Paladin's brain gets destroyed, and she loses the ability to recognise faces.
“Are you going to be OK?” The man’s voice was carefully neutral, and Paladin could not read the expression on his face. In fact, she could no longer see Eliasz’ face at all. Certainly the man had a face, and she could perceive that it possessed the usual group of sensory organs, but nothing about it was recognizable as Eliasz. She knew him by his voice, his bearing, and the cloud of molecules hovering around his body, but his face was merely a concatenation of muscle movements. Her inability to classify the data provided by Eliasz’ expression filled Paladin with panic, which only intensified when she thought about how much her brain meant to him. The arms in Kagu Robotics Foundry had lied. Fang didn’t know what he was talking about. She was crippled without her brain, unable to tell the difference between wrath and laughter, or between a hostile face and a familiar one. How could she possibly aid Eliasz in combat? “I believe I may be too damaged to function in a combat situation.” Eliasz faced her, reaching out a tentative hand to touch the patch over Paladin’s empty brain socket. His face flickered with activity that meant nothing.
Annalee Newitz, Autonomous, pg. 250, loc. 3824-3833