Guangheng Dong

Impulse inhibition in people with Internet addiction disorder: electrophysiological evidence from a Go/NoGo study.

We investigated response inhibition in people with Internet addiction disorder (IAD) by recording event-related brain potentials during a Go/NoGo task. Twelve IAD-afflicted and 12 normal university students participated in the study. Results show that the IAD group exhibited lower NoGo-N2 amplitude, higher NoGo-P3 amplitude, and longer NoGo-P3 peak latency than the normal group. The results also suggest that the IAD students had lower activation in the conflict detection stage than the normal group; thus, they had to engage in more cognitive endeavors to complete the inhibition task in the late stage. In addition, the IAD students showed less efficiency in information processing and lower impulse control than their normal peers.

Precursor or Sequela: Pathological Disorders in People with Internet Addiction Disorder

Background This study aimed to evaluate the roles of pathological disorders in Internet addiction disorder and identify the pathological problems in IAD, as well as explore the mental status of Internet addicts prior to addiction, including the pathological traits that may trigger Internet addiction disorder. Methods and Findings 59 students were measured by Symptom CheckList-90 before and after they became addicted to the Internet. A comparison of collected data from Symptom Checklist-90 before Internet addiction and the data collected after Internet addiction illustrated the roles of pathological disorders among people with Internet addiction disorder. The obsessive-compulsive dimension was found abnormal before they became addicted to the Internet. After their addiction, significantly higher scores were observed for dimensions on depression, anxiety, hostility, interpersonal sensitivity, and psychoticism, suggesting that these were outcomes of Internet addiction disorder. Dimensions on somatisation, paranoid ideation, and phobic anxiety did not change during the study period, signifying that these dimensions are not related to Internet addiction disorder. Conclusions We can not find a solid pathological predictor for Internet addiction disorder. Internet addiction disorder may bring some pathological problems to the addicts in some ways.

Male Internet addicts show impaired executive control ability: evidence from a color-word Stroop task.

This study investigated the executive control ability of male students with Internet addiction disorder (IAD) by recording event-related brain potentials (ERP) during a color-word Stroop task. Seventeen IAD and 17 male normal university students participated. Behavior results showed that IAD students were associated with longer reaction time and more response errors in incongruent conditions than the control group. ERP results revealed that participants with IAD showed reduced medial frontal negativity (MFN) deflection in incongruent conditions than the control group. Both of the behavioral performance and ERP results indicate that people with IAD show impaired executive control ability than the normal group.

What makes Internet addicts continue playing online even when faced by severe negative consequences? Possible explanations from an fMRI study

In this study, we designed a continuous wins-and-losses task to monitor the mental activities during decision-making and their effects on subsequent decisions in Internet addiction disorder (IAD) subjects. In behavioral performance, IAD subjects show longer response time, lower repeat rate and greater Stroop effect than healthy controls. In neuroimaging results, IAD subjects show increased brain activities in the inferior frontal cortex, insula, anterior cingulate cortex and decreased activation in the caudate and posterior cingulate cortex after continuous wins than healthy controls. In addition, IAD subjects show increased brain activities in the inferior frontal gyrus and decreased brain activation in the posterior cingulate cortex after continuous losses. Thus, we concluded that IAD subjects engage more cognitive activities to finish the decision-making task. As a result, they cannot sufficiently focus on the executive function during this process. They also do not pay adequate attention to considering previous selections and relevant outcomes during decision-making.

Alterations in regional homogeneity of resting-state brain activity in internet gaming addicts.

BackgroundsInternet gaming addiction (IGA), as a subtype of internet addiction disorder, is rapidly becoming a prevalent mental health concern around the world. The neurobiological underpinnings of IGA should be studied to unravel the potential heterogeneity of IGA. This study investigated the brain functions in IGA patients with resting-state fMRI.MethodsFifteen IGA subjects and fourteen healthy controls participated in this study. Regional homogeneity (ReHo) measures were used to detect the abnormal functional integrations.ResultsComparing to the healthy controls, IGA subjects show enhanced ReHo in brainstem, inferior parietal lobule, left posterior cerebellum, and left middle frontal gyrus. All of these regions are thought related with sensory-motor coordination. In addition, IGA subjects show decreased ReHo in temporal, occipital and parietal brain regions. These regions are thought responsible for visual and auditory functions.ConclusionsOur results suggest that long-time online game playing enhanced the brain synchronization in sensory-motor coordination related brain regions and decreased the excitability in visual and auditory related brain regions.

Reward/punishment sensitivities among internet addicts: Implications for their addictive behaviors.

