However, your statement is actually vague and ambiguous. "Extra neurons"? Input layer? Output layer? Just before a final, fully-connected layer? Somewhere in b

However, your statement is actually vague and ambiguous. "Extra neurons"? Input layer? Output layer? Just before a final, fully-connected layer? Somewhere in between? "Everything it already knows"? What does it know? Character probabilities, like a charnn? Image categories like in a CNN? Input distributions, like a GAN? From the abstract, I can immediately tell that this paper is about modifying deep auto-encoders in the hidden layers. From that, I can immediately understand that the paper is not about adapting to new input formats or output formats, but instead about inputs from a new distribution but in the same format. The author's intended audience, researchers and academics, do talk like this. They do so because it is quickly understandable and actually information dense, as indicated in my above paragraph.