2022, Vol. 26 ›› Issue (29): 4735-4741

Gaze characteristics of emotional faces in depressed patients: a Meta-analysis based on eye movement studies

Xia Haisha1, Li Yuxi2, Liu Xiaobo1, Fan Jin1, Zhang Jiaming1, Gou Xinyun1, Li Juan1, Zheng Zhong3, Jin Rongjiang1   

Abstract: OBJECTIVE: Relevant Meta-analyses have reported that there is a significant negative fixation pattern in depressed patients, but it is unclear about the magnitude of this pattern and the difference in gaze indicators under different stimuli. To this end, the article systematically evaluates the gaze characteristics of eye tracking in patients with depression under different emotional tasks, providing a reference for clinical outcome and prognostic evaluation.
METHODS: PubMed, The Cochrane Library, EMbase, Web of science, CBM, CNKI, WanFang Database, and VIP database were electronically searched to collect case-control studies on eye tracking in depressive patients from their inception to September 5th, 2021. Two researchers independently screened literature, extracted data and the Newcastle-Ottawa Scale was used to evaluate the quality of the included studies. Meta-analysis was performed by using RevMan5.4 software.   
RESULTS: A total of 12 case-control studies were included, in which 231 subjects (depressed patients) were in the case group and 307 in the control group. The Newcastle-Ottawa Scale scores of the included studies were 5 and above, indicating a higher quality of the included studies. The results of Meta-analysis showed that: for different stimulus types, compared with the control group, the fixation duration of depressed patients was significantly reduced under the positive stimulus [Standardized mean difference (SMD)positive=-1.00, 95% confidence interval (CI) (-1.88, -0.12), P=0.03], and was significantly increased under the negative stimulus [SMDnegative=0.77, 95% CI (0.50, 1.04), P < 0.000 01]. There was no significant difference in fixation duration under the neutral stimulus [SMDneutral=-0.17, 95%CI (-0.48, 0.14), P=0.28]. There was no significant difference in the first fixation duration between the case and control groups [SMDpositive=0.18, 95% CI (-0.25, 0.61), P=0.42; SMDneutral=-0.19, 95% CI (-0.46, 0.08), P=0.17; SMDnegative=0.24, 95% CI (-0.04, 0.52), P=0.09]. Compared with the control group, depressed patients showed a significant reduction in the fixation counts under positive and neutral stimuli [SMDpositive=-3.65, 95% CI (-4.59, -2.71), P < 0.000 01; SMDneutral=-1.08, 95% CI (-1.61, -0.56), P < 0.000 1), while the fixation counts in depressed patients increased significantly under negative stimuli [SMDnegative=1.32, 95% CI (0.78, 1.86), P < 0.000 01].   
CONCLUSION: There are significant differences in the fixation patterns between depression and healthy individuals, mainly in terms of fixation duration and fixation count. Future studies can explore more eye movement indicators and characteristics of fixation patterns in depressed patients.
Key words: depression, eye movement, health, fixation duration, fixation count, systematic review, Meta-analysis, case-control study