The present study investigated basic numerical skills and arithmetic in adults with developmental dyslexia. Participants performed exact and approximate calculation, basic numerical tasks (e.g., counting; symbolic number comparison; spatial–numerical association of response codes, SNARC), and visuospatial tasks (mental rotation and visual search tasks). The group with dyslexia showed a marginal impairment in counting compared to age- and IQ-matched controls, and they were impaired in exact addition, in particular with respect to speed. They were also significantly slower in multiplication. In basic number processing, however, there was no significant difference in performance between those with dyslexia and controls. Both groups performed similarly on subtraction and approximate addition tasks. These findings indicate that basic number processing in adults with dyslexia is intact. Their difficulties are restricted to the verbal code and are not associated with deficits in nonverbal magnitude representation, visual Arabic number form, or spatial cognition.
AckermanP. T.AnhaltJ. M.DykmanR. A. (1986). Arithmetic automatization failure in children with attention and reading disorders: Associations and sequela.Journal of Learning Disabilities19, 222–232.
2.
AshbridgeE.WalshV.CoweyA. (1997). Temporal aspects of visual search studied by transcranial magnetic stimulation.Neuropsychologia35, 81121–1131.
3.
BullR.JohnstonR. S. (1997). Children's arithmetical difficulties: Contributions from processing speed, item identification and short-term memory.Journal of Experimental Child Psychology65, 1–24.
4.
CappellettiM.ButterworthB.KopelmanM. (2001). Spared numerical abilities in a case of semantic dementia.Neuropsychologia39, 111224–1239.
5.
CipolottiL.ButterworthB.DenesG. (1991). A specific deficit for numbers in a case of dense acalculia.Brain114, 62619–2637.
6.
DehaeneS. (2000). Cerebral bases of number processing and calculation.GazzaniggaM. S.The new cognitive neuroscience.Cambridge, MA: MIT Press987–998.
7.
DehaeneS.PiazzaM.PinelP.CohenL. (2005). Three parietal circuits for number processing.CampbellJ. I. D.Handbook of mathematical cognition.New York: Psychology Press433–453.
8.
DehaeneS.SpelkeE.PinelP.StanescuR.TsivkinS. (1999). Sources of mathematical thinking: Behavioural and brain-imaging evidence.Science284, 970–974.
9.
DonlanC.CowanR.NewtonE. J.LloydD. (2007). The role of language in mathematical development: Evidence from children with specific language impairments.Cognition103, 23–33.
10.
GalfanoG.MazzaV.AngrilliA.UmiltàC. (2004). Electrophysiological correlates of stimulus-driven multiplication facts retrieval.Neuropsychologia42, 101370–1382.
11.
GelmanR.ButterworthB. (2005). Number and language: How are they related?.Trends in Cognitive Sciences9, 16–10.
12.
HauserM. D.ChomskyN.FitchW. E. (2002). The faculty of language: What is it, who has it, and how did it evolve?.Science298, 55981569–1579.
13.
HechtS. A.TorgesenJ. K.WagnerR. K.RashotteC. A. (2001). The relations between phonological processing abilities and emerging individual differences in mathematical computation skills: A longitudinal study from second to fifth grades.Journal of Experimental Child Psychology79, 192–227.
14.
HermelinB.O'ConnorN. (1990). Factors and primes: A specific numerical ability.Psychological Medicine20, 1163–169.
15.
HitchG. J.McAuleyE. (1991). Working memory in children with specific arithmetical learning difficulties.British Journal of Psychology82, 375–386.
16.
HoeftF.HernandezA.McMillonG.Taylor-HillH.MartindaleJ. L.MeylerA. (2006). Neural basis of dyslexia: A comparison between dyslexic and nondyslexic children equated for reading ability.The Journal of Neuroscience26, 4210700–10708.
17.
HulmeC.SnowlingM. J. (2009). Developmental disorders of language learning and cognitionOxford, UK: Wiley-Blackwell.
18.
JacksonM.WarringtonE. K. (1986). Arithmetic skills in patients with unilateral cerebral lesions.Cortex22, 4611–620.
