1. Numerical abilities in Williams syndrome Attila Krajcsi 1, Mihály Racsmány 2, János Igács 1, Csaba Pléh 2 1 University of Szeged 2 Budapest University of Technology and Economics Mail: krajcsi@pszichologia.hukrajcsi@pszichologia.hu Web: http://www.staff.u-szeged.hu/~krajcsihttp://www.staff.u-szeged.hu/~krajcsi

2. Outline Numerical abilities Numerical problems and possible causes Study with WS and DC children Conclusion about WS and broader considerations

3. Williams syndrome

4. Numerical abilities

6. Numerical problems and possible causes

7. Developmental dyscalculia (DC) Mathematical ability, as measured by individually administered standardized tests, is substantially below that expected given the person's chronological age, measured intelligence, and age- appropriate education. Normal intelligence Impaired mathematical performance

8. Prevalence DSM: 1% Other studies: 3-6,5% (Shalev, 2001 review) Depending on the criteria, but mainly 3-6%

9. Cooccurence with other problems Mostly: Dyslexia ADHD

10. Numerical problems in genetical disorders Williams syndrome Turner syndrome Developmental Gerstmann syndrome Fragile X syndrome Down syndrome Etc.

11. Adolescents with bad performance on simple arithmetical test Increasement in gray matter Isaacs et al., 2001 Possible causes

12. Several causes A huge amount of ideas explaining numerical problems Working memory problem (verbal, spatial, executive) LTM problem Anxiety Etc. Different types of numerical disabilities Different types of DC Different problems in genetic disorders

13. Study with WS and DC children 1.Methods 2.Presence of effects 3.Mean RTs 4.Selective load method – alternative RT

14. Tasks Simple addition 6 + 3 = 8 Simple multiplication 5 * 4 = 20 Number comparison 72 Dot counting Multiple object tracking Verbal retrieval Number line Visual functions

15. Subjects 7 WS subject 14 DC subject 11 years 11 control subject 10 years

16. Charles vs. controll: number comparison Butterworth, 2003

17. Williams syndrome and DC Krajcsi, Racsmány, Igács, Pléh, 2005

18. Turner syndrome Braundet, Molko, Cohen & Dehaene 2003

19. Krajcsi, Racsmány, Igács, Pléh, 2005

20. Tasks Simple addition Simple multiplication Number comparison Dot counting Multiple object tracking Verbal retrieval Number line Visual functions

21. Number comparison (4) Executive functions Decision (2) Arabic numerical representation (3) Magnitude representation Comparison (1) Visual input (5) Motor region Response

22. Selective load Krajcsi, 2005

24. Counting in WS (Ansari et al., 2003) Counting ability is predicted by spatial abilities In WS it is predicted by verbal abilities

25. ….Landauék…

26. Conclusions Williams syndrome Usual effects are present Relatively bad parietal functions (comparison and dot counting) Relatively good verbal functions (simple addition and multiplication – rote learning) Broader considerations DC is not caused by the deficit of magnitude representation Selective load method validation

27. Thank you for your attention! Attila Krajcsi 1, Mihály Racsmány 2, János Igács 1, Csaba Pléh 2 1 University of Szeged 2 Budapest University of Technology and Economics Mail: krajcsi@pszichologia.hukrajcsi@pszichologia.hu Web: http://www.staff.u-szeged.hu/~krajcsihttp://www.staff.u-szeged.hu/~krajcsi