The impact of internet pornography addiction on brain function: a functional near-infrared spectroscopy study

Abstract

Introduction: There is extensive awareness of internet pornography addiction. It not only affects the mental health of adolescents but also promotes criminal activity. However, the impact of internet pornography addiction on functional in the brain remains unclear.

Methods: 16 healthy college students and five college students with severe internet pornography addiction were invited to participate in the experiment and watch a pornographic video. Functional near-infrared spectroscopy (fNIRS) was used to measure the dynamic changes in hemoglobin in the brain during a 10 min session of viewing internet pornography. Participants completed the Stroop Color and Word Task (SCWT) before and after they had watched the video. Facial expressions and life signs were measured continuously during the experiment.

Results: Compared with the group that frequently viewed pornographic videos, the group with low-frequency pornography viewing exhibited enhanced functional connectivity in the inferior prefrontal cortex and pars triangularis of Broca's area in the frontal lobe, the primary somatosensory cortex in the parietal lobe, and the pre-motor and supplementary motor cortices. Moreover, the high-frequency pornography-viewing group exhibited hyperactive parasympathetic activity, more pronounced sexual arousal, and stronger functional connectivity in the dorsolateral prefrontal cortex and frontopolar area. After viewing the pornography, the high-frequency group demonstrated longer reaction times and significantly reduced accuracy while completing the Stroop Color and Word Test (SCWT) compared to the low-frequency group and also their own performance before and after viewing the pornography.

Discussion: This study demonstrated the hyperactive and inhibited brain areas under the impact of pornography video addiction. The results may strengthen our understanding of neurobiology and facilitate the development of prevention policies for adolescents.

Keywords: addiction; brain function; cognition; functional near-infrared spectroscopy (fNIRS); internet pornography.

FIGURE 1

A schematic of experimental procedure.

FIGURE 2

The general workflow of the study.

FIGURE 3

Detailed schematic of the functional near-infrared spectroscopy (fNIRS) layout.

FIGURE 4

Functional connectivity in the low-frequency (A,B) high-frequency groups while they watched a pornographic video.

FIGURE 5

Stroop Color and Word Test (SCWT) results for the low-frequency (A) and high-frequency (B) groups: accuracy (a,c) and response time (b,d) before and after viewing the pornography (*** < 0.01, ns > 0.5).

FIGURE 6

Life signs in the low-frequency (A) and high-frequency (B) groups: (a) diastolic blood pressure, (b) SD of normal-to-normal intervals, (c) percutaneous oxygen saturation, (d) systolic blood pressure, and (e) heart rate (*** < 0.01, ns > 0.5).

FIGURE 7

Facial expressions in the low-frequency (A) and high-frequency (B) groups while they watched pornography. The x-axis represents the groups, and the y-axis represents the mean values (*** < 0.01).