Diagram of the human brain (credit: Wikimedia Commons)

My last few blogposts describe only the dead ends that have been hit in AI. Other sciences searching for this same holy grail—a clear, evidence-backed model of human thinking—haven’t fared any better. Neurophysiology and Behavioural Psychology also keep striking out.

If a neurophysiologist could set up an MRI or similar imaging device and use his model of thinking to predict which networks of neurons in his brain would be active when he turned the device on and studied pictures of his own brain activities, in real time, then he and his colleagues could finally say they had formulated a reliable working model of what consciousness is. But on both the theoretical and practical sides, neuroscience is not even close to being so complete.

Patterns of neuron firings mapped on one occasion when a subject is performing even a very simple task unfortunately can’t be counted on. We find different patterns of firings every time we look. A human brain contains one hundred billion neurons, each one capable of connecting to as many as ten thousand others, and the patterns of firings in that brain are evolving all the time. Philosophers looking for a solid base for empiricism are disappointed if they go to Neurophysiology for that base.¹²