This study was supported by the National Research Foundation of Korea (NRF) funded by the Ministry of Science and ICT (2015M3C7A1064832, 2015M3C7A1028373, 2018M3A6A3058651) and by the National Institutes of Health (NIHNIMH 1R01MH111896, NIH-NINDS 1R01NS101362).

All experimental procedures presented in this protocol have been approved by the Institutional Review Board and are in accordance with the Declaration of Helsinki.
1. Research Participants
<ol>
	<li>Recruit individuals who report that they play online games (the gamer group) and those who report that they do not play online games (the non-gamer group). 
	NOTE: Here, we included individuals with two or more IGD symptoms according to the Diagnostic and Statistical Manual ...

<ol>
	<li>Chen, Y. F., Peng, S. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=University+students'+Internet+use+and+its+relationships+with+academic+performance,+interpersonal+relationships,+psychosocial+adjustment,+and+self-evaluation.">University students' Internet use and its relationships with academic performance, interpersonal relationships, psychosocial adjustment, and self-evaluation.</a> CyberPsychology &amp; Behavior. 11 (4), 467-469 (2008).</li><li>Ho, R. C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+association+between+internet+addiction+and+psychiatric+co-morbidity:+a+meta-analysis.">The association between internet addiction and psychiatric co-morbidity: a meta-analysis.</a> BMC Psychiatry. 14, 183 (2014).</li><li>Pawlikowski, M., Brand, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Excessive+Internet+gaming+and+decision+making:+do+excessive+World+of+Warcraft+players+have+problems+in+decision+making+under+risky+conditions.">Excessive Internet gaming and decision making: do excessive World of Warcraft players have problems in decision making under risky conditions.</a> Psychiatry Research. 188 (3), 428-433 (2011).</li><li>Zajac, K., Ginley, M. K., Chang, R., Petry, N. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Treatments+for+Internet+gaming+disorder+and+Internet+addiction:+A+systematic+review.">Treatments for Internet gaming disorder and Internet addiction: A systematic review.</a> Psychology of Addictive Behaviors. 31 (8), 979-994 (2017).</li><li>Weinstein, A. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+Update+Overview+on+Brain+Imaging+Studies+of+Internet+Gaming+Disorder.">An Update Overview on Brain Imaging Studies of Internet Gaming Disorder.</a> Frontiers in Psychiatry. 8, 185 (2017).</li><li>Park, B., Han, D. H., Roh, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neurobiological+findings+related+to+Internet+use+disorders.">Neurobiological findings related to Internet use disorders.</a> Psychiatry and Clinical Neurosciences. 71 (7), 467-478 (2017).</li><li>Kober, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Prefrontal-striatal+pathway+underlies+cognitive+regulation+of+craving.">Prefrontal-striatal pathway underlies cognitive regulation of craving.</a> Proceedings of the National Academy of Sciences of the United States of America. 107 (33), 14811-14816 (2010).</li><li>Li, C. S., Luo, X., Yan, P., Bergquist, K., Sinha, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Altered+impulse+control+in+alcohol+dependence:+neural+measures+of+stop+signal+performance.">Altered impulse control in alcohol dependence: neural measures of stop signal performance.</a> Alcoholism: Clinical and Experimental Research. 33 (4), 740-750 (2009).</li><li>Fecteau, S., Fregni, F., Boggio, P. S., Camprodon, J. A., Pascual-Leone, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neuromodulation+of+decision-making+in+the+addictive+brain.">Neuromodulation of decision-making in the addictive brain.</a> Substance Use &amp; Misuse. 45 (11), 1766-1786 (2010).</li><li>Fujimoto, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Deficit+of+state-dependent+risk+attitude+modulation+in+gambling+disorder.">Deficit of state-dependent risk attitude modulation in gambling disorder.</a> Translational Psychiatry. 7 (4), 1085 (2017).</li><li>Choi, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Structural+alterations+in+the+prefrontal+cortex+mediate+the+relationship+between+Internet+gaming+disorder+and+depressed+mood.">Structural alterations in the prefrontal cortex mediate the relationship between Internet gaming disorder and depressed mood.</a> Scientific Reports. 7 (1), 1245 (2017).