Tracking the emergence of location-based spatial representations in human scene-selective cortex

Abstract

<jats:title>Abstract</jats:title><jats:p>Scene-selective regions of the human brain form allocentric representations of locations in our environment. These representations are independent of heading direction and allow us to know where we are regardless of our direction of travel. However, we know little about how these location-based representations are formed. Using fMRI representational similarity analysis and generalised linear mixed models, we tracked the emergence of location-based representations in scene-selective brain regions. We estimated patterns of activity for two distinct scenes, taken before and after participants learnt they were from the same location. During a learning phase, we presented participants with two types of panoramic videos: (1) an overlap video condition displaying two distinct scenes (0° and 180°) from the same location, and (2) a no-overlap video displaying two distinct scenes from different locations (that served as a control condition). In the parahippocampal cortex (PHC) and retrosplenial cortex (RSC), representations of scenes from the same location became more similar to each other only after they had been shown in the overlap condition, suggesting the emergence of location-based viewpoint-independent representations. Whereas potential location-based representations emerged in the PHC regardless of task performance, RSC representations only emerged for locations where participants could behaviourally identify the two scenes as belonging to the same location. The results suggest that we can track the emergence of location-based representations in the PHC and RSC in a single fMRI session and support computational models that propose the RSC plays a key role in using such representations to locate ourselves in space.</jats:p>

Behavior-dependent directional tuning in the human visual-navigation network

“…For example, the RSC and PHG were shown to rapidly encode a novel environment by integrating information across different viewpoints and landmarks. Spatial representations emerging in the RSC were associated with a participant's ability to identify multiple scenes as belonging to the same or different location (Berens et al, 2019), as well as with wayfinding ability by registering landmark permanence (Auger et al, 2017). Consistent with the present results, the RSC activity could hence signal whether an environment has been successfully encoded or not.…”

“…This could aid the integration of different landmarks and viewpoints (Auger et al, 2017;Berens et al, 2019). Importantly, the medial parietal lobe, which comprises the RSC, is known for both its perceptual and mnemonic capacities (O'Craven and Kanwisher, 2000), which might be topologically distributed.…”

Behavior-dependent directional tuning in the human visual-navigation network

“…For example, the RSC and PHG were shown to rapidly encode a novel environment by integrating information across different viewpoints and landmarks. Spatial representations emerging in the RSC were associated with a participant's ability to identify multiple scenes as belonging to the same or different location 80 , as well as with wayfinding ability by registering landmark permanence 81 . Consistent with the present results, the RSC activity could hence signal whether an environment has been successfully encoded or not.…”

“…We observed a broader tuning in RSC in well-compared to poorly performing participants, potentially indicating that the RSC processed information with a broader field of view. This could aid the integration of different landmarks and viewpoints 80,81 . Importantly, the medial parietal lobe, which comprises the RSC, is known for both its perceptual and mnemonic capacities 82 , which might be topologically distributed.…”

Progression from feature-specific brain activity to hippocampal binding during episodic encoding

“…Specifically, successful encoding of the object's color was associated with enhanced activity of right ventral visual cortical areas, whereas subsequent memory for the sound was positively related to activity in bilateral superior temporal (auditory) cortex. Neural correlates of successful scene encoding were more widespread, with positive changes in activity observed in bilateral dorsal medial parietal and occipital cortex, as well as bilateral retrosplenial and parahippocampal cortex, frequently reported to be sensitive to specific representations of spatial locations and perspectives (e.g., Epstein, 2008;Robertson et al, 2016;Robin et al, 2018;Berens et al, 2019). Thus, we were able to detect unique patterns of 15 brain activity that positively tracked different kinds of episodic features encoded simultaneously, with the most widespread effects for encoding scene details.…”