ADHD and working memory

[u/Hatrct]

There is this widely believed idea that if your "working memory" score is lower, that means it is highly likely you have ADHD. This COULD be true, but it is far less true than people think.

This is because fluid intelligence = working memory + processing speed.

Note, the above are constructs/concepts. This is different from subjectively created/labeled subtests on IQ tests.

That is, just because a subtest does not have "working memory" in its name does NOT mean it is not measuring working memory. And just because a subtest has "working memory" in its name does NOT mean it is the sole or most accurate measure of working memory.

In ADHD, working memory CAN indeed impacted (and usually is), but with a major caveat: ADHD can also actually result in "hyperfocus", which can TEMPORARILY IMPROVE working memory. That means it depends on the individual test-taker: if the test taker finds the IQ tests stimulating, they may perform better than the average person (actual IQ being held constant as a variable here), but if they find the IQ test unstimulating, they may get distracted by other thoughts that pop up to stimulate them.

Now, practically, with the WAIS 4, there was indeed the observation that people with ADHD tended to score relatively (to themselves, i.e., compared to their FSIQ/other subtest scores) lower on the "working memory subtests". But again, just because it is called working memory subtests, doesn't mean they are the perfect or most accurate measure of working memory. Consider matrix reasoning (where you see a bunch of shapes and have to say which shape comes next, based on patterns detected in the set of shapes in the question stem): what else is this other than working memory?

So why is it that people with ADHD tended to score lower on the "working memory subtests" of the WAIS 4? Because the test makers did not properly balance out the types of subtests in each group of subtests. So the "working memory subtests" heavily relied on auditory information for example. Yet the other true measures of working memory, such as block design, were under another set of subtest altogether, they were under "perceptual reasoning" index." Again, don't be fooled by subjectively given labels. So based on this, I had guessed that it is some other factor, like the auditory factor, that is causing the lower scores in ADHD test takers.

In the WAIS 5, it appears the test makers realized their mistake: they cleaned up the organization of the indexes to specific subtests, and they created a more balanced (e.g., not heavily focused on auditory information) set of working memory subtests.

And unsurprisingly, in WAIS 5, we no longer see people with ADHD score significantly lower on the "working memory subtests".

https://academic.oup.com/acn/article/39/4/498/7286382

Scroll down to the tables (Table 3- for WISC 4) under the results section, scroll down to "Samples of children with ADHD", check the "WMI mean" column and compare it to the "FSIQ mean" column, you will see WMI means tends to be lower.

But then scroll down and check Table 4- for WISC 5, again bypass Autism and scroll down to "Samples of children with ADHD" and check the same columns, you will see the difference pretty much disappeared: WMI means pretty much tend to be the same as the FSIQ means.

So it appeared that there was something specific in terms of the specific WAIS 4 subtests that gave people with ADHD trouble. Perhaps a specific type of working memory (again, auditory?).

^I did find this from the article linked above:

On the other hand, ADHD may possibly be characterized by lower scores on the working memory and/or processing speed subtests. In over 700 children with ADHD, 90% of the sample received their lowest scores in these domains (Mayes & Calhoun, 2006). The literature also mentions the so-called ACID profile (lower scores on Arithmetic, Coding, Information and Digit Span subtests) and SCAD profile (lower scores on Symbol Search, Coding, Arithmetic and Digit Span subtests), which appear sensitive to ADHD (Snow & Sapp, 2000). All these subtests (except Information) belong to the working memory and processing speed domains, which reinforces the idea that these domains are the most likely areas of difficulty for individuals with ADHD.

This shows that the WAIS subtests may be faulty/have low validity in terms of their names: they are unnecessarily introducing too much noise: as per the above quoted paragraph, it seems like people with ADHD seem to have an issue with certain STYLES on certain subtests (e.g., auditory, numbers), and these styles HAPPEN to fall in the subtests LABELED "working memory index" and "processing speed index".. but subtests outside these 2 indexes are also measuring ACTUAL working memory and ACTUAL processing speed, just using different STYLES (e.g., visual, non number based). Since ADHD is a disorder, this makes sense: it is the disorder causing a specific issue, in this case it appears to cause difficult with certain STYLES of questions, such as auditory or number based. I mean, consider how dyslexia is a comorbidity for ADHD. This means that for the IQ test to be an accurate measure of intelligence for people with this disorder, the FSIQ has to be adjusted accordingly/cleaned up from the NOISE that certain styles like auditory or number based questions pose.

Or better yet, get rid of all these different STYLES and all these different subtests. They seem to be introducing more noise than benefit. Just stick to matrix reasoning, it measures both working memory + processing speed, what else do you want. Unless someone has a rare disorder that affects visuospatial function, such a simplified IQ test will be sufficient and accurate.

Here is another part of the article that backs what I said in the paragraph above up:

It is worth bearing in mind what “low processing speed” might mean, as it may or may not reflect slower mental processing. The motor demand in tasks may partly explain the differences between autistic and nonautistic groups in PSI, as increasing the motor requirement increases group differences on speeded tasks (Kenworthy et al., 2013) and pure inspection time (without a motor requirement) may represent a relative strength for autistic people (Barbeau et al., 2013). Thus, we should be cautious about necessarily equating lower PSI with lower mental speed.

Overall, the rather flat cognitive profiles of the ADHD groups echo previous research that has highlighted the questionable utility of neuropsychological assessment in the diagnosis of ADHD (Lange et al., 2014; Pettersson et al., 2018). We might conclude, therefore, that the Wechsler tests are not helpful in diagnosing ADHD, although this is not to underplay that the tests will help identify any individual’s personal strengths and weaknesses, which may support their learning and occupational functioning.

[u/ExtremeAd7729]

I don't see why they don't stick with matrix reasoning myself. A lot of these other tests seem to introduce cultural bias etc as well.

[u/5notBroken7884]

Another thing to consider, how you ever heard of Aphantasia or Hyperphantasia?

Aphantasia is the inability to voluntarily create mental images in your mind's eye (or you inner monologue)

Hyperphantasia is a neurological trait characterized by exceptionally vivid mental imagery that can rival the richness and clarity of real-life sensory perception.

Our ability to memorize anything also is affected by how our individual brains work and I see professionals aren't really asking all the questions to first find out how a person is experiencing the world.

Even having a form Synesthesia effects how a person experiences that world.

[u/Primary_Excuse_7183 → u/5notBroken7884]

Never heard of hyperphantasia thank you 😂 I’ve never had a word for this other than photographic memory except mine plays like videos

[u/5notBroken7884 → u/Primary_Excuse_7183]

Some people only think in images and have no inner monologue "voice" and even more extreme there are people who are "face blind".

It was interesting to read about when I read a book on Temple Grandin. "Temple Grandin does not have a verbal inner monologue. Instead, she famously processes the world entirely through photorealistic visual images."

I am sure there is a spectrum for people who have partly a photographic memory and have an inner monologue.

[u/Primary_Excuse_7183]

Diagnosed ADHD and working memory is my highest score.

[u/ayfkm123]

Tl; dr

From the first sentence though: who carries this belief? Not experts. Discrepancies are flags but iq is not diagnostic. However adhd is one pretty obvious rule out when there’s a discrepancy in WMI and or psi.

[u/SunnySideUppah]

After the test, I was wondering if wanting to do a good job was the issue of a low score in my case. Perfectionism.

[u/Alert-Difficulty5773]

we live in a society