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White matter hyperintensities among older adults are associated with futile increase in frontal activation and functional connectivity during spatial search.

Lockhart SN, Luck SJ, Geng J, Beckett L, Disbrow EA, Carmichael O, DeCarli C - PLoS ONE (2015)

Bottom Line: The effects of these processes on the function of distributed cognitive networks, however, are poorly understood.Expanding upon previous research, older adults demonstrate activation across a frontal-parietal attentional control network.Further, greater white matter hyperintensity volume was associated with increased activation of a frontal network node independent of chronological age.

View Article: PubMed Central - PubMed

Affiliation: Imaging of Dementia and Aging Lab, University of California Davis, Davis, CA, United States of America; Department of Neurology, University of California Davis, Davis, CA, United States of America; Neuroscience Graduate Group, University of California Davis, Davis, CA, United States of America.

ABSTRACT
The mechanisms by which aging and other processes can affect the structure and function of brain networks are important to understanding normal age-related cognitive decline. Advancing age is known to be associated with various disease processes, including clinically asymptomatic vascular and inflammation processes that contribute to white matter structural alteration and potential injury. The effects of these processes on the function of distributed cognitive networks, however, are poorly understood. We hypothesized that the extent of magnetic resonance imaging white matter hyperintensities would be associated with visual attentional control in healthy aging, measured using a functional magnetic resonance imaging search task. We assessed cognitively healthy older adults with search tasks indexing processing speed and attentional control. Expanding upon previous research, older adults demonstrate activation across a frontal-parietal attentional control network. Further, greater white matter hyperintensity volume was associated with increased activation of a frontal network node independent of chronological age. Also consistent with previous research, greater white matter hyperintensity volume was associated with anatomically specific reductions in functional magnetic resonance imaging functional connectivity during search among attentional control regions. White matter hyperintensities may lead to subtle attentional network dysfunction, potentially through impaired frontal-parietal and frontal interhemispheric connectivity, suggesting that clinically silent white matter biomarkers of vascular and inflammatory injury can contribute to differences in search performance and brain function in aging, and likely contribute to advanced age-related impairments in cognitive control.

No MeSH data available.


Related in: MedlinePlus

Mean trimmed correct log-normalized reaction time values.Values are plotted for each search condition and set size, for older adults.
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pone.0122445.g002: Mean trimmed correct log-normalized reaction time values.Values are plotted for each search condition and set size, for older adults.

Mentions: When examining behavioral data as in our previous work (where performance was outside an MRI), results were largely concordant [9]. Overall accuracy was high (96% for OA), with longer lnRT was associated with more errors in OA (R2 = .25; p <. 001), confirming our results were not confounded by speed-accuracy trade-off. Comparable to previous results [9,51,54], increasing task difficulty (set size or search condition) was associated with increasing lnRT (condition, set size, and condition*set size p's <. 001), shown in Fig. 2.


White matter hyperintensities among older adults are associated with futile increase in frontal activation and functional connectivity during spatial search.

Lockhart SN, Luck SJ, Geng J, Beckett L, Disbrow EA, Carmichael O, DeCarli C - PLoS ONE (2015)

Mean trimmed correct log-normalized reaction time values.Values are plotted for each search condition and set size, for older adults.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4368687&req=5

pone.0122445.g002: Mean trimmed correct log-normalized reaction time values.Values are plotted for each search condition and set size, for older adults.
Mentions: When examining behavioral data as in our previous work (where performance was outside an MRI), results were largely concordant [9]. Overall accuracy was high (96% for OA), with longer lnRT was associated with more errors in OA (R2 = .25; p <. 001), confirming our results were not confounded by speed-accuracy trade-off. Comparable to previous results [9,51,54], increasing task difficulty (set size or search condition) was associated with increasing lnRT (condition, set size, and condition*set size p's <. 001), shown in Fig. 2.

Bottom Line: The effects of these processes on the function of distributed cognitive networks, however, are poorly understood.Expanding upon previous research, older adults demonstrate activation across a frontal-parietal attentional control network.Further, greater white matter hyperintensity volume was associated with increased activation of a frontal network node independent of chronological age.

View Article: PubMed Central - PubMed

Affiliation: Imaging of Dementia and Aging Lab, University of California Davis, Davis, CA, United States of America; Department of Neurology, University of California Davis, Davis, CA, United States of America; Neuroscience Graduate Group, University of California Davis, Davis, CA, United States of America.

ABSTRACT
The mechanisms by which aging and other processes can affect the structure and function of brain networks are important to understanding normal age-related cognitive decline. Advancing age is known to be associated with various disease processes, including clinically asymptomatic vascular and inflammation processes that contribute to white matter structural alteration and potential injury. The effects of these processes on the function of distributed cognitive networks, however, are poorly understood. We hypothesized that the extent of magnetic resonance imaging white matter hyperintensities would be associated with visual attentional control in healthy aging, measured using a functional magnetic resonance imaging search task. We assessed cognitively healthy older adults with search tasks indexing processing speed and attentional control. Expanding upon previous research, older adults demonstrate activation across a frontal-parietal attentional control network. Further, greater white matter hyperintensity volume was associated with increased activation of a frontal network node independent of chronological age. Also consistent with previous research, greater white matter hyperintensity volume was associated with anatomically specific reductions in functional magnetic resonance imaging functional connectivity during search among attentional control regions. White matter hyperintensities may lead to subtle attentional network dysfunction, potentially through impaired frontal-parietal and frontal interhemispheric connectivity, suggesting that clinically silent white matter biomarkers of vascular and inflammatory injury can contribute to differences in search performance and brain function in aging, and likely contribute to advanced age-related impairments in cognitive control.

No MeSH data available.


Related in: MedlinePlus