Please use this identifier to cite or link to this item:
Title: The optical effective attenuation coefficient as an informative measure of brain health in aging
Authors: Chiarelli, Antonio M.
Low, Kathy A.
Maclin, Edward L.
Fletcher, Mark A.
Kong, Tania S.
Zimmerman, Benjamin
Tan, Chin Hong
Sutton, Bradley P.
Fabiani, Monica
Gratton, Gabriele
Keywords: Social sciences::Psychology
Issue Date: 2019
Source: Chiarelli, A. M., Low, K. A., Maclin, E. L., Fletcher, M. A., Kong, T. S., Zimmerman, B., . . . Gratton, G. (2019). The optical effective attenuation coefficient as an informative measure of brain health in aging. Photonics, 6(3), 79-. doi:10.3390/photonics6030079
Journal: Photonics
Abstract: Aging is accompanied by widespread changes in brain tissue. Here, we hypothesized that head tissue opacity to near-infrared light provides information about the health status of the brain’s cortical mantle. In diffusive media such as the head, opacity is quantified through the Effective Attenuation Coefficient (EAC), which is proportional to the geometric mean of the absorption and reduced scattering coefficients. EAC is estimated by the slope of the relationship between source–detector distance and the logarithm of the amount of light reaching the detector (optical density). We obtained EAC maps across the head in 47 adults (age range 18–75 years), using a high-density dual-wavelength optical system. We correlated regional and global EAC measures with demographic, neuropsychological, structural and functional brain data. Results indicated that EAC values averaged across wavelengths were strongly associated with age-related changes in cortical thickness, as well as functional and neuropsychological measures. This is likely because the EAC largely depends on the thickness of the sub-arachnoid cerebrospinal fluid layer, which increases with cortical atrophy. In addition, differences in EAC values between wavelengths were correlated with tissue oxygenation and cardiorespiratory fitness, indicating that information about cortical health can be derived non-invasively by quantifying the EAC.
ISSN: 2304-6732
DOI: 10.3390/photonics6030079
Rights: © 2019 The Author(s). Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (
Fulltext Permission: open
Fulltext Availability: With Fulltext
Appears in Collections:SSS Journal Articles

Citations 50

Updated on Jan 31, 2023

Web of ScienceTM
Citations 50

Updated on Jan 30, 2023

Page view(s)

Updated on Feb 4, 2023

Download(s) 50

Updated on Feb 4, 2023

Google ScholarTM




Items in DR-NTU are protected by copyright, with all rights reserved, unless otherwise indicated.