In Honour of Brian Butterworth. Numeracy skills and Parietal lobes Lisa Cipolotti & Marinella Cappelletti. REVIEW OF PTS WITH UNILATERAL LESIONS Primary dyscalculia does not exist. Only secondary to impairments of: language; memory; visuo-perception; intelligence (as measured by IQ)
Numeracy skills and Parietal lobes
Lisa Cipolotti &
Primary dyscalculia does not exist.
Only secondary to impairments of: language; memory; visuo-perception; intelligence (as measured by IQ)
(Collignon, Leclercq & Mahy’s review, 1977)
‘… a summary of the cases of acalculia since Henschen leads to the conclusion that…..
……there is neither a localised region nor a specific hemisphere underlying the disorder …’
(Kahn & Whitaker, 1991)
Work directly conducted or inspired by Brian
No of papers 1991- to date= at least 60!
LEFT FRONTO PARIETAL DAMAGE
(Cipolotti , Butterworth and Denes, 1991)
An impairment in dealing with quantities
A deficit in the reasoning abilities thought to underlie the concept of numbers
2. Relationship between cultural domains such as number/general semantic Knowldge?CG: Parietal impairment- loss of numbers >4 BUT preserved semantic memory
% correct answers
Animals 80 100
Fruits & Vegetables 100 100
Body Parts 100 100
Musical Instruments 90 100
Vehicle 80 100
Household Objects 100 100
Parietal lobes preserved: Number knowledge intact but impaired Semantic knowledge
e.g. HAB’s spontaneous speech reduced to stereotype phrases ‘I don’t know’ and jargon utterances “millionaire bub”
Average of <2SD above chance
Average of <20% correct
Average of 90% correct
Average of 95% correct
Average of 85% correct
Numerical knowledge √
Semantic knowledge X
writing to dictation
Reading, writing and semantics
Butterworth et al., 2001; Cappelletti et al., 2002
3 patients (Pt R1, Pt R2, Pt W) with left parietal lobe lesions (not exclusively)
Number comprehension √
MRI showing lesion in supramarginal gyrus abutting the left intraparietal sulcus. The right hemisphere is normal.
MRI approximately five centimeters from midline showing complete sparing of the left supramarginal gyrus and left angular gyrus.