Spelling errors reveal underlying sequential and spatial processing deficits in adults with dyslexia.

Recent studies showed that some adults with dyslexia have difficulty processing sequentially arranged information. In a companion study, this deficit manifested as low accuracy during a word pair comparison task involving same/different decisions when two words differed in their letter sequences. This sequential deficit was associated with left/right spatial letter confusion.

Sequential and spatial letter reversals in adults with dyslexia during a word comparison task: demystifying the "was saw" and "db" myths.

Whether sequential and spatial letter reversals characterize dyslexia in children has been unclear, largely due to developmental variability of these errors in children with and without dyslexia. Here we demonstrate both types of reversals for the first time in adults with dyslexia (n = 22) but not in control adults (n = 20). Participants evaluated 576 word pairs that consisted of two identical words or two words that differed subtly, by categorizing them as same or different.