The brain is not yet fully understood, and this is one of the reasons why there’s almost always something to say about it. There are times when it seems like neuroscience offers up a new breakthrough every day.

By the same token, it’s important to realize that some of the stories we hear about the brain and human behavior are still in experimental territory, even when they are presented as established science.

I got a chance to talk to Tom Stafford, who coauthored Mind Hacks: Tips & Tools for Using Your Brainwith Matt Webb. He has a PhD in Cognitive Neuroscience and performs research for the Department of Psychology, University of Sheffield, works as an editor for Psychologist magazine, and has done research for the BBC.

We talked about his book and some of the more experimental subjects in cognitive science.

The Interview

I’ll go ahead and start this off by touching on something I mentioned in an article just a few weeks ago. It was about how our impression of the world around us isn’t a simple recording. The roles of averaging, context, and emotion play an important part in how we think.

You and Matt Webb wrote a great book that gives the reader some background and then walks them through exercises that expose some of these quirks of the brain. So let’s start by talking about how the brain is different from a rational computer, and why.

The fundamental difference is that our brains have been designed by evolution to help us survive and reproduce. This means that they are “rational computers”, but the rationality they obey is very different from the kind we imagine computers obeying.

Computers find exact logic easy, whereas exact logic isn’t too important for evolutionary survival. There’s a quote from the film “Wag The Dog” I like which I think sums up how evolution has crafted our brains: “better a good plan today than a perfect plan tomorrow”.

There’s a bad habit in psychology of finding examples of situations in which humans fail to obey exact logic, like some of the examples given in your post, and stopping at the explanation “Humans are irrational”.

That’s not it. These failures of reasoning are all principled mistakes, there for a reason. Psychology gets interesting when we start to ask questions about why we make the mistakes we do.

Yes, exactly. That’s a subject I find extremely interesting. There is a method to our “madness.” As David DiSalvo told me a few weeks ago, “what constitutes threats to our survival has changed in the last several thousand years.”

Any discussion about “purpose” in human behavior begs another question: “what is the purpose of consciousness?”

Consciousness has traditionally been one of those murky subjects that was best left to philosophical discussion, but some of the technological breakthroughs you discuss in the book have given us tools to start probing this phenomenon.

Are we anywhere near coming up with a scientific definition of consciousness, and is it necessarily synonymous with intelligence?

A friend of mine says that Consciousness is something you start investigating at the end of your scientific career – it doesn’t matter how old you are, as soon as you start investigating Consciousness, he says, that’s the end of your scientific career!

In Mind Hacks we give lots of examples of how your moment-by-moment awareness of the world is constructed, but the implications for Consciousness in the sense of “inner-experience” are not clear. Some people, like Dan Dennett, say that there is no inner experience separate from things like momentary awareness; others insist violently that there is a particular – and unexplained – thing about the first person perspective which third person perspective science can’t explain.

I wish I could help, but I’m in a state of profound confusion about it all still.

You’ll get no complaints from me. Without a specific theoretical framework it’s difficult to imagine how to tackle some of the questions related to consciousness, especially the question of whether it is different from simple “awareness.” It’s an important question, but I don’t think it can be addressed empirically yet, if ever.

Moving on, I recently read an article on Discover Magazine about how the human brain has been shrinking over time. The article presented evidence to suggest that exposure to sedentary living somehow causes the human brain to shrink relative to body size. Some are claiming this is a dietary issue, but others are making bolder claims.

By relying on group intelligence, our individual intelligence may no longer need to be as high. But a hypothesis that I thought was especially interesting was the possibility that humans are self-domensticated, and that the decrease in brain size was the result of a reduction in the faculties for aggression. I’d like to get your opinion on this.

You flatter me with the range of your questions! I didn’t know about the “shrinking brain” data, but it’s a great article and illustrates some of the complexity and excitement of evolutionary studies of humans.

Still, it would take a lot to persuade me of any of these explanations, including the domestication one. The trouble with evolutionary explanations is that they are so much easier to come up with than to test.

Let me illustrate by making up another plausible evolutionary story to explain the shrinking brain data. Let’s say I accept the “decrease in violence” part of the domestication theory; my explanation is that that this decrease in violence led to a decrease in brain size, not because of domestication, but because people were getting brain damage less frequently.

If you’re going to be hit in the head every other day by some ultra-violent proto-human then you need some redundancy in your brain tissue. You have to be able to afford to lose some. If violence declines, than the importance of having “spare” brain declines.

Convincing? It seems to make sense to me, and that’s the problem. We could get ten psychologists and come up with ten evolutionary stories in 15 minutes. But it would take years to properly test each one!

That is certainly one of the biggest problems with evolutionary explanations, and these theories have come to be called “just so stories” because they don’t rely on any evidence outside of their own internal logic. I have mixed feelings about evolutionary psychology for that very reason.

Good hypothesis, by the way.

I’m also interested in the science behind what have been called mirror neurons. It’s been claimed that a portion of our brain has evolved specifically for understanding and empathizing with other human beings. What’s the evidence for this and what does it tell us about the human experience?

There is an important distinction here: you’ve asked about whether there is a portion of the brain that has evolved to understand other humans. That’s easy: undoubtably much of brain’s evolution has been guided by the fact that we are social animals.

The other part of your question is about mirror neurons, which are neurons which “fire” both when you perform an action, and when you see someone else perform that action. The existence of mirror neurons is tremendously exciting, because they seem to give a neural basis for imitation – a common basis for the brain’s representation of our own behaviour and other people’s.

That said, the research into mirror neurons still leaves a lot of questions unanswered; we don’t know much about mirror neurons in humans – they were first discovered in monkeys – and we don’t know how the neuron gets the information that it uses to know when to fire.

In fact, we don’t know for sure what functions – if any – mirror neurons are involved in. Sure, it hurts when you see someone hammer their thumb, or you can learn to throw better by watching someone else throw, but we don’t know mirror neurons are involved.

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