Biobehavioral assessment of the anxiety disorders: Current progress and future directions

Table 1 Eye-tracking differences across DSM diagnoses

Eye tracker information pertinent to differential diagnosis	Anxiety	Generalized anxiety disorder	Depression	Phobia	SAD	Post-traumatic stress disorder	Obsessive compulsive disorder	Attention-deficit hyperactivity disorder
Attentional Bias (the tendency to attend to certain stimuli at the expense of others)		Tend to focus on threatening stimuli. Selectively attend to more threatening stimuli	Tend to focus on mood-congruent stimuli (e.g., SAD, negative)	Tend to avoid feared stimuli	More sensitive to faces showing emotion over neutral faces	Tend to focus on threatening stimuli	Tend to focus on aversive stimuli
Orienting Bias (faster detection of certain stimuli)	Faster detection of threatening stimuli	Faster detection of threatening stimuli. Orientation to threatening faces before neutral faces	Slower to detect threatening stimuli (compared to anxiety or generalized anxiety disorder)	Faster orientation to feared stimulus		Faster detection of threatening stimuli
Frequency of eye movements	Higher frequency of eye-movements	Higher frequency of eye-movements	Slower frequency of eye movements than in anxiety or generalized anxiety disorder				More fixations during a visual search task than anxiety and nonclinical populations	Higher frequency of eye movements
Engagement/disengagement of stimuli				After detecting feared stimulus, quick disengagement with the stimulus	Takes longer to disengage from a threatening facial expression than other expressions	Do not show the same type of disengagement as people with a phobias
Stimulus avoidance			Lack of interest in positive stimuli - focus instead on mood-congruent stimuli	After detecting feared stimulus - quick disengagement and avoidance of feared stimulus	Avoidance of eye-contact and faces in general, even if faces are pleasant. Correlation between severity of SAD and the amount of gaze avoidance
Fixations, saccades, and pupil dilation	Make less fixations (closer to nonclinical populations) than people with obsessive compulsive disorder during a visual search task		Longer fixations on mood-congruent stimuli than those who have anxiety			Greater pupil dilation in general than nonclinical populations	Longer and more frequent fixations towards aversive stimuli. Deficits in goal-oriented visual tasks (higher error rates, inaccurate eye movements for the specific task)	Premature saccades occur more frequently than in nonclinical populations. Higher error rates on anti-saccades tasks than non-clinical populations

SAD: Social anxiety disorder.