Verbal learning in boys with P-type dyslexia, L-type dyslexia, and boys without learning disabilities: Differences in learning curves and in serial position curves

Twenty-five boys with P-dyslexia, 23 with L-dyslexia, and 26 boys without reading disabilities were ad- ministered the Digit Span (Forward and Backward) and the Dutch version of the Rey Auditory-Verbal Learning Test. Compared to normal boys, dyslexic boys exhibited reduced scores on Digits Backward and recalled fewer words during the five learning trials. Nonlinear modeling of the data for the five learning trials revealed that dyslexic boys showed smaller learning parameters than did normal boys and that L- dyslexic boys exhibited more loss of information during learning than did P-dyslexic boys. In dyslexic boys, the word-list primacy effect was strongly reduced. In normal boys, but not in dyslexic boys, Digits Backward correlated moderately with the primacy measure. The results suggest that reduced word-list learning in dyslexics is a consequence of a temporal ordering deficit rather than a rehearsal deficit.