</li><li>Yuan, K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microstructure+abnormalities+in+adolescents+with+internet+addiction+disorder.">Microstructure abnormalities in adolescents with internet addiction disorder.</a> PLoS One. 6 (6), 20708 (2011).</li><li>Ko, C. H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Brain+activities+associated+with+gaming+urge+of+online+gaming+addiction.">Brain activities associated with gaming urge of online gaming addiction.</a> Journal of Psychiatric Research. 43 (7), 739-747 (2009).</li><li>Gordon, H. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Laterality+of+Brain+Activation+for+Risk+Factors+of+Addiction.">Laterality of Brain Activation for Risk Factors of Addiction.</a> Current Drug Abuse Reviews. 9 (1), 1-18 (2016).</li><li>Tian, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=PET+imaging+reveals+brain+functional+changes+in+internet+gaming+disorder.">PET imaging reveals brain functional changes in internet gaming disorder.</a> European Journal of Nuclear Medicine and Molecular Imaging. 41 (7), 1388-1397 (2014).</li><li>Nitsche, M. A., Paulus, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Excitability+changes+induced+in+the+human+motor+cortex+by+weak+transcranial+direct+current+stimulation.">Excitability changes induced in the human motor cortex by weak transcranial direct current stimulation.</a> Journal of Physiology. 527, 633-639 (2000).</li><li>Bikson, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Safety+of+Transcranial+Direct+Current+Stimulation:+Evidence+Based+Update+2016.">Safety of Transcranial Direct Current Stimulation: Evidence Based Update 2016.</a> Brain Stimulation. 9 (5), 641-661 (2016).</li><li>Boggio, P. S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Prefrontal+cortex+modulation+using+transcranial+DC+stimulation+reduces+alcohol+craving:+a+double-blind,+sham-controlled+study.">Prefrontal cortex modulation using transcranial DC stimulation reduces alcohol craving: a double-blind, sham-controlled study.</a> Drug and Alcohol Dependence. 92 (1-3), 55-60 (2008).</li><li>Martinotti, G., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Gambling+disorder+and+bilateral+transcranial+direct+current+stimulation:+A+case+report.">Gambling disorder and bilateral transcranial direct current stimulation: A case report.</a> Journal of Behavioral Addictions. 7 (3), 834-837 (2018).</li><li>Martinotti, G., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transcranial+Direct+Current+Stimulation+Reduces+Craving+in+Substance+Use+Disorders:+A+Double-blind,+Placebo-Controlled+Study.">Transcranial Direct Current Stimulation Reduces Craving in Substance Use Disorders: A Double-blind, Placebo-Controlled Study.</a> Journal of ECT. , (2019).</li><li>Gay, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+single+session+of+repetitive+transcranial+magnetic+stimulation+of+the+prefrontal+cortex+reduces+cue-induced+craving+in+patients+with+gambling+disorder.">A single session of repetitive transcranial magnetic stimulation of the prefrontal cortex reduces cue-induced craving in patients with gambling disorder.</a> European Psychiatry. 41, 68-74 (2017).</li><li>Pettorruso, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dopaminergic+and+clinical+correlates+of+high-frequency+repetitive+transcranial+magnetic+stimulation+in+gambling+addiction:+a+SPECT+case+study.">Dopaminergic and clinical correlates of high-frequency repetitive transcranial magnetic stimulation in gambling addiction: a SPECT case study.</a> Addictive Behaviors. 93, 246-249 (2019).</li><li>American Psychiatric Association. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Diagnostic+and+Statistical+Manual+of+Mental+Disorders,+5th+edn.">Diagnostic and Statistical Manual of Mental Disorders, 5th edn.</a> American Psychiatric Association. , (2013).</li><li>Young, K. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Internet+addiction:+the+emergence+of+a+new+clinical+disorder.">Internet addiction: the emergence of a new clinical disorder.</a> CyberPsychology &amp; Behavior. 1 (3), 237-244 (1998).</li><li>Tangney, J. P., Baumeister, R. F., Boone, A. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High+self-control+predicts+good+adjustment,+less+pathology,+better+grades,+and+interpersonal+success.">High self-control predicts good adjustment, less pathology, better grades, and interpersonal success.</a> Journal of Personality. 72 (2), 271-324 (2004).