Aberrant corticostriatal functional circuits in adolescents with internet addiction disorder

Frontiers in Human Neuroscience

Volumn 9, Issue June, 2015, Pages

  Lin, Fuchun ^a   Zhou, Yan ^b   Du, Yasong ^b   Zhao, Zhimin ^b   Qin, Lindi ^b   Xu, Jianrong ^b   Lei, Hao ^a  

^a Wuhan National Laboratory for Optoelectronics   (China)

^b SHANGHAI JIAO TONG UNIVERSITY   (China)

Author keywords

Corticostriatal circuits; Functional connectivity; Internet addiction disorder; Neuropsychological measures; Resting state fMRI

Indexed keywords

ADOLESCENT; ADOLESCENT BEHAVIOR; ANTERIOR CINGULATE; ARTICLE; BRAIN FUNCTION; BRAIN REGION; CAUDATE NUCLEUS; CLINICAL ARTICLE; CONTROLLED STUDY; CORPUS STRIATUM; CORTICOSTRIATAL FUNCTIONAL CIRCUIT; DORSAL ANTERIOR CINGULATE CORTEX; EMOTION; EXECUTIVE FUNCTION; FEMALE; FUNCTIONAL MAGNETIC RESONANCE IMAGING; GLOBUS PALLIDUS; HUMAN; INFERIOR FRONTAL GYRUS; INSULA; INTERNET ADDICTION; MALE; NERVE CELL NETWORK; POSTERIOR CINGULATE; PREFRONTAL CORTEX; PUTAMEN; RESTING STATE NETWORK; ROSTRAL ANTERIOR CINGULATE CORTEX; THALAMUS ANTERIOR NUCLEUS; VENTRAL STRIATUM;

EID: 84935834143     PISSN: None     EISSN: 16625161     Source Type: Journal    
DOI: 10.3389/fnhum.2015.00356     Document Type: Article

References (85)

