Correlates of virtual navigation performance in older adults

Area of Science:

• Neuroscience
• Cognitive Aging
• Neuroimaging

Background:

• Aging is associated with cognitive decline, particularly in spatial learning and memory.
• The neural underpinnings of age-related spatial navigation deficits require further investigation.
• The virtual Morris water task (vMWT) serves as a human model for spatial navigation research.

Purpose of the Study:

• To investigate longitudinal changes in spatial learning using the vMWT in healthy adults.
• To examine cross-sectional associations between vMWT performance and brain structure/integrity.
• To explore the relationship between spatial navigation and cognitive function across the adult lifespan.

Main Methods:

• Longitudinal study of 51 healthy adults (30-83 years) completing the vMWT and neuropsychological tests at two time points (~8 years apart).
• Cross-sectional analysis of brain structure (gray matter volume) and white matter integrity (fractional anisotropy) using MRI in a subset of 22 participants.
• Correlational analyses between vMWT performance and neuroimaging/neuropsychological measures.

Main Results:

• No significant longitudinal decline in vMWT performance was observed over the ~8-year interval.
• Cross-sectional analyses revealed age-related differences, with younger adults performing better on the vMWT.
• Poorer vMWT performance correlated with reduced gray matter in the hippocampus and thalamus, and lower white matter integrity in the uncinate fasciculus.

Conclusions:

• While vMWT performance may remain stable longitudinally in healthy aging, cross-sectional data highlight age-related differences.
• Structural integrity of brain regions crucial for navigation (hippocampus, thalamus, orbitofrontal cortex, uncinate fasciculus) is associated with spatial learning ability.
• These findings suggest that differences in neural substrates supporting navigation exist across the adult lifespan, even without apparent performance decline over time.