</li><li>Bentourkia, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparison+of+regional+cerebral+blood+flow+and+glucose+metabolism+in+the+normal+brain:+effect+of+aging.">Comparison of regional cerebral blood flow and glucose metabolism in the normal brain: effect of aging.</a> Journal of the Neurological Sciences. 181 (1-2), 19-28 (2000).</li><li>Lee, S. H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transcranial+direct+current+stimulation+for+online+gamers:+A+prospective+single-arm+feasibility+study.">Transcranial direct current stimulation for online gamers: A prospective single-arm feasibility study.</a> Journal of Behavioral Addictions. 7 (4), 1166-1170 (2018).</li><li>Bikson, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Response+to+letter+to+the+editor:+Safety+of+transcranial+direct+current+stimulation:+Evidence+based+update+2016.">Response to letter to the editor: Safety of transcranial direct current stimulation: Evidence based update 2016.</a> Brain Stimulation. 10 (5), 986-987 (2017).</li><li>Chhatbar, P. Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Safety+and+tolerability+of+transcranial+direct+current+stimulation+to+stroke+patients+-+A+phase+I+current+escalation+study.">Safety and tolerability of transcranial direct current stimulation to stroke patients - A phase I current escalation study.</a> Brain Stimulation. 10 (3), 553-559 (2017).</li><li>Thair, H., Holloway, A. L., Newport, R., Smith, A. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transcranial+Direct+Current+Stimulation+(tDCS):+A+Beginner's+Guide+for+Design+and+Implementation.">Transcranial Direct Current Stimulation (tDCS): A Beginner's Guide for Design and Implementation.</a> Frontiers in Neuroscience. 11, 641 (2017).</li><li>Wagner, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transcranial+direct+current+stimulation:+a+computer-based+human+model+study.">Transcranial direct current stimulation: a computer-based human model study.</a> Neuroimage. 35 (3), 1113-1124 (2007).</li><li>Lefaucheur, J. P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evidence-based+guidelines+on+the+therapeutic+use+of+transcranial+direct+current+stimulation+(tDCS).">Evidence-based guidelines on the therapeutic use of transcranial direct current stimulation (tDCS).</a> Clinical Neurophysiology. 128 (1), 56-92 (2017).</li><li>Carvalho, F., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Home-Based+Transcranial+Direct+Current+Stimulation+Device+Development:+An+Updated+Protocol+Used+at+Home+in+Healthy+Subjects+and+Fibromyalgia+Patients.">Home-Based Transcranial Direct Current Stimulation Device Development: An Updated Protocol Used at Home in Healthy Subjects and Fibromyalgia Patients.</a> Journal of Visualized Experiments. (137), (2018).</li><li>Shaw, M. T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Remotely+Supervised+Transcranial+Direct+Current+Stimulation:+An+Update+on+Safety+and+Tolerability.">Remotely Supervised Transcranial Direct Current Stimulation: An Update on Safety and Tolerability.</a> Journal of Visualized Experiments. (128), (2017).</li><li>Bikson, M., Rahman, A., Datta, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Computational+models+of+transcranial+direct+current+stimulation.">Computational models of transcranial direct current stimulation.</a> Clinical EEG and Neuroscience. 43 (3), 176-183 (2012).</li><li>Gandiga, P. C., Hummel, F. C., Cohen, L. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transcranial+DC+stimulation+(tDCS):+a+tool+for+double-blind+sham-controlled+clinical+studies+in+brain+stimulation.">Transcranial DC stimulation (tDCS): a tool for double-blind sham-controlled clinical studies in brain stimulation.</a> Clinical Neurophysiology. 117 (4), 845-850 (2006).</li><li>Cho, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Development+of+the+Internet+addiction+scale+based+on+the+Internet+Gaming+Disorder+criteria+suggested+in+DSM-5.">Development of the Internet addiction scale based on the Internet Gaming Disorder criteria suggested in DSM-5.</a> Addictive Behaviors. 39 (9), 1361-1366 (2014).</li><li>Han, D. H., Hwang, J. W., Renshaw, P. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bupropion+sustained+release+treatment+decreases+craving+for+video+games+and+cue-induced+brain+activity+in+patients+with+Internet+video+game+addiction.">Bupropion sustained release treatment decreases craving for video games and cue-induced brain activity in patients with Internet video game addiction.</a> Experimental and Clinical Psychopharmacology. 18 (4), 297-304 (2010).</li></ol>

