Time course of attention bias in face recognition of patients with depression

Objective To explore the characteristics of cognitive processing over time in recognition of different emotional faces in patients with depression. Methods Totally 29 patients with depression(patient group) and 30 normal control (control group)were selected.Subjects freely viewed positive, sad, threatening and neutral facial stimuli.Eye movement data were collected during the process of watching, and the differences of attention bias in time when the two groups of subjects recognized the four emotional faces were compared.The temporal variation trend of attention between the two groups was analyzed. Results There was no significant difference in the fixation duration between the patient group and the control group in 0-2 s((10.39±1.83)ms, (9.63±1.28)ms), 2-4 s((12.61±2.34)ms, (11.21±3.00)ms), 4-6 s ((12.26±3.11)ms, (10.47±4.06)ms)(all P>0.05). Within 6-8 s((12.64±3.42)ms, (8.90±4.02)ms), 8-10 s((12.55±4.19)ms, (9.36±4.02)ms), the fixation duration in the patient group was significantly longer than that in the control group (P<0.01). The fixation time of the positive faces in the patient group in 0-2 s ((12.07±2.65)ms, (14.50±3.54)ms), 2-4 s((10.69±3.26)ms, (14.66±5.25)ms), 4-6 s((10.11±4.24)ms, (15.43±8.02)ms), 6-8 s((9.39±5.12)ms, (16.88±9.60)ms), 8-10 s ((9.45±4.94)ms, (16.63±10.15)ms) was significantly lower than that in the control group (all P<0.01). Conclusion Patients with depression tend to pay attention to negative stimuli in the later stage of cognitive processing, while the attention to positive stimuli decreases in the early stage of cognitive processing.Cognitive processing of emotional stimuli in patients with depression is manifested as increased attention duration of negative stimuli and decreased attention duration of positive stimuli. Key words: Depression; Attention bias; Face recognition; Eye movement