime.' He was heard saying "Down with Big Brother" in his sleep by his seven year old daughter who immediately reported the matter to the police who arrested and sent him here promptly. Soon Parsons and another woman are sent to "Room 101."

Next, Winston witnesses a horrifyingly brutal scene when a person who tries to give a piece of bread to a starving man is mercilessly beaten up by the guards. Worse, when the starving man is despatched to "Room 101" he screams out:

" 'Do anything to me!' he yelled. 'You've been starving me for weeks. Finish it off and let me die. Shoot me. Hang me. Sentence me to twenty-five years.' "

rather than being sent to "Room 101."

Finally, O'Brien arrives. Only now he realises that it was O'Brien who had betrayed him and he has been imprisoned because of O'Brien. It is then that fear overwhelms him and as the guards begin to beat him up  he remarks:

"Nothing in the world was so bad as physical pain. In the face of pain there are no heroes, no heroes, he thought over and over as he writhed on the floor, clutching uselessly at his disabled left arm."

Orwell in this chapter describes in a chillingly realistic manner the physical and psychological torture totalitarian regimes inflict on political prisoners.