Brain activation during odor perception in males and females

Several studies indicate that women outperform men in olfactory identificat ion tasks. The psychophysical data are more divergent when it comes to gend er differences at levels of odor processing which are cognitively less dema nding. We therefore compared cerebral activation with (H2O)-O-15 PET in 12 females and 11 males during birhinal passive smelling of odors and odorless air. The odorous compounds (odorants) were pure olfactory, or mixed olfact ory and weakly trigeminal. Using odorless air as the baseline condition, ac tivations were found bilaterally in the amygdala, piriform and insular cort ices in both sexes, irrespective of the odor. No gender difference was dete cted in the pattern of cerebral activation (random effect analysis SPM99, c orrected p<0.05) or in the subjective perception of odors. Males and female s seem to use similar cerebral circuits during the passive perception of od ors. The reported female superiority in assessing olfactory information inc luding odor identification is probably an effect of a difference at a cogni tive, rather than perceptive level of olfactory processing. NeuroReport 12: 2027-2033 (C) 2001 Lippincott Williams & Wilkins.