The Aotea Centre had opened up all three levels of the ASB Theatre to accommodate the crowd who gathered to hear Toby Manhire interview neuroscientist, writer, and Harvard professor David Eagleman about brains.
Manhire started with the big question: yanny or laurel? Eagleman explained that we hear different things because that audio file is low quality, which allows your brain to bring its own interpretation to the sound. ‘The brain is locked in silence and darkness inside the skull’ yet we can have a full, rich visual experience with our eyes closed (for example, when we’re dreaming). ‘Your seeing of us now is happening inside your head.’ Already my own head was starting to whirl a bit, but we were only just getting started.
Eagleman has been working on sensory substitution, whereby you feed data into your brain via an unusual sense. For example, deaf people can hear by feeling the sound on their skin. Just when I was trying to figure that one out, we moved on again to the Mr Potato Head model of evolution. I didn’t fully understand it if I’m honest, but it’s got something to do with plugging devices into the brain. For example, could we ‘feel’ the economic movements of the world? Manhire asked whether there was a risk these devices could be hacked. Eagleman said not, but I’m not convinced. That whole thing sounded spooky.
Eagleman compared the brain to an inner cosmos: ‘the densest representation of who you are’. We tend to feel like we know who we are, but the deeper we go into neuroscience, the more uncertain we become. Our brains have a hundred billion neurons with a thousand trillion connections. ‘It’s the kind of thing that totally bankrupts our language.’ No kidding.
Manhire ran through a few brain FAQs. It’s not true that we only use 10% of our brains, actually we’re always using all of it. Consciousness – that tiny part that flickers to life when you wake up – is just a tiny speck of the brain. It’s true that brain cells are not replenished over our lifetime, but false that bigger-brained people are more intelligent.
There was an interesting discussion about how neuroscience can contribute to the criminal justice system. Eagleman told the story of Charles Whitman, who committed the first mass shooting in the US in 1966. Afterwards, he was found to have a brain tumour pressing on his amygdala. So does that mean it wasn’t his fault? ‘It strains our notions about justice. A lot of neuroscientists think we don’t have free will.’
Discussion moved on to the nature of memory. Long story short, it’s nowhere near as reliable as we think. ‘Memory is a myth-making machine. We’re constantly reinventing our past to keep it consistent with who we think we are.’ It doesn’t bode well for this review, that’s for sure. I started to worry that I was taking the wrong notes. I’m including lots of quotes here: what if I’ve misremembered them? Memory is physical change in structure of brain. ‘It’s a live electrical fabric that’s constantly reconfiguring itself.’ We feel we’re the same person we were in the past but in fact we’re completely different. Yikes!
So I’m now a different person from who I was when I became annoyed at a particularly daft audience question – one of those that has led Madeleine Chapman to call for an end to all festival audience questions ever. A person asked, essentially, how can we make wrong people be right? We can’t, nor should we, was Eagleman’s response – if memory serves.
Reviewed by Elizabeth Heritage
The Runaway Species: How Human Creativity Remakes the World
by David Eagleman and Anthony Brandt
The Brain: The Story of You
by David Eagleman