Attentional biases to emotional information in clinical depression: A systematic and meta-analytic review of eye tracking findings.

BACKGROUND: In the last decade, eye-tracking technology has been increasingly used to investigate attention orientation in depression. The aim of the current review was to summarize the available eye-tracking research specifying the effects of clinical depression on early and late attention allocation during visual perception of emotional material.
METHODS: The literature search identified sixteen relevant publications, including twelve free-viewing studies in which multiple stimulus arrays with images (scenarios) or faces were administered. Meta-analyses were conducted to evaluate the impact of acute depression on attentional maintenance during free viewing as a function of type and emotional quality of stimulus material.
RESULTS: Moderate (to large) differences were observed between depressed and healthy individuals in maintained attention to dysphoric images (Hedges' g = .66) and sad faces (g = .58). Moderate group differences were also revealed for maintained attention to positive images (g = -.51) and happy faces (g = -.54). Age of patients explained between study variance in effect sizes for attention to happy faces. No group differences in initial attention orientation were found. LIMITATIONS: The number of free-viewing studies based on images was low (n=4).
CONCLUSIONS: Our results suggest that clinical depression is characterized by medium-sized increases of attention maintenance for dysphoric and medium-sized decreases for positive stimuli compared to healthy individuals. Therefore, both alterations represent equally important targets for attention modification programs. Depressed patients seem not to manifest abnormalities in early orienting to emotional stimuli. Differences between patients and healthy subjects in attention to positive stimuli may diminish with age.