An error-related negativity potential investigation of response monitoring function in individuals with internet addiction disorder

A comprehensive evaluation of the neurocognitive predictors of problematic alcohol use, eating, pornography, and internet use: A 6-month longitudinal study

Background and aims

Cognitive control and reward-related abnormalities are centrally implicated in addiction. However, findings from longitudinal studies addressing neurocognitive predictors of addictive behaviors are mixed. Further, little work has been conducted predicting non-substance-related addictive behaviors. Our study aimed to assess predictors of substance and non-substance addictive behaviors in a community sample, systematically evaluating each neurocognitive function's independent influence on addictive behavior.

Methods

Australians (N = 294; 51.7% female; M[SD] age = 24.8[4.7] years) completed online neurocognitive tasks and surveys at baseline and 3-month follow-up. Self-report scales assessed problematic alcohol use, addictive eating (AE), problematic pornography use (PPU), and problematic internet use (PUI) at 3- and 6-month follow-ups. Linear regressions with bootstrapping assessed neurocognitive predictors for each addictive behavior across a 6-month period.

Results

Neurocognition at baseline did not predict AE or PUI severity at 6-month follow-up. Less delay discounting at baseline predicted higher PPU at 6-month follow-up (β = -0.16, p = 0.005). Poorer performance monitoring at baseline predicted higher AE at 3-month follow-up (β = -0.16, p = 0.004), and more reward-related attentional capture at 3-months predicted higher AE at 6-month follow-up (β = 0.14, p = 0.033). Less reward-related attentional capture (β = -0.14, p = 0.003) and less risk-taking under ambiguity (β = -0.11, p = 0.029) at baseline predicted higher PUI at 3-month follow-up. All findings were of small effect size. None of the neurocognitive variables predicted problematic alcohol use.

Discussion and conclusions

We were unable to identify a core set of specific neurocognitive functions that reliably predict multiple addictive behavior types. However, our findings indicate both cognitive control and reward-related functions predict non-substance addictive behaviors in different ways. Findings suggest that there may be partially distinct neurocognitive mechanisms contributing to addiction depending on the specific addictive behavior.

Neuropsychological Deficits in Disordered Screen Use Behaviours: A Systematic Review and Meta-analysis

Over the last few decades, excessive and disordered screen use has become more prevalent, prompting investigations into its associated consequences. The extent to which disordered screen use behaviours impact neuropsychological functioning has been reportedly mixed and at times inconsistent. This review sought to synthesise the literature and estimate the magnitude of overall cognitive impairment across a wide range of disordered screen use behaviours. We also sought to determine the cognitive domains most impacted, and whether the observed impairments were moderated by the classification of screen-related behaviours (i.e., Internet or gaming) or the format of cognitive test administration (i.e., paper-and-pencil or computerised). A systematic search of databases (Embase, PsycINFO, MEDLINE) identified 43 cross-sectional articles that assessed neuropsychological performance in disordered screen use populations, 34 of which were included in the meta-analysis. A random-effects meta-analysis revealed significant small/medium (g = .38) cognitive deficits for individuals with disordered screen use behaviours relative to controls. The most affected cognitive domain with a significant medium effect size (g = .50) was attention and focus followed by a significant reduction in executive functioning (g = .31). The classification of disordered screen use behaviours into Internet or gaming categories or the format of cognitive testing did not moderate these deficits. Additionally, excluding disordered social media use in an exploratory analysis had little effect on the observed outcomes. This study highlights a number of methodological considerations that may have contributed to disparate findings and shows that disordered screen use can significantly impact cognitive performance. Recommendations for future research are also discussed. Data for this study can be found at https://osf.io/upeha/ .

Dissociation of prepotent response inhibition and interference control in problematic internet use: evidence from the Go/No-Go and Flanker tasks

BACKGROUND

Problematic Internet Use (PIU), characterized by failures to control the overuse of internet, is associated with a range of functional impairments. However, there is limited research on the specific impact of PIU on inhibitory control functions, particularly in terms of differentiating between prepotent response inhibition and interference control. Therefore, the main objective of this study is to investigate these two components of inhibitory control in individuals with PIU.

