I noticed the processing speed and memory are grouped together in the WISC series of IQ testing. Are processing speed and working memory related? Why are they grouped together?

What are things that cause low processing speed relative to everything else?

Thanks for your thoughts.

WMI and PSI are grouped together because one of the rotations on the factor analysis groups them together. That's the simplest explanation. From a functional standpoint, they group together because they both impact efficiency (hence the Cognitive Proficiency Index in the Wechsler family). It is not uncommon for gifted individuals to sacrifice efficiency for maximum accuracy and precision (which often involves mulling over all the possible permutations and angles of a problem).

WMI and PSI both have been associated with ADHD--WMI because it's hard to hold things continuously in your memory if you have dysregulated attention, PSI because of various factors, including impulsive responding (high error rate) and difficulty sustaining attention throughout a somewhat monotonous task. But some kids with ADHD score very high on PSI because they don't know how to put the brakes on. If your impulsive responding is highly accurate, then it becomes kind of an advantage.

Vision issues would definitely differentially affect PSI, as it consists entirely of tasks which require attention to visual detail, often with visual-motor responses. The remaining visual stimuli on the WISC-IV are relatively large, brightly colored, and can generally be recognized from the overall shape. (Unless the supplementary Picture Completion subtest is administered. That is specifically a task of attention to visual detail.)

DS is very mathy and had a similar pattern.
WMI>PRI>VCI>PSI and WMI-PSI=55.
No "issues" that I know of. DS can be fast at some tasks and slow at others, so I'm not sure what PSI is really measuring.

FWIW, my DD9 has the pattern VCI>PRI>PSI>WMI and there is a 3 sigma spread between the highest and the lowest cluster.

The VCI and PRI are within 1 sigma of one another (5 point spread) the PSI is just under 2 sigmas below that and the WMI is a full sigma below the PSI.


She has successfully completed a year as a skipped 4th grader and is enthusiastic about starting 5th grade this morning. She has 'blue' bars on her AoPS pre -algebra II progress report so I do not see her average WMI holding her back at all. So far..

I just got my son's reports. He has a much lower WMI and PSI than he other subtests. There is a 43 pt spread between his PRI (137) and his PSI (94). He also has a low Working Memory.

DD's processing speed was around 93 with working memory over 30 points higher (but processing speed and working memory were both lower than PRI and VCI). It meant that her GAI is a lot higher than FSIQ. She does have ADHD, and the slow processing speed does show up in school (she is usually one of the last to get things done). She tends to be meticulous with her work and doesn't make many errors, which slows her down, but I also suspect handwriting is an issue for her, in that she is slower than normal.

DD's processing speed was 85. Everything else was around 110-113, including Working Memory, although the entire test was a bit "off", so we are still investigating.

I was told, and aeh (or anyone else), can correct me if I am wrong, that my DC's pattern of very high VCI and PRI (so high reasoning skills), combined with somewhat lower PSI or WMI (or both), is not unusual for HG+ kids.

DD9 is VCI (by far, the highest)>PRI>PSI (very high)>WMI (barely above average!) - much like madeinuk's DD.

DS6 is VCI>PRI (PRI higher than DD's, but much less spread than DD's between VCI and PRI)>WMI (very high)>PSI (high average)

Neither child has a 2e diagnosis, although DD has sometimes seemed a tad ADDish. Both are high achievers so far.

I have wondered about the interplay between PSI and WMI, since both of my DC are very strong in opposite areas, and less strong in the other area!

I was told this from the gifted psycologist my son has been seeing. It's not the psyc as the one who just tested him, and I'm now anxious to see what she says about my DS's scores. She told me that she interprets the data differently for gifted kids.

I believe that this observation was the reason for the NAGC's statement on WISC IV interpretation:

http://www.nagc.org/sites/default/f...20WISC-IV%20for%20Gifted%20Education.pdf

Thanks for the link, this looks like it applies to my son. Going to request that the GAI is put on my son's evaluation.

As others have already noted, yes to the gifted profile of WMI/PSI.

I usually look for WMI or PSI that are below the high average range as potentially of concern in gifted kids. So, for instance, I would not bat an eyelash at your DS's scores, but would keep an eye on working memory in your DD, especially where she also has a marked difference between VCI and PRI. I would also pay attention to how she does when she reaches geometry and physics. She might do fine, but I wouldn't be surprised if she had to put a little unaccustomed effort into them.