Attentional bias for emotional faces in depressed and non-depressed individuals: an eye-tracking study

Current assessment tools for clinicians in mental health evaluation relies mostly on patient self-report and clinician's judgement. Recent studies suggest that affective disorders are correlated to attentional bias for visual information. This study used eye-tracking technology to measure attentional bias for faces in depressed and non-depressed individuals. The experiment was based on a free-viewing task of pair of faces including 4 types of expressions: neutral, sad, happy and angry. 69 individuals took part in this study. All the participants completed the Beck Depression Inventory II (BDI-II) to evaluate the severity of depressive symptoms. The attention indexes were total time for eye events, total fixation duration, ratio of total fixation and eye events, and fixation duration on each face. The results showed that depressed individuals have a significant (p = 0.005) difference in the total time of eye events (302.4±41.2) compared to non-depressed individuals (331.5±39.3) and revealed a tendency to disengage from emotional stimuli with differences in the total fixation in pair of faces. The study demonstrated that the use of eye-tracking is a valuable tool to asses attentional bias and important technology that could be used to improve diagnosis technics.