Depression has seriously effect on the lives and work of patients as well as their families, and is characterized by the high prevalence, low cure and high recurrence rate. The reason of the difficult treatment to this disease is largely related to that the psychological mechanism of disease is unclear. Negative attention bias is one of the main features of depression, which has important impact on the occurrence, development and prognosis of depression. In this study, we explored the psychological mechanism of negative attention bias in depression by investigating the formation mechanism of negative attention bias and the cognitive control function in the negative attention bias in depression using behavioral and EEG techniques.
The first part explored the negative perception bias and negative attention bias of depression through the face judgement the target detection task. This study found that: (1) Depressive patients have negative perceptual bias. Although the rate of ambiguous faces were perceived as negative in depression was not more than those in healthy, the most difficult judgement of the faces were more sad than those for the healthy. (2) negative attention bias in depression were derived from the combined effect of the facilitation of attention engagement and the difficulty of attention disengagement.
The second part probe the effcet of conflict monitoring function and response suppression function in cognitive control on negative attention bias of depression by Flanker and Stop-signal task. It has shown that: (1) depression were more sensitive to conflict than healthy controls. Because patients are more adept at emotional processing, it was easier to deal with emotional conflict than gender for depression, and healthy control groups show the opposite pattern. Depression had faster negative emotional perception than healthy, specifically, there VPP latency for the positive face processing was earlier than those of negative faces. (2) depression patients need greater efforts to achieve the same processing level of the healthy. Although there was no significant difference between the two groups in reaction time, the N1 amplitude of patients with depression was significantly higher than that of the healthy control group under the stop signal condition.
The factors related to depression were evaluated in the third part. The results had showed that the social support level, the comprehension to social support, the interpersonal relationships, the social emotional experiences, the emotional stability, the personality traits of the individual were significantly related to the severity of depression. When SOA was 100 ms, the grating angle is 10 degrees and the target orientation and space position was consistent, the disengagement index in the target detection task was high related to the severity of depression as well as the other scales scores related to depression. which indicated this index should be expected to a new criteria of depression assessment and screening.
In general, this study supports depression had negative emotional information processing advantages, this processing advantage may resulted to the negative attention bias in depression, but when there was external demand, depression patients could also well process positive emotion, which suggested that it could be expected to alter the negative attention bias of depressed by changing the focus of attention in depression.