19.
KovasY.PlominR. (2007). Learning abilities and disabilities: Generalist genes, specialist environments.Current Directions in Psychological Science16, 5284–288.
20.
LanderlK.BevanA.ButterworthB. (2004). Developmental dyscalculia and basic numerical capacities: A study of 8–9-year-old students.Cognition93, 99–125.
21.
LeatherC. V.HenryL. A. (1994). Working memory span and phonological awareness tasks as predictors of early reading ability.Journal of Experimental Child Psychology58, 88–111.
22.
LewisC.HitchG. J.WalkerP. (1994). The prevalence of specific arithmetic difficulties and specific reading difficulties in 9- to 10-year-old boys and girls.Journal of Child Psychology & Psychiatry35, 283–292.
23.
LorchR. F.Jr.MyersJ. L. (1990). Regression analyses of repeated measures data in cognition research.Journal of Experimental Psychology: Learning, Memory, and Cognition16, 149–157.
24.
MilesT. R. (1983). Dyslexia: The pattern of difficulties.Oxford, UK: Blackwell.
25.
OldfieldR. C. (1970). The assessment and analysis of handedness: The Edinburgh inventory.Neuropsychologia9, 97–113.
26.
PassolunghiM. C.SiegelL. S. (2004). Working memory and access to numerical information in children with disability in mathematics.Journal of Experimental Child Psychology88, 4348–367.
27.
PicaP.LemerC.IzardV.DehaeneS. (2004). Exact and approximate arithmetic in an Amazonian indigene group.Science306, 5695499–503.
28.
PritchardR. A.MilesT. R.ChinnS. J.TaggartA. T. (1989). Dyslexia and knowledge of number facts.Links14, 317–20.
29.
PughK. R.MenclW. E.ShaywitzB. A.ShaywitzS. E.FulbrightR. K.SkudlarskiP. (2000). The angular gyrus in developmental dyslexia: Task specific differences in functional connectivity in posterior cortex.Psychological Science11, 51–56.
30.
RamusF.RosenS.DakinS. C.DayB. L.CastelloteJ. M.WhiteS. (2003). Theories of developmental dyslexia: Insights from a multiple case study of dyslexic adults.Brain126, 841–865.
31.
RasmussenC.BisanzJ. (2005). Representation and working memory in early arithmetic.Journal of Experimental Child Psychology91, 137–157.
32.
RumseyJ. M.HorwitzB.DonohueB. C.NaceK. L.MaisogJ. M.AndreasonP. (1999). A functional lesion in developmental dyslexia: Left angular gyral blood flow predicts severity.Brain & Language70, 187–204.
33.
ShepardR. N.MetzlerJ. (1971). Mental rotation of three-dimensional objects.Science171, 701–703.
34.
SimmonsF. R.SingletonC. (2006). The mental and written arithmetic abilities of adults with dyslexia.Dyslexia12, 96–114.
35.
SimmonsF. R.SingletonC. (2008). Do weak phonological representations impact on arithmetic development? A review of research into arithmetic and dyslexia.Dyslexia14, 277–94.
36.
SnowlingM. J. (2000). Dyslexia.Oxford, UK: Blackwell.
37.
SnowlingM. J. (2008). Specific disorders and broader phenotypes: The case of dyslexia.The Quarterly Journal of Experimental Psychology61, 1142–156.
38.
SpelkeE. (2003). What makes us smart? Core knowledge and natural language.GentnerD.Goldin-MeadowS.Language in mind: Advances in the study of language and thought.Cambridge, MA: MIT Press277–311.
39.
SteevesK. J. (1983). Memory as a factor in the computational efficiency of dyslexic children with high abstract reasoning ability.Annals of Dyslexia33, 141–152.
40.
TorgesenJ. K.WagnerR. K.RashotteC. A. (1999). Test of Word Reading EfficiencyAustin, TX: Pro-Ed.
41.
Turner EllisS. A.MilesT. R.WheelerT. J. (1996). Speed of multiplication in dyslexics and non-dyslexics.Dyslexia2, 121–139.
