08:30 - 10:00
Mon-B21-Talk I-
Mon-Talk I-
Room: B21
Chair/s:
Sein Jeung, Klaus Gramann
This session puts together research works that are central to understanding spatial navigation and its neural underpinnings. The talks will introduce the neural basis of spatial navigation in animal and human research along with new insights from studies coupling mobile brain imaging with virtual reality (VR) and real-world tasks as well as works on
geometric representations of space and the impact of aging on navigation abilities. Different navigation strategies such as path integration and landmark-based navigation are supported by neural populations in the medial temporal lobe [1]. Electrophysiology recorded in animals can be used to establish, validate, and refine computational models that are linked with testable behavioral predictions on how space is represented and remembered. Methodological advances such as immersive VR and mobile brain imaging enable the translation of key findings from animal research on the aforementioned brain regions to humans. The use of VR in spatial navigation research allows for flexible manipulation of space in a way that is not possible in physical space, while providing participants with rich, naturalistic stimuli [2,3]. By enabling participants to make use of a natural mode of locomotion (e.g., walking through physical space), mobile brain imaging methods such as mobile EEG [2,5] afford the investigation of how body-based information influences navigation strategies. A better understanding of how humans navigate through space is of great applied value as they inform us about the nature of cognitive decline in older adults [4] and support development of effecient navigation aids [5].
Path integration in healthy older adults and population with subjective cognitive decline
Mon-B21-Talk I-04
Presented by: Vladislava Segen
Vladislava Segen, Thomas Wolbers
DZNE, Magdeburg
Path integration deficits are apparent in healthy older adults and Alzheimer’s disease (AD) patients. Yet, it remains unclear which specific aspects of the path integration process are most affected and whether these processes are differentially affected in older adults and those with AD. Here, we used immersive virtual reality to characterise path integration deficits in healthy older adults and those with subjective cognitive decline (SCD). During the task participants had access to multisensory self-motion cues (visual, vestibular and proprioceptive) as they were immersed in an open-field virtual environment and guided along short, curved paths. At certain points participants were asked to stop and indicate their initial heading orientation and start location. Overall, we found impaired path integration performance in the SCD group. These differences were not explained by general cognitive status, visuospatial working memory, subjective spatial abilities as well as balance. To further characterise the sources of the observed errors we used a computational model that allows us to decompose different parameters that contribute to the observed path and angular integration errors. Preliminary analysis suggests that memory leak, and randomly accumulating noise (across distance) is larger in the SCD group. Accumulating noise was also a key parameter in predicting path integration error in both groups, however, its contribution was larger in healthy older adults. These results will be discussed with reference to different mechanisms contributing to path integration deficits in healthy older adults and those with SCD.
Keywords: Navigation, Aging, Alzheimer Disease, Spatial cognition