The brain: A reductionist approach

Scientists study “the brain” (rather than brains), but there is no object in the universe that can be considered the brain. My brain differs from yours, rodents’ brains, and worms’ brains, yet they are all studied under the same scientific effort: understanding the brain.

“The brain” refers to an abstract idea, a profound assumption that states that all brains have some core principles in common. Neuroscience aims to investigate these principles. Moreover, this implies a reductionist approach: studies involving rodents or even worms might provide insight into human brain function.

In the past it was considered a wild speculation, given how much more functionally advanced the human brain seems than any other creature. The origins of this line of thinking can be traced back to Claud Bernard, the father of the scientific method in medicine. He insisted that all living creatures were bound by the same laws of inanimate matter.

In my opinion, Eric R. Kandel’s work on Aplysia illustrates the reductionist approach perfectly.

Eric Kandel Aplysia

Using this strange-looking animal, and its simple nervous system, he discovered one of neuroscience’s most fundamental mechanisms: neuroplasticity. In his explorations of various animals, Kandel discovered that the Aplysia displayed memory-based behavior. As a result, he began researching the biological mechanisms responsible for memory. Over time, it was realized that this mechanism is found in every animal species on earth.

The first evidence was found by taking an enormous leap of faith when it was first discovered, even though this approach looks trivial today.

Evolution serves as both the common ancestor of all living organisms and the tinkerer of biological systems. In light of this, evolution is considered to be the primary justification for the reductionist approach.

I would like to question this reasoning by deconstructing evolution into its components and asking how these shared mechanisms came into existence. More on that in the next post…

Written on August 12, 2022