Memory effects on symptom reporting in a respiratory learning paradigm.

With odors as conditioned stimuli (CSs) and CO2-enriched air as the unconditioned stimulus, participants learned to exhibit respiratory responses and somatic complaints on presentation of only the odor CS+. Studied was whether complaints during CS+-only trials were inferred from the conditioned somatic responses or were based on activated memory of the complaints during acquisition. Participants (N = 56) were either attentionally directed away or not from the complaints during acquisition, and the effects on somatic complaints during test were studied. Respiratory responses, heart rate, and somatic complaints were measured. No physiological conditioning effects were found. However, more complaints were reported to the CS+ than to the CS- odor, but only when the CS+ was foul smelling. This effect was modulated by the attention manipulation, showing that the learned complaints during the test phase were based on memory of the acquisition complaints and not on physiological responses during the test.