Eye movement assessment in individuals with social phobia: differential usefulness for varying presentation times?

Visual dot probe tasks are used to examine attentional biases towards threat faces in social phobia. Based on eye movement assessments, short presentation times of stimuli have been proposed to investigate initial attentional processes. However, it remains unclear if eye movements contribute to anxiety related biases as measured in dot probe tasks when presentation times below 200 ms are used. In this study the electrooculogram (EOG) was recorded in a sample of 17 participants with social phobia and 13 controls performing a visual dot probe task in two presentation time conditions. In the 175 ms condition, half of the participants moved their eyes in only 10% of the trials. Significantly more participants moved their eyes in the 600 ms condition and individuals with social phobia directed their gaze more often to the threat faces than to the neutral faces. Eye movement measures were not related to reaction time measures but the number of initial eye movements towards threatening faces correlated with measures of social anxiety. For dot probe paradigms, the additional use of eye movement measures seems to be particularly appropriate for longer presentation times. The dissociation between attentional bias scores as measured with reaction time versus eye movement measures and their relation to different presentation times underlines the need for both measures when conducting visual probe studies.