Hippocampal spatial view cells, place cells, and concept cells: View representations

Abstract

A commentary is provided on issues raised in the Special Issue of Hippocampus (2023) on hippocampal system view representations. First, the evidence for hippocampal and parahippocampal spatial view cells in primates including humans shows that the allocentric representations provided by at least some of these cells are very useful for human memory in that where objects and rewards are seen in the world "out there" is a key component of episodic memory and navigation. Spatial view cell representations provide for memory and navigation to be independent of the place where the individual is currently located and of the egocentric coordinates of the viewed location and the facing direction of the individual. Second, memory and navigation in humans are normally related to the visual cues encoded by spatial view cells that define a location "out there" such as a building, hill, and so forth, not to an unmarked place without local cues and identified only by distant environmental/room cues. Third, "mixed" representations, for example of particular combinations of spatial view and place, can arise if the training has been for only some combinations of place and view, for that is what can then be learned by the hippocampus. Fourth, rodents, with their much less good visual acuity ($1 cycle/ in rats, compared with $60 cycles/ for the human fovea), and rodents' very wide viewing angle for the world ($270 ) might be expected, when using the same computational mechanisms as in primates, to use widely spaced environmental cues to define a place where the rodent is located, supported by inputs about place using local olfactory and tactile cues. Fifth, it is shown how view-point dependent allocentric representations could form a view-point independent allocentric representation for memory and navigation. Sixth, concept cells in humans and primates with connectivity to the hippocampus are compared.concept cells in humans and macaques, episodic memory, hippocampus, navigation, parahippocampal scene area, place cells, spatial view cells | INTRODUCTIONThis is a commentary on issues important in understanding hippocampal function that are raised by papers in the Special Issue of Hippocampus (2023) entitled "Hippocampal system neurons encoding views in different species" (Alexander et al., 2023;

The memory systems of the human brain and generative artificial intelligence

“…It is important in understanding the hippocampo-cortical memory system in humans and other primates that what it encodes for memories and navigation is very different from the neuronal representation by ‘place’ cells found in the rodent hippocampus of the place where the individual is located [ 4 , 5 , [35] , [36] , [37] , [38] , [39] ]. In contrast, in primates the predominant spatial representation in the hippocampus and parahippocampal cortex is provided by spatial view neurons that code for the location ‘out there’ where the primate or human is looking in space [ 1 , 2 , [40] , [41] , [42] , [43] , [44] ]. This discovery, together with much recent evidence from primates [ [45] , [46] , [47] , [48] , [49] ] and humans [ [50] , [51] , [52] ] (see the Special Issue of Hippocampus, May 2023), is leading to a revolution in our understanding of hippocampal function in primates including humans, in that this allows memories to be formed of where people and objects are in spatial scenes even though the viewer may never have visited the places being viewed.…”

“…This discovery, together with much recent evidence from primates [ [45] , [46] , [47] , [48] , [49] ] and humans [ [50] , [51] , [52] ] (see the Special Issue of Hippocampus, May 2023), is leading to a revolution in our understanding of hippocampal function in primates including humans, in that this allows memories to be formed of where people and objects are in spatial scenes even though the viewer may never have visited the places being viewed. This is prototypical of human memory, and means that hippocampo-neocortical function as we now understand it is highly relevant to understanding human generative memory brain systems [ 1 , 2 , 40 ].…”

“…One problem is that place cells, which encode where the individual is located, are the predominant spatial representation in the rodent hippocampus [ 4 , 5 , [35] , [36] , [37] , [38] , [39] ]. In contrast, in primates the predominant spatial representation in the hippocampus and parahippocampal cortex is provided by spatial view neurons that code for the location ‘out there’ where the primate or human is looking in space [ 1 , 2 , [40] , [41] , [42] , [43] , [44] ]. This discovery is supported by much recent evidence from primates [ [45] , [46] , [47] , [48] , [49] ] and humans [ [50] , [51] , [52] ].…”

Hippocampal system neurons encoding views in different species: Introduction to the Special Issue of Hippocampus 2023

“…Rolls (2023b) considers how allocentric spatial view representations are important not only for understanding episodic memory, which requires an allocentric representation that is nevertheless subject to view‐dependent effects that are found on different sides of a scene, but also in a sense provide the world‐based anchoring of place cells in rodents to the world, and how they relate to concept cells and the semantic systems found in humans. Rolls emphasizes that egocentric representations may be fine in primates for implementing actions in peripersonal space and in rodents for avoiding obstacles, but allocentric view representations are essential for remembering where objects and people have been seen in the world, and for navigation.…”

Integrated Three-Electrode Dual-Mode Detection Chip for Place Cell Analysis: Dopamine Facilitates the Role of Place Cells in Encoding Spatial Locations of Novel Environments and Rewards

“…The brain, as a complex network of neurons, coordinates a wide range of cognitive functions through its vast scale and diverse patterns of connections. These functions include memory formation and spatial navigation, which are crucial for an individual’s adaptation and survival within their environment. , Within this intricate network, place cells in the hippocampus play a pivotal role in encoding and representing spatial information, essential for an animal’s spatial navigation and the construction of cognitive maps. Place cells, a subset of neurons predominantly located in the hippocampal structure, exhibit location-specific firing patterns as animals explore their surroundings.…”