1. Alexander, G. E., DeLong, M. R., and Strick, P. L. (1986). Parallel organization of functionally segregated circuits linking basal ganglia and cortex. Annu. Rev. Neurosci. 9, 357-381. doi: 10.1146/annurev.neuro.9.1.357
2. Beard, K. W., and Wolf, E. M. (2001). Modification in the proposed diagnostic criteria for internet addiction. Cyberpsychol. Behav. 4, 377-383. doi: 10.1089/109493101300210286
3. Beckmann, M., Johansen-Berg, H., and Rushworth, M. F. S. (2009). Connectivity- based parcellation of human cingulate cortex and its relation to functional specialization. J. Neurosci. 29,1175-1190. doi: 10.1523/jneurosci.3328-08.2009
4. Birmaher, B., Khetarpal, S., Brent, D., Cully, M., Balach, L., Kaufman, J., et al. (1997). The screen for child anxiety related emotional disorders (SCARED): scale construction and psychometric characteristics. J. Am. Acad. Child Adolesc. Psychiatry 36, 545-553. doi: 10.1097/00004583-199704000-00018
5. Botvinick, M. M., Cohen, J. D., and Carter, C. S. (2004). Conflict monitoring and anterior cingulate cortex: an update. Trends Cogn. Sci. 8, 539-546. doi: 10.1016/j.tics.2004.10.003
6. Bozkurt, H., Coskun, M., Ayaydin, H., Adak, I., and Zoroglu, S. S. (2013). Prevalence and patterns of psychiatric disorders in referred adolescents with internet addiction. Psychiatry Clin. Neurosci. 67, 352-359. doi: 10.1111/pcn.12065
7. Burguiere, E., Monteiro, P., Mallet, L., Feng, G., and Graybiel, A. M. (2015). Striatal circuits, habits and implications for obsessive-compulsive disorder. Curr. Opin. Neurobiol. 30, 59-65. doi: 10.1016/j.conb.2014.08.008
8. Bush, G., Luu, P., and Posner, M. I. (2000). Cognitive and emotional influences in anterior cingulate cortex. Trends Cogn. Sci. 4, 215-222. doi: 10.1016/s1364-6613(00)01483-2
9. Cao, F., and Su, L. (2007). Internet addiction among Chinese adolescents: prevalence and psychological features. Child Care Health Dev. 33, 275-281. doi: 10.1111/j.1365-2214.2006.00715.x
10. Cao, F. L., Su, L. Y., Liu, T. Q., and Gao, X. P. (2007). The relationship between impulsivity and internet addiction in a sample of Chinese adolescents. Eur. Psychiatry 22,466-471. doi: 10.1016/j.eurpsy.2007.05.004
11. Chambers, C. D., Garavan, H., and Bellgrove, M. A. (2009). Insights into the neural basis of response inhibition from cognitive and clinical neuroscience. Neurosci. Biobehav. Rev. 33, 631-646. doi: 10.1016/j.neubiorev.2008.08.016
12. Choi, E. Y., Yeo, B. T. T., and Buckner, R. L. (2012). The organization ofthe human striatum estimated by intrinsic functional connectivity. J. Neurophysiol. 108, 2242-2263. doi: 10.1152/jn.00270.2012
13. Courtney, K. E., Ghahremani, D. G., and Ray, L. A. (2013). Fronto-striatal functional connectivity during response inhibition in alcohol dependence. Addict. Biol. 18, 593-604. doi: 10.1111/adb.12013
14. Dalbudak, E., Evren, C., Aldemir, S., Coskun, K. S., Ugurlu, H., and Yildirim, F. G. (2013a). Relationship of internet addiction severity with depression, anxiety and alexithymia, temperament and character in university students. Cyberpsychol. Behav. Soc. Netw. 16,272-278. doi: 10.1089/cyber.2012.0390
15. Dalbudak, E., Evren, C., Topcu, M., Aldemir, S., Coskun, K. S., Bozkurt, M., et al. (2013b). Relationship of internet addiction with impulsivity and severity of psychopathology among Turkish university students. Psychiatry Res. 210, 1086-1091. doi: 10.1016/j.psychres.2013.08.014
16. Di Martino, A., Kelly, C., Grzadzinski, R., Zuo, X. N., Mennes, M., Mairena, M. A., et al. (2011). Aberrant striatal functional connectivity in children with autism. Biol. Psychiatry 69, 847-856. doi: 10.1016/j.biopsych.2010.10.029
17. Di Martino, A., Scheres, A., Margulies, D. S., Kelly, A. M. C., Uddin, L. Q., Shehzad, Z., et al. (2008). Functional connectivity ofhuman striatum: a resting state fMRI study. Cereb. Cortex 18, 2735-2747. doi: 10.1093/cercor/bhn041
