Multiplication engages phonological networks in Broca's area differently for deaf signers and hearing non-signers
2012 (English)Conference paper (Other academic)
In hearing individuals, multiplication relies mainly on the phonological loop while subtraction relies on the visuo-spatial sketchpad (VSSP; Lee & Kang, 2002). Little is known about arithmetic neural networks in deaf signers (DS). Since DS often perform worse than hearing non-signers (NH) on arithmetic in general and multiplication in particular (Traxler, 2000), we hypothesized that there are strategic differences between how groups recruit the phonological loop in multiplication, but not in subtraction, leading to differential activation of phonological processing areas in left inferior frontal gyrus (Broca’s area). We investigated this using a blocked fMRI-design in which nine DS and 17 HN matched on age, gender, education and non-verbal intelligence (Raven & Raven, 1998) were tested on tasks of multiplication, subtraction and phonology (rhyme). The contrasts rhyme versus multiplication and rhyme versus subtraction were examined across groups within the region of interest defined by a probability map of Broca’s area (Amunts, 1999). We observed a significant interaction between task (multiplication and rhyme) and group (F = 12.64, p = .034, FWE-corrected), where the HN showed higher activation for rhyme than for multiplication (T = 4.55, p = .001, FWE-corrected) whereas there were no differences in activations between tasks for DS. For subtraction versus rhyme no interaction with group was found. These results suggest that there are differences between DS and HN in the phonology dependent neural networks in Broca’s area used during multiplication, which may be part of the explanation for poorer performance in DS.
Place, publisher, year, edition, pages
Social Sciences Interdisciplinary
IdentifiersURN: urn:nbn:se:liu:diva-76679OAI: oai:DiVA.org:liu-76679DiVA: diva2:515827
19th cognitive neuroscience society annual meeting, Chicago, 31 March - 3 April, 2012