DyscalculiaDyscalculia

Frederick HerrmannFrederick Herrmann

DyscalculiaDyscalculia

•• DefinitionDefinition•• PrevalencePrevalence•• ComorbidityComorbidity•• EtiologyEtiology•• AssessmentAssessment•• EvaluationEvaluation•• RemediationRemediation

DefinitionDefinition

•• Dyscalculia is an impairment specific to Dyscalculia is an impairment specific to mathematical cognition.mathematical cognition.

•• Difficulty with mathematical cognition Difficulty with mathematical cognition must not be attributable to any other must not be attributable to any other disability.disability.

•• Dyscalculia falls under the heading of a Dyscalculia falls under the heading of a Learning Disability under IDEA. Learning Disability under IDEA.

Types of DyscalculiaTypes of Dyscalculia

•• Developmental Dyscalculia Developmental Dyscalculia –– Inherited Inherited &/or acquired during prenatal or early &/or acquired during prenatal or early developmental period.developmental period.

•• PostPost--Lesion Dyscalculia Lesion Dyscalculia –– Acquired during Acquired during an incident of Traumatic Brain Injury an incident of Traumatic Brain Injury affecting relevant areas of the brain.affecting relevant areas of the brain.

•• PseudoPseudo--Dyscalculia Dyscalculia –– The result of The result of inadequate instruction.inadequate instruction.

PrevalencePrevalence

•• Dyscalculia is estimated to affect 3Dyscalculia is estimated to affect 3--6% of 6% of the population.the population.

•• This statistic is consistent with This statistic is consistent with international estimates (Shalev, et al., international estimates (Shalev, et al., 2004; Ramaa & Gowramma, 2002).2004; Ramaa & Gowramma, 2002).

•• Boys and girls show equal susceptibility.Boys and girls show equal susceptibility.

ComorbidityComorbidity

•• Dyscalculia exhibits an exceedingly high Dyscalculia exhibits an exceedingly high comorbidity with ADHD: 15comorbidity with ADHD: 15--26%26%

•• As well as with dyslexia: 17As well as with dyslexia: 17--64% 64% (Wilson, 2008)(Wilson, 2008)

•• [The range of these statistics [The range of these statistics demonstrates the infancy of study of demonstrates the infancy of study of dyscalculia dyscalculia –– a full 30 years behind the a full 30 years behind the study of dyslexia.]study of dyslexia.]

Yet Distinct from ADHDYet Distinct from ADHD

•• A study by Shalev, et al. (2001), has A study by Shalev, et al. (2001), has determined that dyscalculia is a family determined that dyscalculia is a family learning disability learning disability –– ““shows significant shows significant familial aggregationfamilial aggregation”” (p. 59).(p. 59).

•• A study by Monuteaux, et al. (2005), has A study by Monuteaux, et al. (2005), has determined that ADHD and dyscalculia determined that ADHD and dyscalculia exhibit exhibit ““independent familial independent familial transmission.transmission.””

Yet Distinct from DyslexiaYet Distinct from Dyslexia•• An Italian study (Tressoldi, et al., 2007) and an An Italian study (Tressoldi, et al., 2007) and an

Israeli study (Rubenstein, et al., 2006), both Israeli study (Rubenstein, et al., 2006), both relying on a battery of mathematical tests, have relying on a battery of mathematical tests, have determined that dyscalculia and dyslexia are determined that dyscalculia and dyslexia are functionally different.functionally different.

•• ““ The dyscalculia group has problems in automatically associating Arabic numerals with their internal representation of magnitudes but has no problems in automatically associating letters with their phonemes, whereas the dyslexia group shows the opposite pattern”(ibid., p. 863).

EtiologyEtiology•• The etiology of developmental dyscalculia The etiology of developmental dyscalculia

is not well understood.is not well understood.•• The genetic component is inferred in The genetic component is inferred in

familial prevalence familial prevalence –– 10x higher than the 10x higher than the general population (Shalev, et al., 2001).general population (Shalev, et al., 2001).

•• May occur with or as a result of Fetal May occur with or as a result of Fetal Alcohol Syndrome, TurnerAlcohol Syndrome, Turner’’s Syndrome, s Syndrome, Fragile X Syndrome, and premature birth Fragile X Syndrome, and premature birth or low birth weight.or low birth weight.

Different Areas of the BrainDifferent Areas of the Brain

Sums (left), Approximations (right)BBC News

Different areas of the brain are responsible for different mathematical functions.

Dyscalculia is BrainDyscalculia is Brain--RelatedRelated•• An experiment (Kadosh, et al., 2007) An experiment (Kadosh, et al., 2007)

produced produced ““virtual dyscalculiavirtual dyscalculia”” by by stimulating the right intraparietal sulcus.stimulating the right intraparietal sulcus.

