Geofizz,
FWIW, my son is definitely NOT a visual thinker, yet he has similar troubles to your son with writing ("Journal time is torture"--I'm SO with you, unfortunately)--with the exception that often if he is assigned a topic, he can't do it because he "doesn't know what to write." If he picks his own topic, he does a lot better. Don't know if you've checked whether that's true for your son. In any case, completing stem sentences is a lot easier for him than free writing on any topic.
Also--in case it's at all helpful--my son is exceptionally gifted in math and also is erratic about showing his work. Maybe partly because of the writing thing and partly because it's so obvious and partly because he doesn't see the value in writing down the steps.
amazedmom and polarbear--Thanks so much for the feedback! Will write more when I am reunited with the rest of my son's test scores (at home, where I am not). In the meantime, I really appreciate your many thoughts! I do know that his achievement scores were along the lines of
--off the chart in math (something like 22nd grade or something similarly ludicrous--definitely above the 99.9th percentile)
--quite good in terms of expression (sophistication, content, etc.)
--average for grade level on spelling (though weak on sight words).
Anyway, I'll look it all up and avail myself of your brain power and experience later!
