Peppermint scent can increase attention and create an arousal response, though not as intensely as ammonia. The smell of peppermint can wake you up because it triggers specific olfactory neurons that communicate with the specific centers of the brain, mainly the amygdala.
"Peppermint is mentioned as a scent that can increase attention and create an arousal response. The podcast suggests the smell of peppermint can wake you up and is good to sniff for focus."