Meta-analyses on the functional neural alternations in Internet

gaming disorder: similarities and differences across different

paradigms

Supplement Methods

The IGD scale for each study

Table S1 Detail about the IGD scale used in each studyIGD scale BDI FIND

Study Scale

name

IGD

Mean±sd

Control

Mean±sd

IGD

Mean±sd

Control

Mean±sd

IGD

Mean±sd

Control

Mean±sd

Han et al. 2010 YIAT 71.2±9.4 27.1±5.3 6.8±3.7 8.4±3.4 NaN NaN

Han et al. 2012 YIAT 75.1±11.2 34.5±9.6 NaN NaN NaN NaN

Ko et al. 2009 CIAS 77.1±8.28 45.4±14.16 NaN NaN NaN NaN

Ko et al. 2013b CIAS 75.69±13.19 27.06±2.38 NaN NaN NaN NaN

Ko et al. 2013a CIAS 76±12.09 26±0 NaN NaN 5±2.06 0

Liu et al. 2016 YDQ NAN NAN 11.8±1 5.4±.8 NaN NaN

Liu et al. 2017b CIAS 75.59±8.82 45.65±9.8 7.49±5.84 2.91±3.12 2±1.87 0

Sun et al. 2012 CIAS 67.39±5.12 39.8±9.47 NaN NaN NaN NaN

Zhang et al. 2016a CIAS 79.88±8.67 42.11±8.27 9.13 ±5.5 2.79±4.2 3.25±.5 0

Liu et al. 2014 CIAS 75.8±9.76 40.63±12.27 NaN NaN NaN NaN

Lorenz et al. 2013 WWAI 2.2±.8 1±0 8.9±5.2 3.4±3.5 NaN NaN

Han et al. 2016 YIAT 59.1±9.8 26.2±5.7 12.1±7.0 21.7±5.5 NaN NaN

Chen et al. 2015 CIAS 76±12.09 26±0 NaN NaN NaN NaN

Ding et al. 2014 CIAS 65.82±3.25 42.88±9.68 NaN NaN NaN NaN

Ko et al. 2014 CIAS 84.96±12.94 39.68±11.92 NaN NaN NaN NaN

Luijten et al. 2015 VAT 3.34±.45 1.26±.19 NaN NaN NaN NaN

Dong et al. 2012 YIAT >80 NaN NaN NaN NaN NaN

Dong et al. 2013ca YIAT >80 NaN NaN NaN NaN NaN

Dong et al. 2014 YIAT >50 NaN NaN NaN NaN NaN

Zhang et al. 2016b YIAT >80 NaN NaN NaN NaN NaN

Na et al. 20104 NaN NaN NaN NaN NaN NaN NaN

Kim et al. 2012a YIAT 72.2±8.4 41.4±4.5 9.4±2.5 7.1±4.9 NaN NaN

Dong et al. 2011 YIAT >80 NaN NaN NaN NaN NaN

Dong et al. 2013a YIAT >80 NaN NaN NaN NaN NaN

Dong et al. 2013b YIAT >80 NaN NaN NaN NaN NaN

Dong et al. 2017 YIAT 79.5±.71 32.48±4.59 2.66±.36 1.89±.24 NaN NaN

Dong and Potenza

2016

YIAT >50 NaN NaN NaN NaN NaN

Lin et al. 2015 YIAT 64±9.78 31±11.96 NaN NaN NaN NaN

Wang et al. 2017 YIAT 65.55±10.65 31±11.93 NaN NaN NaN NaN

Kim et al. 2017 YIAT 62.78±10.3 29.75±5.9 14.17±8.8 6.45±4.9 NaN NaN

Lee et al. 2016 YIAT 50.9±12.9 27.5±13.3 8.9±4.7 6.5±5.8 NaN NaN

Liu et al. 2017ab CIAS 79.66±8.5 40.22±9.44 8.63±4.9 3.41±5.43 2±0 0

Qi et al. 2015 YIAT 70.35±10.76 33.42±7.75 NaN NaN NaN NaN

Qi et al. 2016 YIAT 70.71±10.8 33.2±7.8 NaN NaN NaN NaN

Kim et al. 2012b K-AIAS 62.76±10.19 30.29±6.1 NaN NaN NaN NaN

Leménager et al.

