We had DD8 tested on the WISC IV finally and as expected, her processing speed was below average. I expected this because she is incredibly slow with written work in class and also has ADHD (although she is a lot better medicated than unmedicated).
Her working memory, however, was Ok and much higher than processing speed. Working memory was 96th percentile and processing speed was 34th percentile. Has anyone else seen a gap like that? She had an 8 on coding and a 10 on symbol search. For the working memory index, she had a 14 on arithmetic and 15 on Letter-Number Sequence.
When we had DS, my other kid, evaluated for ADHD, the neuropsych was looking specifically at working memory. But DD's working memory was fine. It would be interesting to test her again and see how she does on both indexes without meds. The psych who tested her showed me her handwriting on coding and did mention possible perfectionism. She is not like that when unmedicated and her handwriting is very sloppy. But unmedicated, she would probably not be able to stay focused on the task at all.
I found this interesting article on processing speed and "The Tortoise Hypothesis". I wish I could find more info on what it means if working memory is fine but processing speed is poor.
http://www.davidsongifted.org/db/Articles_id_10447.aspx