What use is neuroscience?

I love neuroscience. The brain is complicated and fascinating. A few hundred grams of fat, protein, salts and water is somehow home to our conscious experiences, hopes and fears, memories and identities. How this is the case is one of the biggest puzzles we know of, and the answer goes to the heart of the human condition.

But lately I have started wondering just how useful neuroscience is. Altering the brain’s function in a predictable way is hard. The blood-brain barrier makes getting drugs into the brain more difficult than other organs. More genes are expressed in the brain than most other tissues, which means there’s more chance of drugs finding the wrong target, leading to side effects. And the complexity of neural systems means that it’s not easy to predict how altering one part of the brain will affect the overall system. Our track record on developing drugs for neurological and psychiatric conditions is pretty poor. There are exceptions, deep brain stimulation is a notable one, but when it comes to drug discovery, neuroscience is known for its failures rather than its triumphs.

I hear you say ‘but we’d never have gone to the moon if we gave up just because it was hard’. Quite right. Though I sometimes wonder if we overemphasise neuroscience in tackling psychiatric and neurological illness might distract us from more effective psychological and public health approaches. We already know that you can lower your risk of dementia by eating healthily, getting exercise, not smoking and not drinking too much. And talking therapies are as effective as drugs for treating depression, and their effects may last longer. But neither of those things involves giant electromagnets or fancy genetic sequencing, so they don’t get so much funding. MQ’s research portfolio is heavy on basic neuroscience, when applied research on cost-effective treatments and public mental health interventions might be better investments.

But what’s been bugging me more is that neuroscience is also not particularly helpful for public health and public policy more generally. If we understand the patterns in human behaviour, then how much does knowing that this or that brain region, or gene, or receptor, is involved, really add? If we know that people tend to be loss-averse, does it matter that this depends on activity levels in the striatum or ventromedial prefrontal cortex? If we know that aggression is to some extent heritable, what in practical terms are we supposed to do with that knowledge? Short of CRISPR-ing children of violent criminals, it’s not clear to me how this kind of information can inform policy. Essentially, many findings in neuroscience have to be taken as fixed variables in the policy equation.

Chiara Varazzani has tackled this issue over at Behavioural Scientist. She argues that examples of ‘neurohacking’ such as removal of conditioned fears and sleep conditioning show that neuroscience has practical use. But it’s not clear to me that either of these couldn’t be done without using neuroscientific techniques like brain scans (which are currently still very expensive too).

I’m more persuaded by Varazzani’s second argument — that neuroscience helps us to have more confidence that behavioural findings are robust, and that we understand them properly enough to use them in practice. But I don’t think we need to know the neural basis of a robust behavioural pattern to be able to start using it in practice. This is different from the scientific question of whether a finding is ‘real’. Those of us who believe that the brain and the mind are the same thing will reserve judgement on where a behavioural phenomenon is ‘real’ until we feel that we understand how a behaviour is generated by the brain. But that doesn’t preclude the use of the behavioural finding on its own to inform public policy.

These thoughts aren’t my final view on this subject, more an attempt to start a discussion. What I’ve tried to do here is sum up all my doubts about the practical usefulness of a field I spent four years studying and still love to bits. If I find reasons to change my mind, I’ll revisit this blog.

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