Attempts to increase acetylcholine, norepinephrine, and serotonin using drugs like amphetamine or nicotine paired with a tone did not yield significant changes in neural activity.

“And so I did exactly what you said. I said, "What are the ways to increase acetylcholine norepinephrine serotonin?" Microdialysis made it clear which things do it. Amphetamine, of course, nicotine, all these things, it's very easy. Cocaine, all these things do it. And I did experiment, after experiment, after experiment, after experiment. I still feel bad for the graduate students who did all of those experiments. - Adderall? - Did they... - Did Adderall, did all of them. Paired with a tone, and it just didn't change anything.”