•• Research has show (Rotzer, et al., 2008) Research has show (Rotzer, et al., 2008) that children with dyscalculia have that children with dyscalculia have ““significantly reduced gray matter volume significantly reduced gray matter volume in the right intraparietal sulcus (IPS)in the right intraparietal sulcus (IPS)”” as as well as less white matter in well as less white matter in ““the left the left frontal lobe and in the right frontal lobe and in the right parahippocampal gyrusparahippocampal gyrus”” (abstract).(abstract).

AssessmentAssessment

•• Delayed/impaired ability to count.Delayed/impaired ability to count.•• Delayed/impaired ability to problem solve.Delayed/impaired ability to problem solve.•• Difficulty reading numbers.Difficulty reading numbers.•• Difficulty recalling numbers in sequence.Difficulty recalling numbers in sequence.•• Difficulty with specific operations.Difficulty with specific operations.•• Difficulty with organizational skills.Difficulty with organizational skills.•• Low ability in estimation or approximation Low ability in estimation or approximation

(including time).(including time).•• Poor sense of direction and disorientation. Poor sense of direction and disorientation.

(NCLD, 2008)(NCLD, 2008)

PredictorsPredictors

•• A study carried out in Mexico (Rosselli, et A study carried out in Mexico (Rosselli, et al., 2006) demonstrated that Working al., 2006) demonstrated that Working Memory tests (digits backwards and Memory tests (digits backwards and sentence repetition) were best predictors sentence repetition) were best predictors of math scores and of math scores and ““may represent a major cognitive defect in children with specific defects in mathematics” (p. 801).

EvaluationEvaluation

•• Interviews and Paper & Pencil tests Interviews and Paper & Pencil tests (reading, math, attention, and IQ) must (reading, math, attention, and IQ) must determine that the disability is specific to determine that the disability is specific to mathematical cognition.mathematical cognition.

•• Mathematical ability must be significantly Mathematical ability must be significantly lower than expected (i.e. compared to IQ).lower than expected (i.e. compared to IQ).

•• Math tests should determine the childMath tests should determine the child’’s s strengths and weaknesses.strengths and weaknesses.

TestsTests

• Neuropsychological Test Battery for Number Processing and Calculation in Children (NUCALC) – contains 11 subtests with categories of number processing and calculation.

• Piagetian test of number conservation, classification (sets), and seriation.

• The Rey-Osterrieth’ Complex Figure Test – copy geometric figures and draw from memory.

• Many educators are developing tests.

DiagnosesDiagnoses

•• Quantitative Dyscalculia Quantitative Dyscalculia –– ““A deficit in the A deficit in the skills of counting and calculating.skills of counting and calculating.””

•• Qualitative Dyscalculia Qualitative Dyscalculia –– ““The result of The result of difficulty in comprehension of instructions difficulty in comprehension of instructions or the failure to master the skills required or the failure to master the skills required for an operation.for an operation.”” (Vaidya, 2004, p. 718)(Vaidya, 2004, p. 718)

•• Visuospatial Dyscalculia. (Geary, 1993)Visuospatial Dyscalculia. (Geary, 1993)•• Number Fact Dyscalculia. Number Fact Dyscalculia.

(dyscalculiaforum.com, 2008)(dyscalculiaforum.com, 2008)•• There is no official consensus on types.There is no official consensus on types.

RemediationRemediation

•• It is It is hopedhoped that early detection and that early detection and remediation will work through BRAIN remediation will work through BRAIN PLASTICITY to fix dyscalculia.PLASTICITY to fix dyscalculia.

•• Example: CAPD & auditory trainingExample: CAPD & auditory training•• Example: Dyslexia & auditory trainingExample: Dyslexia & auditory training

The Harrow Dyscalculia ProjectThe Harrow Dyscalculia Project

•• A research project at BritainA research project at Britain’’s Harrow s Harrow schools (Messenger, et al., 2007) is schools (Messenger, et al., 2007) is working to develop modules (games and working to develop modules (games and activities) to help dyscalculic children learn activities) to help dyscalculic children learn numbers and operations.numbers and operations.

Classroom AdaptationsClassroom Adaptations

•• Dyscalculic children will need more Dyscalculic children will need more time to perform math work.time to perform math work.

•• Math work should be at the Math work should be at the appropriate level.appropriate level.

•• Written instructions are helpful.Written instructions are helpful.

Focus on UnderstandingFocus on Understanding

•• ConcreteConcrete--toto--Abstract strategiesAbstract strategies•• ProblemProblem--solving strategies other than solving strategies other than

memorizationmemorization•• Frequent questions to promote Frequent questions to promote

metacognitionmetacognition

Individual TutoringIndividual Tutoring

•• Tutoring is recommended by the Tutoring is recommended by the NCLD (2008) and Dyscalculia Forum NCLD (2008) and Dyscalculia Forum (2008).(2008).

•• Tutors can target the specific trouble Tutors can target the specific trouble area.area.

•• The child will not catch up without The child will not catch up without special assistance.special assistance.

ResourcesResources

•• Wilson (2007) recommends Butterworth and Yeo, but Wilson (2007) recommends Butterworth and Yeo, but many resources are available.many resources are available.

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