METHODS

Thirty participants who met the PIU criteria and 30 control participants were included in the present study. All participants completed the Go/No-Go and Flanker tasks, in which internet-related images and words were used as task stimuli.

RESULTS

In the Go/No-Go task, all participants exhibited poorer performance in inhibiting internet-related stimuli compared to internet-unrelated stimuli, during the No-Go trials. In the Flanker task, results revealed a three-way interaction of Group, Stimulus type and Congruency. Specifically, in the incongruent condition, participants with PIU exhibited slower responses for internet-unrelated targets compared to internet-related targets, whereas no similar effect was observed among individuals with low internet use.

CONCLUSIONS

The findings suggest that difficulties in controlling the interference effect of internet-related information represent a key dysfunction in inhibitory control of PIU.

The neurocognitive correlates of non-substance addictive behaviors

Neurocognitive deficits have been implicated as transdiagnostic risk markers of substance use disorders. However, these have yet to be comprehensively evaluated in other, non-substance addictions. In a large, general community sample (N = 475) the present study evaluated the neurocognitive correlates of problem alcohol use and three non-substance-related addictive behaviors: addictive eating (AE), problematic pornography use (PPU), and problematic use of the internet (PUI), to identify potential shared and distinct neurocognitive correlates. A sample of Australian residents (54.4 % female M[SD] age = 32.4[11.9] years) completed a comprehensive online assessment of neurocognitive tasks tapping into eight distinct expert-endorsed domains purportedly associated with addiction. Multiple linear regressions with bootstrapping were used to examine associations among each addictive behavior of interest and neurocognition, trait impulsivity, and compulsivity, as well as key covariates. Neurocognition was differentially associated with each addictive behavior. None of the neurocognitive domains were significantly associated with problematic alcohol use or AE (p >.05), poorer performance monitoring was significantly associated with higher levels of PPU and PUI (β = -0.10, p =.049; β = -0.09, p =.028), and a preference for delayed gratification was associated with more severe PUI (β = -0.10, p =.025). Our findings have theoretical implications for how we understand non-substance addiction and suggest the need for a more nuanced approach to studying addictive behaviors that take into account the underlying neurocognitive mechanisms associated with each type of addiction.

Longitudinal evidence that Event Related Potential measures of self-regulation do not predict everyday goal pursuit

Self-regulation has been studied across levels of analysis; however, little attention has been paid to the extent to which self-report, neural, and behavioral indices predict goal pursuit in real-life. We use a mixed-method approach (N = 201) to triangulate evidence among established measures of different aspects of self-regulation to predict both the process of goal pursuit using experience sampling, as well as longer-term goal progress at 1, 3, and 6-month follow-ups. While self-reported trait self-control predicts goal attainment months later, we observe a null relationship between longitudinal goal attainment and ERPs associated with performance-monitoring and reactivity to positive/rewarding stimuli. Despite evidence that these ERPs are reliable and trait-like, and despite theorizing that suggests otherwise, our findings suggest that these ERPs are not meaningfully associated with everyday goal attainment. These findings challenge the ecological validity of brain measures thought to assess aspects of self-regulation.

Self-regulation helps people to achieve their goals, and has been studied across modalities. Here, the authors present longitudinal evidence suggesting that common neural and behavioral measures of self-regulation derived from laboratory tasks do not predict everyday goal pursuit.

Effect of a Strategic Physical Activity Program on Cognitive Flexibility among Children with Internet Addiction: A Pilot Study

The purpose of this study was to explore whether a strategic physical activity program can improve cognitive flexibility among children with Internet addiction. Ten school-aged children were recruited by distributing flyers at an elementary school in Taiwan. The participants were screened using the Chinese Internet Addiction Scale. Their executive functions were assessed by a task-switching paradigm and their motor competence was evaluated by the Movement Assessment Battery for Children–Second Edition (MABC-2) before and after a 12-week strategic physical activity intervention (twice per week, 90 min per session). The posttest scores showed significant improvements in accuracy in the pure, mixed, and switch trials and in the manual dexterity and total score of the MABC-2 compared with the pretest scores. Despite the inherited limitations of a single group pretest-posttest design this study employed, the findings shed light on the possibility that a strategic physical activity intervention might be a feasible and effective behavioral approach to enhance cognitive function and motor competence in children with Internet addiction. Further studies including a control group, preferably with a randomized controlled trial design, will be needed to validate the findings.

