Attentional Bias Of Sleep-related Information And Its Neural Mechanism In Patients With Insomnia

The proportion of patients with insomnia is increasing year by year.Sleep problems are not only medical problems,but also a huge social and economic burden.There are many models about insomnia,among which Harvey’s cognitive model and Espie’s attention-intention-effort path model are widely used.Both models mentioned that insomnia patients’ excessive attention to sleep,bad cognition of sleep,and coping style lead to the decline of sleep quality.Therefore,some researchers began to explore the role of attentional bias in the occurrence and maintenance of insomnia.Attentional bias means that pre-attention processing will lead people to automatically capture relevant information prematurely even without consciously acquiring information.It mainly includes three components: attentional relief difficulty,attentional avoidance,and attentional enhancement.Sleep-related attentional bias refers to the tendency to selectively pay attention to sleep-related cues,which is related to the top-down and bottom-up processing mechanisms of attention.Some previous studies suggest that the attentional bias of insomnia patients may be related to the top-down dysregulation,but there is no relevant research to verify it at present.There are very little researches on the brain mechanism of attentional bias of insomnia patients.Due to the gap in the research field,the understanding of attentional bias in patients with insomnia is not comprehensive,so this study will explore the above issues through two experiments.In Experiment 1,we used a modified version of the spatial cues task to explore sleep-related attentional bias and its components in patients with insomnia,using sleep-related negative emotion pictures and non-sleep-related negative emotion pictures as experimental materials.The insomnia patients were all from the outpatient department of the sleep department of a hospital in Chongqing.The healthy control group came from the local school and the community.The insomnia group and the control group had 31 people in each group.All participants completed the Pittsburgh Sleep Quality Index Questionnaire(PSQI),insomnia Severity Index(ISI),Self-rating Depression Scale(SDS),Self-rating Anxiety Scale(SAS),The hyperarousal Scale(HAS),Fatigue Severity Scale(FSS),Epworth Sleepiness Scale(ESS),etc.Questionnaire information and behavioral testing of spatial clue tasks.The results showed that:(1)there was attentional bias to sleep-related negative pictures in the insomnia group,which showed attentional avoidance to sleep-related negative pictures;(2)The score of attentional orientation was negatively correlated with depression,anxiety,sleep-related quality index and sleep severity index,and the higher the score of sleep quality and emotional state,the lower the score of attentional orientation;(3)Emotional state and sleep quality were positively correlated with arousal state.In Experiment 1,we found that compared with the healthy control group,insomnia patients showed attention avoidance to the negative emotion pictures related to sleep,which was not consistent with the results of previous studies.Therefore,the top-down regulation imbalance of insomnia patients does not apply to the findings of this study.The two critical networks for attentional bias are the dorsal attentional network,which is mainly responsible for top-down attentional regulation,and the ventral attentional network,which is mainly responsible for bottom-up attentional regulation.When the imbalance between top-down attentional regulation and bottom-up attentional regulation occurs,the contention for attentional resources may lead to attentional bias.At the same time,some scholars found that the connectivity between the dorsal attention network and the sensorimotor network of individuals with emotional neglect was enhanced.Resting-state functional connectivity data also showed an inverse correlation between dorsal attention and default mode network,which may reflect the spontaneous fluctuation between external and internal focused attention.Therefore,in Experiment 2,resting-state magnetic resonance imaging was used to explore the changes of brain network activity and functional connectivity in patients with insomnia,and Pearson correlation coefficient was used to calculate the relationship between the above indicators and attention bias score.The results showed that:(1)the activity intensity of subcortical network(SC)of insomnia patients was lower than that of the control group;(2)the network connection between visual network(VS)and sensorimotor hand network(SH)of insomnia patients was lower;(3)there was a significant negative correlation between visual network and SDS score,but there was no significant correlation between attention orientation score and brain network activity and functional connectivity.The results of this study indicate that patients with insomnia have sleep-related attentional bias,which is manifested as attention avoidance.Although the neural mechanism of attention bias in patients with insomnia has not been found,this study provides a new research idea for attention bias in patients with insomnia.