Nonsymbolic Comparison in Deaf Students: No Evidence for a Deficit in Numerosity Processing.

It is commonly found that deaf and hard of hearing (DHH) students experience delayed mathematical achievement. The present study used two nonsymbolic comparison tasks to explore the basic numerical skills of DHH students. Nine prelocutive DHH students with cochlear implants and nine hearing students, matched on nonverbal IQ, visual short-term memory, and verbal comprehension, were recruited. The participants performed two different collection comparison tasks with different ratios and under different perceptual conditions. Analyses by task showed similar response times, accuracy, and ratio effects for both groups on the Low Perceptual Condition task, a finding suggesting that the two groups accessed similar representations of quantity. Differences in performance on the simpler High Perceptual Condition task, on which the DHH group showed slower response times, probably were strategic in origin. The results suggest that DHH students have no deficits in basic numerical skills.