2014

AICA 18.75±7.34 1.59±2.21 NaN NaN NaN NaN

Dieter et al. 2015 AICA 18.53±7.55 9.53±10.1 NaN NaN NaN NaN

Chun et al. 2015 K-S 37.56±5.16 24.68±4.45 12.5±11.9 5.29±4.99 NaN NaN

Lee et al. 2015 K-S NaN NaN 11.5±11.5 4.4±4.6 NaN NaN

Yip et al. 2018 CIAS 70.13±10.48 35.04±10.62 7.29±7.67 2.22±3.22 .17±.65 0

BDI=Beck's Depression Inventory, 21 items range 0-63;

FIND= Fagerstrom Test of Nicotine Dependence, 6 items range 0-10;

YIAT=Young’s Internet Addiction Test, 20 items range 20-100;

CIAS=Chen Internet Addiction Scale, 26 items range 26-104;

YDQ=Proposed modification of the diagnostic criteria for Internet addiction;

WWAI=World of Warcraft Addiction Inventory;

VAT=Video Game Addition Test, 14 items average range 1-5;

K-S=Korean Internet Addiction Proneness Scale, 15 items range 15-60;

AICA=Addiction severity assessed based on the previous 30 days, 6 criteria range

0-30;

Supplement Reuslts

Table S2. two group compare of adolescent group and adult group

Brain regions*

Maximum Cluster

MNI

coordinates x, y,

z

SDM-Z pVoxels

Number

breakdown

adult>adolescent

Bilateral anterior thalamic

projections

12,8,4 1.630 0.00089180

5

400

12,8,4 1.630 0.00089180

5

87 Right anterior

thalamic projections

45 Left anterior thalamic

projections

42 Right caudate nucleus

34 Left caudate nucleus

-8,12,10 1.627 0.00090831

5

25 Left caudate nucleus,

BA 25

-6,14,2 1.561 0.00129020

2

25 Left striatum

18,12,0 1.530 0.00150078

5

20 Right striatum

Right middle temporal gyrus,

BA 20

60,-34,-12 1.665 0.00071835

5

281

76 Right middle temporal

gyrus, BA 21

75 Right inferior

temporal gyrus, BA 20

69 Right middle temporal

gyrus, BA 20

Left precentral gyrus, BA 6 -52,2,34 1.601 0.00105178

4

238

-52,0,40 1.597 0.00106310

8

138 Left precentral gyrus,

BA 6

-48,8,36 1.465 0.00209528

2

58 Left precentral gyrus,

BA 44

Right superior frontal gyrus,

medial, BA 10

6,58,20 1.422 0.00258249

0

137

Left anterior cingulate /

paracingulate gyri

-2,14,22 1.516 0.00161325

9

26

Left cerebellum, crus I-8,-78,-22 1.366 0.00337928

5

23

adult<adolescent

Right heschl gyrus, BA 48

38,-22,14 -1.437 0.00097644

3

771

40,-18,18 -1.420 0.00105488

