ISSN 0439-755X
CN 11-1911/B

中国科学院心理研究所

• 研究报告 •

### 背外侧前额叶对主动遗忘负性社会反馈的作用：针对抑郁症的TMS研究

1. 1深圳大学心理学院, 深圳 518060
2华中科技大学协和深圳医院, 深圳 518052
3深圳英智科技有限公司, 深圳 518010
4深港脑科学创新研究院, 深圳 518055
5深圳大学磁共振成像中心, 深圳 518060
• 收稿日期:2021-05-05 出版日期:2021-10-25 发布日期:2021-08-23
• 通讯作者: 张丹丹 E-mail:zhangdd05@gmail.com
• 基金资助:
国家自然科学基金面上项目(31970980);国家自然科学基金面上项目(31871115);广东省哲学社会科学规划(GD20CXL08);深港脑科学创新研究院(2021SHIBS0003);广东省科技厅国际科技合作领域项目(2019A050510048)

### The role of dorsolateral prefrontal cortex on voluntary forgetting of negative social feedback in depressed patients: A TMS study

CHEN Yuming1, LI Sijin1, GUO Tianyou1,2, XIE Hui1, XU Feng3, ZHANG Dandan1,4,5()

1. 1School of Psychology, Shenzhen University, Shenzhen 518060, China
2Union Shenzhen Hospital (Nanshan Hospital), Shenzhen 518052, China
3Shenzhen Yingchi Technology Co. Ltd., Shenzhen 518010, China
4Shenzhen-Hong Kong Institute of Brain Science, Shenzhen 518055, China
5Magnetic Resonance Imaging Center, Shenzhen 518060, China
• Received:2021-05-05 Online:2021-10-25 Published:2021-08-23
• Contact: ZHANG Dandan E-mail:zhangdd05@gmail.com

Abstract:

Depression is a common mental disorder characterized by persistent low mood and anhedonia. While healthy people can voluntarily forget unpleasant events, depressed patients cannot or have difficulty in forgetting negative stimuli. Studies focused on healthy population have found that memory suppression is not only associated with decreased neural activation in the hippocampus, but also significantly activates a wide network in the prefrontal cortex, especially the right dorsolateral prefrontal cortex (DLPFC). Meanwhile, studies have demonstrated that depressed participants could not effectively recruit their frontal brain network responsible for inhibition control of negative materials. Thus, the key question of this study is to examine whether an enhancement of the neural activation in DLPFC using transcranial magnetic stimulation (TMS) could improve the ability of voluntary forgetting of negative information in depressed patients.
We recruited a total of 123 participants. Among them, 31 healthy participants were stimulated by TMS at the right DLPFC (right DLPFC-activated controls), 32 patients and 30 patients were stimulated by TMS at the left and right DLPFC respectively (left and right DLPFC-activated patients). The other 30 patients were assigned into a sham TMS group. This study contained three independent variables. The two within-subject variables were TMS (baseline or TMS condition) and directed forgetting instruction (remember or forget), and the between-subject variable was group (left or right DLPFC-activated patient, or right DLPFC-activated control). We focused on the memory suppression of social feedbacks in this study, since social feedback processing plays a vital role in everyday interpersonal activities. Previous studies have found that depressed patients cannot perceive and evaluate social feedbacks accurately and adaptively, which makes negative social experiences being an important inducing factor of depression. Meanwhile, evidence indicates that depressed patients have more deficits in processing social relative to nonsocial information.
Results of the explicit memory test showed that the recall accuracy of social rejection was higher in patients than healthy controls in baseline condition, suggesting that patients had difficulty in voluntarily forgetting negative social feedback. After we used the TMS to activate the left or right DLPFC of participants, we found no significant difference in the recall accuracy of social rejection between the three groups. This result suggested that the ability of memory suppression for negative social feedback was improved by TMS in patients. Moreover, it was also found that patients rated the feedback senders as being more attractive after they had forgotten negative social feedback provided by these feedback senders.
The main contribution of this study is that we first attempt to improve the ability of memory suppression of negative information in depressed patients using the TMS technique. Still now, there have been only two neuroscience studies focusing on the deficits of directed forgetting in depression ( Xie, Jiang, & Zhang, 2018; Yang et al., 2016). Beyond these two studies, we demonstrated a causal relationship between the DLPFC and memory suppression impairment in depressed patients by employing TMS to facilitate the function of DLPFC. Thus, we provide a potential neural target for the clinical treatment of depressed patients with voluntary forgetting deficits. In addition to depression, difficulties in voluntary forgetting is a common problem found in patients diagnosed with post-traumatic stress disorder, anxiety disorder (including obsessive compulsive disorder), schizophrenia and many other mental disorders. Meanwhile, difficulties in forgetting the euphoria or enjoyment coming from drugs or high-calorie foods might be an important reason for the persistence and aggravation of drug addiction and bulimia. Our finding suggests that the right DLPFC may be a potential brain target for the treatment of memory suppression deficits in these disorders. Facilitating the cognitive control of this brain region using the TMS is expected to restore the inhibitory control function of patients and thus significantly improve their voluntary forgetting ability, helping them to relieve symptoms and recover from disorders.