Abstract:

Mood-congruent cognitive bias (“cognitive bias” for short) is defined as a cognitive processing bias towards negative stimuli in depressed individuals. The cognitive bias mainly includes biased processing in perception, attention, memory and interpretation. We summarized the associated behavioral, electrophysiological and neuroimaging studies in this field and proposed that the severe bias in depressed individuals is characterized by preferring negative stimuli and insufficient processing for positive stimuli. Accordingly, the brain mechanism shows that the limbic system (amygdala) is hyperactive in response to negative stimuli while the striatum is hypoactive in response to positive stimuli; the activation in frontal area is also abnormal. However, there are three problems unsolved in this area: (1) Data indicate that different cognitive biases are correlated with each other (Everaert, 2012), which is currently not clearly understood; (2) The causality between cognitive bias and depression is not clear; (3) Inconsistent results are often achieved in different studies, which is usually interpreted as demographic and methodological issues. We argue the discrepancy of effect sizes of experimental paradigm and the influence of self-relevance materials may also contribute to the inconsistence. Future cognitive bias studies in depression might help for solving these problems.

Key words: mood-congruent bias, depression, perception, attention, memory, interpretation