A review of executive function deficits in autism

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This topic and related topics have come up on WP more than once.
I came across this article from 2016 and I thought I would share.
The link leads to the full article, but I have quoted the abstract here.
Post a reply if you have comments.

A review of executive function deficits in autism spectrum disorder and attention-deficit/hyperactivity disorder

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4869784/

2016 May 12

Abstract

Executive dysfunction has been shown to be a promising endophenotype in neurodevelopmental disorders such as autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD). This article reviewed 26 studies that examined executive function comparing ASD and/or ADHD children. In light of findings from this review, the ASD + ADHD group appears to share impairment in both flexibility and planning with the ASD group, while it shares the response inhibition deficit with the ADHD group. Conversely, deficit in attention, working memory, preparatory processes, fluency, and concept formation does not appear to be distinctive in discriminating from ASD, ADHD, or ASD + ADHD group. On the basis of neurocognitive endophenotype, the common co-occurrence of executive function deficits seems to reflect an additive comorbidity, rather than a separate condition with distinct impairments.
Keywords: executive function, autism spectrum disorder, attention-deficit/hyperactivity disorder, ASD + ADHD, neurocognitive endophenotype

I'm trying to work out what that means in plain English.
I think they're saying that Executive Function deficit is not a consistent thing deserving its own diagnosis. Rather it has several components (or types of executive dysfunction), some of which can be found in both ASD and ADHD (such as flexibility and planning issues, and disinhibited responses), but many of which are distinct to one group or the other.
Have I interpreted that correctly?

I understand it that when we split executive disfunctions into parts, the picture is:

Problems with flexibility and planning are common in ASD;
Disinhibition is common in ADHD;
ASD+ADHD commonly shows both difficulty with flexibility and planning and disinhibition;
other executive disfunctions (deficit in attention, working memory, preparatory processes, fluency, and concept formation) are equally common in all.

By the way, I wonder if they screened it against stress level NDs experience, because attention, working memory and concept formation definitely can be impaired by long-term elevated stress.

Indeed, many related disorders have many shared characteristics.

ADHD and autism have very much in common.

Yes, I think I understand now.
While many people with ASD have difficulties with flexibility and planning, they might not have the disinhibited responses of those with ADHD - and vice versa - unless they have both conditions.

This makes sense to me, as I've noticed that people with ADHD seem to have more difficulty with disinhibition and impulsivity and not finishing things they've started, whereas with autism there are more issues around planning and breaking down tasks and not being able to change track easily. But all of these issues seem to come under the broad umbrella of executive function difficulties.

One might say that executive function issues are when our frontal lobes are not in complete control of the rest of the brain. So parts of the brain go off and do their own thing, but in autism this tends to be insisting on doing the same thing over and over, whereas in ADHD it is getting distracted by other things. Same concept but different result.

Thanks for the English translation - I don't know how the original authors managed to make it so inaccessible, or why they did.

Even then it was only clear to me when I further translated it into 3 separate lists as follows:

ASD ONLY:
flexibility and planning
attention
working memory
preparatory processes
fluency
concept formation

ASD +ADHD
disinhibition
flexibility and planning
attention
working memory
preparatory processes
fluency
concept formation

ADHD ONLY
disinhibition
attention
working memory
preparatory processes
fluency
concept formation

Hope that's accurate. Does anybody else find that clearer, or is it just me? It was just that from the point of view of the person affected by ASD and / or ADHD, it seems easier for them to just pick the list that corresponds to the condition(s) they have, rather than having to fish around in those sentences. But maybe the difficulty I have in doing that is unusual? Don't know what executive disfunction you'd call it, or even if it is one, but I often have to reformat other people's information like that or it's just a mess to me. When I show my new format to others, some of them seem to think I've made it clearer, others don't seem able to understand why it was necessary.

Thanks for clarifying it.

So the only difference of ASD vs ASD + ADHD is Disinhibition?

I'm diagnosed with ASD and combined-presentation ADHD. I don't have disinhibition. I have Inhibition if there's such a word clinically. My anxiety causes me to be scattered and avoid tasks. That leads to poor Executive Function. Sometimes the anxiety (Inhibition) is because I know I'll have to confront sensory issues when I do the task. Sometimes it's trauma-related anxiety making me avoid memories, or sometimes just general anxiety about time management or performance anxiety. I'm totally inhibited.

My OT who helps me with EF says that anxiety is a common reason for poor executive function. We actually tackle EF by starting with Interoceptive / Proprioceptive exercises to calm my lizard brain (limbic system). The body can't do higher order cognitive planning if its basic primitive physical needs aren't met via regulation of the nervous system.

Assuming my reformatting was error-free, yes.

Your lack of disinhibition would seem to show that their findings don't apply to every case of ADHD. I guess it must be a spectrum disorder, though I know little about it. ASD is definitely a spectrum disorder so I wouldn't expect those executive function traits to be hard and fast either. I suppose the research findings are more relevent to the study of general trends than to any particular individual who actually has the condition(s), though they may provide a starting point - a list of disfunctions for the individual to look at and ponder which ones they actually have.

