Updated: Jul 22
I can explain. When I saw that Dr Hannah Critchlow, (one of my favourite speakers and writers on Neuroscience) was speaking at New Scientist Live, I knew I'd have to make a day of it.
So there I found myself, a wine lover, turning up at The Excel Centre on a rainy Thursday, amidst throngs of school kids, and engineer-types.
Here are 5 fascinating things I learnt about the mind and the senses.
1. WE HAVE A SIXTH SENSE - AND IT'S CALLED INTEROCEPTION
We’re familiar with the idea of the 5 senses: smell, taste, touch, hearing and sight. They come under the banner of “Exteroception” - the senses which translate external stimuli from the world to our brain. Another is called “Proprioception” - our ability to sense our body’s position in space.
But have you heard of ‘Interoception’: our ability to sense internal signals from the body: for example our heartbeat, butterflies in the stomach, or the sensation of being hungry or full.
So what? Well it turns out that increasing our awareness of these bodily signals may allow us to make better gut decisions, have better intuitive reasoning and even decrease anxiety.
A part of the brain called the Anterior Insula is involved in translating these bodily signals into how we feel emotionally. It’s the basis of embodied empathy responses and emotional contagion between humans. For example, studies show that when you look into the eyes of a person who is sad, your own pupils will constrict, mirroring those of the sad person. Merely watching someone plunge their hand into icy cold water, you will also experience a small drop in body temperature. Another fascinating study showed how the heartbeat of people watching a man walk over hot coals synced up with the heartbeat of the firewalker himself.
Apparently the thickness of the neural substrates in this Anterior Insula area correlates with how good you are at sensing these signals in the body - i.e. our ‘Interoceptive Accuracy’.
In her talk “What The Heart Knows”, Dr Sarah Garfinkel, a neuroscientist at The University Of Sussex, showed how this idea of Interoceptive Accuracy (or lack of) was linked with things like anxiety, and even financial performance over time in one study on financial traders.
Accuracy however, and subjective reports of accuracy can differ. As in, you can think you’re very good at reading those signals, but actually you may not be - something which apparently can be at play in autism, where there can be an altered connectivity & reactivity in terms of translating these biological signals into how we feel. It seems this dissonance may manifest as a kind of anxiety.
In fact our heart has a lot to answer for. We often set up a dichotomy between the head and the heart, i.e. thinking with our head versus our heart. But actually it turns out our heart signals actually change the way the brain processes stimuli:
" Our heart signals actually change
the way the brain processes stimuli"
At each exact moment our heart beats, certain brain processes like attention, and memory encoding, are interfered with, as if we’re momentarily dumbstruck. Our heart interferes with our brain’s clear thinking.
Intuitively we know this. If your heart is racing it’s harder to concentrate. Imagine driving a car in a highly excited state - a recipe for disaster.
But wait, wouldn’t that mean that when we’re scared we’re at a disadvantage?
It seems nature has a work around for it. It turns out the amygdala (part of the brain involved in fear processing) is more active at the moment of heartbeat. In other words, fear overcomes the inhibitory effect of the heart. Handy.
It was a fascinating talk on an under researched but hugely exciting area.
So, that hollywood trope of the Zen Master, who has some kind of special insight and inner intuition may have some kind of scientific basis. We do have a kind of sixth sense, a gut instinct, if we can just tune into it.
2. WE SEE THE FUTURE
Gustav Kuhn gave a mind-bending talk on magic, and the perceptual psychology behind it. One magic trick was simply throwing a golf ball up the air, and catching it again in the same hand. Once, twice, thr… hang on - where did it go? The illusion is powerful. You clearly see the ball rising in the air, but on the third time it doesn’t fall back down. It simply disappears in thin air. Where did it go? The magician opens his hand and there it is, as if by magic.
How does this illusion work? It relies on the fact perception happens in the brain. Not the eyes. Far from our intuitive understanding that what we see is reality (“‘seeing is believing”; "I saw it with my own eyes”) there is always an element of illusion and interpretation in what we believe we are seeing.
