The Science of Significance - empathy in the amygdala
How do we know our mum is our mum? What does it mean to have ‘déjà vu’ and what makes us gaze in wonder at our surrounding universe?
The answer may lie in a small part of the brain called the amygdala.
An almond shaped region sitting close to the hippocampus, the amygdala has numerous vital neurological roles, which include interpreting social signals and controlling emotional responses.It is also thought to be involved in providing a sense of self.
Such correlative examples merely skim the surface of the amygdala’s functions, many of which we still do not know. When primate amygdalas were experimentally severed it was found that they were no longer able to respond to social cues, became withdrawn and, critically, lost their previously held positions in the social group hierarchy.
Just like monkeys, human society operates through social hierarchies. As group sizes grew in our ancestral apes, so did the evolutionary drive for social behaviours and thus the development of associated brain regions, including the amygdala. One of the vital traits that resulted from this development was the ability to empathise.
The ability to imagine oneself in another’s place is generally thought to be unique to humans and requires complex neurological processes. This includes the ability to associate significance to the behaviour of others, which means, for example, being able to appreciate instinctively what makes a laugh nervous, a glance stern, a gaze loving or a smile fake and to understand the driving force behind why another displays such behaviour. It then requires the association of an adequate response to that behaviour, such as suspicion, fear, anger or laughter. The part of the brain correlated with these functions is once again the amygdala.
“Neuronal recycling” - what our brains evolved to do vs what they CAN do - and whither the twain shall meet
The next giant leap in human evolution may not come from new fields like genetic engineering or artificial intelligence, but rather from appreciating our ancient brains.[…]
This mystery mechanism of human transformation is neuronal recycling, coined by neuroscientist Stanislas Dehaene, wherein the brain’s innate capabilities are harnessed for altogether novel functions.
Neuronal recycling exploits this wellspring of potent powers. If one wants to get a human brain to do task Y despite it not having evolved to efficiently carry out task Y, then a key point is not to forcefully twist the brain to do Y. Like all animal brains, human brains are not general-purpose universal learning machines, but, instead, are intricately structured suites of instincts optimized for the environments in which they evolved. To harness our brains, we want to let the brain’s brilliant mechanisms run as intended—i.e., not to be twisted. Rather, the strategy is to twist Y into a shape that the brain does know how to process.
We have already been transformed via harnessing beyond what we once were. We’re already Human 2.0, not the Human 1.0, or Homo sapiens, that natural selection made us. We Human 2.0’s have, among many powers, three that are central to who we take ourselves to be today: writing, speech, and music (the latter perhaps being the pinnacle of the arts). […]
In this transition from Human 1.0 to 2.0, we didn’t directly do the harnessing. Rather, it was an emergent, evolutionary property of our behavior, our nascent culture, that bent and shaped writing to be right for our visual system, speech just so for our auditory system, and music a match for our auditory and evocative mechanisms.
And culture’s trick? It was to shape these artifacts to look and sound like things from our natural environment, just what our sensory systems evolved to expertly accommodate.
There are characteristic sorts of contour conglomerations occurring among opaque objects strewn about in three dimensions (like our natural Earthly habitats), and writing systems have come to employ many of these naturally common conglomerations rather than the naturally uncommon ones. Sounds in nature, in particular among the solid objects that are most responsible for meaningful environmental auditory stimuli, follow signature patterns, and speech also follows these patterns, both in its fundamental phoneme building blocks and in how phonemes combine into morphemes and words. And we humans, when we move and behave, make sounds having a characteristic animalistic signature, something we surely have specialized auditory mechanisms for sensing and processing; music is replete with these characteristic sonic signatures of animal movements, harnessing our auditory mechanisms that evolved for recognizing the actions of other large mobile creatures like ourselves.
[Mark Changizi Humans, Version 3.0 in Seed Magazine. Emphasis added.]
Yes, yes, fascinating, great point, hmmm, and yes.
I’ve always been intrigued by the difference between (inherent) capability as opposed to (expressed) ability - especially when it comes to primate (and human) behaviour.
Let’s take language in extant primates. Chimpanzees, when taught, can become reasonably fluent (I’m using that word broadly) in sign language. They have been known to teach it to each other. After becoming familiar and comfortable with speaking, they are distressed when they are placed with chimps who cannot speak - to the point that they refuse to acknowledge, refuse to identify, those other chimps.
And, yet: it is an indisputable fact that, had they not been taught sign language, had they not been taught a language, they would not have invented one on their own. They didn’t “evolve” to speak - and yet, they can. They don’t regularly express the ability, yet they are nonetheless capable.
Language isn’t the best example, because there is good reason to believe that the ability was under direct selective pressure (which is to say that those individuals with better lingustic facilities were indeed more capable of survial and reproduction).
On the other hand, we’re also beginning to realize that, no matter how good at language the brain is, the portions of the brain that are primarily concerned with language not only had to come from somewhere (which is to ask, what were they doing before they were helping us talk) - but, they might have been shaped by a pressure to do something other than talk - at least, at first. (Visual processing, spacial awareness, and mental imaging being surprisingly and intriguingly related to language. One of the theories suggests that mental modeling and visualization - building, forming, and holding a mental reconstruction of, say, the landscape - was the mental “facility” that was, primarily, providing a survival benefit - and that language was a side-effect, a symptom, of the same constructs which enabled “mapping”.)
An even worse analogy would be to compare it to a disease vs its symptoms: we’re increasingly well aware of what we do (the symptoms) but unfortunately ignorant of the mechanisms and the causes and how we came to do it (the disease).
What else can a (primate) brain do - that it hasn’t yet been asked to? That it wasn’t, five million years ago as the forests began to withdraw and the savanna spread, immediately advantageous to do - but that might be related, use the same mechanisms?
And, for my to-read-list… jumping straight to the top.