I've heard of a psychology term "behavioural inhibition":
https://scales.arabpsychology.com/s/adu ... tion-ambi/
I don't know how to work out the score - they don't seem to explain that - but it doesn't seem hard to guess what answers would indicate a positive result. It looks to me as if most of those things would be often seen in ASD, which might suggest that applying the term to an Aspie wouldn't be helpful, though I think it's always useful for any individual to ponder questions about themselves, even if there's no useful label at the end of it. Personally I don't worry much about psych labels at all, and I think I could drive myself mad trying to figure out what labels to stick on myself, perhaps because the whole labelling system is pretty complex and might not represent reality very well at all. But traits, such as attention problems, working memory problems, inhibition / disinhibition, I can ponder those a lot more comfortably, presumably because they're simpler and because (I think) they're more objective.

I completely agree that anxiety would get right in the way of any kind of intricate functioning.

Maybe by "Disinhibition" they mean that I'm not scared to avoid things? LOL, but really. Maybe it means people are supposed to be Inhibited by the idea of not doing something and disappointing themselves or others, but people with ADHD say "Screw that, I'm just not doing it!"

If that makes sense?

My crude grasp of the terms is that behavioural inhibition is an unusually strong fear of taking risks (especially social ones, it seems) and "letting the hair down," while disinhibition is poor self-control and disregard for danger, in a word, impulsive. But that's just my glib idea and there are probably more precise definitions out there.

I scored high on that inhibition test, probably deservedly so, but I think it's more complicated than that for me. Meshed in with the shyness is a rogue tendency that bursts out from time to time, not aggressive outbursts but sudden unexpected risk taking, though never anything really serious.

One example is when I was having some driving practice. I was waiting to turn left (in the USA, driving on the right) off a main into a dirt road, and there were some cars approaching me. The gap was borderline safe but the wise thing to do would have been to wait and let them pass. But I just thought "what the hell" and made the turn very quickly - it got me out of the way of the approaching cars well enough, but I skidded on the dirt road and came close to losing control of the car. It hadn't been exactly a dangerous manoevre - even if I'd lost control of the car there'd have been little or no harm done - but it was impulsive for sure. That's about the most dangerous thing I've done for a long time, it's otherwise been safer stuff than that, but it's there, and comes as a marked contrast to my general behaviour. There are other things such as a streak of immediacy in my social interactions that often shows if I happen to be feeling reasonably confident.

I understand and agree. I have Disinhibition related to ADHD because I blurt out answers and do impulsive things. That's not related to Executive Function though. The article was specifically about EF for ADHD people.

Your driving example is a good one, but again that's not related to EF.

Or maybe it is? I guess making a decision impulsively instead of planning in a careful, linear way still counts as poor EF - even if it's in a split second driving decision.

My idea of inhibition and disinhibition goes like this:
My right arm has two mussels - one pulls the forearm closer to the shoulder, and the other pulls it further away.
There is a number of ways that these two mussls can be "not working right" and a very few where they work properly:
1) one can pull while the other cannot pull - then my arm could either bend or unbend but not both.
2) they can both pull at the same time and always be fighting each other
3) they can both pull in the right amount, but be poorly co-ordinated and so my hand shakes, my handwriting is unreadable and I cannot eat soup with a spoon
4) my brain has perfect control of both. I can bend and unbend my arm, I can write, I can put a key in a lock and turn it without breaking it - my arm works just fine.

With ADHD I sometimes do not have impulse control - I do things before I can think to-not-to - or I do things even though I do think to-not-to. Sometimes my impulse control is stuck - I can stay put but I cannot start. Or I can start but I don't know how to stop.

When the inhibition and the initiation are working well together then things are smooth - sometimes they will not work together.

Well, disinhibition is one of the things they mention in the article, which is about executive disfunction, so I thought it was. Being ASD-only, I'm not supposed to have it, except that Aspies are sometimes said to be somewhat impulsive. Except that I've never been tested for ADHD so I can't be sure what my impulsiveness comes from. I'm sure one of the reasons I stick to traits rather than diagnostic labels is that the latter is just too mysterious for me to get my brain round.

I didn't even read the article (lol). I just looked at your summary lists because I didn't have enough EF to open the link and read it all.

Good point about the traits vs labels. I have so many labels I don't know which behaviour belongs where, and it's easier not to try sorting them out.

I've always preferred to discuss traits because my understanding is that diagnostic labels merely describe collections of traits.

Well, we have some lists of (EF) traits now, and predictably my main interest is to look at them and try to understand them. Judging by the thread title I needn't worry too much about what's ASD and what's ADHD, which is just as well because although the abstract was much concerned with that, it's Greek to me.

I think I know roughly what disinhibition is, and maybe I've got a streak of that, or maybe it's plain Aspie impulsiveness and maybe it's not really the same thing. I don't know any way of finding out, and I don't see how it could be helpful if I did.

The other traits are flexibility and planning, attention, working memory, preparatory processes, fluency, and concept formation. I know what working memory is, and attention I guess is fairly obvious. I don't understand why they group flexibility with planning or how preparatory processes are different from planning. All I understand about fluency is the idea of a skill being easy to operate, e.g. fluent in French would mean being able to communicate in French effortlessly and at good speed. I guess a concept is an idea, a presumably abstract notion that the mind is accustomed to using. But maybe there are better definitions of those things.

Frankly if I had to write an essay about executive function without being able to refer to source material such as what's in this thread, I doubt if I could remember much or do a very good job.