Behavioral And ERPs Study On The Characteristics Of Attentional Bias In Clinically Depressed Patients

Objective:(1)To investigate whether clinically depressed patients show attentional bias and the time characteristics of their attentional bias. (2)To explore the time course of ERPs when clinically depressed patients perform the dot-probe task.Methods:Subjects were required to finish a series of psychological tests,such as Beck Depression Inventory(BDI).In a dot-probe task, affective pictures selected from International Affective Picture System (IAPS)were presented for 100ms or 500ms,and subjects(29 Clinically depressed patients;30 control subjects)were asked to judge where were the probes replacing the pictures,while the ERPs were recorded during the subjects performing the task.The mean reaction latencies were subjected to ANOVA with repeated measures.The ERPs waves under four different conditions were overlapped and averaged separately and then the peak latencies and peak amplitudes of related ERPs components were compared between depression group and control group.Results:(1)Compared to the control subjects,clinically depressed patients got higher scores on the negative coping dimension and its subscales(self-blame,rumination,catastrophizing,and blaming others), while got lower scores on positive coping dimension and its subscale (acceptance,refocusing on planning,positive reappraisal,putting into perspective).(2)The average response latencies made by clinically depressed patients were longer than those made by control participants. When the picture-pairs were displayed for 500ms,the depression group had higher disengaging scores for the negative stimulus compared with the control group.(3)P2 and P3 were elicited by both depression group and control group during performing the dot-probe task.When the affective pictures were presented for 100ms,the P3 peak latencies of depression group were longer than those of control group.Meanwhile,in the parietal region,the P3 peak amplitudes were marginly signifinant lower than those of control group.(4)When the affective pictures were presented for 500ms,the P2 peak amplitudes of depression group were significantly larger than those of control group,and when the probes replacing the positive/negative pictures,but not the neutral pictures,the P2 peak amplitudes under condition of negative pictures were significantly larger than those under condition of positive pictures presented.Conclusions:(1)Clinically depressed patients have difficulty in identifing and describing feelings,and more often use negative coping strategies to regulate emotion,such as self-blame,rumination, catastrophizing and blaming others,while less use positive coping strategies,which suggests that depressed patients have cognitive processing deficit for emotional information and have deficit in emotion regulation.(2)The clinically depressed patients have difficulties in disengaging attention from negative information at 500ms but not at 100ms.(3)The ERPs data suggests that the depression group have attention characteristics different from the control group,no matter whether the affective pictures were presented for 100ms or 500ms.