A variety of human behaviours are controlled and regulated by the “reward system” of the brain. The chemical that plays a crucial role in this system is Dopamine, which releases pleasurable and enforcing feedback in the brain.
What is Dopamine?
Dopamine is a brain chemical neurotransmitter that communicates with and influences the brain’s reward system. It also directs movements and responses so that humans can see the rewards and action in a way that grabs them. A deficit in dopamine leads to Parkinson’s disease or the higher risk to addiction problems.
Investigation of the Substantia Nigra
A region of the brain where dopaminergic neurons or dopamine-carrying neurons are located is called the substantia nigra, a brain structure in the midbrain or the mesencephalon. People suffering from Parkinson’s disease are those with dead dopamine-containing neurons in the substantia nigra.
A recent study conducted by a team of neuroscientists and surgeons at the University of Pennsylvania showed that electrically stimulating the substantia nigra area can effect the learning process. They examined the function of substantia nigra brain structure with the help of patients with Parkinson’s diseases who were undergoing neurological surgery. The research was led by Ashwin Ramayya, Gordon Baltuch and Michael Kahana, psychology and neurology scholars of the University of Pennsylvania.
What the Research entailed
During the trial, the participants who were in the process of getting a deep brain stimulation remedy for Parkinson’s disease were given a computer game to play. They had pairs of objects with different rewards to choose from. The participants made their choice by pushing the button representing each object. When they received a reward, a green screen was shown and the sound of a cash register played, similar to what occurs in a casino when a patron wins.
There is no way that they could tell which one to choose to get a reward. All the actions were based on trial and error. When the participants received the stimulation that followed the reward, they tended to repeat the choice they made that led to the reward. This result continued even though the object with reward was no longer related to the button that was pressed and it led to a lower score in the game when there was stimulation provided.
This study was the first of its kind to demonstrate that electrical stimulation in the dopamine-containing neurons can alter the learning process in humans. One of the researchers concluded that stimulating the area of substantia nigra at the same time when the participants received a reward made them repeat the action that resulted in the rewards. This meant that the midbrain region plays a crucial role in adjusting the associative learning system based on actions.
This finding can be incorporated into clinical remedies to readjust the pathological reward-based learning in patients with drug addiction, substance abuse, or gambling addiction, as well as for those with neurological deficits.
At Learning Discoveries, we offer a range of Neurofeedback and neuromodulation techniques that can indirectly target the substantia nigra to teach the brain to modify its response to addictive substances and pastimes.