A tiny selection of the flavor compounds in pumpkin and pumpkin-pie spices is enough to make our brain think, "Ah, pumpkin pie!" when we drink a pumpkin pie latte. Ashley MacKinnon/Flickr hide caption

itoggle caption Ashley MacKinnon/Flickr

Pumpkins for sale at the Mt. Rogers Pumpkin Patch in the a parking lot in Centreville, Va. Paul J. Richards/Getty hide caption

itoggle caption Paul J. Richards/Getty