Why are there no big ideas in neuroscience?

By “big” ideas, I mean schools of thought, philosophies, or movements. Psychology has had, and continues to have, plenty of them: behaviorism, cognitivism, Freudianism, social constructionism, to name a few. But whenever I’ve tried to think of the neuroscience equivalents of these big ideas, I’ve drawn a blank.

Neuroscientists don’t seem to disagree on the big issues.

This doesn’t mean that we agree on everything. The field has plenty of controversies and debates, but they are focused around particular experiments and hypotheses. Factions can form, e.g. there are enthusiasts and skeptics in (say) mirror neurons. But these aren’t schools of thought in a real sense. Most neuroscientists don’t need to take sides, because mirror neurons are just one neural system.

By contrast, strict behaviorism (say) questions the foundations of the whole of psychology. Has there ever been an idea big enough to question the whole of neuroscience?

Psychology has an intellectual history, whereas neuroscience doesn’t really. We can trace the history of psychology from early philosophical approaches, to introspectionism, to empiricism, Freud, then Skinner’s behaviorism, Chomsky, the cognitive revolution, and so on. It’s a simple model but it does have some validity: we can trace how psychologists thought, and how they changed their minds, over time. We can track the rise and fall of -isms.

In neuroscience, on the other hand, this kind of history just doesn’t work. Our knowledge of the brain has grown over time, but it’s hard to point to a time when neuroscientists “changed their minds”, except on specific issues. The history of neuroscience is little more than a timeline of who discovered what, when.

Possibly the closest thing neuroscience has to big idea in the psychology sense is the Bayesian Brain, the idea that the brain is built around Bayesian inference. As far as I can see Karl Friston’s Bayesian Free Energy Principle (FEP) is neuroscience’s only candidate for a theory on the scale of (say) Freud’s.

Where are all other big ideas? And is it a good thing or a bad thing that neuroscience lacks them?

• “Psychology has an intellectual history, whereas neuroscience doesn’t really.” Isn’t the history of neuroscience embedded in the broader history of biology? In which case, I would argue that the “big idea” in neuroscience is reductionism, which has been in place for hundreds of years, so it’s hard for us to see that as an intellectual movement.

• In my lifetime, one example of a paradigm-changing big idea would be the acceptance of the chemical theory of neurotransmission. Jack Eccles originally championed electrical transmission between neurons, and he fought against the chemical theory for the longest time until he saw evidence in his own work to make him change his mind. Then he led the charge by establishing the reality of chemical neurotransmission in the central nervous system (acetylcholine at the Renshaw cell). All of neuropharmacology and psychopharmacology rest on that insight.

• It could be several things.

  “Consciousness” is a unifying feature of the intellectual landscape. What the brain does is not very controversial. How it does it has more potential and there are differing ideas on this, but the evidence is still too sparse for a polarisation of opinion.

  The “science” is largely descriptive. For example describing the connectome. What role would a big idea play in such an enterprise? And the level of detail is not sufficient to support any solid conjecturing about how the brain produces consciousness yet. It’s hard to disagree that the brain produced consciousness – though there are speculative disagreement over how, we still don’t have the kind of experiment that would be decisive one way or the other.

  I don’t think it’s a good or bad thing, it’s just inevitable given the state of play. The observations being made do not lend themselves to large scale theorisation. Yet.