Methods for Managing Intrusive Thoughts

In EXP-G, exposure proceeded hierarchically from mildly, to moderately, to highly intense stimuli so that exposure intensity gradually built between (but not within) sessions.

In EXP-V, exposure stimuli were chosen at random (i.e., pieces of paper with exposure stimuli written on them were pulled randomly from an opaque container) so that mild, moderate, and high intensity exposures could occur in any order during any of the sessions (the participant was not informed which level was coming next). This aimed to maximize (a) uncertainty, (b) variability in exposure intensity, and (c) variability in corresponding physiological arousal.