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Aug 19

More on the Mystery of Executive Function

Those of us who are neuroexceptional are known to have difficulty with many of the cognitive processes that fall under the general rubric of “executive functions.” Why is that? If I knew that answer to that, there would probably be a Nobel Prize waiting for me. Still, I have given this a lot of thought. My interest is a pragmatic one. Through intense self-analysis, I have gained control over some of the important executive functions (such as impulse control and emotional regulation), but I still am frustrated by other aspects (such as task planning and initiation).

In an earlier post, I recorded an (uncharacteristic) triumph over my bank statements. That victory was short-lived, and I am now back in that limbo of not knowing exactly where all my finances stand. This is not to say that I don’t pay bills as they come due, but I certainly don’t do it in an organized and optimal way; I have only a vague sense of anticipation and planning.

Why is this kind of planning so difficult for me? I sometimes use my poor sense of personal finance as an example of how autistic brains struggle with this thing neuroscientists call “executive function.” It is for me an ironic shortcoming because I made my living as a financial analyst. I could invent new investment products and strategies for clients to help them meet their goals. I could use my computer-modelling prowess to scan the world’s markets and tell which countries’ bond markets offered the best risk-adjusted value, where foreign currency exchange rates were most likely headed, which stocks in the S&P 500 index were cheap by historical standards, and so on. Yet, I could not keep my checkbook in balance.

Often as not, when I offered this example, people would look at me, puzzled, and say, “But lots of people have trouble balancing their checkbooks. What is so autistic about that?” And, they have a point. There has to be more to it than that.

As should be clear by now, I identify as being autistic. I began this post with the more general term “neuroexceptional” because I realize that there are many people with different diagnoses who share a similar neural structure, and one that is very different from those who are “neurotypical.” I will have more to say in another post about the neural similarities of autism, schizophrenia, bipolar, and some forms of dyslexia. Clearly, these are very different from each other in terms of behavioral outcomes as well as being very heterogeneous from the point of view of neuroscience, yet they all stand apart from the neurotypical brain structure, and may share some common characteristics, such as difficulty with executive functioning.

The mystery of executive function is multidimensional. I’ve recently read a couple of things that may shed light on this mystery, but before I comment on those, let me take a moment to better define what is meant by and what is covered by the term.

“Executive functions” is an umbrella term for functions such as planning, working memory, inhibition, mental flexibility, as well as the initiation and monitoring of action. [Chan et al]

The study of executive functions falls under a field known as cognitive neuroscience. A related field (about which more in a moment) is computational neuroscience. To oversimplify, executive functions arise from the prefrontal cortex, which is the last part of the brain to have evolved in humans. Right below that part of the brain lies the anterior cingulate cortex, which seems to be implicated in brain imaging studies as the source of some of the different behaviors associated with autism.

It is thought that the development of these parts of the brain is what has given homo sapiens the right to its name (“wise”). Humans are able, perhaps better than any other species, to use these newer parts of the brain to override signals that arise in earlier parts of the brain. Which is not to say, by the way, that older parts of the brain have not evolved. At one time, scientists speculated that emotions arose in the older parts of the brain (collectively known as the limbic system), and that intellectual functioning was centered in the cortex (the outer layer and newest part of the brain). This is now known to be an oversimplification, since these regions of the brain interact with each other in complex ways. Still, for purposes of this post, it may be helpful to accept this distinction.

The purpose of executive functions, then, is to evaluate (and potentially override) the impulses that first arise in other parts of the brain. As an example, it is clear that xenophobia was programmed into the human psyche eons ago. It is a subset of those reactions (“fight or flight”) we experience when we encounter something that is “off” – I see this behavior in my horse when I go for a ride. If we are riding along a familiar trail, but something has changed, he will shy away from it. I’m amazed at his visual memory, but of course it arises from a keen survival instinct. Similarly, it may be that when we encounter a person for the first time who does not look like us (different skin color, different clothing style, different behavior), we may shy away from that person. Does this mean we are prejudiced? No, it means that our limbic system is doing its job of alerting us to a potential danger. We can consciously choose to override that reaction if our cognition tells us that the person is not dangerous, but just different. If we end up treating the person as a danger or as an “other” (inferior) without just cause, then we are acting in a prejudicial way. Prejudice, then, is a cognitive decision, though of course it might be operative at a subconscious level.

