Brain is an analogue device
Even if neuron firings are all-or-none, the message pulses that carry neural information are analogue. They involve complex graded and nonlinear factors. So the brain seems to be an analogue device.
John von Neumann (1958) as articulated by Hubert Dreyfus (1972).
Note: Von Neumann subjects the relationship between brain and computer to extensive analysis, and his classic lecutres on the subject are still relevant today.