We have presented a tDCS and neuroimaging protocol for online gamers and assessed its feasibility. The results demonstrated that repeated sessions of tDCS over the DLPFC reduced online game addiction symptoms and average time spent on games and increased self-control. An increase in self-control was correlated with a decrease in addiction symptoms. Moreover, the abnormal asymmetry of rCMRglu in the DLPFC where the right side was greater than the left side was improved after the tDCS sessions in the gamer group. These res...

In recent years, increasing attention has been paid to excessive online game use since its associations with negative impact on mental health and daily functioning as well as with internet gaming disorder (IGD) have been reported1,2,3. Although several treatment strategies including pharmacotherapy and cognitive-behavioral therapy have been evaluated, evidence for their effectiveness is limited4.
Previous studies have suggested that IGD may share clinical and neurobiological similarities with other behavioral addictions and substance use disorders5,6. It has been reported that the dorsolateral prefrontal cortex (DLPFC) is closely involved in the pathophysiology of substance and behavioral addiction such as craving7, impulse control8, decision making9, and cognitive flexibility10. Several neuroimaging studies on IGD have reported structural and functional impairments in the DLPFC6. In particular, structural neuroimaging studies revealed a reduction in gray matter density in the DLPFC11,12 and a functional magnetic resonance imaging (fMRI) study found an altered cued-induced activity in the DLPFC of patients with IGD13. In addition, functional asymmetry of the brain may contribute to impulsivity and craving in addictions including IGD. For instance, cue-induced craving for online gaming could be related to right prefrontal activations14. However, alterations of regional cerebral metabolic rate of glucose (rCMRglu) associated with excessive online game use or IGD remain to be further investigated compared to other brain deficits15.
Transcranial direct current stimulation (tDCS) is a noninvasive brain stimulation technique that applies a weak electric current (1-2 mA) through electrodes attached to the scalp to modulate neuronal membrane potentials. Generally, the cortical excitability is increased under the anode electrode and decreased under the cathode electrode16. tDCS has become a popular method because it is simple, inexpensive, and safe to administer compared to other brain stimulation techniques such as transcranial magnetic stimulation (TMS) that uses a magnetic pulse to generate an electrical current in the brain tissue under the coil. According to a recent review, the use of conventional tDCS protocols has not produced any serious adverse effects or irreversible injury and is associated with only mild and transient itching or tingling sensation under the stimulation area17.
Several studies have demonstrated favorable results of tDCS18,19,20 and repetitive TMS21,22 over the DLPFC for treating behavioral and substance addiction. However, further studies are needed to investigate the effects of brain stimulation techniques on online game use and the underlying brain changes.
The aim of this study is to present a protocol for applying repeated sessions of tDCS over the DLPFC and neuroimaging to examine the underlying neural correlates in gamers using 18F-&#64258;uoro-2-deoxyglucose positron emission tomography (FDG-PET), as well as to assess its feasibility. Specifically, we focused on changes in addiction symptoms, average time spent on games, self-control, and asymmetry of rCMRglu in the DLPFC.