Single-trial detection of EEG error-related potentials in serial visual presentation paradigm

When the outcome of an event is not the same as expected, the cognitive state that monitors performance elicits a time-locked brain response termed as Error-Related Potential (ErrP).Objective-In the existing work, ErrP is not recorded when there is a disassociation between an object and its description. The objective of this work is to propose a Serial Visual Presentation (SVP) experimental paradigm to record ErrP when an image and its label are disassociated. Additionally, this work aims to propose a novel method for detecting ErrP on a single-trial basis.Method-The method followed in this work includes designing of SVP paradigm in which labeled images from six categories (bike, car, flower, fruit, cat, and dog) are presented serially. In this work, a text (visual) or an audio clip describing the image in one word is presented as the label. Further, the ErrP is detected on a single-trial basis using novel electrode-averaged features.Results -The ErrP data recorded from 11 subjects' have consistent characteristics compared to existing ErrP literature. Detection of ErrP on a single-trial basis is carried out using a novel feature extraction method on two type labeling types separately. The best average classification accuracy achieved is69.09±4.70%and63.33±4.56%for the audio and visual type of labeling the image, respectively. The proposed feature extraction method achieved higher classification accuracy when compared with two existing feature extraction methods.Significance -The significance of this work is that it can be used as a Brain-Computer Interface (BCI) system for quantitative evaluation and treatment of mild cognitive impairment. This work can also find non-clinical BCI applications such as image annotation.

Diminished error-related negativity and error positivity in children and adults with externalizing problems and disorders: a meta-analysis on error processing

BACKGROUND

Deficits in error processing are reflected in an inability of people with externalizing problems to adjust their problem behaviour. The present study contains 2 meta-analyses, testing whether error processing - indexed by the event-related potentials error-related negativity (ERN) and error positivity (Pe) - is reduced in children and adults with externalizing problems and disorders compared to healthy controls.

METHODS

We conducted a systematic search in PubMed (1980 to December 2018), PsycInfo (1980 to December 2018) and Scopus (1970 to December 2018), identifying 328 studies. We included studies that measured error processing using the Eriksen flanker task, the go/no-go task or the stop-signal task in healthy controls and in adults or children with clearly described externalizing behavioural problems (e.g., aggression) or a clinical diagnosis on the externalizing spectrum (e.g., addiction).

RESULTS

Random-effect models (ERN: 23 studies, 1739 participants; Pe: 27 studies, 1456 participants) revealed a reduced ERN amplitude (Hedges' g = 0.44, 95% confidence interval [CI] 0.29 to 0.58) and a reduced Pe amplitude (Hedges' g = -0.27, 95% CI -0.44 to -0.09) during error processing in people with externalizing problems or disorders compared to healthy controls. Type of diagnosis, age and the presence of performance feedback or comorbidity did not moderate the results. The employed cognitive task was a moderator for Pe but not for ERN. The go/no-go task generated a greater amplitude difference in Pe than the Eriksen flanker task. Small-sample assessment revealed evidence of publication bias for both event-related potentials. However, a p curve analysis for ERN showed that evidential value was present; for Pe, the p curve analysis was inconclusive.

LIMITATIONS

The moderators did not explain the potential heterogeneity in most of the analysis, suggesting that other disorder- and patient-related factors affect error processing.

CONCLUSION

Our findings indicate the presence of compromised error processing in externalizing psychopathology, suggesting diminished activation of the prefrontal cortex during performance monitoring.

