Project Abstract/Summary
Aging is associated with decline in spatial navigation and episodic memory function. Theoretical models argue
that navigation and episodic memory are intricately linked – spatial contexts serve as scaffolds for episodic
memory, facilitating the encoding, organization, and retrieval of memories. One set of processes that could
contribute to both navigational and episodic memory impairments in aging is diminished attention; reduced
attentional control and diminished sustained attention in older adults could lead to poor spatial representation,
suboptimal navigational strategies, and subsequent declines in memory. The proposed research program will
leverage a series of virtual-reality (VR) spatial navigation paradigms, in combination with behavioral and neural
markers of attention, spatial coding, and memory to examine how attentional deficits in aging relate to navigation
and episodic memory difficulties. Aim 1 will use a VR spatial navigation task to examine how moment-to-moment
selective attention and sustained attention (assessed through eye-tracking and pupillometry) relate to spatial
navigation performance in older relative to young adults. Expt 1 will assess both age-related and individual
differences in (a) how attention relates to navigation performance, (b) the relative salience of types of spatial
cues (distal vs. proximal) that influence navigation strategies, and (c) how attention during initial environment
encoding affects the ability to calculate new spatial trajectories following changes in the environment. Aim 2 will
investigate how age-related differences in behavioral and neural markers of attention relate to differences in the
representation of spatial context and in context-mediated regulation of memory integration and interference. Expt
2 will examine how (a) behavioral measures of attention to spatial context relate to episodic memory, influencing
when two overlapping events are discriminated (pattern separation), diminishing interference, and when two
overlapping events are integrated, enabling novel inferences. Expt 3 will use fMRI to examine (a) age-related
differences in the function of neural systems of attention (e.g., frontoparietal cortical networks, locus coeruleus)
and episodic memory (e.g., medial temporal lobe) during spatial navigation and associative encoding, along with
concurrent pupillometry to (b) measure how trial-by-trial differences in behavioral markers of sustained attention
influence neural representations of spatial context and episodic memory and (c) investigate how age-related
differences in interactions between attentional and memory systems influence memory integration and
interference. Collectively, these studies will advance and link theories of attention, spatial navigation, and
memory to early cognitive, behavioral, and neural changes in aging, and promise to enable future study of how
attention, navigation, and memory interactions are affected by disease processes (e.g., Alzheimer’s disease).