Table 5.

Detailed overview of pooled effect sizes on subgroup level of discrete moderator variables

Moderator subgroups	k	Estimate	SE	t	p
Experimental design
Between-subjects	17	0.124	0.125	0.996	.425
Between-subjects baseline	19	0.147	0.058	2.531	.240
Within-subjects	22	− 0.129	0.038	− 3.411	.088
Mixed	19	0.102	0.129	0.796	.522
Blinding
Single	11	− 0.069	0.123	− 0.561	.633
Double	48	0.065	0.068	0.951	.389
Not reported	18	0.029	0.177	0.165	.896
Cognitive Domain
Executive functions	19	0.017	0.089	0.191	.861
Impulsivity	14	− 0.088	−	−	−
Language	6	0.221	0.112	1.971	.299
Reward Learning	6	0.284	−	−	−
Social Cognition	32	− 0.057	0.082	− 0.695	.559
Target brain area
Central prefrontal	20	0.107	0.102	1.045	.409
Right prefrontal	13	− 0.035	0.066	− 0.523	.652
F3	22	− 0.099	0.065	− 1.521	.225
P6	15	0.076	0.271	0.281	.826
Timing
Online	44	0.019	0.073	0.263	.806
Offline	33	0.030	0.097	0.305	.776
Electrode distance
Two	18	0.030	0.177	0.172	.892
Mixed	19	− 0.030	0.100	− 0.300	.815
Other	22	0.073	0.125	0.582	.602
Nr	15	− 0.017	0.043	− 0.391	.763
Measure
Reaction time	38	− 0.001	0.071	− 0.014	.989
Accuracy	18	0.082	0.123	0.667	.531
other	21	0.010	0.094	0.108	.924
Stimulation intensity
1 mA	30	0.024	0.073	0.329	.761
1.5 mA	7	− 0.177	0.044	− 3.997	.156
2 mA	40	0.095	0.107	0.894	.436

Number of effect sizes per subgroup (k), Hedge’s g (SMD), standard error, test statistic and corresponding p value are shown