Researchers from the RIKEN Center for Brain Science (CBS) and collaborators in Japan have found particular neurons in the brain that monitor whether predictions made by fish in fact become a reality. By utilizing a brand-new virtual reality-outfitted aquarium where brain imaging of zebrafish can be done as they find out and navigate through virtual truth cues, scientists found neurons that allow effective risk avoidance and develop a “risk map” in the brain that enables escape to safety.
When real circumstances do not match expectations, the brain creates “forecast mistakes,” which let us know that our expectations were off. Expectations are formed by internal models of the environment, and simply like people, the brand-new study discovered that fish have such models in their brains. The researchers kept track of prediction-error associated brain activity in real-time as zebrafish found out to prevent danger in their tank.
Expectations are formed by internal designs of the environment, and just like people, the brand-new study discovered that fish have such models in their brains. Controling the virtual truth enabled scientists to record brain activity related to prediction mistake– when reality does not match what is predicted or anticipated.
As zebrafish discovered to prevent threat in virtual reality, the time-lapse change in their brain activity was recorded, leading to the discovery of nerve cells that represent the forecast error.
“We believe this population of neurons is encoding a prediction error in the brain, comparing the actual view of their surroundings with the anticipated view that they have discovered would get them to security if they acted in a certain way,” says lead author Makio Torigoe.
Schematic of the setup. Tail motions made by the fish were examined in real-time and the scene projected the fish was adjusted appropriately to make them feel like they were swimming. Manipulating the virtual truth enabled scientists to record brain activity associated to prediction mistake– when reality does not match what is forecasted or anticipated.
Zebrafish are small and transparent, that makes it simple to record the activity of the entire brain. In the experiment, the fish saw a choice between blue or red virtual truth zones as they practically swam and found out to associate the colors of the virtual zones with risk or security. The scientists were particularly interested in a front part of the brain called the telencephalon, which corresponds to the cerebral cortex and other structures in mammals, and which adds to decision-making. As zebrafish discovered to avoid danger in virtual truth, the time-lapse change in their brain activity was tape-recorded, resulting in the discovery of neurons that represent the forecast error.
Distinct active populations of nerve cells emerged as fish started to find out that choosing the virtual route through blue surroundings led to threat and picking the red path meant security. In another modification to the virtual truth area, the landscapes was modified so that it did not alter based on the tail motions of the fish. “We think this population of nerve cells is encoding a prediction error in the brain, comparing the real view of their environments with the predicted view that they have actually learned would get them to safety if they acted in a particular method,” states lead author Makio Torigoe.
” Every animal has to make forecasts for its future based on what it has discovered before,” adds research study team leader Hitoshi Okamoto. “Now we understand how these predictions are compared to what animals in fact come across in the world, and which parts of the zebrafish brain drive the subsequent decision-making.”
Reference: “Zebrafish efficient in generating future state prediction mistake show enhanced active avoidance habits in virtual reality” by Makio Torigoe, Tanvir Islam, Hisaya Kakinuma, Chi Chung Alan Fung, Takuya Isomura, Hideaki Shimazaki, Tazu Aoki, Tomoki Fukai and Hitoshi Okamoto, 29 September 2021, Nature Communications.DOI: 10.1038/ s41467-021-26010-7.