18. Dong, G., Devito, E. E., Du, X., and Cui, Z. (2012b). Impaired inhibitory control in ‘internet addiction disorder’: a functional magnetic resonance imaging study. PsychiatryRes. 203, 153-158. doi: 10.1016/j.pscychresns.2012.02.001
19. Dong, G.H., Zhou, H., and Zhao, X. (2011). Male internet addicts show impaired executive control ability: evidence from a color-word Stroop task. Neurosci. Lett. 499, 114-118. doi: 10.1016/j.neulet.2011.05.047
20. Epstein, N. B., Baldwin, L. M., and Bishop, D. S. (1983). The McMaster family assessment device. J. Marital Fam. Ther. 9, 171-180. doi: 10.1111/j.1752-0606.1983.tb01497.x
21. Feil, J., Sheppard, D., Fitzgerald, P. B., Yucel, M., Lubman, D. I., and Bradshaw, J. L. (2010). Addiction, compulsive drug seeking and the role of frontostriatal mechanisms in regulating inhibitory control. Neurosci. Biobehav. Rev. 35, 248-275. doi: 10.1016/j.neubiorev.2010.03.001
22. Forbes, E. E., Rodriguez, E. E., Musselman, S., and Narendran, R. (2014). Prefrontal response and frontostriatal functional connectivity to monetary reward in abstinent alcohol-dependent young adults. PLoS One 9:e94640. doi: 10.1371/journal.pone.0094640
23. Furman, D. J., Hamilton, J. P., and Gotlib, I. H. (2011). Frontostriatal functional connectivity in major depressive disorder. Biol. Mood Anxiety Disord. 1:11. doi: 10.1186/2045-5380-1-11
24. Gabbay, V., Ely, B. A., Li, Q. Y., Bangaru, S. D., Panzer, A. M., Alonso, C. M., et al. (2013). Striatum-based circuitry of adolescent depression and anhedonia. J. Am. Acad. ChildAdolesc. Psychiatry 52, 628-641.e13. doi: 10.1016/j.jaac.2013.04.003
25. Goldstein, R. Z., and Volkow, N. D. (2011). Dysfunction of the prefrontal cortex in addiction: neuroimaging findings and clinical implications. Nat. Rev. Neurosci. 12, 652-669. doi: 10.1038/nrn3119
26. Goodman, R. (1997). The strengths and difficulties questionnaire: a research note. J. Child Psychol. Psychiatry 38, 581-586. doi: 10.1111/j.1469-7610.1997.tb01545.x
27. Gordon, E. M., Devaney, J. M., Bean, S., and Vaidya, C. J. (2015). Resting- state striato-frontal functional connectivity is sensitive to DAT1 genotype and predicts executive function. Cereb. Cortex 25, 336-345. doi: 10.1093/cercor/bht229
28. Greicius, M. D., Flores, B. H., Menon, V., Glover, G. H., Solvason, H. B., Kenna, H., et al. (2007). Resting-state functional connectivity in major depression: abnormally increased contributions from subgenual cingulate cortex and thalamus. Biol. Psychiatry 62, 429-437. doi: 10.1016/j.biopsych.2006.09.020
29. Haber, S. N. (2003). The primate basal ganglia: parallel and integrative networks. J. Chem. Neuroanat. 26, 317-330. doi: 10.1016/j.jchemneu.2003.10.003
30. Haber, S., and McFarland, N. R. (2001). The place of the thalamus in frontal cortical-basal ganglia circuits. Neuroscientist 7, 315-324. doi: 10.1177/107385840100700408
31. Harrison, B. J., Soriano-Mas, C., Pujol, J., Ortiz, H., Lopez-Sola, M., Hernandez- Ribas, R., et al. (2009). Altered corticostriatal functional connectivity in obsessive-compulsive disorder. Arch. Gen. Psychiatry 66, 1189-1200. doi: 10.1001/archgenpsychiatry.2009.152
32. Hong, L. E., Gu, H., Yang, Y., Ross, T. J., Salmeron, B. J., Buchholz, B., et al. (2009). Association of nicotine addiction and nicotine’s actions with separate cingulate cortex functional circuits. Arch. Gen. Psychiatry 66, 431-441. doi: 10.1001/archgenpsychiatry.2009.2
33. Hong, S. B., Harrison, B. J., Dandash, O., Choi, E. J., Kim, S. C., Kim, H. H., et al. (2015). A selective involvement of putamen functional connectivity in youth with internet gaming disorder. Brain Res. 1602, 85-95. doi: 10.1016/j.brainres.2014.12.042
34. Hong, S. B., Kim, J. W., Choi, E. J., Kim, H. H., Suh, J. E., Kim, C. D., et al. (2013a). Reduced orbitofrontal cortical thickness in male adolescents with internet addiction. Behav. Brain Fund. 9:11. doi: 10.1186/1744-9081-9-11