Internet addiction disorder (IAD) has raised widespread public health concerns. In this study, we used a gambling task to simulate extreme win/lose situations to find the reward/punishment sensitivities after continuous wins and losses. FMRI data were collected from 16 IAD subjects (21.4±3.1years) and 15 healthy controls (HC, 22.1±3.6years). Group comparisons showed higher superior frontal gyrus activations after continuous wins for IAD subjects than for HC. The brain activities in IAD subjects were not disturbed by their losses. In addition, IAD participants showed decreased posterior cingulate activation compared to HC after continuous losses. These results indicated that IAD participants showed preference to win while neglecting their losses. Therefore they engaged less executive endeavor to control their frustration after continuous losses. Taken together, we concluded that IAD subjects showed enhanced sensitivity to win and decreased sensitivity to lose. This can help us understand why IAD subjects continue playing online even after noticing the severe negative consequences of their behaviors.

Impaired risk evaluation in people with Internet gaming disorder: fMRI evidence from a probability discounting task

This study examined how Internet gaming disorder (IGD) subjects modulating reward and risk at a neural level under a probability-discounting task with functional magnetic resonance imaging (fMRI). Behavioral and imaging data were collected from 19 IGD subjects (22.2 ± 3.08 years) and 21 healthy controls (HC, 22.8 ± 3.5 years). Behavior results showed that IGD subjects prefer the probabilistic options to fixed ones and were associated with shorter reaction time, when comparing to HC. The fMRI results revealed that IGD subjects show decreased activation in the inferior frontal gyrus and the precentral gyrus when choosing the probabilistic options than HC. Correlations were also calculated between behavioral performances and brain activities in relevant brain regions. Both of the behavioral performance and fMRI results indicate that people with IGD show impaired risk evaluation, which might be the reason why IGD subjects continue playing online games despite the risks of widely known negative consequence.

Decreased functional connectivity in an executive control network is related to impaired executive function in Internet gaming disorder

BACKGROUND Resting brain spontaneous neural activities across cortical regions have been correlated with specific functional properties in psychiatric groups. Individuals with Internet gaming disorder (IGD) demonstrate impaired executive control. Thus, it is important to examine executive control networks (ECNs) during resting states and their relationships to executive control during task performance. METHODS Thirty-five IGD and 36 healthy control participants underwent a resting-state fMRI scan and performed a Stroop task inside and outside of the MRI scanner. Correlations between Stroop effect and functional connectivity among ECN regions of interest (ROIs) were calculated within and between groups. RESULTS IGD subjects show lower functional connectivity in ECNs than do HC participants during resting state; functional-connectivity measures in ECNs were negatively correlated with Stroop effect and positively correlated with brain activations in executive-control regions across groups. Within groups, negative trends were found between Stroop effect and functional connectivity in ECNs in IGD and HC groups, separately; positive trends were found between functional connectivity in ECNs and brain activations in Stroop task in IGD and HC groups, separately. CONCLUSIONS Higher functional connectivity in ECNs may underlie better executive control and may provide resilience with respect to IGD. Lower functional connectivity in ECNs may represent an important feature in understanding and treating IGD.

Abnormal gray matter and white matter volume in ‘Internet gaming addicts’

Internet gaming addiction (IGA) is usually defined as the inability of an individual to control his/her use of the Internet with serious negative consequences. It is becoming a prevalent mental health concern around the world. To understand whether Internet gaming addiction contributes to cerebral structural changes, the present study examined the brain gray matter density and white matter density changes in participants suffering IGA using voxel-based morphometric analysis. Compared with the healthy controls (N=36, 22.2 ± 3.13 years), IGA participants (N=35, 22.28 ± 2.54 years) showed significant lower gray matter density in the bilateral inferior frontal gyrus, left cingulate gyrus, insula, right precuneus, and right hippocampus (all p<0.05). IGA participants also showed significant lower white matter density in the inferior frontal gyrus, insula, amygdala, and anterior cingulate than healthy controls (all p<0.05). Previous studies suggest that these brain regions are involved in decision-making, behavioral inhibition and emotional regulation. Current findings might provide insight in understanding the biological underpinnings of IGA.

Cognitive flexibility in internet addicts: fMRI evidence from difficult-to-easy and easy-to-difficult switching situations

Internet addiction disorder (IAD) has raised widespread public health concerns. In this study, we explored the cognitive flexibility in IAD subjects using a color-word Stroop task. Behavioral and imaging data were collected from 15 IAD subjects (21.2±3.2years) and 15 healthy controls (HC, 22.1±3.6years). Group comparisons found that IAD subjects show higher superior temporal gyrus activations than healthy controls in switching (easy to difficult; difficult to easy) than in repeating trials. In addition, in difficult-to-easy situation, IAD subjects show higher brain activation in bilateral insula than healthy controls; in easy-to-difficult situation, IAD subjects show higher brain activation in bilateral precuneus than healthy controls. Correlations were also performed between behavioral performances and brain activities in relevant brain regions. Taken together, we concluded that IAD subjects engaged more endeavors in executive control and attention in the switching task. From another perspective, IAD subjects show impaired cognitive flexibilities.