Event-related potential (ERP) measures of error processing as biomarkers of externalizing disorders: A narrative review

Previous studies have shown that electrophysiological measures of error processing are affected in patients at risk or diagnosed with internalizing disorders, hence, suggesting that error processing could be a suitable biomarker for internalizing disorders. In this narrative review, we will evaluate studies that address the role of event-related potential (ERP) measures of error-processing in externalizing disorders and discuss to what extend these can be considered a biomarker for externalizing disorders. Currently, there is evidence for the notion that electrophysiological indices of error processing such as the error-related negativity (ERN) and error positivity (Pe) are reduced in individuals with substance use disorders, attention-deficit/hyperactivity disorder, and in forensic populations. However, it remains unclear whether this is also the case for other understudied disorders such as behavioral addiction. Furthermore, to fully understand how these deficits affect day to day behavior, we encourage research to focus on testing current theories and hypotheses of ERN and Pe. In addition, we argue that within an externalizing disorder, individual differences in error processing deficits may be related to prognosis and gender of the patient, methodological issues and presence of comorbidity. Next, we review studies that have related treatment trajectories with ERP measures of error processing, and we discuss the prospect of improving error processing as a treatment option. We conclude that ERP measures of error processing are candidate biomarkers for externalizing disorders, albeit we strongly urge researchers to continue looking into the predictive value of these measures in the etiology and treatment outcome through multi-method and longitudinal designs.

Video gaming addiction and its association with memory, attention and learning skills in Lebanese children

BACKGROUND

Examining whether any association exists between addiction to video games and cognitive abilities in children could inform ongoing prevention and management of any possible harm. The objective of this study was to investigate the associations between addiction to video games, and memory, attention and learning abilities among a sample of Lebanese school children.

METHODS

This cross-sectional study, conducted between January and May 2019, enrolled 566 school children aged between 9 and 13 years. Three private schools were chosen conveniently for this study. Students were randomly chosen from the list given by the school administration. The students' parents are those who responded to the questionnaire.

RESULTS

The results showed that higher addiction to video gaming salience was significantly associated with worse episodic memory, problem solving, basic reading skills, written expression skills and worse clinical attention. Higher addiction to video gaming tolerance were significantly associated with worse novel problem solving and worse attention. Higher addiction to video gaming withdrawal were significantly associated with worse attention, factual memory, attention, processing speed, visual spatial organization, sustained sequential processing, working memory, novel problem solving and worse written expression skills.

CONCLUSION

The results suggest a correlation between addiction to video games and worse memory, attention, as well as cognitive and academic abilities among school children. Those findings indicate the need for more extensive research, and serve to highlight vital next steps needed in future papers, such as identifying predicting factors that could aid in early detection of video gaming addiction in children.

7,8-Dihydroxyflavone Attenuates Alcohol-Related Behavior in Rat Models of Alcohol Consumption via TrkB in the Ventral Tegmental Area

Alcohol use disorder (AUD) is a ubiquitous substance use disorder in the world, of which neural mechanisms remain unclear. Alcohol consumption induces neuro-adaptations in the dopaminergic system originating from the ventral tegmental area (VTA), an important brain region for the reward function in AUD. Endogenous brain-derived neurotrophic factor (BDNF)-TrkB implicated in the development of neuroplasticity, including long-term potentiation of GABAergic synapses (LTP _GABA ). We previously found that ethanol blocks LTP _GABA in the VTA, either in vivo or in vitro. 7,8-dihydroflavone (7,8-DHF), a BDNF-mimicking small compound, was recently found to penetrate the blood-brain barrier to mimic the biological role of BDNF-TrkB. In this study, we demonstrate that repeated ethanol consumption (including intermittent and continuous ethanol exposure) results in low expression of BDNF in rat VTA. The amount of ethanol intake enhances significantly in rats with intermittent ethanol exposure after 72 h abstinence. Withdrawal signs emerge in rats with continuous ethanol exposure within 3 days after abstinence. Using behavioral tests, intraperitoneal injection of 7,8-DHF can reduce excessive ethanol consumption and preference as well as withdrawal signs in rats with repeated ethanol exposure. Interestingly, microinjection of K252a, an antagonist of TrkB, into the VTA blocks the effects of 7,8-DHF on ethanol-related behaviors. Furthermore, direct microinjection of BDNF into the VTA mimics the effect of 7,8-DHF on ethanol related behaviors. Taken together, 7,8-DHF attenuates alcohol-related behaviors in rats undergoing alcohol consumption via TrkB in the VTA. Our findings suggest BDNF-TrkB in VTA is a part of regulating signals for opposing neural adaptations in AUD, and 7,8-DHF may serve as a potential candidate for treating alcoholism.

