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

Abstract

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.

Keywords: Behavioral addiction; Executive control network; Functional connectivity; Internet gaming disorder; Resting state fMRI.

Figure 1. The brain regions in ECNs and the FC between IGD and HC groups

a, The ROIs that were used in left and right ECNs and the FC calculated among ROIs are displayed. For each ROI, a representative BOLD time course was obtained by averaging the signal of all the voxels within the ROI. The ECN templates were downloaded from Stanford's Functional Imaging in Neuropsychiatric Disorders lab (http://findlab.stanford.edu/functionalROIs.html). b1-b4, The FC values between IGD and HC subjects are displayed in different ECNs. We used four ECNs in our study: LECN, RECN, HECN, and TECN. c, The Stroop effect between IGD and HC groups is displayed.

Figure 2. Correlations between FC in different ECNs and Stroop effect

Left row, correlations between FC in different ECNs and Stroop effect in the total sample are displayed. Right row, correlations between FC in different ECNs and Stroop effect in IGD and HC subjects, separately, are displayed.

Figure 3. Clusters surviving after comparing IGD to HC subjects on Stroop task performance

a, The brain map of surviving clusters when comparing IGD to HC subjects is shown. b1-b5, Beta values of the surviving clusters in incongruent and congruent trials in IGD and HC groups. c, Correlation between Stroop effect and beta values in the five surviving clusters.

Figure 4. Correlations between FC in different ECNs and brain activations in Stroop task

For each ROI, a representative BOLD beta value was obtained by averaging the signal of all the voxels within the ROI. Left row, Correlations between FC and beta values in all decreased ROIs in the total sample are displayed. Right row, Correlations between FC and beta values in all decreased ROIs in IGD and HC subjects, separately, are displayed.