"There is always an element of illusion and interpretation
in what we believe we are seeing".
Our eyes receive light information, which is conveyed through the optic nerve, where it is processed by the visual cortex.
This happens pretty damn fast, but not instantly. There is a 1/10th of a second delay. But rather than ‘see’ the world in the past, our visual system interprets the future. It used information from the past to predict the future. Your visual system is interpreting the now.
"Your visual system is interpreting the now".
Just let that sink it for a moment!! That’s why our brain believes it saw the ball rising in the air for the third time. We’ve seen it happen twice before, we recognise the same hand movement, we expect to see the ball, and so we do. It takes a moment for the brain to catch up, hence an entire audience momentarily dumb struck by a golf ball vanishing into thin air, right in front of our eyes.
3. BUT WE'RE ALSO BLIND FOR 1/4 OF THE DAY
Do you remember the classic blind spot trick? Where an image of a rabbit in a top hat (or whatever) is placed on the right hand side of a postcard.
You hold the postcard out at arms length and slowly bring it closer. Eventually, the rabbit seems to disappear, only to then pop back a second later as the postcard comes even closer.
As you probably remember, it’s to do with our blind spot. The surface of the retina which receives light information, is interrupted by the optic nerve, like a big plug hole. Light information hitting that exact spot isn’t processed. But rather than present us with an image with a hole in it, the brain simply fills in with something sensible; a blank background as in the case of the rabbit. In this way a seamless image is served up to our conscious brain.
We are therefore oblivious to our blind spot, even though with every eye movement we are blind for 100milliseconds, Gustav explained. We move our eyes 3 times per second. We make 50,000 eye movements in a day. That means, for 4 hours of the day, we are blind. That’s a quarter of our day!!
We don’t notice it because our brain just fills in the gaps. Again, our intuition is that we see the world in full sensory detail, but that’s just not the case.
" Our intuition is that we see the world in full
sensory detail, but that’s just not the case."
4. A LIFE LESSON FROM ANTS (OR WHAT NOT TO BRING ON A PICNIC)
Humans use words to communicate. We navigate the world with our eyes. Insects use smells.
The membrane at the end of a dead bee’s sting, the part that’s left in your body if you’re unlucky enough to be stung, sends out a warning signal to other bees in the form of a pheromone. It makes the other bees more likely to sting and less inhibited. It smells (in part) of 2-Heptanone, Isoamyl Acetate, 2-Nonanol, and Citral. That’s Stilton Cheese, Banana, Oysters and Lemon, to you and me, (and so, maybe don't take those all items on a picnic?!)
Another brilliant example is the trail pheromone of the leaf cutting ant. They live in a different sensory world to us, where they are guided by this trail pheromone, which we can’t sense. Just 0.33 mg of this pheromone would leave a detectable trail around the earth’s equator.
"Just 0.33 mg of this pheromone would leave
a detectable trail around the earth’s equator".
They follow the pheromone trail religiously, as they know it will lead them to food. But apparently If you were to lay a pheromone trail in a circle, the ants would go round and round in that circle until they died.
Ant survival relies on 10-15% of rebel ants, who resist the pheromone and forge their own path, in search of new food. As Professor Adam Hart said, there’s a lesson in there somewhere from these rebel ants.
5. WE LIVE ON PLANET NEUROTYPICAL - BUT WE MIGHT NOT BE FROM THERE
Not all of us process things in the same way. Some people notice patterns and colours that other people take for granted. Some people are good with words, while some people process things best with visuals. Some people are hypersensitive to sound, and visuals; everything is amplified - a crowded room can feel like a football pitch.
We are familiar with the idea of diversity… but how about neurodiversity? We don't know how many of us could fall under the banner of “neuro-divergent” as opposed to “neuro-typical”, but it could be anywhere from 10 - 35% of the population.