Neurophysiological and Cognitive Correlates of Error Processing Deficits in Internet Gaming Disorder

The ability to detect and correct errors is a critical aspect of human cognition. Neuronal dysfunction in error processing has been reported in addictive disorders. The aim of this study was to investigate neural systems underlying error processing using event-related potentials (ERPs) and current source localization as well as neurocognitive executive function tests in patients with Internet gaming disorder (IGD). A total of 68 individuals (34 patients with IGD and 34 healthy controls [HCs]) were included, and two ERP components, error-related negativity (ERN) and error positivity (Pe), were extracted during a GoNogo task. Patients with IGD exhibited significantly reduced ERN and Pe amplitudes compared with HCs. Standardized low-resolution brain electromagnetic tomography (sLORETA) in between-group comparisons revealed that patients with IGD had decreased source activations of the Pe component in the anterior cingulate cortex (ACC) under the Nogo condition. These ERP changes were associated with deficits in decision-making and response inhibition in IGD patients. The results suggest that IGD may be associated with functional abnormalities in the ACC and alterations in neural activity related to both the early unconscious and the later conscious stages of error processing, as well as deficits in area of decision-making.

Investigation the relationship between internet dependence with anxiety and educational performance of high school students

BACKGROUND

Internet is one of the most advanced modern communication technologies. Despite the positive uses of internet, the existence of extreme behaviors and its harmful consequences has attracted the attention of all. The aim of this study was to determine the relationship between internet addiction with anxiety and educational performance.

MATERIALS AND METHODS

This research is a descriptive correlative study. The statistical population of the study includes a total number of 4401 female students in the high school in the city of Ilam-Iran in the academic year of 2017-2018. The sample size includes353 students estimated using Cochran's formula. They were selected by random cluster sampling. For data collection, the Young's Internet Dependency Questionnaire, Academic Performance Inventory, and Marc et al., anxiety Scale were used. Data were analyzed at the significant level of α = 0.05.

RESULTS

The results showed a positive and significant correlation between internet dependency and students' anxiety (P < 0.01). There is also a negative and significant correlation between internet dependency and academic performance of students (P < 0.01), and also a negative and significant correlation between anxiety and educational performance of students (P < 0.01).

CONCLUSION

On the one hand, the results indicate a high prevalence of internet dependency and its significant relationship with anxiety and academic performance in students, and on the other hand, the negative effect of internet dependency on the students' educational performance. Therefore, it is necessary to design some intervention programs to prevent harm to students who are increasingly interacting with internet. In addition, raising the level of the students' awareness on the complications of internet addiction and the proper use of the internet seems to be necessary.

Error-related negativity predicts failure in competitive dual-player video games

Along with improvement in electroencephalogram (EEG)-measurement technology, limitations on the situations in which data can be recorded are gradually being overcome. EEG measurement in real environments has become increasingly important as a means to monitor brain activity in our daily lives, such as while playing consumer games in the living room. The present study measured brain EEG activity while two players engaged in a competitive consumer baseball game in conditions that closely resembled daily life. The recorded brain activity was thus likely related to natural mental reactions and cognitive function that occur in similar daily life activities. To measure the EEG from participants who freely moved while playing the game, we developed EEG devices that incorporated a wireless time synchronization system using Global Positioning Satellite (GPS) signals. These devices stamped the time obtained from the GPS signals onto each data sample, which was then used to synchronize the data that were recorded by different devices. When the batter in the game swung and missed, the error-related negativity component of the event-related EEG potential was strongly evoked in frontal electrodes of the participant controlling the batter. Furthermore, the error-related negativity was modulated according to who was winning and by how much. Thus, here we have demonstrated "real-world" brain activity using a competitive consumer game, which increases intrinsic participant motivation.

