Sunday, November 11, 2018

Inside Out

How do you pick a favourite Pixar movie? They speak to so many different parts of ourselves. But if you happen to be obsessed with how brains work (rather than with fatherhood or art, at least this week), you probably should choose Inside Out.

As a person living with Post-Traumatic Stress Disorder, Inside Out helps me explain the long-term impact of trauma. Experiences create memories. (In the movie, coloured glass globes represent individual memories.) Our brains automatically process, sort, select, and store memories for potential retrieval later. The interaction of our feelings, thoughts, and sensory experiences constantly updates the complex array of our stored memories.

Inside Out shows how memories of trauma can be painfully powerful. Sometimes traumatic memories are repressed or twisted in ways whose impact may not become apparent until years later. When you encounter a triggering stimulus that your brain associates with the poorly-processed-and-stored traumatic memory, whole systems can go haywire.

Inside Out also introduced a second important part of our model of how the brain works: modules. The film represents this concept by placing the brain’s control panel in the hands of five competing colour-coordinated emotions: Fear, Joy, Anger, Disgust, and Sadness. 

Specific structures and neural networks in your brain are associated with particular emotions. Neurobiologists have identified priming effects that correspond to each of these brain areas, such as the amygdala, nucleus accumbens, hypothalamus, insular cortex, and anterior cingulate cortex. Both our perceptions and our actions will depend on which of these modules is activated at any given time. This process happens much faster than we can possibly be consciously aware of, let alone choose to act deliberately.

Inside Out shows the power of particular brain modules. When activated, each specific module directly affects not only what we remember, but also how we think and make decisions.

Fear is associated with the area of the brain called the amygdala. The name is Greek for “almond,” which is what primitive dissectionists thought the structure resembles. The amygdala is part of our brain’s ancient “fight or flight” impulse, and tiggers the release of adrenaline and cortisol.

Humans ordinarily are “loss averse” – more afraid of losing what we have than excited by the prospect of a potential gain. Damaging the amygdala removes that bias. As social animals, we are also programmed to automatically divide the world into “Us” and “Them.” Destruction of the amygdala results in treating everyone as part of “Us.”

Joy corresponds to our dopamine system, which bathes our brains with bliss-inducing chemicals. It appears to be centered in the nucleus accumbens.

Multiple stimuli can activate the dopamine system: sugar, sex, religious ecstasy, exercise, flow, love, most interesting drugs, etc. Choose your poison. Then enjoy gazing at a rose-coloured world.

But only for a little while. Unfortunately, most pleasures are fleeting. In fact, according to biologist/philosopher Robert Wright, “pleasure is designed by natural selection to evaporate so that the ensuing dissatisfaction will get us to pursue more pleasure.”   

Like fear, Anger is processed by the brain’s evolutionarily ancient limbic system, including the amygdala and the hypothalamus. Anger is more sophisticated than fear. And more social.

As Wright observes, “you can see why natural selection would have made righteous rage attractive: in a small hunter-gatherer village, if someone took advantage of you – stole your food, stole your mate, or just generally treated you like dirt – you needed to teach him a lesson. After all, if he learns he can get away with abusing you, he may do it again and again. Worse still, others in your social universe will see that you can be thus exploited, so they may start treating you badly.”

Although a “desire to punish people who treat you unfairly or show you disrespect is deeply human,” our anger impulse is less adaptive in a contemporary setting, where we regularly interact with complete strangers. “Road rage” demonstrates “the absurdity of the way this feeling can play out on a modern highway.”

As the parent of two thirteen-year-old girls and a ten-year-old boy, I can attest that humans are born with a burning sense of injustice. And a hair-trigger. 

Disgust, which involves another reptilian connection between mind and emotion, is centered in your insular cortex. As with other animals, our brains have a prudently negative reaction when exposed to unhealthy tastes or smells. 

With humans, disgust also acts metaphorically. The same brain structures light up when we’re exposed to homeless people, drug addicts, or others with low social status. Interestingly, scientists have demonstrated that social disgust is only triggered by real people, and not by computer simulations.

Wacky academics keep designing new experiments to gauge the effects of various stimuli. For example, if you put people in a room with smelly garbage, they become more socially conservative.

I started this essay months ago, but I got stuck trying to write about Sadness. 

My life is depressing. Some days when the kids are gone I can't get out of bed, let alone write. More importantly, I didn’t want to characterize this emotion as a mere negative – an insufficient supply of dopamine. To the contrary, the complex relationship between Sadness and Joy is at the center of the movie Inside Out.  

Then at my friend Henry’s suggestion I read Robert Sapolsky’s Behave: The Biology of Humans at our Best and Worst. Sapolsky is an excellent writer, and he does an amazing job of explaining brain function and its relationship to other physiological and social processes. Behave starts at the level of the individual neuron, and telescopes out to address neural networks, brain modules, hormones, developmental biology, genetics, cultural transmission, and natural selection. 

Sapolsky discusses the role of the brain’s Anterior Cingulate Cortex region. The ACC monitors our internal and external environments for any discrepancies with our expectations. The ACC not only identifies “unexpected pain,” but it also helps us process the "meaning of pain." For example, major depression is linked to ACC dysfunction. 

Significantly, the ACC also plays a key part in a uniquely human trait: empathy. Observing and understanding pain – ourselves’ and others’ – apparently is essential to our shared humanity.

According to Robert Wright, “the original function of good feelings and bad feelings was to get organisms to approach things or avoid things that are, respectively, good for them or bad for them.” As a result, “natural selection didn’t design your mind to see the world clearly; it designed your mind to have perceptions and beliefs that would help take care of your genes.”

Wright’s most recent book is called Why Buddhism is True: The Science and Philosophy of Meditation and Enlightenment. Wright discusses how traditional Buddhist meditative practices can help us learn to overcome the impact of emotion and bias and see the world more clearly, including ourselves. But he probably could have written a book called Why the Christian Gospels are True, or Why Mindfulness is True. Or the Golden Rule, or Humanism, or Kant’s Categorical Imperative. Each of these great moral guides has a shared message: See clearly, unclouded by the effects of emotion. Then then treat everyone, including yourself, equally and with equanimity.

So if you want to become a good person, all you need to do is to stop letting strong emotions grab your brain’s control panel. How hard can that be? 

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