Playing video games and surfing the internet results in dopamine being released by the presynaptic neuron into the synapse where it's received by the receptors on the surface of the postsynaptic neuron.
This is the part of the brain that transmits pleasure. It is the same pathway that is present when someone becomes intoxicated with substances.
Why is dopamine a problem?
It is not a problem when it rewards healthy behavior. But when the pleasurable activity is done excessively for hours on end, it can become worrisome.
When a brain is used excessively, it gets tired. It needs to save energy. So it does something called downregulation. Downregulation erases some of the dopamine receptors on the surface of the postsynaptic cell. The longer an activity continues, the more downregulation occurs.
The result? There are now fewer receptors to catch dopamine. Thus, the user has created a tolerance. He or she now requires MORE dopamine to acquire the same amount of pleasure. This is a reason why people who play video games for hours and hours may not experience as much pleasure in their everyday activities.
Furthermore, since the child now has fewer receptors for dopamine, he/she is actively absorbing less of it. This is called withdrawal. During this time you will likely see the child going through moodiness, irritability, and anxiety.
"You can think of dopamine as the driver of the brain, and you can think of the prefrontal cortex as the brakes. And when we’re going after what we want, for example, when we are playing Minecraft for hours on end, it’s like stepping on the gas. But if a parent comes up and says it’s time to do your homework, you have to stop playing Minecraft; we have to step on the breaks. Our brake is our prefrontal cortex, which sort of counters the effect of dopamine."— Dr. Clifford Sussman, MD.
Watch full interview here
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