35. Hong, S. B., Zalesky, A., Cocchi, L., Fornito, A., Choi, E. J., Kim, H. H., et al. (2013b). Decreased functional brain connectivity in adolescents with internet addiction. PLoS One 8:e57831. doi: 10.1371/journal.pone.0057831
36. Hou, H. F., Jia, S. W., Hu, S., Fan, R., Sun, W., Sun, T. T., et al. (2012). Reduced striatal dopamine transporters in people with internet addiction disorder. J. Biomed. Biotechnol. 2012:854524. doi: 10.1155/2012/854524
37. Hu, Y. Z., Salmeron, B. J., Gu, H., Stein, E. A., and Yang, Y. (2015). Impaired functional connectivity within and between frontostriatal circuits and its association with compulsive drug use and trait impulsivity in cocaine addiction. JAMA Psychiatry 72, 584-592. doi: 10.1001/jamapsychiatry.2015.1
38. Huang, X., and Zhang, Z. (2001). The compiling of the adolescence time management disposition scale. Acta Psychol. Sin. (Chinese) 33, 338-343.
39. Irvine, M. A., Worbe, Y., Bolton, S., Harrison, N. A., Bullmore, E. T., and Voon, V. (2013). Impaired decisional impulsivity in pathologicalvideogamers. PLoS One 8:e75914. doi: 10.1371/journal.pone.0075914
40. Johansen-Berg, H., Gutman, D. A., Behrens, T. E. J., Matthews, P. M., Rushworth, M. F. S., Katz, E., et al. (2008). Anatomical connectivity of the subgenual cingulate region targeted with deep brain stimulation for treatment-resistant depression. Cereb. Cortex 18, 1374-1383. doi: 10.1093/cercor/bhm167
41. Kelly, C., de Zubicaray, G., Di Martino, A., Copland, D. A., Reiss, P. T., Klein, D. F., et al. (2009). L-dopa modulates functional connectivity in striatal cognitive and motor networks: a double-blind placebo-controlled study. J. Neurosci. 29, 7364-7378. doi: 10.1523/JNEUR0SCI.0810-09.2009
42. Kim, S. H., Baik, S. H., Park, C. S., Kim, S. J., Choi, S. W., and Kim, S. E. (2011). Reduced striatal dopamine D2 receptors in people with internet addiction. Neuroreport 22, 407-411. doi: 10.1097/wnr.0b013e328346e16e
43. Klein, T. A., Endrass, T., Kathmann, N., Neumann, J., von Cramon, D. Y., and Ullsperger, M. (2007). Neural correlates of error awareness. Neuroimage 34, 1774-1781. doi: 10.1016/j.neuroimage.2006.11.014
44. Ko, C. H., Hsieh, T. J., Chen, C. Y., Yen, C. F., Chen, C. S., Yen, J. Y., et al. (2014). Altered brain activation during response inhibition and error processing in subjects with internet gaming disorder: a functional magnetic imaging study. Eur. Arch. Psychiatry Clin. Neurosci. 264, 661-672. doi: 10.1007/s00406-013-0483-3
45. Ko, C.-H., Liu, G.-C., and Yen, J.-Y. (2015). Functional imaging of internet gaming disorder. Internet Addiction, Neuroscientific Approaches and Therapeutical Interventions 2015, 43-64. doi: 10.1007/978-3-319-07242-5_3
46. Kuhn, S., and Gallinat, J. (2014). Brain structure and functional connectivity associated with pornography consumption: the brain on porn. JAMA Psychiatry 71, 827-834. doi: 10.1001/jamapsychiatry.2014.93
47. Kuss, D. J., and Griffiths, M. D. (2012). Internet and gaming addiction: a systematic literature review of neuroimaging studies. Brain Sci. 2, 347-374. doi: 10.3390/brainsci2030347
48. Lee, S., Lee, E., Ku, J., Yoon, K. J., Namkoong, K., and Jung, Y. C. (2013). Disruption of orbitofronto-striatal functional connectivity underlies maladaptive persistent behaviors in alcohol-dependent patients. Psychiatry Investig. 10, 266-272. doi: 10.4306/pi.2013.10.3.266
49. Li, B., Friston, K. J., Liu, J., Liu, Y., Zhang, G., Cao, F., et al. (2014). Impaired frontal-basal ganglia connectivity in adolescents with internet addiction. Sci. Rep. 4:5027. doi: 10.1038/srep05027
50. Li, C. S. R., and Sinha, R. (2008). Inhibitory control and emotional stress regulation: neuroimaging evidence for frontal-limbic dysfunction in psychostimulant addiction. Neurosci. Biobehav. Rev. 32, 581-597. doi: 10.1016/j.neubiorev.2007.10.003
51. Limbrick-Oldfield, E. H., van Holst, R. J., and Clark, L. (2013). Fronto- striatal dysregulation in drug addiction and pathological gambling: consistent inconsistencies? Neuroimage Clin. 2, 385-393. doi: 10.1016/j.nicl.2013.02.005