3

247 Right rolandic

operculum, BA 48

42,-12,14 -1.421 0.00104457

1

177 Right insula, BA 48

44,-18,8 -1.405 0.00113534

9

114 Right heschl gyrus, BA

48

84 Right superior

temporal gyrus, BA 48

Left arcuate network,

posterior segment

-48,-50,2 -1.469 0.00083297

5

53

Table S3. jackknife analysisJackknife analysis

hyper-activityhypo-

activity

Remove study Bilateral

precuneus； Bilateral median

cingulate

Left

Precentral

gyrus

Right inferior

frontal gyrus

Left frontal

orbito-polar

tract

Left inferior

network

D. H. Han et al., 2010 Y Y Y Y Y

Han et al., 2012 Y Y Y N Y

Ko et al., 2009 Y Y Y N Y

Ko et al., 2013a Y Y Y Y Y

Ko et al., 2013b Y Y Y Y Y

J. Liu et al., 2016 Y Y Y Y Y

L. Liu et al., 2017a Y Y* Y Y Y

Sun et al., 2012 Y Y Y Y Y

Zhang et al., 2016b Y Y Y Y Y

Liu et al., 2014 Y Y Y Y Y

Lorenz et al., 2013 Y Y Y Y Y

Han et al., 2016 Y Y Y Y Y

Chen et al., 2015 Y Y Y Y Y

(W. Ding et al., 2014) Y Y Y Y Y

Ko et al., 2014 Y Y Y N Y

Luijten et al., 2015 Y Y Y Y Y*

Dong et al., 2012 Y Y Y Y Y

Dong et al., 2013a Y Y Y Y Y

Dong et al., 2014 Y Y Y Y Y

Zhang et al., 2016 Y Y Y Y Y

Na et al., , 20104 Y Y Y Y Y

Kim et al., 2012a Y Y Y Y Y

Dong et al., 2011 Y Y Y Y Y

Dong et al., 2013b Y Y Y Y Y

Dong et al., 2013c Y Y Y N Y

Dong et al., 2017 Y Y Y Y Y

Dong & Potenza, 2016 Y Y Y Y Y

Lin et al., 2015 Y Y Y Y Y

Y. Wang et al., 2016 Y Y Y Y Y

Kim, & Kang, 2017 Y Y Y Y Y

D. Lee et al., 2016 Y Y Y Y Y

L. Liu et al., 2017b Y Y Y N Y

Qi et al., 2015 Y Y Y Y Y

Qi et al., 2016 Y Y Y Y Y

Kim et al., 2012b Y Y Y Y Y

Lemenager et al., 2014 Y Y Y Y Y

Dieter et al., 2015 Y Y Y Y Y

Chun et al., 2015 Y Y Y Y Y

J. Lee et al., 2015 Y Y Y Y Y

Yip et al., 20171 Y Y Y Y Y

Sum 40 40 40 35 40

Subgroup analysis 　 　 　 　 　Only China study(n=20) Y Y Y* N N*

Only Koera study(n=10) N Y* Y* N N*

Only Taiwan study(n=6) N Y N N N

Only adult (n=31) Y Y Y N Y*

Multiple comparisons（n=31） Y Y Y Y Y

Report YIAT(n=18) Y* N Y N Y

Report DICA(n=12) Y Y Y Y N

Only Siemens scan(n=24) Y* Y Y* N Y

Only use spm（n=35） Y Y Y N Y

FWHM=7-8mm（n=16） Y* Y* Y* N N

FWHM=5-6mm（n=21） Y* Y Y Y Y*

*numbers of voxels in this brain area are reduced;

