Anne Fleur Kortekaas-Rijlaarsdam

89 MPH EFFECTS ON MATH PERFORMANCE: INFLUENCE OF COGNITION, MOTIVATION AND PERCEIVED COMPETENCE 4 Table 4.2 Effects of MPH on Cognition, Academic Motivation and Self-perceived Academic Competence ADHD TD PLA MPH PLA v MPH PLA v TD M SD M SD M SD t d t d Cognition Verbal working memory Number correct*achieved level (DS) 13.98 9.81 16.22 12.89 15.58 9.02 486(W) 1779.5(U) Visuospatial working memory Number correct*achieved level (Grid) 54.95 33.86 57.66 37.27 76.30 35.21 .47 3.52** .63 RT speed IE (Flanker, neutral condition) 628.86 133.41 625.51 135.18 610.92 136.76 4284(W) -.75 Lapses of attention Tau (Flanker, neutral condition) 150.33 74.72 135.57 88.06 100.52 75.14 -1.77 + 0.32 -3.74** .67 Interference control IE (Flanker, incongruent – congruent) 100.18 63.94 104.77 135.11 85.54 63.72 .62 1 2339(U) Motivation and competence Intrinsic motivation General (CAIMI) 60.05 8.47 60.13 9.91 62.48 8.24 .17 1.65 Intrinsic motivation Math (CAIMI) 76.34 20.70 77.37 20.39 84.39 13.87 .90 2.61* 0.46 Intrinsic motivation Reading (CAIMI) 80.08 19.99 81.33 19.85 83.75 17.21 1.04 1.12 Reward responsivity (SPSRQ-C) 22.32 4.99 21.77 5.22 19.26 4.24 -.98 -3.73** .67 Sensitivity to punishment (SPSRQ-C) 38.23 9.32 37.69 10.12 35.35 7.72 -.94 -1.90 ++ 0.34 Self-perceived competence (SPPC-S) 15.05 3.17 15.41 3032 17.03 2.52 1.30 3.96** 0.70 Parent-rated self-perceived competence (SPPC-S) 14.40 2.82 15.44 3.37 17.97 2.78 2.93** 0.53 7.18** 1.28 Teacher-rated self-perceived competence (SPPC-S) 14.19 2.99 14.32 3.25 17.38 3.20 .87 5.80** 1.03 Note. ADHD Attention-deficit hyperactivity disorder; TD Typically developing controls; PLA placebo; MPH methylphenidate; SAT Speeded arithmetic test; WP Mathematical word problems; DS Digit span backward; CAIMI Children’s academic intrinsic motivation inventory; SPPC-S Self perception profile for children – school scale; SPSRQ-C Sensitivity to punishment and sensitivity to reward questionnaire for children; IE inverse efficiency calculated as mean RT/proportion correct; RT reaction time; W = Wilcoxon signed-rank test statistic; U = Mann-Whitney U test statistic; Accuracy = items correct / items completed x 100%; Productivity = items completed / items available x 100%; 1 treatment (MPH versus placebo) by condition (congruent versus incongruent) interaction * p < .05 ** p < .01. + p=.08 ++ p=.06