Named for the Wrong Job

Three molecules everyone can name, and the three jobs nobody explained

A course on the thought of The Reward System.

Psychology · Neuroscience

What you will learn

  • Describe what self-stimulation is and why it was read as evidence of a pleasure centre.
  • State what the human patients actually reported, and how it differs from what the name predicts.
  • Recognise that the discoverer moved away from the pleasure reading decades before the field did.
  • Locate the dopamine response in a learned sequence and explain why it moves.
  • State what quantity the response encodes, and show why it is relative rather than absolute.
  • Explain why an uncertain reward produces more anticipatory activity than a guaranteed one.
  • Define harm aversion and distinguish it from a judgement about outcomes.
  • Explain what a second, different drug in a trial rules out that a placebo alone cannot.

Course outline

  1. The Rat That Would Not Stop — The accident that opened this field, the name it was given, and the transcripts that show the name was wrong from the first day.
  2. The Molecule of Almost — Where the dopamine actually shows up in a learned sequence, why the size of the reward turns out not to matter, and why a maybe beats a certainty.
  3. What You Are Willing To Do — The clearest experimental result on serotonin has nothing to do with mood. It is about whether you will punish someone who has treated you unfairly.
  4. The Molecule of Us — The one sold as connection. What it does to how you treat your own group, what it does to how you treat everyone else, and how young this research is.
  5. Not a See-Saw — The picture you were given, the reason it cannot be right, and the picture that replaces it — which you assemble yourself.
  6. What It Actually Predicts About You — One measurable difference between people that is genuinely tied to this machinery — and, beside it, a claim of the same shape that the evidence does not carry.

Works read in this course

  • Pleasures of the Brain
  • Affective Neuroscience
  • Behave
  • Serotonin selectively influences moral judgment and behavior through effects on harm aversion
  • The Molecule of More

Terms introduced

reward prediction error, anticipation, intermittent reinforcement, harm aversion, temporal discounting, neurotransmitter, hormone, self-stimulation

Part of the Simposeum course library.