Through the use of MRE, our lab seeks to better understand and characterize the role of mechanics in describing brain tissue structure and how it underpins neurological function. We achieve this through advanced mapping of the heterogeneous brain tissue viscoelasticity; identifying patterns of mechanical properties that differ with age or between groups; and relating these signatures to performance on cognitive assessments. Overall, our goal is to harness the inherent sensitivity of tissue mechanics to microstructural composition and organization to provide quantitative insight into the brain.
Ongoing research directions include:
- Mechanical mapping of the cerebral cortex: Following on previous work in characterizing the stiffness of specific white matter tracts and subcortical gray matter structures, we are currently expanding our capabilities to reliably map the mechanical properties of the entire cerebral cortex through refinement of our high-resolution methodology.
- Structural correlates of memory performance: We are further developing the use of MRE structural biomarkers of cognitive function, especially in the realm of memory performance. Our initial work suggests MRE measures are very sensitive to the underlying hippocampal structure that influences relational memory. This project seeks to further identify quantitative structural biomarkers implicated across domains of memory processing.
- Mechanics of the aging brain: This project aims to identify regionally dependent patterns of viscoelasticity changes with aging, and to determine the relationships between these patterns and functional performance. Ultimately, such a characterization may uncover imaging signatures of the transition to dementia in the elderly, or as targets modifiable through lifestyle interventions to improve cognition.
- Mechanics of the developing brain: Similar to the interest in the aging brain, we aim to characterize the developing brain in children as they mature through adulthood and understand relationships with learning and decision-making.
G McIlvain, et al, "Mechanical Properties of the In Vivo Adolescent Human Brain," Developmental Cognitive Neuroscience, 2018.
LV Hiscox, et al, “High-Resolution Magnetic Resonance Elastography Reveals Differences in Subcortical Gray Matter Viscoelasticity Between Young and Healthy Older Adults,” Neurobiology of Aging, 2018.
CL Johnson, et al, "Double Dissociation of Structure-Function Relationships in Memory and Fluid Intelligence Observed with Magnetic Resonance Elastography," NeuroImage, 2018.
CL Johnson, EH Telzer, “Magnetic Resonance Elastography for Examining Developmental Changes in the Mechanical Properties of the Brain,” Developmental Cognitive Neuroscience, 2017.
H Schwarb, et al, “Aerobic Fitness, Hippocampal Viscoelasticity, and Relational Memory Performance,” NeuroImage, 2017.
H Schwarb, et al, “Medial Temporal Lobe Viscoelasticity and Relational Memory Performance,” NeuroImage, 2016.
CL Johnson, et al, “Viscoelasticity of Subcortical Gray Matter Structures,” Human Brain Mapping, 2016.
CL Johnson, et al, “Local Mechanical Properties of White Matter Structures in the Human Brain,” NeuroImage, 2013.