Impaired disengagement of attention from computer-related stimuli in Internet Gaming Disorder: Behavioral and electrophysiological evidence

BACKGROUND AND AIMS

Attentional biases contribute to the maintenance of addictive behaviors. For the problematic use of online gaming - recognized as Internet Gaming Disorder (IGD) - first evidence points to a bias towards in-game stimuli. This study aimed to provide behavioral and electrophysiological evidence for a generalized bias towards computer-related stimuli, and to identify the specific attentional processes contributing to this bias: facilitated attention deployment, impaired disengagement or failed suppression.

METHOD

Twenty participants with IGD and 23 casual gamers performed a visual search task with photographs of real-world objects. Either the target or a to-be-ignored distractor was addiction-relevant (computer-related), whereas all other items were addiction-irrelevant (related to cars or sport). Event-related potential components associated with facilitated attentional deployment to the target (NT), its post-selection processing (SPCN), and suppression of irrelevant information (PD) were analyzed.

RESULTS

Unlike casual gamers, gamers with IGD exhibited prolonged reaction times and increased SPCN amplitudes for computer-related stimuli, reflecting their continued attentional processing. At the individual level, larger SPCN amplitudes were associated with longer delays in reaction time.

DISCUSSION AND CONCLUSIONS

This pattern of results indicates that the disengagement of attention from computer-related stimuli is impaired in IGD. More generally, our findings demonstrate that conditioning processes occur in IGD, and thus open up new avenues for treatment.

Acute Exposure to the Cold Pressor Stress Impairs Working Memory Functions: An Electrophysiological Study

The results of previous literature focusing on the effects of acute stress on human working memory (WM) are equivocal. The present study explored the effects of acute stress on human WM processing using event-related potential (ERP) techniques. Twenty-four healthy participants were submitted to stressful treatments and control treatment at different times. Cold pressor stress (CPS) was used as stressful treatment, while warm water was used as the control treatment before the WM task. Exposure to CPS was associated with a significant increase in blood pressure and salivary cortisol. After the 3-min resting period, systolic blood pressure (SBP) and diastolic blood pressure (DBP) for the CPS session significantly increased relative to the control treatment session (all p ≤ 0.01), and data also showed a significant increase of 20-min post-treatment cortisol concentration (p < 0.001) for CPS. Data from the CPS session showed significantly longer reaction times, lower accuracy, and WM capacity scores than that of the control treatment session. Interestingly, a difference between the two sessions was also found in N₂pc and the late contralateral delay activity (late CDA) components. Specifically, although non-significant main effects of treatment were found for N₂pc amplitudes, there was a significant interaction between treatments and stimuli conditions (processing load) [F _(2,46) = 3.872, p = 0.028, η2 p = 0.14], which showed a pronounced trend toward equalization of N₂pc amplitude across stimuli conditions during the CPS session clearly different from that of control treatment. As for amplitudes for late CDA, a nearly significant main effect of Treatment was found (p = 0.069). That is, the mean amplitude of the late CDA (-2.56 ± 0.27) for CPS treatment was slightly larger than that (-2.27 ± 0.22) for warm water treatment. To summarize, this study not only reported performance impairments in the WM task during CPS trials but also provided high temporal resolution evidence for the detrimental effects of acute stress on processes of information encoding and maintenance.

Spatially Specific Attention Mechanisms Are Sensitive to Competition during Visual Search

Extensive studies have focused on selection mechanisms during visual search. One important influence on these mechanisms is the perceptual characteristics of the stimuli. We investigated the impact of perceptual similarity between targets and nontargets (T-N similarity) in a visual search task using EEG. Participants searched for a predefined target letter among five nontargets. The T-N similarity was manipulated with three levels: high, middle, and low. We tested for the influences of T-N similarity on an ERP (e.g., N2pc) and alpha oscillations. We observed a significant N2pc effect across all levels of similarity. The N2pc amplitude was reduced and occurred later for high similarity relative to low and middle similarities. We also showed that the N2pc amplitude was inversely correlated with the RTs across all similarities. Importantly, we found a significant alpha phase adjustment about the same time as the N2pc for high similarity; by contrast, no such effect was observed for middle and low similarities. Finally, we showed a positive correlation between the phase-locking value and the N2pc—the stronger the alpha phase-locking value, the larger the N2pc, when the T-N similarity was high. In conclusion, our results provide novel evidence for multiple competitive mechanisms during visual search.

Neural Evidence for the Contribution of Active Suppression During Working Memory Filtering

In order to efficiently process incoming visual information, selective attention acts as a filter that enhances relevant and suppresses irrelevant information. In this study, we used an event-related potential (ERP) approach with systematic lateralization to investigate enhancement and suppression during encoding of information into visual working memory (WM) separately. We used a change detection task in which observers had to memorize some items while ignoring other items. We found that the to-be-ignored items elicited a PD component in the ERP, suggesting that irrelevant information is actively suppressed from WM. The PD amplitude increased with distractor load and decreased with the ability to group distractors according to Gestalt principles. This suggests that the PD can be used as an indicator of how efficiently items can be suppressed from entering WM. Furthermore, while lateral memory-targets elicited a "traditional" CDA (starting ~300 ms), lateral memory-distractors elicited a sustained positivity contralateral to memory-distractors (CDAp, starting ~400 ms). In sum the results suggest that inhibition of irrelevant information is an important factor for efficient WM and is reflected in spontaneous (PD) and sustained suppression (CDAp).