Table 1.
Dyscalculic participants’ performance in the Dyscalculia Screener and in other background tasks. Percent correct or scaled-scores.
| Tasks performed | Individual DD |
||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| All DD (N=12) | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | |
| IQa | 110.29 | 113.5 | 117 | 105 | 150 | 112.5 | 98.5 | 94 | 118 | 102 | 103.5 | 102.5 | 107 |
| DD screenerb | |||||||||||||
| Capacity subscale | 2.46 | 2 | 1.5 | 2 | 2.5 | 4.5 | 2.5 | 1.5 | 2.5 | 2.5 | 4.5 | 2 | 1.5 |
| Dot enumeration | 3 | 2 | 2 | 3 | 3 | 3 | 1 | 4 | 3 | 3 | 2 | 1 | |
| Number comparison | 1 | 1 | 2 | 2 | 6 | 2 | 2 | 1 | 2 | 6 | 2 | 2 | |
| Achievement subscale | 2.42 | 3 | 2 | 2 | 3.5 | 3 | 1.5 | 2 | 3.5 | 1.5 | 3 | 2.5 | 1.5 |
| Addition | 4 | 2 | 2 | 3 | 3 | 2 | 2 | 4 | 2 | 4 | 3 | 2 | |
| Multiplication | 2 | 2 | 2 | 4 | 3 | 1 | 2 | 3 | 1 | 2 | 2 | 1 | |
| GDA (N=24)c | 7.08 [3] | 10 [3] | 8 [3] | 5 [1] | 8 [3] | 7 [3] | 3 [1] | 6 [2] | 10 [3] | 7 [3] | 10 [3] | 3 [1] | 8 [3] |
| WAIS maths (N = 20)d | 6.6 | 8 | 6 | 6 | 8 | 8 | 6 | 7 | 9 | 6 | 6 | 6 | 4 |
| Number comparison (N = 68) | 96.39 | ||||||||||||
| RTs: 878.8 ms | |||||||||||||
| (dee184.9 ms) | |||||||||||||
| Digit spanf | 17.91 | 23 | 18 | 20 | 17 | 15 | 15 | 20 | 27 | 13 | 13 | 15 | 19 |
aWAIS-3 (Wechsler, 1986).
bStanine score ranging from 1 to 9 whereby the better the performance the higher the stanine score (see Butterworth, 2003).
cGraded Difficulty Arithmetic Test, Jackson and Warrington, 1986; scaled-score and correspondent level of performance in brackets (1 = defective, 2 = borderline, 3 = dull average).
dAge-adjusted scores on a scale between 1 and 19 where 10 is average.
ede, distance effect (mean across DD participants in milliseconds, ms); significantly different from controls [79.82 ms, t(11) = 7.56, p = 0.001].
fIncludes forward and backward; max combined score = 30.
Impaired performance is shown in bold.