On each test day , participants completed an olfactory detection threshold test for two different odors : ( 1 ) lyral , a synthetic fragrance compound for which patients with schizophrenia have specific olfactory detection threshold deficits , possibly related to decreased cyclic adenosine 3 ' ,5 ' - monophosphate ( cAMP ) signaling ; and ( 2 ) anise , a compound for which olfactory detection thresholds change with menstrual cycle phase in women .