Aug 29, 2022 08:37 PM
https://www.advancedsciencenews.com/is-d...d-hormone/
EXCERPTS: . . . Dopamine, a brain chemical that has often been touted to be the “reward neurotransmitter”, has been known to play a role in learning these cue-reward associations. But what happens if a reward precedes a cue? Scientists have now found that spikes in dopamine might be important for learning these more complex associations as well.
In a study published in Current Biology, Benjamin Seitz and colleagues from the University of California, Los Angeles used rats to show that dopamine spikes in an area of the midbrain were important for the animals to learn the “backward associations” between two events, where a cue follows a reward.
But why is this important to study? We know it is essential to learn standard cue-reward associations — we need to learn what comes before a reward so that we can try and seek out those things.
“For instance, if you see a tree and then find some food, you want to learn that tree-food connection and seek out more trees,” said Seitz, lead author of the paper, in an email.“But sometimes you stumble upon something rewarding (like food) and then notice a stimulus (the tree).
[...] While control rats tended to press on the lever that would give them the alternate reward, the rats with inactivated midbrain dopamine neurons showed no such bias, indicating that intact dopamine activity is essential for the learning of reward-cue associations.
According to Seitz, “The most important implication of this finding is that it forces us to recognize that a very simple and elegant model of how dopamine contributes to learning is incorrect. We used to think that spikes in midbrain dopamine were assigning value to the things that came before reward. Our findings suggest dopamine is involved in much more complex learning scenarios and might in some situations, like Schizophrenia, be causing subjects to over-learn connections between stimuli that don’t functionally need to be connected.” (MORE - missing details)
EXCERPTS: . . . Dopamine, a brain chemical that has often been touted to be the “reward neurotransmitter”, has been known to play a role in learning these cue-reward associations. But what happens if a reward precedes a cue? Scientists have now found that spikes in dopamine might be important for learning these more complex associations as well.
In a study published in Current Biology, Benjamin Seitz and colleagues from the University of California, Los Angeles used rats to show that dopamine spikes in an area of the midbrain were important for the animals to learn the “backward associations” between two events, where a cue follows a reward.
But why is this important to study? We know it is essential to learn standard cue-reward associations — we need to learn what comes before a reward so that we can try and seek out those things.
“For instance, if you see a tree and then find some food, you want to learn that tree-food connection and seek out more trees,” said Seitz, lead author of the paper, in an email.“But sometimes you stumble upon something rewarding (like food) and then notice a stimulus (the tree).
[...] While control rats tended to press on the lever that would give them the alternate reward, the rats with inactivated midbrain dopamine neurons showed no such bias, indicating that intact dopamine activity is essential for the learning of reward-cue associations.
According to Seitz, “The most important implication of this finding is that it forces us to recognize that a very simple and elegant model of how dopamine contributes to learning is incorrect. We used to think that spikes in midbrain dopamine were assigning value to the things that came before reward. Our findings suggest dopamine is involved in much more complex learning scenarios and might in some situations, like Schizophrenia, be causing subjects to over-learn connections between stimuli that don’t functionally need to be connected.” (MORE - missing details)