<table border="0" cellpadding="0" cellspacing="0" style="width:1425px;" width="1425">
	<colgroup>
		<col />
		<col />
		<col />
		<col />
	</colgroup>
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:299px;">Discovery STE PET/CT Imaging System</td>
			<td style="width:389px;">GE Healthcare</td>
			<td style="width:161px;"></td>
			<td style="width:576px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:299px;">MarsBaR region of interest toolbox for SPM</td>
			<td style="width:389px;">Matthew Brett</td>
			<td style="width:161px;"></td>
			<td>Neuroimaging analysis software; http://marsbar.sourceforge.net/</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:299px;">Statistical Parametric Mapping 12</td>
			<td>Wellcome Centre for Human Neuroimaging</td>
			<td style="width:161px;"></td>
			<td>Neuroimaging analysis software; https://www.fil.ion.ucl.ac.uk/spm/software/spm12/</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:299px;">Transcranial direct current stimulation device</td>
			<td style="width:389px;">Ybrain</td>
			<td style="width:161px;">YDS-301N</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:299px;">WFU_PickAtlas</td>
			<td colspan="2">ANSIR Laboratory, Wake Forest University School of Medicine</td>
			<td>Neuroimaging analysis software; https://www.nitrc.org/projects/wfu_pickatlas/</td>
		</tr>
	</tbody>
</table>

transcranial direct current stimulation for online gamers

Transcranial direct current stimulation (tDCS) is a noninvasive brain stimulation technique that applies a weak electric current to the scalp to modulate neuronal membrane potentials. Compared to other brain stimulation methods, tDCS is relatively safe, simple, and inexpensive to administer.
Since excessive online gaming can negatively affect mental health and daily functioning, developing treatment options for gamers is necessary. Although tDCS over the dorsolateral prefrontal cortex (DLPFC) has demonstrated promising results for various addictions, it has not been tested in gamers. This paper describes a protocol and a feasibility study for applying repeated tDCS over the DLPFC and neuroimaging to examine the underlying neural correlates in gamers.
At baseline, individuals who play online games report average weekly hours spent on games, complete questionnaires on addiction symptoms and self-control, and undergo brain 18F-&#64258;uoro-2-deoxyglucose positron emission tomography (FDG-PET). The tDCS protocol consists of 12 sessions over the DLPFC for 4 weeks (anode F3/cathode F4, 2 mA for 30 min per session). Then, a follow-up is conducted using the same protocol as the baseline. Individuals who do not play online games receive only baseline FDG-PET scans without tDCS. Changes of clinical characteristics and asymmetry of regional cerebral metabolic rate of glucose (rCMRglu) in the DLPFC are examined in gamers. In addition, asymmetry of rCMRglu is compared between gamers and non-gamers at baseline.
In our experiment, 15 gamers received tDCS sessions and completed baseline and follow-up scans. Ten non-gamers underwent FDG-PET scans at the baseline. The tDCS reduced addiction symptoms, time spent on games, and increased self-control. Moreover, abnormal asymmetry of rCMRglu in the DLPFC at baseline was alleviated after tDCS.
The current protocol may be useful for assessing treatment efficacy of tDCS and its underlying brain changes in gamers. Further randomized sham-controlled studies are warranted. Moreover, the protocol can be applied to other neurological and psychiatric disorders.

A total of 15 gamers (Table 1) and 10 non-gamers were recruited. The mean age of the gamer group (21.3 &#177; 1.4) was significantly lower than that of the non-gamer group (28.8 &#177; 7.5) (t = -3.81, p &#60; 0.001). There were 8 men in the gamer group and 6 men in the non-gamer group (&#967;2 = 0.11, p = 0.74).
Behavioral results using linear mixed models indicate that the tDCS sessions successfully lowered the IAT score (z = -4.29, p &#60; 0.001), weekly hours sp...

Watch this Scientific Journal Video about Transcranial Direct Current Stimulation for Online Gamers at JoVE.com

Transcranial Direct Current Stimulation for Online Gamers

We present a protocol and a feasibility study for applying transcranial direct current stimulation (tDCS) and neuroimaging assessment in online gamers.

Transcranial direct current stimulation (tDCS) is a noninvasive brain stimulation technique that applies a weak electric current to the scalp to modulate ...

