title: The hands have it: number representations in adult deaf signers.
abstract: This study examines a wide range of numerical representations (i.e., quantity, knowledge of multiplication facts, and use of parity information) in adult deaf signers. We introduce a modified version of the number bisection task, with sequential stimulus presentation, which allows for a systematic examination of mathematical skills in deaf individuals in different modalities (number signs in streaming video vs. Arabic digit displays). Reaction times and accuracy measures indicated that deaf signers make use of several representations simultaneously when bisecting number triplets, paralleling earlier findings in hearing individuals. Furthermore, some differences were obtained between the 2 display modalities, with effects being less prominent in the Arabic digit mode, suggesting that mathematical abilities in deaf signers should be assessed in their native sign language.
authors.affiliation: Section Neuropsychology, Department of Neurology, University Hospital, RWTH Aachen University, Pauwelsstrasse 30, 52074 Aachen, Germany. korvorst@neuropsych.rwth-aachen.de
authors.forename: Marjolein
authors.initials: M
authors.lastname: Korvorst
authors.forename: Hans-Christoph
authors.initials: HC
authors.lastname: Nuerk
authors.forename: Klaus
authors.initials: K
authors.lastname: Willmes
mesh_terms: D000328:Adult; D003638:Deafness; D005260:Female; D006225:Hand; D006801:Humans; D008297:Male; D008433:Mathematics; D008875:Middle Aged; D011930:Reaction Time; D012813:Sign Language