52. Lin, F., and Lei, H. (2015). Structural brain imaging and internet addiction. Internet Addiction, Neuroscientific Approaches and Therapeutical Interventions 2015,21-42. doi: 10.1007/978-3-319-07242-5_2
53. Lin, F. C., Zhou, Y., Du, Y. S., Qin, L. D., Zhao, Z. M., Xu, J. R., et al. (2012). Abnormal white matter integrity in adolescents with internet addiction disorder: a tract-based spatial statistics study. PLoS One 7:e30253. doi: 10.1371/journal.pone.0030253
54. Liston, C., Chen, A. C., Zebley, B. D., Drysdale, A. T., Gordon, R., Leuchter, B., et al. (2014). Default mode network mechanisms of transcranial magnetic stimulationindepression. Biol. Psychiatry 76,517-526. doi: 10.1016/j.biopsych.2014.01.023
55. Ma, N., Liu, Y., Li, N., Wang, C. X., Zhang, H., Jiang, X. F., et al. (2010). Addiction related alteration in resting-state brain connectivity. Neuroimage 49, 738-744. doi: 10.1016/j.neuroimage.2009.08.037
56. Manza, P., Zhang, S., Hu, S., Chao, H. H., Leung, H. C., and Li, C. S. R. (2015). The effects of age on resting state functional connectivity of the basal ganglia from young to middle adulthood. Neuroimage 107, 311-322. doi: 10.1016/j.neuroimage.2014.12.016
57. Mayberg, H. S., Liotti, M., Brannan, S. K., McGinnis, S., Mahurin, R. K., Jerabek, P. A., et al. (1999). Reciprocal limbic-cortical function and negative mood: converging PET findings in depression and normal sadness. Am. J. Psychiatry 156, 675-682.
58. Meng, Y., Deng, W., Wang, H., Guo, W., and Li, T. (2014). The prefrontal dysfunction in individuals with internet gaming disorder: a meta-analysis of functional magnetic resonance imaging studies. Addict. Biol. doi: 10.1111/adb.12154 [Epub ahead ofprint].
59. Menon, V., and Uddin, L. Q. (2010). Saliency, switching, attention and control: a network model of insula function. Brain Struct. Funct. 214, 655-667. doi: 10.1007/s00429-010-0262-0
60. Park, H. S., Kim, S. H., Bang, S. A., Yoon, E. J., Cho, S. S., and Kim, S. E. (2010a). Altered regional cerebral glucose metabolism in internet game overusers: a F- 18-fluorodeoxyglucose positron emission tomography study. CNS Spectr. 15, 159-166.
61. Park, S. Q., Kahnt, T., Beck, A., Cohen, M. X., Dolan, R. J., Wrase, J., et al. (2010b). Prefrontalcortexfails to learnfromreward predictionerrors in alcohol dependence. J. Neurosci. 30, 7749-7753. doi: 10.1523/jneurosci.5587-09.2010
62. Patton, J. H., Stanford, M. S., and Barratt, E. S. (1995). Factor structure of the Barratt impulsiveness scale. J. Clin. Psychol. 51, 768-774. doi: 10.1002/1097-4679(199511)51:6<768::aid-jclp2270510607>3.0.co;2-1
63. Petry, N. M., Rehbein, F., Gentile, D. A., Lemmens, J. S., Rumpf, H. J., Moofile, T., et al. (2014). An international consensus for assessing internet gaming disorder using the new DSM-5 approach. Addiction 109, 1399-1406. doi: 10.1111/add.12457
64. Posner, J., Marsh, R., Maia, T. V., Peterson, B. S., Gruber, A., and Simpson, H. B. (2014). Reduced functional connectivity within the limbic cortico- striato-thalamo-cortical loop in unmedicated adults with obsessive-compulsive disorder. Hum Brain Mapp 35, 2852-2860. doi: 10.1002/hbm.22371
65. Postuma, R. B., and Dagher, A. (2006). Basal ganglia functional connectivity based on a meta-analysis of 126 positron emission tomography and functional magneticresonanceimagingpublications. Cereb. Cortex 16,1508-1521. doi: 10.1093/cercor/bhj088
66. Rudebeck, P. H., Putnam, P. T., Daniels, T. E., Yang, T. M., Mitz, A. R., Rhodes, S. E. V., et al. (2014).Arole forprimate subgenual cingulate cortex in sustaining autonomic arousal. Proc. Natl. Acad. Sci. USA 111, 5391-5396. doi: 10.1073/pnas.1317695111
67. Sheehan, D. V., Sheehan, K. H., Shytle, R. D., Janavs, J., Bannon, Y., Rogers, J. E., et al. (2010). Reliability and validity of the mini international neuropsychiatric interview for children and adolescents (MINI-KID). J. Clin. Psychiatry 71, 313-326. doi: 10.4088/JCP.09m05305whi
