Encoding and retrieval of landmark‐related spatial cues during navigation: An fMRI study

Abstract

To successfully navigate, humans can use different cues from their surroundings. Learning locations in an environment can be supported by parallel subsystems in the hippocampus and the striatum. We used fMRI to look at differences in the use of object-related spatial cues while 47 participants actively navigated in an open-field virtual environment. In each trial, participants navigated toward a target object. During encoding, three positional cues (columns) with directional cues (shadows) were available. During retrieval, the removed target had to be replaced while either two objects without shadows (objects trial) or one object with a shadow (shadow trial) were available. Participants were informed in blocks about which type of retrieval trial was most likely to occur, thereby modulating expectations of having to rely on a single landmark or on a configuration of landmarks. How the spatial learning systems in the hippocampus and caudate nucleus were involved in these landmark-based encoding and retrieval processes were investigated. Landmark configurations can create a geometry similar to boundaries in an environment. It was found that the hippocampus was involved in encoding when relying on configurations of landmarks, whereas the caudate nucleus was involved in encoding when relying on single landmarks. This might suggest that the observed hippocampal activation for configurations of objects is linked to a spatial representation observed with environmental boundaries. Retrieval based on configurations of landmarks activated regions associated with the spatial updation of object locations for reorientation. When only a single landmark was available during retrieval, regions associated with updating the location of oneself were activated. There was also evidence that good between-participant performance was predicted by right hippocampal activation. This study therefore sheds light on how the brain deals with changing demands on spatial processing related purely to landmarks.

Influence of Landmarks on Wayfinding and Brain Connectivity in Immersive Virtual Reality Environment

“…This result confirmed the first hypothesis that landmark would facilitate successful wayfinding, and; this finding aligns with previous studies (Jansen-Osmann and Wiedenbauer, 2004; Jansen-Osmann and Fuchs, 2006; Wegman et al, 2014). An earlier rodent study (Youngstrom and Strowbridge, 2012) confirmed the pivotal role of landmarks in the spatial representation for successful wayfinding.…”

“…Electrophysiological and imaging studies have pointed out the importance of landmarks and their corresponding locations in wayfinding (Jansen-Osmann and Wiedenbauer, 2004; Janzen and Jansen, 2010; Wegman et al, 2014). For example, Janzen and Jansen (2010) showed the involvement of Para-Hippocampal Gyrus (PHG) in object and scene recognition.…”

Sex differences in spatial navigation and perception in human adolescents and emerging adults

“…It is generally accepted that optimal performance in the WMT is based on the use of spatial information provided from visual environmental cues, for example, based on the fixed spatial relationship between the platform and the available visual cues (O'Keefe et al, 1978) or the contributions of visual cues to the selection of trajectories to the platform location (Knierim et al, 2011). The hippocampus plays an integral role in memory function; it is critical for processing spatial and contextual information and for generating and maintaining representations utilized for navigating in space (Jarrard, 1993; O'Keefe et al, 1978; Wegman et al, 2014). To this end, rodents with hippocampal lesions have been shown to exhibit deficits in spatial learning on this task, as evidenced by an inability to efficiently navigate to the hidden platform (Morris et al, 1982; Sutherland et al, 1982).…”

Hippocampal volume reduction in female but not male recent abstinent methamphetamine users

“…Patients with right hippocampus damage have shown a selective spatial memory deficit (36). An fMRI study found that good between-participant performance in spatial processing tasks was predicted by right hippocampal activation (37). A volumetric analyses of structural MRI data indicated that the size of right posterior hippocampus predicted the ability to use spatial knowledge to make inferences about the relative positions of different buildings on campus (38).…”