Update: My best current theory [ hasn’t changed in a few months but I figured it might be worth posting ] is that composite smell data [i.e. the better part of smell processing] is passed directly from the olfactory bulb to somewhere in the entorhinal-amygdalar-temporal area, while there are a few scents that function as pheromones in the sense that we have innate responses to the scents as opposed to their associated experiences [ so, skunk and feces as well as the scent of eligible mates ] and data about these scents is relayed by thin, almost invisible projections to the hypothalamus or other nuclei in the “emotional motor system” so the behavioral responses can bootstrap.
Update: My best current theory [ hasn’t changed in a few months but I figured it might be worth posting ] is that composite smell data [i.e. the better part of smell processing] is passed directly from the olfactory bulb to somewhere in the entorhinal-amygdalar-temporal area, while there are a few scents that function as pheromones in the sense that we have innate responses to the scents as opposed to their associated experiences [ so, skunk and feces as well as the scent of eligible mates ] and data about these scents is relayed by thin, almost invisible projections to the hypothalamus or other nuclei in the “emotional motor system” so the behavioral responses can bootstrap.