Group independent component analysis reveals alternation of right executive control network in Internet gaming disorder

OBJECTIVE

Previous studies have demonstrated that individuals with Internet gaming disorder (IGD) showed attentional bias toward gaming-related cues and exhibited impaired executive functions. The purpose of this study was to explore the alternations in related functional brain networks underlying attentional bias in IGD subjects.

METHODS

Eighteen IGD subjects and 19 healthy controls (HC) were scanned with functional magnetic resonance imaging while they were performing an addiction Stroop task. Networks of functional connectivity were identified using group independent component analysis (ICA).

RESULTS

ICA identified 4 functional networks that showed differences between the 2 groups, which were related to the right executive control network and visual related networks in our study. Within the right executive control network, in contrast to controls, IGD subjects showed increased functional connectivity in the temporal gyrus and frontal gyrus, and reduced functional connectivity in the posterior cingulate cortex, temporal gyrus, and frontal gyrus.

CONCLUSION

These findings suggest that IGD is related to abnormal functional connectivity of the right executive control network, and may be described as addiction-related abnormally increased cognitive control processing and diminished response inhibition during an addiction Stroop task. The results suggest that IGD subjects show increased susceptibility towards gaming-related cues but weakened strength of inhibitory control.

Increased Insular Cortical Thickness Associated With Symptom Severity in Male Youths With Internet Gaming Disorder: A Surface-Based Morphometric Study

With the rising increase in Internet-usage, Internet gaming disorder (IGD) has gained massive attention worldwide. However, detailed cerebral morphological changes remain unclear in youths with IGD. In the current study, our aim was to investigate cortical morphology and further explore the relationship between the cortical morphology and symptom severity in male youths with IGD. Forty-eight male youths with IGD and 32 age- and education-matched normal controls received magnetic resonance imaging scans. We employed a recently proposed surface-based morphometric approach for the measurement of cortical thickness (CT). We found that youths with IGD showed increased CT in the bilateral insulae and the right inferior temporal gyrus. Moreover, significantly decreased CT were found in several brain areas in youths with IGD, including the bilateral banks of the superior temporal sulci, the right inferior parietal cortex, the right precuneus, the right precentral gyrus, and the left middle temporal gyrus. Additionally, youths with IGD demonstrated a significantly positive correlation between the left insular CT and symptom severity. Our data provide evidence for the finding of abnormal CT in distributed cerebral areas and support the notion that altered structural abnormalities observed in substance addiction are also manifested in IGD. Such information extends current knowledge about IGD-related brain reorganization and could help future efforts in identifying the role of insula in the disorder.

The Neural Correlates of Implicit Cognitive Bias Toward Internet-Related Cues in Internet Addiction: An ERP Study

Internet addiction is a sort of non-psychoactive substance dependence. The Implicit Association Test (IAT) is used to measure implicit cognition. Event-related potential (ERP) is one of the most widely used methods in cognitive neuroscience research to investigate the physiological correlates of cognitive activity associated with processing information. Further investigating the ERP characteristics of implicit cognitive bias in Internet addiction would be helpful in understanding the nature of Internet addiction. This study investigated the ERP characteristics of implicit cognitive bias in Internet addiction. The participants included 60 Internet-addicted individuals (IAG) and 60 normal controls (NCG). All participants were measured with ERPs using the IAT. The results showed that there was a significant difference in the Internet-related IAT effect for reaction times between IAG and NCG, and there were stronger positive implicit associations toward Internet related cues in IAG than NCG. Using P1, N2, P3, and N4 as dependent variables, a mixed repeated-measures analysis of variance (ANOVA) on the mean latencies and mean amplitudes revealed a significant interaction between the groups (IAG vs. NCG) and stimulus condition (compatible trials vs. incompatible trials) for the N2 and P3 amplitudes; the simple effects analysis showed that the N2 and P3 amplitudes were larger under the IAG-compatible trial conditions than under the IAG-incompatible trial conditions. In the IAG group, the positive implicit associations with Internet-related cues elicited larger N2 and P3 amplitudes at the occipital lobe sites. These results indicated that Internet addictive individuals show stronger positive implicit associations toward Internet-related cues, and the positive implicit associations toward Internet-related cues elicited ERP changes at occipital lobe sites.

