Table 3.

ANOVA results for the MEG-based auditory-evoked P1 response

MTPLPs (n = 49; 29 males, 20 females)HPs (n = 53; 22 males, 31 females)AD(H)D (n = 20; all males)Significance of MTPSignificance of groupPost hoc comparisons of groupSignificance of group for boys only
P1 (R) amplitude (nAm)1
2
24.4 ± 1.5
31.2 ± 1.6
34.6 ± 1.4
34.5 ± 1.5
19 ± 2.3
29.1 ± 2.5
n.s.F(2,119) = 28.6; p = 7.3 × 10−11; partial η2 = 0.32LP versus HP, p = 0.0003; LP versus AD(H)D, n.s.; HP versus AD(H)D, p = 7.8 × 10−6F(2,119) = 17.1; p = 9.8 × 10−7; partial η2 = 0.33
P1 (L) amplitude (nAm)1
2
25.6 ± 1.4
32.6 ± 1.6
36.9 ± 1.3
36.8 ± 1.6
19.4 ± 2.2
28.6 ± 2.5
n.s.F(2,119) = 3.6; p = 0.032; partial η2 = 0.06LP versus HP, n.s.; LP versus AD(H)D, n.s.; HP versus AD(H)D, p = 0.05n.s.
P1 (R) latency (ms)1
2
91 ± 2
87 ± 1
89 ± 2
81 ± 1
82 ± 2
79 ± 2
F(1,119) = 126.2; p = 2.1 × 10−20; partial η2 = 0.52F(2,119) = 4.6; p = 0.012; partial η2 = 0.07LP versus HP, n.s.; LP versus AD(H)D, p = 0.016; HP versus AD(H)D, n.s.F(2,119) = 4.1; p = 0.02; partial η2 = 0.11
P1 (L) latency (ms)1
2
96 ± 2
91 ± 2
92 ± 2
84 ± 2
103 ± 3
100 ± 3
F(1,119) = 81.2; p = 1 × 10−13; partial η2 = 0.41F(2,119) = 10.2; p = 8 × 10−5; partial η2 = 0.15LP versus HP, p = 0.04; LP versus AD(H)D, p = 0.05; HP versus AD(H)D, p = 1.3 × 10−4F(2,119) = 5.7; p = 0.005; partial η2 = 0.14
P1 (R) latency reduction (ms)1–24.8 ± 0.78.5 ± 0.73.0 ± 1.1F(2,119) = 12.2; p = 1.6 × 10−5; partial η2 = 0.17LP versus HP, p = 8.6 × 10−4; LP versus AD(H)D, n.s.; HP versus AD(H)D, p = 2.1 × 10−4F(2,119) = 4.2; p = 0.019; partial η2= 0.11
P1 (L) latency reduction (ms)1–24.9 ± 0.98.1 ± 0.83.4 ± 1.4F(2,119) = 5.9; p = 0.004; partial η2 = 0.09LP versus HP, p = 0.031; LP versus AD(H)D, n.s.; HP versus AD(H)D, p = 0.014n.s.
Bilateral P1 asynchrony |R–L| (ms)1
2
7.4 ± 0.9
6.9 ± 1.0
4.4 ± 0.9
3.9 ± 1.0
22.9 ± 1.4
22.2 ± 1.6
n.s.F(2,119) = 61.5; p = 4.6 × 10−19; partial η2 = 0.51LP versus HP, p= 0.016; LP versus AD(H)D, p = 8.4 × 10−6; HP versus AD(H)D, p = 6.4 × 10−7F(2,119) = 31.7; p = 1.9 × 10−10; partial η2 = 0.48
  • ANOVA group comparisons for MEG-based auditory-evoked P1. Right (R) and left (L) hemispheric amplitudes, latencies, and bilateral asynchronies at both MTPs and P1 latency reduction over time. P1 amplitude (nanoamperemeter; nAm) and latency (ms): Peak value and time point of the primary response arising from HG; Bilateral P1 asynchrony: P1 latency difference |R-L|; mean ± SEM. To test whether the unequal gender distributions in the three groups [all AD(H)D children were male] may be responsible for some of the observed effects, the right column shows the corresponding results for boys only.