Language processing in Internet use disorder: Task-based fMRI study

Abstract

Internet use disorder (IUD) is generally conceptualized as a fast-growing behavioral addiction. Several structural and functional brain alterations have been revealed in this condition, but previous behavioral studies indicated that language systems may also be impaired. We used a silent word generation task to induce brain activation in Broca's area and other parts of the language system. Blood-oxygen-level-dependent activation analysis and psychophysiological interaction analysis were applied to assess functional brain changes. IUD was measured by the Problematic Internet Use Questionnaire and two additional questions concerning usage time and subjective rating of addiction. According to our key findings, areas strongly related to the default mode network were altered in IUD during the task. Moreover, Broca's area showed altered functional connectivity with other language network and occipital areas in IUD. These findings may address the neural background of decreased verbal fluency performance previously reported in the literature, and we emphasize that beside the brain's reward and inhibitory control systems, the language system is the next candidate to be involved in the pathogenesis of IUD.

Fig 1. Group level negative associations between BOLD signal changes during verbal fluency task and PIUQ scores (control and total) or Q2 scores (“How much time do you spend on the Internet each day”).

Images were thresholded using clusters determined by Z > 3.1 and a corrected cluster significance threshold of p  =  0.05. Light blue–dark blue colors indicate negative correlations.

Fig 2. Group level negative associations between PIUQ neglect, obsession, total scores, and Q1 (“To what extent are you addicted to the Internet?”) score and the results of psychophysiological interaction analysis.

Images were thresholded using clusters determined by Z > 2.3 and a corrected cluster significance threshold of p = 0.05. Light blue–dark blue colors indicate negative correlations.