Me, I perceive things more like the picture on the left. I know -- I mean, I can tell -- I don't have normal dopamine processing. As an example... The ayuderdic herb, mucuna pruriens, is one of the only things that naturally contains the most direct precursor of dopamine. It has legitimate medical uses. Some people, if they weren't used to it, would find that it made them more than usually cheerful or confident. Some would find that it sent them right over the edge into anxiety, agitation, mania -- like caffeine, but likely worse. (Some of the disorders that frequently show dopamine overactivity: schizophrenia, bipolar disorder, anxiety.) My reaction to mucuna pruriens is that is calming and sometimes sleep-inducing. I consider it a preventative measure when it comes to bad dreams.
Sometimes coffee brings me down, too. Going to sleep on stimulants is not an uncommon reaction... for a person with ADHD. I don't have ADHD, but there are common threads. There's a theory that people with ADHD procrastinate so that they can add excitement to a task, so they can stir up enough stimulants in their brain that they are actually able to do the task. Me, I don't do that. It's when it comes to human relationship, very specifically, that I behave as an underwhelmed person. I have consistently, across most of my life, been attracted to people who are far, far more emotional than the norm, who are simply over the top. I have consistently been attracted to situations -- human situations -- where the stakes were high. My emotions are aroused. My bonding impulses come more strongly into play. Low stakes human situations fail to motivate me to the point where... where I can function.
I think it would fly in the face of logic, for a lot of people, that my reactions to certain substances would be characteristic of the underwhelmed as opposed to the overwhelmed. And yet it seems so obvious to me. I am the polar opposite of the hyperaroused person... when it comes to just strolling around. (Though yes, I do respond in intense, 0 to 90 ways to a very few things -- the same ones, predictably, year in, year out... Hey, do you think the light in the corner stands out maybe even a little more on the picture on the left, where there is so little contrast. maybe that's why I calm a little on stimulants. More of the world starts popping out a little and commanding my interest.)