Seven and a half lessons about the brain, Lisa Feldman Barrett, 2020 – (To be read with Attenborough’s voice) Ancient creatures like the Amphioxus which lived 550 million years ago and are still alive today have cells for sensing directly connected to its cells for movement – it didn’t need a brain to process information about the environment. We tell ourselves that our brains were evolved to think but this couldn’t be further from the truth.
The Cambrian explosion transformed the world into predator and prey, and consequently made the world a dangerous place. Sophisticated sensory systems evolved as a means to hunt and to escape – creatures could finally “see”, unlike the Amphioxus which would only sense light and dark. These creatures also evolved finer, sophisticated kinds of movement – evolution understandably favoured these.
Allostasis, or body budgeting involves keeping track of what’s earned and spent – eating and sleeping vs swimming and running. To balance a budget well is to avoid surprises and that involves prediction, than reaction. Prediction involves determination of value of action and thus actively drives decisions. More complex creatures like us, have a cardiovascular system, a respiratory system, immune system etc. – balancing this budget needed an accounting department and thus a command centre – the brain.
The brain supervises 6000 muscles in motion, balances dozens of different hormones, looks over the heart that pumps 2000 gallons of blood per day, regulates energy of a billion brain cells, digests food, excretes waste and fights illnesses – nonstop for an avg of 72 yrs. It continually invests your energy to earn good return to find yourself food, shelter, affection or physical protection – so you can pass on your genes to the next gen.
Triune brain theory – or the lizard brain (instincts), limbic brain (emotions) and neocortex (rationality) theory of brain being in layers with the ancient lizard brain in the center is one of the most widespread errors of science. Lizard brain theory runs rampant in popular science books once Carl Sagan introduced it in ‘77 (Munger talks about it a lot too). In reality bad behaviour doesn’t come from lizard brain and good ones from rationality – these don’t even live in separate parts of the brain.
Our brains are not very different from other vertebrates in terms of manufacturing plan or biological building blocks – the building block for cerebral cortex runs longer in humans than in lizards. So contrary to popular opinion, neocortex is not new. Neither is our cerebral cortex large – its like a large house with a large kitchen in proportion (scaled-up monkey brain or scaled-down elephant brain). The size of the cerebral cortex has little to do with rationality and thinking driven by emotions is not always bad – provided your brain is adjusted to the environment it lives in.
Left-brain being rational and right-brain being creative or system-1 and system-2 are just metaphors and not reality of the brain. A metaphor’s simplicity can become its greatest failing if people start treating it as an explanation. Reality is 128 billion neurons networked with 500 trillion neuronal connections (not every neuron speaks to every other) that become weaker or stronger as you go through the experience of life. Hubs form strong local connections while maintaining connections globally across the brain. Hub damage is linked with depression, schizophrenia, dyslexia, chronic pain, dementia, parkinson’s and other disorders (Efficiency leads to vulnerability)
Neurotransmitters (glutamate, serotonin and dopamine etc) and neuromodulators (endorphins, oxytocin etc.) help in changing the functioning of the brain network though the physical neuronal connections remain same. When neurons fire together, connections become stronger, leading to plasticity. Neurons can have many jobs and there are some whose only job is to have many jobs (dorsomedial prefrontal cortex that regulates memory, emotion, perception etc). Even a simple repeated action can be guided by different set of neurons each time (degeneracy). Brain network may extend to gut and intestines and even microbes in the gut can communicate with the brain via neurotransmitters. (Guilia Enders talks about this in ‘Gut’)
It takes 25 years for an adult human brain to be fully formed – for the wiring to be complete. The wiring is influenced by genes as well as the environment (nature and nurture), the environment being both physical and social. Tuning (strengthening connections) and pruning (if you don’t use it, lose it) helps in improving efficiency.
Memories aren’t stored as much as they are recreated every time (and by different sets of neurons – hence memory can be deceiving). Same is true with experiences – your brain combines information from outside and inside your head to produce everything you see, hear, smell, taste and feel. An artist only does 50% of the work in creating art – the rest is done by the viewer’s brain (the beholder’s share). Your day to day experience is a carefully controlled hallucination, tightly controlled by the brain.
Predictions are just brain’s way of having a conversation with itself. Your brain predicts continuously and checks against sense data. Brains aren’t wired for accuracy, they are wired to keep us alive, hence we act before we are aware of the senses (though we may rationalise later). But you can change this by curating new experiences and trying new activities that rewire the brain. Everything you learn today seeds your brain to act differently tomorrow.
If you and your partner feel your relationship is intimate and caring, you are less likely to get sick. We are a social species and thus solitary confinement or enforced loneliness can be like capital punishment in slow motion. Most species in the animal kingdom regulate each other through chemicals like pheromones but human beings can also do it with words. A kind word at the end of a hard day can calm you. The language network in fact controls the insides of your body, including major organs and systems that support your body budget – the language network can guide your heart rate up or down (All is well)
While occasional stress can create a stronger, better you, chronic stress (physical illness, financial stress, hormone surges, not sleeping or exercising enough) can eat away at your brain and cause illnesses to your body. Social stress within 2 hours of a meal can make your body metabolise food in a way that adds 104 calories to the meal. The brain burns 20% of body’s entire metabolic budget, making it the most expensive organ in the body.
Human brains make different kinds of minds and this variety is essential for the survival of the species. Mind and body are strongly linked and the boundary between the two is porous. We try to infer what other person is thinking or feeling and this mental inference is a valuable skill of our culture. Myers-Briggs Type Indicator (MBTI) might help find your type but is often misleading as it relies on your inputs. Author likes the Hogwarts Sorting test.
Affect (or mood) – the general sense of being that comes from your body – may be pleasant or unpleasant and can impact how we perceive things. It can make things profound or sacred or trivial or vile. Affect hints at whether your body’s budget is in green or red (Lack of sleep, hunger, physical pain, social stress can cause it to go to red).
The boundary between social reality and physical reality is porous – wine tastes better when people believe its expensive, as does Coffee that’s labeled eco-friendly. Your social reality can change your brain’s predictions. Your brain creates social reality through creativity (made up concepts like borders, citizenship), communication (sharing ideas through language), copying (how to prepare food, what to wear), cooperation (A can of food could involve thousands of people coming together) and compression (abstracting information). These 5 Cs allow us to bend the world to our will. Social reality helps people (like driving laws) or could hurt (slavery) so we must bear responsibility while using this superpower.
This is a short read and can be a good start to understand our brain, its powers and its limitations. 9/10
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