2) His processing speed doesn't actually look slow in that his block design score was high and in line with his other abilities and block design is also a timed test. I'd wonder about whether distractibility, like you mention, or anxiety, or lots of mistakes, or fatigue played more into the speed index than true low speed.
Processing speed can in fact be that slow even though a child has a high score in block design - my ds12 scored 8 on coding, and 11s on symbol search and cancellation in his most recent WISC-IV (10 years old), but hit the ceiling on block design (19, did not answer any questions incorrectly). My understanding is that the block design subtest has the child recreate abstract visual designs using blocks; coding, symbol search and cancellation all require a child to use a pencil to make a mark while being timed - this is where kids who have fine motor dysgraphia are particularly challenged - their brain may process visual information very quickly, but their brain's ability to control their fine motor skills is challenged. It's not the same thing as having a slow processing speed due to cognitive issues - it's a symptom of the brain not being able to communicate the process that's required to use handwriting.
polarbear
