Prefrontal cortex responses to game rewards and losses in individuals with Internet Gaming Disorder: Insights from fNIRS during mobile gameplay

Abstract

Aims: This study aimed to explore the brain activity characteristics of individuals with Internet Gaming Disorder (IGD) during mobile gameplay, focusing on neural responses to positive and negative game events. The findings may enhance our understanding of the neural mechanisms underlying IGD.

Methods: Functional near-infrared spectroscopy (fNIRS) was employed to measure hemodynamic responses (HbO/HbR) in the prefrontal cortex of both IGD participants and recreational gaming users (RGU), during solo and multiplayer mobile gameplay.

Results: In solo mode, IGD participants exhibited stronger activation in the dorsolateral prefrontal cortex (dLPFC), frontopolar area (FPA), orbitofrontal cortex (OFC) in response to positive events compared to RGU. Negative events led to reduced activation in the FPA among IGD participants. In multiplayer mode, IGD participants displayed lower activation in the dLPFC and ventrolateral prefrontal cortex (vLPFC), although overall brain response trends to positive and negative events were similar between IGD and RGU.

Conclusions: This study suggests that individuals with IGD exhibit heightened sensitivity to rewards and diminished sensitivity to losses, along with potential impairments in the executive control network. These results contribute to a better understanding of the neural mechanisms of IGD and offer insights for developing targeted interventions aimed at addressing abnormal reward and loss processing.

Keywords: Internet Gaming Disorder; prefrontal cortex; recreational gaming users; reward/loss processing.

Fig. 1.

Experimental procedure and game process (a) Procedure of experiment 1 and experiment 2, participants were in a relatively calm state before engaging in the gaming part, the experimental procedure began by requesting subjects to sit quietly and relax for 3 min. Upon hearing a prompt sound signal, indicated by a “beep,” participants were instructed to pick up their mobile devices and prepare for the game. After that, participants were required to play two rounds of the game, with a break period between rounds. Once participants were ready, they could proceed to the next round until the end of the game. (b) Real experiment process. Honor of Kings, developed and operated by Tencent Games TiMi Studios Group for Android, IOS, and Nintendo Switch platforms. (c) Solo game process, players select their preferred heroes and solo engage in a duel on a small-scale map. The objective of the game is to defeat the opponent and destroy defense towers to achieve victory. (d) Multiplayer game process, players were randomly assigned to teams via an automated matching system. They independently selected their in-game characters and engaged in formal gameplay, participating in multiplayer confrontations on a big-scale map. (e) Schematic representation of the 42-channel fNIRS probe sets placed on a standard brain template. A 3D digitizer (Vpen, Polhemus Patriot) was employed to determine the locations of the Cz, Iz, Nz, AR, and AL points, as well as positions of the probes and each channel. The distribution of channels was as follows: Right dLPFC: Channel 2/3/4/11/12/19/36; Left dLPFC: Channel 5/6/7/14/15/24/41; Right vLPFC: Channel 1/9/10/18/26/27/35; Left vLPFC: Channel 8/16/17/25/33/34/42; FPA: Channel 13/20/21/22/23/28/29/30/31/32; OFC: Channel 37/38/39/40. This setup allowed for comprehensive coverage of the PFC regions, ensuring that data on brain activity could be accurately recorded during the gaming sessions

Fig. 2.

The analytical pipeline of this study (a) Two project members independently conducted frame-by-frame analysis of the participants' game recordings. Subsequently, a third member cross-checked the time points marked. Inconsistencies in the marked time points (with a total frequency of approximately 5.37% across experiments 1 and 2) were reanalyzed to identify the occurrence of positive or negative game events. (b) The coefficient of variation (CV) of each channel was calculated by multiplying the standard deviation of the channel's data by 100 and dividing it by the mean. (c) The threshold for motion artifact correction by channel was set at tMotion = 0.5, tMask = 2.0, STDEV thresh = 16.5, and AMP thresh = 3.5. The concentration signal was then filtered using a band-pass filter with a range of 0.015–0.20 Hz to remove artifacts such as baseline drift and cardiac interference. (d) The data were converted from molar (M) to micromolar (μM) by multiplying by 1 × 10^{^6}

Fig. 3.

HbO/HbR responses during positive and negative game events in solo gameplay (a–d) present the HbO/HbR response t-maps for the IGD and RGU groups during positive and negative events in solo gameplay, respectively. (e) highlights the specific regions of difference, with the dLPFC, FPA, and OFC regions showing significantly stronger HbO responses in the IGD group during positive game events, and the FPA region showing significantly weaker HbO responses in the IGD group during negative game events. (f) in channel 13, as an example, shows a significant interaction. Abbreviations: IGD_N = IGD during negative game event, IGD_P = IGD during positive game event, RGU_N = IGD during negative game event, RGU_P = IGD during positive game event.

Fig. 4.

HbO/HbR responses during positive and negative game events in multiplayer gaming (a–d) present the HbO/HbR response t-maps for the IGD and RGU groups during positive and negative events in multiplayer gameplay, respectively.

Fig. 5.

Linear regression between HbO/HbR responses and IGDT-10 scores during positive/negative game events in solo/multiplayer gameplay (a) In solo gameplay, during positive game events, the HbO/HbR responses in the dLPFC, vLPFC, and FPA regions were positively correlated with IGDT-10 scores. During negative game events, the negative HbR responses in the dLPFC region were positively correlated with IGDT-10 scores. The figure only presents the results for channels 7/8/15. (b) In multiplayer gameplay, during positive game events, the HbO response in the dLPFC and FPA regions and the HbR response in the dLPFC were positively correlated with IGDT-10 scores. During negative game events, the HbR response in the dLPFC region was positively correlated with IGDT-10 scores. The figure only presents the results for channels15/41. These findings underscore the critical role of PFC activity in the neural mechanisms underlying IGD.