Significance of visual scene‐based learning in the hippocampal systems across mammalian species

Abstract

The hippocampus and its associated cortical regions in the medial temporal lobe play essential roles when animals form a cognitive map and use it to achieve their goals. As the nature of map-making involves sampling different local views of the environment and putting them together in a spatially cohesive way, visual scenes are essential ingredients in the formative process of cognitive maps. Visual scenes also serve as important cues during information retrieval from the cognitive map. Research in humans has shown that there are regions in the brain that selectively process scenes and that the hippocampus is involved in scene-based memory tasks. The neurophysiological correlates of scene-based information processing in the hippocampus have been reported as "spatial view cells" in nonhuman primates. Like primates, it is widely accepted that rodents also use visual scenes in their background for spatial navigation and other kinds of problems. However, in rodents, it is not until recently that researchers examined the neural correlates of the hippocampus from the perspective of visual scene-based information processing. With the advent of virtual reality (VR) systems, it has been demonstrated that place cells in the hippocampus exhibit remarkably similar firing correlates in the VR environment compared with that of the real-world environment. Despite some limitations, the new trend of studying hippocampal functions in a visually controlled environment has the potential to allow investigation of the input-output relationships of network functions and experimental testing of traditional computational predictions more rigorously by providing well-defined visual stimuli. As scenes are essential for navigation and episodic memory in humans, further investigation of the rodents' hippocampal systems in scene-based tasks will provide a critical functional link across different mammalian species.

A place with a view: A first‐person perspective in the hippocampal memory space

“…A provocative thought is that rodent place cells embody such conceptual representations through a sensory binding which links all views within the place a rodent is in. In line with this, in this issue Lee et al (2022), suggest that “visual scenes perceived by animals at specific locations and times are analogous to individual puzzle pieces that, when associated, allow forming a cognitive map of the environment.” Given that regions processing these scenes in the post rhinal cortex or parahippocampal cortex in primates, project on entorhinal cortex, one could speculate that the hippocampus performs a plasticity driven fast binding of these views in a place code. Furthermore, given that visual scenes are perceived through a larger FOV in rodents, than they are in primates, an alternate, parsimonious hypothesis to explain rodent place cells' invariance to head direction is that they represent position via a trilateration of objects (Araujo et al, 2001) or the local view pertaining to a place (McNaughton et al, 1996).…”

“…This can sometimes lead to having to turn the map on the phone (or the phone) upside down to align the heading to the viewer's perspective. Following the idea suggested by Lee et al (2022) scenes can play a critical role in effectively retrieving relevant information from a cognitive map, therefore affording predictions and trajectories. This is also in line with what is proposed by Naya and collaborators (Yang et al., 2023), in which the viewer centered signals (which are intrinsically egocentric) enable recall suitable for navigation.…”

“…This commentary discusses the species dependent reference frames used to perceive scenes, which are issues raised in papers published in the Special Issue of Hippocampus (2023) entitled “Hippocampal system neurons encoding views in different species.” The papers are Corrigan et al (2023), LaChance and Taube (2023), Lee et al (2022), Quian Quiroga (2023), Yang et al (2023), and Zhu et al (2023).…”

Using multi-task experiments to test principles of hippocampal function

“…Advances in virtual reality systems that are becoming more and more available in research settings also open up exciting possibilities to perform multi-task experiments by allowing rapid switches between different task and environment settings. This enables researchers to more fully characterize hippocampal coding of different spatial variables, often in combination with more complex and naturalistic environments, as further discussed elsewhere in this special issue (S. Lee et al, 2023).…”

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

“…This 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; Corrigan et al, 2023; Donoghue et al, 2023; LaChance & Taube, 2023; Lee et al, 2023; Quian Quiroga, 2023; Rolls, 2023b; Ryom et al, 2023; Wang et al, 2023; Wirth, 2023; Yang et al, 2023; Zhu et al, 2023).…”