A trans-diagnostic perspective on obsessive-compulsive disorder

Progress in understanding the underlying neurobiology of obsessive-compulsive disorder (OCD) has stalled in part because of the considerable problem of heterogeneity within this diagnostic category, and homogeneity across other putatively discrete, diagnostic categories. As psychiatry begins to recognize the shortcomings of a purely symptom-based psychiatric nosology, new data-driven approaches have begun to be utilized with the goal of solving these problems: specifically, identifying trans-diagnostic aspects of clinical phenomenology based on their association with neurobiological processes. In this review, we describe key methodological approaches to understanding OCD from this perspective and highlight the candidate traits that have already been identified as a result of these early endeavours. We discuss how important inferences can be made from pre-existing case-control studies as well as showcasing newer methods that rely on large general population datasets to refine and validate psychiatric phenotypes. As exemplars, we take 'compulsivity' and 'anxiety', putatively trans-diagnostic symptom dimensions that are linked to well-defined neurobiological mechanisms, goal-directed learning and error-related negativity, respectively. We argue that the identification of biologically valid, more homogeneous, dimensions such as these provides renewed optimism for identifying reliable genetic contributions to OCD and other disorders, improving animal models and critically, provides a path towards a future of more targeted psychiatric treatments.

Performance monitoring in nicotine dependence: Considering integration of recent reinforcement history

INTRODUCTION

Impaired monitoring of errors and conflict (performance monitoring; PM) is well documented in substance dependence (SD) including nicotine dependence and may contribute to continued drug use. Contemporary models of PM and complementary behavioural evidence suggest that PM works by integrating recent reinforcement history rather than evaluating individual behaviours. Despite this, studies of PM in SD have typically used indices derived from reaction to task error or conflict on individual trials. Consequently impaired integration of reinforcement history during action selection tasks requiring behavioural control in SD populations has been underexplored.

METHODS

A reinforcement learning task assessed the ability of abstinent, satiated, former and never smokers (N=60) to integrate recent reinforcement history alongside a more typical behavioural index of PM reflecting the degree of reaction time slowing following an error (post-punishment slowing; PPS).

RESULTS

On both indices there was a consistent pattern in PM data: Former smokers had the greatest and satiated smokers the poorest PM. Specifically satiated smokers had poorer reinforcement integration than former (p=0.005) and never smokers (p=0.041) and had less post-punishment slowing than former (p<0.001), never (p=0.003) and abstinent smokers (p=0.026).

CONCLUSIONS

These are the first data examining the effects of smoking status on PM that use an integration of reinforcement history metric. The concordance of the reinforcement integration and PPS data suggest that this could be a promising method to interrogate PM in future studies. PM is influenced by smoking status. As PM is associated with adapting behaviour, poor PM in satiated smokers may contribute towards continued smoking despite negative consequences. Former smokers show elevated PM suggesting this may be a good relapse prevention target for individuals struggling to remain abstinent however prospective and intervention studies are needed. A better understanding of PM deficits in terms of reinforcement integration failure may stimulate development of novel treatment approaches.

Working memory, executive function and impulsivity in Internet-addictive disorders: a comparison with pathological gambling

OBJECTIVE

The purpose of the present study was to test whether individuals with Internet addiction disorder (IAD) presented analogous characteristics of working memory, executive function and impulsivity compared with pathological gambling (PG) patients.

METHODS

The subjects included 23 individuals with IAD, 23 PG patients and 23 controls. All of the participants were measured with the digit span task, Wisconsin Card Sorting Test, go/no-go task and Barratt Impulsiveness Scale-11 (BIS-11) under the same experimental conditions.

RESULTS

The results of this study showed that the false alarm rate, total response errors, perseverative errors, failure to maintain set and BIS-11 scores of both the IAD and PG groups were significantly higher than that of the control group. In addition, the forward scores and backwards scores, percentage of conceptual level responses, number of categories completed and hit rate of the IAD and PG groups were significantly lower than that of the control group. Furthermore, the false alarm rate and BIS-11 scores of the IAD group were significantly higher than those of PG patients, and the hit rate was significantly lower than that of the PG patients.

