Project R-15210

Testing the compensation versus dedifferentiation theories of cognitive aging by modulating excitability in the motor cortex using motor learning and non-invasive brain stimulation (tDCS) (Research)

Cortical hyperactivation refers to the recruitment of additional brain regions in older adults (OA) compared to young adults (YA) when performing the same task. While extensive research has already explored this phenomenon across various tasks and brain regions, the functional implications of this hyperactivation remain unknown and debated between two theories: compensation (adaptive role) or dedifferentiation (specialized processing breakdown). My project will utilize optimized, multitarget brain stimulation and multimodal neuroimaging to directly modulate motor hyperactivity in OA. This will enable directly testing compensation against dedifferentiation theories by elucidating causal effects on behavior, brain activation patterns, and neurotransmitter levels. The central objectives are to: (i) evaluate feasibility of using optimized, multi-target HD-tDCS to modulate premotor and sensorimotor hyperactivity; (ii) characterize effects of hyperactivation on behavior and neurotransmitter levels; and (iii) synthesize neuroimaging, electrophysiological and performance outcomes to determine whether observed relationships better fit the compensation or dedifferentiation theory. This innovative research pioneers optimized multi-target non-invasive brain stimulation, enabling direct modulation of age-related motor hyperactivation. The results will advance our understanding of age-related decline to inform interventions bolstering rehabilitation and healthy aging.

01 November 2024 - 31 October 2025