Neuro-divergent covers things like autism, but also subtler forms of cognitive difference.
We simply aren't all wired in the same way, but we live in a world that prioritises certain types of intelligence. We live on Planet Neurotypical.
What do we know about Planet Neurotypical? It's a ‘word-heavy world, where words get you through life’s barriers” - school exams, job applications etc. It's a place that makes certain assumptions, for example that a brightly-coloured, open-plan office environment is the best for it's workers.
We heard from Leena Haque, who is austistic, about her experiences at school. In lessons, she’d constantly be in trouble for drawing pictures and doodles. Her teachers would think she wasn't taking things seriously; in fact she was merely trying to process things as best she could.
Her teachers came to the conclusion she wouldn't amount to much, and this judgement seemed to become a self-fulfilling prophecy as she struggled with uni applications and then job applications in our word-heavy world.
As Einstein said, "Everyone is a genius but if you judge a fish by its ability to climb a tree it will spend its whole life believing it’s stupid.
The BBC, where Leena works, is pioneering the idea of neuro-inclusive spaces considering things like lighting, sound, colours, challenging that assumption that “open-plan”, and brightly coloured and cheerful is always best.
It's in all our interests to consider how to be more neuro-inclusive since cognitive diversity is essential for problem solving. You just need to look at our current dysfunctional government of old-Etonians for proof of this!
6. THERE ARE WAYS TO BOOST YOUR FREE WILL
Hannah Critchlow spoke about consciousness. What is consciousness? Perhaps it can be defined as an ability to form a subjective view of the world.
She spoke about how the way our brains are wired is inextricably linked to how we experience the world. We make sense of the world based on our past experiences, memories and prior information.
Have you heard of dendrites? They are like a beautiful tree canopy inside the brain, allowing each brain cell to connect to up to 10,000 other cells via a dendritic spine. There are around 100 trillion connections inside the brain. A sugar grain sized piece of brain would contain 10,000 nerve cells.
They create the connections in the brain, creating a unique cartography and circuitry in the brain. This is the basis in the brain for bad habits, assumptions, negative and positive associations and feelings. What fires together, wires together.
What is fascinating and perhaps scary is that memories may be passed down from one generation to the next.
" Memories may be passed down
from one generation to the next."
In an experiment on mice, they were taught to fear the smell of cherries, as they would be delivered an electric shock at the same time, a kind of pavlovian response. What happened was these memories were passed onto their children and grandchildren, as those mice would also tense up at the smell of cherries, even they hadn't been exposed to any prior cherry-pain conditioning.
The mechanism was seemingly via epigenetic. As Dr Critchlow explained, (and I will attempt to summarise) the experience caused a change in the DNA packing code in the sperm of the grandfather mouse, which affected how enzymes could get access to genes. This change in shape of the DNA led to a change in how the gene was instructed to express itself. The nerve cell track was altered, and the electrical signal rewired in relation to the amygdala (the fear centre of the brain).
In this way our ancestors can provide us with memories and information.
Apparently there are a 350 milliseconds between when we are conscious of an action and the moment we automatically made it.
The big question is how much of our life is based on conscious free will, rather an automatic behaviour, whether we realise it or not.
Is there a way to strip away bad habits, assumptions and negative associations? To overcome our pre-programming?
She finished by posing the question that perhaps freewill is the ability to take advantage of that pause button in the brain.
Dr Critchlow had a few suggestions, and, helpfully, they tally with most advice around a healthy mental and physical life.
By boosting alpha waves, you can boost creativity. (Seems you can do this by deep breathing, mindfulness and meditation).
Getting out in nature.
Mild forms of exercise.
Find ways to engage disparate regions of brain to engage all areas. (Wine tasting is one of these by the way!)
Stay physically and socially active.
Surround yourself with positive influences.
So, I hope you found all of those a mind blowing as I did, if you enjoyed it, please give it a thumbs up!