Less wiring, more firing: low-performing older adults compensate for impaired white matter with greater neural activity.
dc.contributor.author | Daselaar, Sander M | |
dc.contributor.author | Iyengar, Vijeth | |
dc.contributor.author | Davis, Simon W | |
dc.contributor.author | Eklund, Karl | |
dc.contributor.author | Hayes, Scott M | |
dc.contributor.author | Cabeza, Roberto E | |
dc.coverage.spatial | United States | |
dc.date.accessioned | 2015-07-13T15:09:40Z | |
dc.date.issued | 2015-04 | |
dc.description.abstract | The reliable neuroimaging finding that older adults often show greater activity (over-recruitment) than younger adults is typically attributed to compensation. Yet, the neural mechanisms of over-recruitment in older adults (OAs) are largely unknown. Rodent electrophysiology studies have shown that as number of afferent fibers within a circuit decreases with age, the fibers that remain show higher synaptic field potentials (less wiring, more firing). Extrapolating to system-level measures in humans, we proposed and tested the hypothesis that greater activity in OAs compensates for impaired white-matter connectivity. Using a neuropsychological test battery, we measured individual differences in executive functions associated with the prefrontal cortex (PFC) and memory functions associated with the medial temporal lobes (MTLs). Using event-related functional magnetic resonance imaging, we compared activity for successful versus unsuccessful trials during a source memory task. Finally, we measured white-matter integrity using diffusion tensor imaging. The study yielded 3 main findings. First, low-executive OAs showed greater success-related activity in the PFC, whereas low-memory OAs showed greater success-related activity in the MTLs. Second, low-executive OAs displayed white-matter deficits in the PFC, whereas low-memory OAs displayed white-matter deficits in the MTLs. Finally, in both prefrontal and MTL regions, white-matter decline and success-related activations occurred in close proximity and were negatively correlated. This finding supports the less-wiring-more-firing hypothesis, which provides a testable account of compensatory over-recruitment in OAs. | |
dc.identifier | ||
dc.identifier | bht289 | |
dc.identifier.eissn | 1460-2199 | |
dc.identifier.uri | ||
dc.language | eng | |
dc.publisher | Oxford University Press (OUP) | |
dc.relation.ispartof | Cereb Cortex | |
dc.relation.isversionof | 10.1093/cercor/bht289 | |
dc.subject | DTI | |
dc.subject | MTL | |
dc.subject | PFC | |
dc.subject | elderly | |
dc.subject | fMRI | |
dc.subject | frontal | |
dc.subject | Aged | |
dc.subject | Aging | |
dc.subject | Brain Mapping | |
dc.subject | Diffusion Tensor Imaging | |
dc.subject | Executive Function | |
dc.subject | Female | |
dc.subject | Humans | |
dc.subject | Magnetic Resonance Imaging | |
dc.subject | Male | |
dc.subject | Memory | |
dc.subject | Neural Pathways | |
dc.subject | Neuropsychological Tests | |
dc.subject | Prefrontal Cortex | |
dc.subject | Temporal Lobe | |
dc.subject | White Matter | |
dc.title | Less wiring, more firing: low-performing older adults compensate for impaired white matter with greater neural activity. | |
dc.type | Journal article | |
duke.contributor.orcid | Davis, Simon W|0000-0002-5943-0756 | |
duke.contributor.orcid | Cabeza, Roberto E|0000-0001-7999-1182 | |
pubs.author-url | ||
pubs.begin-page | 983 | |
pubs.end-page | 990 | |
pubs.issue | 4 | |
pubs.organisational-group | Center for Cognitive Neuroscience | |
pubs.organisational-group | Center for Population Health & Aging | |
pubs.organisational-group | Clinical Science Departments | |
pubs.organisational-group | Duke | |
pubs.organisational-group | Duke Institute for Brain Sciences | |
pubs.organisational-group | Duke Population Research Institute | |
pubs.organisational-group | Duke Science & Society | |
pubs.organisational-group | Duke-UNC Center for Brain Imaging and Analysis | |
pubs.organisational-group | Initiatives | |
pubs.organisational-group | Institutes and Centers | |
pubs.organisational-group | Institutes and Provost's Academic Units | |
pubs.organisational-group | Neurology | |
pubs.organisational-group | Neurology, Behavioral Neurology | |
pubs.organisational-group | Psychiatry & Behavioral Sciences | |
pubs.organisational-group | Psychiatry & Behavioral Sciences, Brain Stimulation and Neurophysiology | |
pubs.organisational-group | Psychiatry & Behavioral Sciences, Geriatric Behavioral Health | |
pubs.organisational-group | Psychology and Neuroscience | |
pubs.organisational-group | Sanford School of Public Policy | |
pubs.organisational-group | School of Medicine | |
pubs.organisational-group | Trinity College of Arts & Sciences | |
pubs.organisational-group | University Institutes and Centers | |
pubs.publication-status | Published | |
pubs.volume | 25 |
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