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Jul 05

On Beyond Brain Plasticity

What is the Basis of Our Emotional Style?

Is it a birthright, based on our genetic inheritance, or is it something we develop as we age? The answer, perhaps not surprisingly, is “both.”

In recent years, the old debate over nature versus nurture has taken a new twist.

It was once thought (not that long ago) that one was born with all the brain cells one would ever have, and that one’s genetic inheritance was pretty much the last word on the person an infant was to become.

Not so, in either case, it turns out. Our brains develop and change as we age and learn. Neural connections can become stronger or weaker; and new cells can appear, to replace damaged ones or to expand an area of the brain that is being heavily used. Even more dramatically, it has been clearly demonstrated in a wide variety of studies that even the genetic component of our brains can change over time. Our DNA itself doesn’t change, of course, that is our inheritance, but its expression can be enhanced or suppressed by life experience, including intentional experience (i.e training).

Here is an ancient (2004) talk on brain plasticity, given by Michael Merzenich, a neuroscientist who “studies neuroplasticity – the brain’s powerful ability to change itself and adapt” (NB someone who wasn’t with it created a URL with the word “elastic” in it – which is, amusingly, the opposite of “plastic”!).

This is my third in a series of posts based on “Emotional Styles” described in the book The Emotional Life of Your Brain, by Richard Davidson with Sharon Begley, Hudson Street Press, 2012. The first and second of this series addressed my speculation that there is a distinct autistic personality style, but my takeaway from this book is that it cannot be identified as simply as by ranking a person on the emotional styles described by Davidson.

What, Then, is the Connection With Autism?

Even my casual readers will know that the amateur neuroscientist in me springs not from a random late-life academic pursuit, but is born of my deep interest in understanding my own origins and how I fit into the world. I am reading books, watching videos, attending conferences, and questioning experts because I want to know what makes me tick, what it is about being autistic that has made my life better or worse, and why. And, even more importantly, how I can use that knowledge to bring deeper meaning and fulfillment to my life, both directly and through the satisfaction of helping others.

Beyond that, I’m having fun! It is very exciting to have new worlds to explore, new myths to fathom, new horizons to reach for. There is something pleasurable about stretching my mind, and every “aha” is rewarding. I’ll probably develop more insight into why that is so, too!

I love it when patterns begin to emerge. It’s almost as exciting as anticipating the next symmetry event on my odometer. While reading the book that is the basis for these essays, I am regaling in the examples of brain function, which compliment and extend what I have already learned from other sources.

The Important Role of the Prefrontal Cortex

One such observation is the confirmation that the prefrontal cortex plays a huge role in many neural differences that I have come to associate with autism. Early in life (almost certainly in the prenatal period) the autistic brain takes an atypical developmental pathway. Brain size (and perhaps body size) seems to be somewhat larger for autistic people. There is a delay in myelination in the autistic brain, which may explain many of the features of autism.

It’s still hard for me to grok how much the behaviors we associate with autism come from delayed development versus how much comes from the secondary effects of such delay. By this I mean that delays in the appearance of certain abilities (as compared with neurotypical [NT] people) might create feedback conditions that influence development (usually in negative ways). I will have much more to say about this at a later time, but don’t want to get sidetracked here.

Suffice it to give one example from the book [page 68]: “… the prefrontal cortex, site of such executive functions as planning and judgment, controls how emotionally resilient people are.”

It is well known that this part of the brain is the last to fully develop. Even in NTs, significant changes and development go on well into the late 20s or even early 30s. Not that many generations ago, life expectancy wasn’t too much longer than that, which may be why so many cultures revere and respect elders; they were the rare ones whose cranial capabilities had reached the level of integration and understanding that is known as “wisdom.”

Here’s where it becomes hard to distinguish the cause or source of certain behaviors. I am, for example, swift to indignation. I am even quicker to blame – it’s almost as if I really believe I’m perfect, and therefore anything that goes wrong in my life must, by definition, be someone else’s fault, or the fault of the world at large. I mention these foibles not just because I experience them; I know from talking to many autistic people that these are shared tendencies.

Now, is my defensiveness (one might even say paranoia) a result of my autistic wiring, or it is a result of my life experiences? And, by extension, would the same be true of my fellow autistics? It could be some of each, of course, but I’m inclined to think it’s a deadly combination of being easily confused by the strange world in which we find ourselves and the fact that we have been told (probably every day of our lives) that we are doing something wrong. It’s not too hard to see how that could produce a defensive reaction, and create an underlying rage at a world that is not only unfathomable but unfair. When you feel unjustly accused of wrongdoing with incredible frequency and consistency, it’s hard not to start from a place of anticipatory aggression.

Obviously, this is all material for another essay. Let me just mention, before moving on, that one of my most difficult (and most rewarding) learnings has been to engage in a conversation –  after I think (know!) I have been wronged –  with a friendly, polite, and open mind.

Left Brain, Right Brain – More Complex Than Pop Science Would Have You Believe

Of perhaps even more interest than the role of delayed development to me is the hemispheric differentiation that may give even more clues to what is different about the autistic brain.

I will continue that discussion in the next post of this series. Here is a preview:

I’m coming to the suspicion that there is asymmetric delay in the development of the autistic brain. That there is delay has long been known. The left side of the prefrontal cortex seems to develop more slowly in autistic brains. This is associated with higher shyness, depression, and discontent. It is also associated with lower communication and social skills, though that is more likely to be centered in Broca’s area, also a left-side part of the brain (which is also thought to be rich in motor neurons).

Much, much more to come. Stay tuned!

Never far from my mind is one of my favorite quotations: “Ce que nous connaissons est peu de chose, ce que nous ignorons est immense.” (That which we know is tiny; that of which we are ignorant is vast.)

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  1. Is There An Autistic Personality? Part II | Michael Forbes Wilcox

    [...] On Beyond Brain Plasticity » [...]

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