Dopamine
Any sentence of the type ‘dopamine makes us do this’ is most probably just wrong. At best, it might be a gross simplification.
I find ‘motivation’ to be a loosely defined concept. Or at least I am not aware of a precise and shared definition. Some behavioral measure relative to the initiation of an action might be labelled as measure of ‘motivation’, but imply different physiological processes.
The experiments on mice with dopamine KO.
Dopamine is a neuromodulator. Dopamine is a signal.
The reward pathway in the brain. Prefrontal cortex. Lymbic system (nucleus accumbens, ventral tegmental area)
Homeostasis as a general mechanism in multiple brain functions?
We are wired for survival in a word of scarcity. Our brains are effectively mismatched to the world that we live in.
Symptoms of withdrawal: anxiety, irritability, insomnia, depression, craving.
Our brain confuses ricreational stimuli with ‘natural stimuli’ necessary for survival. Natural rewards require a lot of upfront effort, we do a lot of work, and we get a little bit of reward, dopamine. Modern recreational substances or devices gives us veryu potent dopamine release with little efforts, which is not what our brain evolved with.
The experiment of the mice and the cocaine: with a extreme stressor they go back to pressing the lever. Our brain tells us go do that behavior that gives you dopamine, because I want to be relieved of that stress.
HALT: hungry, angry, lonely, tired. These are four of the main stress factors. They are so obvious, that you might neglect them.
https://youtu.be/R6xbXOp7wDA?t=3200