Many other examples could be given, but suffice it to say that “the optimal deployment of executive functions is invariably context-dependent.” This means that every decision we make will be influenced by our experience, our values, and our reasoning power. This might be a good place to slip in a discussion of “wisdom” (which may grow as we age and acquire a larger storehouse of experiences), but I will use my executive functioning to override that impulse, and save that discussion for a later post! :)

Notice, however, that I did slip in the word “values” and this is where computational neuroscience comes in. A full discussion will have to wait for another time, because I want to focus on the subject at hand. The thoughts that follow were inspired by the book Why Choose This Book? by Read Montague.

In his Introduction, Montague states that our minds “are quite literally valuation machines.” He says that computational neuroscience “stands on the shoulders of evolutionary biology.” And, since that’s another of my interests, it all fits very nicely for me. He goes on to “propose a new guiding idea – efficient computation.” Essentially, the rest of his book is full of examples and explanations of how efficiency in the brain is both a physical property (using, for example, as little energy as possible) and a goal- (value-) oriented activity.

The point of this essay (yes, there is one) is that Montague’s book led me to think in a different way about why executive functions might be so difficult for the autistic brain. I say “different” because I already had done plenty of speculating about this subject.

My autism diagnosis came to me late in life (at age 61, just 5 years ago), and started me on a journey to redefine in my own mind who I am and where I came from, both psychologically and in terms of my inheritance. Many of the quirks that had annoyed and puzzled me all my life came suddenly into sharp focus, and I began a journey of self-awareness, self-understanding, and self-acceptance. All of this brought a sense of peace that I had never before experienced.

Despite my new cognizance, my problems and challenges did not disappear. The brain is plastic (it can be changed, or rewired), especially so the autistic brain. Yet, change does not come easily. I spent long hours of introspection, set goals for myself, and purposefully changed my attitudes and actions. I also had the aid of two different therapists and a partner who was willing to do mirroring with me to help me become a better listener, and to acquire an awareness that I did not have a monopoly on reality.

I attended conferences and seminars, I read books, blogs, and academic papers. I spoke to many different audiences, participated in panels, and helped teach a graduate-level course; learning as much from the questions and comments I received as I did from my own preparation.

When all was said and done, I felt I had a good understanding of how I had overcome my shortcomings in many areas of executive functioning, such as impulse control and emotional regulation. Yet, more remained to be done, and I was mystified as to why I was not able to make more headway.

Somewhere in Montague’s discussion of how the brain functions (not physically, but when thought of as a computing machine), a light went on for me. I’ll have a post with quotations from his book and more about what I learned from it, but for now let me just focus on one aspect. Without getting into an extended discussion of it (see pages 60-62 and 279 of the book), let me just highlight his observations that “the prefrontal cortex plays a role in working memory, task or context switching, and executive control related to both.” He combines this with the concept of a “virtual machine” (which traces its roots back to the autistic genius Alan Turing), a concept that “blurs the the distinction between a device and an algorithm.”

…the prefrontal cortex is capable of cycling through entire virtual machines for solving particular problems; each machine would use its own working memory contrived for a task, would have some kind of executive control, and would be able to task-switch … This is of course just a speculation on my part…

In my words: our brains cycle through a series of “what if?” scenarios, tries to predict the outcome of each, based on our experience and knowledge, and evaluates each one based on how close it would bring us to our goals. We are then poised to take the action that makes the most sense under the circumstances.

Unless, that is, you are autistic, and cycling is not an easy thing to do. If the brain gets stuck on one scenario and analyzes it to death, the cycling, for all practical purposes, comes to a halt, and indecision is the result. We have clearly entered the realm of speculation piled upon speculation, so the mystery of poor executive function remains just that. Yet, I feel that I have found fertile ground for further cogitation, and will report back when I have had some time to stew on it.

 

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  1. Rachel

    I really resist any characterization of all autistic people as sharing any particular characteristic. My executive functioning is quite good, and always has been. I am far more organized than most NTs I know, and cycle through “what if?” scenarios without getting stuck when needing to make a decision. My only real challenge is working memory for auditory phenomena, but that’s because I have difficulties with auditory processing, and have to work so hard to parse words that it’s difficult to keep everything in mind at once; give me the same information in writing, and I’ll remember it forever, and use it quite easily. And my difficulties with working memory of auditory phenomena only started in adulthood; as a child, I could recite back entire conversations and make very practical use of the information.

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