Abstract: A well-established cognitive feature of depression involves a working memory bias towards negative stimuli. Due to limited capacity, working memory requires filtering efficiency—a selective mechanism that dynamically coordinates the admission of relevant information and the exclusion of irrelevant input. Whether depression impairs filtering efficiency and subsequently leads to working memory bias remains unclear. According to the subcomponents model of depression, the processing bias towards negative emotional information and mental imagery maintain depressive states. However, researchers have overlooked the role of mental imagery in working memory bias research. Given that mental imagery and working memory share overlapping neural representations in the primary visual cortex, depression likely influences filtering efficiency through its effect on mental imagery.
Depressive tendency, which refers to a subclinical depressive status between clinically diagnosed depression and a healthy state, can predict the onset of depressive disorders two years later. This predictability makes individuals with these tendencies an ideal target for early detection and intervention. Therefore, the present study included three experiments to investigate the moderating role of mental imagery in the relationship between depressive tendency and the filtering efficiency of task-irrelevant emotional stimuli. A filtering change detection task with emotional face stimuli was employed to explore this relationship. In Study 1, participants (n = 108) completed the Center for Epidemiologic Studies Depression Scale (CES-D), the Vividness of Visual Imagery Questionnaire and the filtering change detection task. The experimental design included two emotional filtering conditions (two neutral targets with two positive distractors and two neutral targets with two negative distractors) and two nonfiltering conditions (two neutral targets and four neutral targets). These conditions allowed for exploration of the relationship amongst depression, filtering efficiency across emotional valences and the vividness of mental imagery. Furthermore, the study classified participants into a depressive tendency group (CES-D scores ≥ 16, n = 59) and a control group (CES-D scores < 16, n = 45) to examine the influence of depressive tendency on filtering efficiency. Study 2 (n = 25 in the depressive tendency group, n = 25 in the control group) and Study 3 (n = 24 in the depressive tendency group, n = 25 in the control group) examined the effects of positive and negative mental imagery on filtering efficiency for negative distractors, respectively.
Results showed that depression was negatively associated with mental imagery ability and the filtering efficiency of negative information. Individuals with depressive tendency exhibited lower filtering efficiency for negative distractors than for positive distractors; however, no such difference appeared in the control group. Compared with neutral mental imagery, positive mental imagery increased the filtering efficiency of negative information for individuals with depressive tendency but not for controls. Conversely, negative mental imagery decreased the filtering efficiency of negative information in the control group but did not affect individuals with depressive tendency.
These findings indicate that mental imagery moderates the relationship between depression and the filtering efficiency of task-irrelevant negative information. Specifically, positive mental imagery can guide individuals with depressive tendency to ignore task-irrelevant negative information, thereby improving their filtering efficiency. These findings expand the depression subcomponent model and provide a new perspective for early intervention for individuals at risk of depression.

Key words: depressive tendency, working memory, filtering efficiency, positive mental imagery, negative mental imagery