Using Motion Tracking to Measure Avoidance in Children and Adults: Psychometric Properties, Associations With Clinical Characteristics, and Treatment-Related Change.

Avoidance is implicated in many areas of psychopathology, particularly anxiety and its disorders. Accurate, reliable, valid, and objective measurement of avoidance behavior poses methodological challenges. Two key technological advances, increased computing power and the advent of motion-tracking technology, offer novel solutions to these challenges. We describe a series of three studies using a novel motion-tracking system to measure avoidance in children and adults. The first study examined behavioral avoidance of spider stimuli in large samples of children and adults (N = 200 each; the adults were the mothers of the children). Behavioral avoidance was associated with self-rated fear of spiders and increased state anxiety from before to after the task. The second study examined avoidance of threat faces in children and adults (N = 35 each; the adults were the mothers of the children) and test-retest reliability in the adults. Avoidance of threat faces was associated with broadband anxiety symptom severity. Test-retest correlations in behavioral avoidance measured 6 weeks apart was high and significant. The third study examined behavioral avoidance of spiders in clinically anxious children (N = 25) before and after cognitive-behavioral therapy for childhood anxiety disorders. Behavioral avoidance was significantly reduced following cognitive-behavioral therapy and reduction in behavioral avoidance correlated significantly with improvement in child-rated anxiety symptoms. Taken together, these studies provide strong support for the promise of motion-tracking technology to enable a new phase of behavioral avoidance research with sensitive, valid, reliable, and cost- and time-effective measurement of behavioral avoidance across the lifespan.