Our protocol uses a noninvasive brain modulation technique called transcranial direct current stimulation, or tDCS, to reduce online gaming use. tDCS is simple, safe and inexpensive to administer, compared to other brain stimulation techniques. We also use neuroimaging to assess brain changes related to stimulation.After recruiting both online game playing and non-online game playing individuals, explain to each participant the aim of the study, the main experimental procedures, and any potential risks associated with participating in the study. After answering any questions, obtain written consent. Have each participant fill out questionnaires, such as the Internet Addiction Test and Brief Self Control Scale;and ask the participants to report the average weekly hours spent playing games.To perform an FDG PET scan, inject each participant with 185 to 222 megabecquerels of FDG;and have the participants rest for 45 minutes, in a supine position, in a dark and quiet room, with their eyes closed, to allow FDG uptake. At the end of the uptake period, use a PET/CT scanner to acquire transaxial emission images and CT images in about 15 minutes, applying standard attenuation correction, filtering, and reconstruction techniques. Within a week after the baseline assessment, seat the participant in a chair in the exam room, and set the parameters of the tDCS device to ramp up to 2 milliamps over 30 seconds.Remain at this current for 29 minutes before returning to zero milliamps over the last 30 seconds. Place a head cap, constructed in accordance with the International 10-20 system, on the participant's head, and mark the left dorsolateral prefrontal cortex at F3, and the right dorsolateral prefrontal cortex at F4.After removing the head cap, place two sponge electrodes in the rubber holders of the tDCS headband, and soak the electrodes with saline solution. Remove any makeup, dirt, or sweat from the scalp where the electrodes will be applied, and place the headband on the participant's head, with the anodal electrode over F3, and the cathodal electrode over F4.Then use the cable to connect the electrodes to the tDCS device.Turn on the device and ask the participant to report any adverse effects during or after the tDCS session. At the end of the 30 minute stimulation, turn off the device and remove the electrodes from the participant. Within a week after the last session, administer the same questionnaires, and acquire a post treatment FDG-PET scan.For preprocessing of the imaging data, use an appropriate software package to convert the DICOM files to NIfTI files, and spatially normalize all of the PET images to the standard PET template. After creating binary masks for the left and right dorsolateral prefrontal cortices, use the masks to extract the Regional Cerebral Metabolic Rate of Glucose of the left and right dorsolateral prefrontal cortices. Then calculate the Asymmetry Index of the Regional Cerebral Metabolic Rate of Glucose in the dorsolateral prefrontal cortex.A positive index indicates a right greater than left asymmetry of glucose metabolism. In this representative analysis, a total of 15 gamers and 10 non-gamers were recruited. The tDCS sessions successfully lowered the Internet Addiction Test score and weekly hours spent playing games, and improved the Brief Self Control Scale score in gamers.A significant negative correlation was also found between the changes in the Internet Addiction Test score and the changes observed in the Brief Self Control Scale score in gamers. PET analysis revealed that the Asymmetry Index of the Dorsolateral prefrontal cortex was significantly different between the gamer group and the non-gamer group at baseline. Notably, following the tDCS sessions, the Asymmetry Index of the Dorsolateral prefrontal cortex in the gamer group was significantly decreased.While performing this procedure, it is important to ensure that the parameters are set correctly, and the electrodes are positioned accurately over the stimulation site. Active tDCS can be compared to Sham tDCS to validate its efficacy. Also, other neuroimaging methods, such as fMRI, can be used to assess the brain changes.These protocols can be adapted to explore new treatment options, or other psychiatric or neurological disorders.

transcranial-direct-current-stimulation-for-online-gamers

Research

JoVE Journal

Behavior

7.8K 조회수.  The Catholic University of Korea. 우리의 프로토콜은 온라인 게임 사용을 줄이기 위해 경두개 직접 전류 자극 또는 tDCS라는 비침습적 뇌 변조 기술을 사용합니다. tDCS는 다른 뇌 자극 기술에 비해 간단하고 안전하며 관리하기가 저렴합니다. 우리는 또한 자극과 관련된 뇌 변화를 평가하기 위해 신경 이미징을 사용합니다.온라인 게임 플레이와 비온라인 게임 플레이 개인을 모두 모집한 후 각 참가자에게 ...