A THEORY OF INTELLIGENCE: vision and action in mice (Identity)

by David Turell @, Tuesday, July 03, 2018, 19:04 (169 days ago) @ David Turell

Another study in brain networks, this time in mice seeing patterns and licking:

https://medicalxpress.com/news/2018-07-brain.html

"in a new study in Nature Communications, a team at MIT's Picower Institute for Learning and Memory provides evidence that one crucial brain region called the posterior parietal cortex (PPC) plays an important role in converting vision into action.

"'Vision in the service of action begins with the eyes, but then that information has to be transformed into motor commands," said senior author Mriganka Sur, Paul E. and Lilah Newton Professor of Neuroscience in the Department of Brain and Cognitive Sciences. "This is the place where that planning begins."

"In the new study, the research team pinpointed the exact role of the PPC in mice and showed that it contains a mix of neurons attuned to visual processing, decision-making and action.

"'This makes the PPC an ideal conduit for flexible mapping of sensory signals onto motor actions," said Gerald Pho,

***

"Neurons in the PPC showed more varied responses. Some acted like the visual cortex neurons but most (about 70 percent) were active based on whether the pattern was moving the right way for licking (upward) and only if the nozzle was available. In other words, most PPC neurons were selectively responsive not merely to seeing something, but to the rules of the task and the opportunity to act on the correct visual cue.

"'Many neurons in the PPC seemed to be active only during particular combinations of visual input and motor action," Goard said. "This suggests that rather than playing a specified role in sensory or motor processing, they can flexibly link sensory and motor information to help the mouse respond to their environment appropriately."

"But even the occasional error was instructive. Consider the case when the nozzle was available and the stripes were moving sideways. In that case, a mouse should not lick even though it could. Visual cortex neurons behaved the same way regardless of the mouse's decision, but PPC neurons were more active just before a mouse licked by mistake, than just before a mouse didn't lick. This suggested that many PPC neurons are oriented toward acting.

"Not yet fully convinced that the PPC encoded the decision to lick based on seeing the correct stripe movement, the researchers switched the rules of the task. Now, the nozzle would drip out the reward upon licking to the sideways stripe pattern and emit the bitter liquid when the stripes moved up. In other words, the mouse still saw the same things, but what they meant for action had reversed.

"With the same mice re-trained, the researchers then looked again at the same neurons in the same regions. Visual cortex neurons didn't change their activity at all. Those that followed the upward pattern or sideways pattern still did as before. What the mice were seeing, after all, hadn't changed.

"However, the neural responses in PPC changed along with the rules for action. Neurons that had been activated selectively for upward visual patterns now responded instead to sideways patterns. In other words, learning of the new rules was directly evident in the changed activity of neurons in the PPC. The researchers therefore observed a direct correlate of learning at the cellular level, strongly implicating the PPC as a critical node for where seeing meets acting on that information.

"'If you flipped the rules of traffic lights so that red means go, the visual input would still be driven by the colors, but the linkage to motor output neurons would switch, and that happens in the PPC," Sur said.

"The findings extend earlier results made by other researchers in primates, the researchers wrote, suggesting that mice bear the needed similarity to aid further studies of the PPC.

"'Our understanding of how decisions are computed and visuomotor transformations are made, will be greatly aided by future circuit-level analyses of PPC function in this powerful model system," they concluded."

Comment: More evidence of available network usage. This is a study on the material brain networks, but what is to understood is the immaterial animal conscious soul is hidden in the background running the show.


Complete thread:

 RSS Feed of thread

powered by my little forum