View the original post on Musing.io
It has a part to do with addiction and habits, your brain is plastic and gets affected by everything you do. whenever you do something some neurons fire in a pattern to describe what happens. Thereafter when you try to recall the memory your brain tries to recreate the same firing of neurons to have the same sensation. And provided that you encounter this stimuli a lot you would have better connections between those firing neurons and if the encounter proceed ( rehearsal) your brain would mark that memory important and it would be transfer it to the long term memory through the hippocampus. (this information was from a game theory video and I can not manage to find it)
Habits relay on implicit memory that is "unconscious memory" that uses past experiences to let to remember things without thinking about them, here comes the aforementioned part about earlier about forming memories, as procedural memory( a subset of implicit memory that makes you able to do stuff without thinking about them like walking) is formed by doing something enough times that the neurons gets coded with this information. strengthening synaptic connections between neurons through repeated signals, the difference being that it does not use the hippocampus to be formed as other types of long term memory, proven by the incident that happened to HM, where his hippocampus and other parts of the brain was extracted in an effort to stop seizures,he could not form long term memories,yet his motor systems remembered the tasks he was handled and he improved in them . Thus the procedural memory relaysmore on the basal ganglia and cerebellum.
Habits mainly form due to three part process called "habit loop" where you are cued by something reminding you of what you want to do for example, you want to ride the bike more often so you relate it to groceries. Needing groceries for break fast is the cue. then there is the routine; riding the bike to the grocery shop. after that the dopamine rush for getting your groceries with your bike and not a car.
Do that enough times and a habit would form whenever you want to buy something you would go with your bike without consciously thinking about it. Habits relay in something called the basal ganglia. whenever you enter habit mode your section of the brain responsible for decision making, prefrontal cortex, goes to sleep mode. Resulting in the brain expending less work in your action when doing a habit. Hence you can redirect your mental activity to something else.
Habits as a result becomes an automatic response to the cue, making good habits become a effortless part of out life and bad habits a nuisance to break.
Now there is something called the dopamine pathway, as things that are most difficult to unlearn are habits that release more and more dopamine whenever you practice them. As dopamine is the hormone of "want" that is released when you do something that can prolong you existence or make you feel good, like eating lots of sugar to reward. Then whenever you encounter anything that relates to the habit your brain starts firing dopamine to encourage you to do that action to make you feel better.
What makes you crave even more of the thing you do is that. prolonged exposure to that stimuli would make you brain bored from that stimuli so it would begin to shut down dopamine receptors. Thus you would need more stimuli to reach the same level of dopamine, resulting in you practicing more of what you are addicted to. Since, being exposed to high levels of dopamine leads you to want the same levels.
References
https://www.npr.org/2012/03/05/147192599/habits-how-they-form-and-how-to-break-them
https://www.livescience.com/43595-procedural-memory.html
please inform me if there is any mistakes in that answer