I mean in the floating point / quantized numbers and the connections that make the model? I'm not sure I follow, the analogy to the human brain has always been obvious, it's even in the name (artificial neural network) ...

The analogy is just that: an analogy, and a very imperfect, misleading one. The working of the brain may have motivated early research, but GPT (as instantiated in hardware) does not operate or learn in a way similar to a human brain.