Page 17 - ITPS-7-4

INNOSC Theranostics and
Pharmacological Sciences Neurobiology of gaming disorder

Table 1. Brief explanations for the technical terms related to brain imaging techniques
Structural brain imaging
Voxel-based Measuring gray matter volume
morphometry (VBM)
Diffusion-tensor imaging Observing the anatomical connectivity, primarily by measuring the distribution of nerve fibers in white matter
(DTI) *Fractional anisotropy (FA): An index of integrity and organization of white-matter tracts in DTI, with higher FA
suggesting greater structural integrity of white matter
Functional brain imaging
Functional magnetic Identifying functionally active regions of the brain involved in various tasks and cognitive processes
resonance *Resting-state functional connectivity (rsFC): Functional connectivity between different brain regions during a state of
imaging (fMRI) rest in fMRI, reflecting intrinsic functional networks of the brain
Event-related potentials Measuring brain electrical changes recorded through electroencephalography during stimulus presentation to study
(ERP) cognitive process
*Late positive potential (LPP): A positive electrical brain response occurring later in time in ERP, often associated with the
processing of emotionally significant stimuli
*P100: A positive peak in ERP occurring approximately 100 ms after the onset of a visual stimulus, often associated with
early visual processing and perceptual mechanisms

of addiction such as tolerance, withdrawal, cravings, and with GD may have higher reward sensitivity and improved
compulsive substance use. 17 coordination between sensory and motor processing.
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Changes in the reward circuit accompanied by positive In contrast, other studies on GD have used DTI-based
reinforcement were also observed in individuals with GD. structural connectivity and resting-state functional
Koepp et al. conducted studies comparing dopamine connectivity (rsFC), which have shown a decrease rsFC
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release in the striatum during gaming and non-gaming and structural connectivity of VTA–NA in GD when
periods in healthy adult males without GD. The results compared to healthy controls. 24,25 Furthermore, rsFC of
showed increased dopamine release in the striatum these regions was significantly negatively associated with
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during gaming compared to non-gaming periods, with the craving rating for Internet gaming. These findings
higher levels of gaming associated with greater dopamine suggest a decrease in sensitivity to reward, making the
release, particularly in the ventral striatum. Regarding individuals prone to seeking more intense rewards in GD.
D2R availability, studies on men with GD found decreased 3. Frontostriatal circuit dysfunction
D2R availability in the striatum compared to individuals
without GD. Furthermore, the D2R availability negatively Changes in the dopamine system also trigger neuroplasticity
correlated with the severity of addiction assessed by the in the frontostriatal circuits (Figure 1B). These circuits can
Young’s Internet Addiction Test (YIAT). 19,20 be divided into two pathways in addiction: the ventral
Structural brain imaging studies have shown valuation pathway, which is responsible for reward
differences in NA volume between individuals with GD processing, and the dorsal control pathway, which is
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and controls. A study using voxel-based morphometry involved in cognitive inhibitory control. As addiction
(VBM) demonstrated a decrease in the volume of the NA progresses, the locus of control within the striatum shifts
in subjects with GD compared to recreational game users from the ventral to the dorsal region, and the influence of
(RGU) and its association with lifetime gaming usage. In the prefrontal cortex (PFC) weakens. 27
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contrast, in a study by Yuan et al., increased gray matter Previous studies have shown evidence of dysfunction
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(GM) volume of the NA was observed in subjects with GD in fronto-striatal circuits in GD, including structural
compared to healthy controls, and the NA volume was and functional impairments. In a longitudinal study
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positively correlated with YIAT scores. that evaluated structural brain imaging and functional
A study using diffusion-tensor imaging (DTI), connectivity in individuals with GD, follow-up assessments
which may characterize microstructural white-matter were conducted after an average of 21.2 months. The results
organization, showed that online game playing is associated did not show any difference in changes in GM volume of
with increased fractional anisotropy (FA), regarded as both the dorsal and ventral striatum. However, subjects
an index of coherence of white-matter fiber tracts, in the with GD exhibited a decrease in functional connectivity
reward circuity and sensory and motor control systems between the left dorsal putamen and the left medial PFC
relative to RGU. These findings suggest that individuals (mPFC), as well as an increase in functional connectivity

Volume 7 Issue 4 (2024) 3 doi: 10.36922/itps.3326