68. Shepherd, G. M. G. (2013). Corticostriatal connectivity and its role in disease. Nat. Rev. Neurosci. 14, 278-291. doi: 10.1038/nrn3469
69. Shima, K., and Tanji, J. (1998). Role for cingulate motor area cells in voluntary movement selection based on reward. Science 282, 1335-1338. doi: 10.1126/science.282.5392.1335
70. Spada, M. M. (2014). An overview of problematic internet use. Addict. Behav. 39, 3-6. doi: 10.1016/j.addbeh.2013.09.007
71. Swick, D., Ashley, V., and Turken, U. (2011). Are the neural correlates of stopping and not going identical? Quantitative meta-analysis of two response inhibition tasks. Neuroimage 56, 1655-1665. doi: 10.1016/j.neuroimage.2011.02.070
72. Tian, M., Chen, Q. Z., Zhang, Y., Du, F. L., Hou, H. F., Chao, F. F., et al. (2014). PET imaging reveals brain functional changes in internet gaming disorder. Eur. J. Nucl. Med. Mol. Imaging 41, 1388-1397. doi: 10.1007/s00259-014-2708-8
73. Vogt, B. A., Vogt, L., and Laureys, S. (2006). Cytology and functionally correlated circuits of human posterior cingulate areas. Neuroimage 29, 452-466. doi: 10.1016/j.neuroimage.2005.07.048
74. Volkow, N. D., Wang, G. J., Tomasi, D., and Baler, R. D. (2013). Unbalanced neuronal circuits in addiction. Curr. Opin. Neurobiol 23, 639-648. doi: 10.1016/j.conb.2013.01.002
75. Wang, Y. R., Zhu, J., Li, Q., Li, W., Wu, N., Zheng, Y., et al. (2013). Altered fronto-striatal and fronto-cerebellar circuits in heroin-dependent individuals: a resting-state fMRI study. PLoS One 8:e58098. doi: 10.1371/journal.pone.0058098
76. Wee, C. Y., Zhao, Z., Yap, P. T., Wu, G., Shi, F., Price, T., et al. (2014). Disrupted brain functional network in internet addiction disorder: a resting- state functional magnetic resonance imaging study. PLoS One 9:e107306. doi: 10.1371/journal.pone.0107306
77. Weng, C. B., Qian, R. B., Fu, X. M., Lin, B., Han, X. P., Niu, C. S., et al. (2013). Gray matter and white matter abnormalities in online game addiction. Eur. J. Radiol. 82, 1308-1312. doi: 10.1016/j.ejrad.2013.01.031
78. Wilcox, C. E., Teshiba, T. M., Merideth, F., Ling, J., and Mayer, A. R. (2011). Enhanced cue reactivity and fronto-striatal functional connectivity in cocaine use disorders. Drug Alcohol Depend. 115, 137-144. doi: 10.1016/j.drugalcdep.2011.01.009
79. Xiuqin, H., Huimin, Z., Mengchen, L., Jinan, W., Ying, Z., and Ran, T. (2010). Mental health, personality and parental rearing styles of adolescents with internet addiction disorder. Cyberpsychol. Behav. Soc. Netw. 13, 401-406. doi: 10.1089/cyber.2009.0222
80. Young, K. S. (1996). Psychologyofcomputeruse: XL. Addictive use ofthe internet: a case that breaks the stereotype. Psychol. Rep. 79, 899-902. doi: 10.2466/pr0.1996.79.3.899
81. Yuan, K., Cheng, P., Dong, T., Bi, Y., Xing, L., Yu, D., et al. (2013). Cortical thickness abnormalities in late adolescence with online gaming addiction. PLoS One 8:e53055. doi: 10.1371/journal.pone.0053055
82. Yuan, K., Qin, W., Wang, G., Zeng, F., Zhao, L., Yang, X., et al. (2011). Microstructure abnormalities in adolescents with internet addiction disorder. PLoS One 6:e20708. doi: 10.1371/journal.pone.0020708
83. Zhang, H. X., Jiang, W. Q., Lin, Z. G., Du, Y. S., and Vance, A. (2013). Comparison of psychological symptoms and serum levels of neurotransmitters in shanghai adolescents with and without internet addiction disorder: a case-control study. PLoS One 8:e63089. doi: 10.1371/journal.pone.0063089
84. Zhou, Y., Lin, F. C., Du, Y. S., Qin, L. D., Zhao, Z. M., Xu, J. R., et al. (2011). Gray matter abnormalities in internet addiction: a voxel-based morphometry study. Eur. J. Radiol. 79, 92-95. doi: 10.1016/j.ejrad.2009.10.025
85. Zhou, Z. H., Yuan, G. Z., and Yao, J. J. (2012). Cognitive biases toward internet game-related pictures and executive deficits in individuals with an internet game addiction. PLoS One 7:e48961. doi: 10.1371/journal.pone.0048961