Table S4. Egger’s test

Mean analysis result Bias t df p

Bilateral precuneus; Bilateral median cingulate 0.43 0.83 38 0.412

Left middle frontal gyrus 0.44 0.63 38 0.530

Right inferior frontal gyrus -0.20-

0.2638 0.796

Left frontal orbito-polar tract -0.08-

0.1238 0.906

Left inferior network 0.56 1.24 38 0.224

Table S5. Meta-regression analysis

Brain regions*

Maximum Cluster

MNI coordinates x, y,

zSDM-Z p

Voxels

Number

IGD>HC

Right middle temporal gyrus, BA 21 62, -34, -2 62, -34, -

2

62, -34, -2521

Left anterior thalamic projections -38, 44, 0 2.298 0.00026631

4

158

Left superior parietal gyrus, BA 7 -18, -70, 50 1.651 0.00368481

9

32

Left inferior frontal gyrus, triangular part, BA

48

-44, 24, 22 1.631 0.00397384

2

21

Right insula, BA 48 38, -12, 16 1.664 0.00348871

9

18

IGD<HC

Right striatum 22, 14, 2 -1.853 0.00083500

1

100

Right inferior frontal gyrus, opercular part, BA

44

50, 6, 24 -1.674 0.00190126

9

63

Left precentral gyrus, BA 6 -54, 6, 44 -1.724 0.00151729

6

30

Figure S1. Two group compare from all studies(adult-adolescent)

Figure S2. Heterogeneity and statistical map for all studies

Right heschl gyrus(BA 48, x=46, y=-18, z=12, sdm-z=1.409, voxels=516), Right inferior

frontal gyrus(opercular part, BA 44, x=50, y=10, z=26, sdm-z=2.492, voxels=273), Left

median cingulate(paracingulate gyri, BA 23, x=0, y=-26, z=34, sdm-z=1.279, voxels=474),

Right calcarine fissure(surrounding cortex, BA 30, x=12, y=-58, z=16, sdm-z=2.444,

voxels=213), Left precentral gyrus(BA 6, x=-50, y=4, z=38, sdm-z=1.605, voxels=157) and

Right precuneus(x=2, y=-58, z=44, sdm-z=1.160, voxels=202).

Figure S3. The funnel plot for mean meta-analysis

From top to bottom were bilateral precuneus and bilateral cingulate, left precentral gyrus,

right inferior frontal gyru, left frontal orbito-polar tract and left inferior network

Figure S4. Meta-regression analyses for game time

Group comparisons

Compared with the adolescent group studies (n=8), the adult group studies

(n=31) showed significant hyperactivity in the bilateral anterior thalamic

projections (caudate and striatum), right middle temporal gyrus (MTG; BA 20),

left precentral gyrus (BA 6, BA 44), right superior frontal gyrus (medial, BA 10),

left anterior cingulate / paracingulate gyri, and left cerebellum (crus I). Adult

group studies (n=31) had significant hypoactivity in right Heschl gyrus (BA 48)

and left arcuate network (posterior segment). Detail is shown in Table S2 and

Figure S1.

Sensitivity and heterogeneity analysis

The jackknife analysis removes one study and repeats the mean analysis. The

idea is that if a significant brain region remains significant in all or most of the

combinations of studies, it can be concluded that this finding is highly replicable.

The details are shown in Table S3. The MCC and right IFG were replicable in all

40 analyses; the bilateral precuneus, bilateral median cingulate, left MFG, right

IFG and left inferior network were replicable in all 40 analyses, and the left

frontal orbitopolar tract was replicable in 35 analyses.

The statistical heterogeneity analysis was examined using a random effects

model with Q statistics ( 2) transformed to z distribution (0-1). The χ

heterogeneity and statistical maps are both shown for visual inspection in Figure

S2. Egger’s test can identify publishing bias. This analysis found that there was

no significant bias in any of the mean results, and the details are shown in Table

S3. However, d showed some heterogeneity, as shown in Figure S3.

Insert Table 3 and Table 3 here

Meta-regression analysis

This study explored gaming time (hours per week) and found differences

between IGDs with maximum gaming time and IGDs with minimum gaming time.

Form the slope map, with the increase of game time, IGDs had significant hyper-

activity in right middle temporal gyrus (MTG, BA 21), left anterior thalamic

projections, left superior parietal gyrus (BA 7), left inferior frontal gyrus

(triangular part, IFG, BA 48), right insula (BA 48). And IGDs had significant hypo-

activity in the right striatum, right inferior frontal gyrus (opercular part, IFG, BA

44), left precentral gyrus (BA 6). As shown in Table S5 and Figure S4.

Insert Table S5 and Figure S4 here