Table 3.

Combined Effect Sizes for Mu Desynchronization During Observation

Moderators	k	N	d	95% CI	Q homogeneity	Qa contrast
Total for mu desynchronization for central scalp locations	80	1508	.31***	.26, .35	161.70***
Object-directed						.65
No	32	668	.29***	.22, .35	82.34***
Yes	48	840	.32***	.26, .38	73.86**
Type of stimulus observed						5.74
Biological	69	1320	.30***	.26, .35	141.24***	.49
Social	6	109	.25***	.10, .41	7.07
Nonsocial	63	1211	.31***	.26, .36	134.16***
Nonbiological	5	99	.51***	.31, .71	1.64
Biological & nonbiological	4	66	.23	−.00, .46	2.66
Auditory	2	23	.15	−.03, .34	.12
Type of stimulus observed						.72
Dynamic	68	1271	.31***	.26, .36	140.95***
Static	9	204	.37***	.24, .50	9.00
Type of stimulus observed						.32
Live	16	284	.33***	.23, .44	20.32
Video	54	1021	.30***	.24, .35	119.00***
Type of baseline						2.00
Static	27	510	.33***	.26, .40	32.48
Dynamic	31	590	.31***	.24, .38	49.32*
No stimulus	21	396	.26***	.18, .33	60.90***
Type of baseline						1.91
Biological	12	241	.32***	.21, .43	14.80
Nonbiological	46	859	.32***	.26, .38	67.27*
No stimulus	21	396	.26***	.18, .33	60.90***
Age						3.41
0–4 years	17	360	.23***	.14, .32	19.93
5–18 years	8	112	.33***	.18, .48	6.38
>18 years	55	1036	.33***	.28, .38	131.43***
Gender						1.65
>70% male	9	124	.38***	.24, .53	4.76
>70% female	15	301	.27***	.18, .36	20.94
Mixed	49	950	.31***	.25, .36	109.31***
Effect size						17.64***
Reported	57	1059	.36***	.31, .42	123.07***
Estimated	23	449	.18***	.11, .25	18.84
Noncentral scalp locations						n.a.
Frontal	14	263	.21***	.10, .31	22.67*
Parietal	9	125	.39***	.23, .54	10.86
Temporal	3	36	.23	−.00, .47	.56
Occipital	16	394	.28***	.19, .38	31.53**

Note. k = number of study outcomes; N = total sample size; d = effect size (Cohen’s d); 95% CI = 95% confidence interval around the point estimate of the effect size; Q_homogeneity = homogeneity statistic; Q_contrast = moderation statistic; n.a. = not applicable.

^aSubgroups with k < 4 excluded from contrast.

^*p < .05.

^*p < .01.

^***p < .001.