Impaired inhibitory control in 'internet addiction disorder': a functional magnetic resonance imaging study

Abstract

'Internet addiction disorder' (IAD) is rapidly becoming a prevalent mental health concern in many countries around the world. The neurobiological underpinnings of internet addiction should be studied to unravel the potential heterogeneity in the disorder. The present study examines the neural correlates of response inhibition in males with and without IAD using an event-related functional magnetic resonance imaging (fMRI) Stroop task. The IAD group demonstrated significantly greater 'Stroop effect'-related activity in the anterior and posterior cingulate cortices compared with their healthy peers. These results may suggest diminished efficiency of response-inhibition processes in the IAD group relative to healthy controls.

Figure 1

Activation differences in internet addicts and control groups following incongruent stimuli (p<0.05 corrected and with extent threshold: k>10 voxels.). The figures are shown in different coordinates to give the most complete view of the results.

Figure 2

Left: Correlation between peak ‘Stroop effect’-related ACC activation and reaction time form incongruent trials. Right: Correlation between peak ‘Stroop effect’-related ACC activation and proportion correct for incongruent trials.

Figure 3

Group average hemodynamic response curves generated from 12 IAD subjects and 12 healthy controls. The hemodynamic response function plot described the temporal changes in the activated brain region in anterior cingulated cortex (circled with green in figure 1) after the stimuli onset. The analyses supposed the activation is 0 in the onset of the stimuli and sampled every 2s (TR=2s) in 20 seconds. The plot was automatically created by NeuroElf (www.neuroelf.net).