3 ms·
Very interesting: > “Dopamine encodes what are called reward-prediction errors – the ongoing difference between reward expectations and the actual rewards expe
by sawwit 11y ago
Very interesting:
> “Dopamine encodes what are called reward-prediction errors – the ongoing difference between reward expectations and the actual rewards experienced,” Montague said. “From just dopamine signals, we can see when a person expects a reward and whether the person receives the reward. But in our most recent study, we found this earlier model of reward-prediction error to be incomplete. Rather, dopamine pulses appear to combine information about what might have happened with information about what actually happened. This is an entirely new way of viewing the role of dopamine signaling in the human brain.” The idea that “what could have been” is part of how people evaluate actual outcomes is not new. But no one expected that dopamine would be doing the job of combining this information in the human brain. “We married two known computational models into something new,” Montague said. “In doing so, we found dopamine tracking and combining two streams of information into one chemical pulse.”
- austinjp 11y agoDopamine as the mediator molecule foe comparison of actual vs expected experiences, very interesting indeed. Seems to add a tiny sliver more evidence to my strong suspicion that the brain contains "emulators", the output from which arrives milliseconds before perception arrives from The Real World, allowing for pseudo-Bayesian updating of the emulator(s), and of the whole-brain representation of the world, it's effect on us, and our effect on it. I come to this from a neuromusculoskeletal perspective, which is where I first started reading about emulators. But I suspect they're a brain-wide phenomenon, accounting for all sorts of oddness, including apparent "lag" in consciousness. More in my previous comments https://news.ycombinator.com/item?id=9931041 https://news.ycombinator.com/item?id=9931041
- amelius 11y agoBy "emulators", do you perhaps mean "predictors"?
- Phemist 11y agoThis view is quite common in computational neuroscience. Rather than calling it Real World emulators, they call it predictive coding[1][2]. Models that are able to predict statistical properties of "percepts", are able to store these percepts in a much smaller coding scheme (information-wise). These models generate predictions continuously (or emulate the Real World), and only update themselves if supplied with sufficiently contrasting information. 1. http://www.ncbi.nlm.nih.gov/pubmed/10195184 http://www.ncbi.nlm.nih.gov/pubmed/10195184 2. https://en.wikipedia.org/wiki/Bayesian_approaches_to_brain_function https://en.wikipedia.org/wiki/Bayesian_approaches_to_brain_f...