Big brain evolution: space representation in the brain (Evolution)

by David Turell @, Sunday, February 17, 2019, 21:49 (210 days ago) @ David Turell
edited by David Turell, Sunday, February 17, 2019, 22:04

A sort of GPS is described:

“'It has long been a common prejudice in cognitive science that the brain is either a Turing machine working with symbols or a connectionist system using neural networks.” In Krakow, Gärdenfors pushed against that prejudice. In his talk, “The Geometry of Thinking,” he suggested that humans are able to do things that today’s powerful computers can’t do—like learn language quickly and generalize from particulars with ease (to see, in other words, without much training, that lions and tigers are four-legged felines)—because we, unlike our computers, represent information in geometrical space.

"In a 2018 Science paper, ...Gärdenfors, of the University of Lund, buttressed his idea with recent advances in brain science. He argued that the brain represents concepts in the same way that it represents space and your location, by using the same neural circuitry for the brain’s “inner GPS.”

“'Cognitive spaces are a way of thinking about how our brain might organize our knowledge of the world,” Bellmund said. It’s an approach that concerns not only geographical data, but also relationships between objects and experience. “We were intrigued by evidence from many different groups that suggested that the principles of spatial coding in the hippocampus seem to be relevant beyond the realms of just spatial navigation,” Bellmund said. The hippocampus’ place and grid cells, in other words, map not only physical space but conceptual space. It appears that our representation of objects and concepts is very tightly linked with our representation of space.

"Work spanning decades has found that regions in the brain—the hippocampus and entorhinal cortex—act like a GPS. Their cells form a grid-like representation of the brain’s surroundings and keep track of its location on it. Specifically, neurons in the entorhinal cortex activate at evenly distributed locations in space: If you drew lines between each location in the environment where these cells activate, you would end up sketching a triangular grid, or a hexagonal lattice. The activity of these aptly named “grid” cells contains information that another kind of cell uses to locate your body in a particular place. The explanation of how these “place” cells work was stunning enough to award scientists John O’Keefe, May-Britt Moser, and Edvard Moser, the 2014 Nobel Prize in Physiology or Medicine. These cells activate only when you are in one particular location in space, or the grid, represented by your grid cells. Meanwhile, head-direction cells define which direction your head is pointing. Yet other cells indicate when you’re at the border of your environment—a wall or cliff. Rodent models have elucidated the nature of the brain’s spatial grids, but, with functional magnetic resonance imaging, they have also been validated in humans.

"Recent fMRI studies show that cognitive spaces reside in the hippocampal network—supporting the idea that these spaces lie at the heart of much subconscious processing.


"But the usefulness of a cognitive space isn’t just restricted to already familiar object comparisons. “One of the ways these cognitive spaces can benefit our behavior is when we encounter something we have never seen before,” Bellmund said. “Based on the features of the new object we can position it in our cognitive space. We can then use our old knowledge to infer how to behave in this novel situation.” Representing knowledge in this structured way allows us to make sense of how we should behave in new circumstances.

"Data also suggests that this region may represent information with different levels of abstraction. If you imagine moving through the hippocampus, from the top of the head toward the chin, you will find many different groups of place cells that completely map the entire environment but with different degrees of magnification. Put another way, moving through the hippocampus is like zooming in and out on your phone’s map app. The area in space represented by a single place cell gets larger. Such size differences could be the basis for how humans are able to move between lower and higher levels of abstraction—from “dog” to “pet” to “sentient being,” for example.


"It appears that the hippocampus is able to represent two environments without confounding the two. This property of place cells could be useful for constructing cognitive spaces, where avoiding cross-contamination would be essential. “By connecting all these previous discoveries,” Bellmund said, “we came to the assumption that the brain stores a mental map, regardless of whether we are thinking about a real space or the space between dimensions of our thoughts.'”

Comment: This brain facility was developed before humans. However what our brain can do is develop abstract concepts based on space as the article describes.

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