CONCLUSIONS

Individuals with IAD and PG patients present deficiencies in working memory, executive dysfunction and impulsivity, and individuals with IAD are more impulsive than PG patients.

Impaired inhibition and working memory in response to internet-related words among adolescents with internet addiction: A comparison with attention-deficit/hyperactivity disorder

Impairments in response inhibition and working memory functions have been found to be closely associated with internet addiction (IA) symptoms and attention-deficit/hyperactivity disorder (ADHD) symptoms. In this study, we examined response inhibition and working memory processes with two different materials (internet-related and internet-unrelated stimuli) among adolescents with IA, ADHD and co-morbid IA/ADHD. Twenty-four individuals with IA, 28 individuals with ADHD, 17 individuals with IA/ADHD, and 26 matched normal controls (NC) individuals were recruited. All participants were measured with a Stop-Signal Task and 2-Back Task under the same experimental conditions. In comparison to the NC group, subjects with IA, ADHD and IA/ADHD demonstrated impaired inhibition and working memory. In addition, in comparison to internet-unrelated conditions, IA and co-morbid subjects performed worse on the internet-related condition in the Stop trials during the stop-signal task, and they showed better working memory on the internet-related condition in the 2-Back Task. The findings of our study suggest individuals with IA and IA/ADHD may be impaired in inhibition and working memory functions that might be linked to poor inhibition specifically related to internet-related stimuli, which will advance our understanding of IA and contribute to prevention and intervention strategies.

Neuroscience of Internet Pornography Addiction: A Review and Update

Many recognize that several behaviors potentially affecting the reward circuitry in human brains lead to a loss of control and other symptoms of addiction in at least some individuals. Regarding Internet addiction, neuroscientific research supports the assumption that underlying neural processes are similar to substance addiction. The American Psychiatric Association (APA) has recognized one such Internet related behavior, Internet gaming, as a potential addictive disorder warranting further study, in the 2013 revision of their Diagnostic and Statistical Manual. Other Internet related behaviors, e.g., Internet pornography use, were not covered. Within this review, we give a summary of the concepts proposed underlying addiction and give an overview about neuroscientific studies on Internet addiction and Internet gaming disorder. Moreover, we reviewed available neuroscientific literature on Internet pornography addiction and connect the results to the addiction model. The review leads to the conclusion that Internet pornography addiction fits into the addiction framework and shares similar basic mechanisms with substance addiction. Together with studies on Internet addiction and Internet Gaming Disorder we see strong evidence for considering addictive Internet behaviors as behavioral addiction. Future research needs to address whether or not there are specific differences between substance and behavioral addiction.

Internet addictive individuals share impulsivity and executive dysfunction with alcohol-dependent patients

Internet addiction disorder (IAD) should belong to a kind of behavioral addiction. Previous studies indicated that there are many similarities in the neurobiology of behavior and substance addictions. Up to date, although individuals with IAD have difficulty in suppressing their excessive online behaviors in real life, little is known about the patho-physiological and cognitive mechanisms responsible for IAD. Neuropsychological test studies have contributed significantly to our understanding of the effect of IAD on the cognitive function. The purpose of the present study was to examine whether Internet addictive individuals share impulsivity and executive dysfunction with alcohol-dependent individuals. Participants include 22 Internet addictive individuals, 22 patients with alcohol dependence (AD), and 22 normal controls (NC). All participants were measured with BIS-11, go/no-go task, Wisconsin Card Sorting Test, and Digit span task under the same experimental condition. Results showed that Barratt impulsiveness scale 11 scores, false alarm rate, the total response errors, perseverative errors, failure to maintain set of IAD and AD group were significantly higher than that of NC group, and hit rate, percentage of conceptual level responses, the number of categories completed, forwards scores, and backwards scores of IAD and AD group were significantly lower than that of NC group, however, no differences in above variables between IAD group and AD group were observed. These results revealed that the existence of impulsivity, deficiencies in executive function and working memory in an IAD and an AD sample, namely, Internet addictive individuals share impulsivity and executive dysfunction with alcohol-dependent patients.