488. SALIENCE NETWORK ALTERATIONS RELATED TO PERSONALITY TRAITS IN ADOLESCENTS WITH EXCESSIVE SMARTPHONE USE

Abstract Background In recent days, smartphone usage is inescapable in everyday life and has increased drastically over recent decades not only in adults but also in adolescents. Even though smartphone provides convenience and produces personal pleasure, the potential causable problems due to excessive smartphone use (ESU) of adolescents have been reported continuously. As ESU of adolescents became one of the important social issue, the connection between specific personality traits and ESU is being studied continuously. Aims & Objectives This study explored altered resting state functional connectivity (rsFC) of the salience network in ESU compared to healthy controls (HCs). Furthermore, we investigated whether the altered salience network is related to personality traits and other psychological factors in adolescents demonstrating ESU compared to HCs. Method In this study, 475 adolescents aged 12-18 were recruited through online. Within these participants, 35 adolescents were classified as ESU by using Smartphone Addiction Proneness Scale for Adolescents (SAPS) for Youth assessment. Subsequently, 37 age-matched adolescents of healthy control group were recruited. From these participants four participants from ESU and six participants from HCs were excluded due to psychiatric disorders, IQ below 80 and distorted imaging data. Eventually, 31 PSU adolescents (18 males and 13 females) and 31 HC (20 males and 11 females were included in our analysis. In order to examine the personality traits of the adolescents, Adolescent version of temperament and character inventory (JTCI) was used to measure personality traits in this study. For rsFC analysis, Mid cingulate cortex (MCC) and Insula, which are part of the salience network (SN) was focused brain network in the analysis. Seed to Voxel functional connectivity analysis was analyzed by CONN and statistical analyses was conducted by SPSS. Results In the rsFC, the ESU group showed higher functional connectivity between the left MCC and left insula cortex compared to HCs. In addition, ESU showed higher functional connectivity between the left insula and bilateral precuneus, which is part of the default mode network (DMN). The hyper-connectivity between Insula and precuneus in excessive smartphone used individuals demonstrates enhanced connection between reward sensitivity and self-referential thinking. However, ESU had decreased functional connectivity between the left MCC and both the right and left postcentral gyrus, as well as the right precentral gyrus, in comparison to HCs. Moreover, the negative correlation was revealed between MCC-insula rsFC strength and persistence score of JTCI in ESU group. Mean scores of ESU adolescents were lower in persistence than HCs. This outcome establishes that the higher hyperactivity between MCC and insula correlated with lower persistence in ESU adolescents. Discussion & Conclusions This study suggests that smartphone proneness was associated with low persistence in terms of temperament and was engaged in functional alterations. Hyper-connectivity between the MCC and insula showed dysregulated connectivity within the SN network, while the hyper-connectivity between the insula and precuneus illustrated dysregulated connectivity between SN and DMN. The hyper-connectivity between the MCC and insula in smartphone addiction adolescents suggests that smartphone use is closely linked to emotional rewards, resulting in difficulties in regulating impulsive behavior.