The enduring mystery of how a brain becomes a mind

our Twitter (X) feedView our Youtube channelView our Instagram feedView our Substack feedView our Spotify feed Complexity may explain how billions of simple neurons give rise to thought, creativity, and consciousness. Adapted from The Shortest History of Reality: From Plato’s Cave to the Mind-Bending Discoveries of Modern Physics — The Human Quest to Explain the World by Geraint F. Published by The Experiment.

Gottfried Wilhelm Leibniz, best known for his discovery of calculus and ensuing mathematical feud with Isaac Newton, supported Descartes’s view on the separation of the brain and the mind. He invited you to imagine yourself shrunk to the size of a flea, and then to join him on a tour of the brain at this tiny scale. (In fact, a flea would be a bit too large to properly explore the nooks and crannies of the brain, but let’s go with it.) As you wander around, there would be no indication of thoughts within the fleshy material, no ideas bubbling away inside all the biological machinery. No, he argued, the mind must be something separate, something distinct from the brain.

With the arrival of 20th-century science, Descartes’s dualism came under sustained attack. Advances in technology and biological understanding began to explore the physical workings of the brain, attempting to identify consciousness and thought in action. Researchers discovered that chemical imbalances across certain cells in the brain, known as neurons, trigger tiny bursts of electrical current.

Each neuron is small and relatively simple, yet it processes signals from other neurons and, when it fires, transmits a signal to others. It was confirmed that the secret to the mind lies in electricity, and the living, active brain is awash with these bursts of electricity across its complex network of neurons. Real-time mapping of signals coursing through the neurons revealed that Leibniz’s flea might not see any thoughts because thoughts seem to be invisible to the naked eye.

The brain pulses and bursts with electrical activity, with different regions lighting up in response to various stimuli. The information relayed to your brain from your optic nerve is processed in a region at the back of your brain, where the images you perceive as the world around you are created. Smell, taste, and touch are also processed in specific regions, with the front of the brain, the cortex, thought to be responsible for thought.

The mind, it seems, is purely physical — but it is built on complexity. The brain’s highly convoluted network comprises over 80 billion neurons and countless interconnections. Signals trigger new signals that flow throughout the network, with electrical activity surging and cycling, building up and fading away.