Abstract The present study examined patterns of electrocortical and heart rate activity in obsessive-compulsive (OC) patients, and both high and low trait anxious control groups. Physiological patterns were examined in light of an intake-rejection attentional paradigm. For each group, electrocortical and cardiac activity were recorded during conditions of mental rest and mental activity requiring the internal versus external processing of information. The pattern of heart rate activity observed in the present study validated the choice of tasks used to examine intake and rejection attentional processes. Overall, the study reported three major findings. First, at baseline, both OC patients and high trait anxious subjects showed a pattern of activity in their EEG spectrum that differed significantly from low trait anxious subjects. Second, similar heart rate differences for the intake and rejection tasks were detected in all three groups. Third, EEG patterns unique to OCs were evidenced in the frontal region during intake and rejection tasks.