RESEARCH ARTICLE


Midlife Arterial Stiffness and Brain Activation During Working Memory Task



Kayla A. Steward1, Evan Pasha2, Katyoon Goudarzi1, Ahmed Elmenshawy2, Mohammed Alkatan2, Astrid Villalpando1, Hirofumi Tanaka2, Andreana P. Haley1, 3, *
1 Department of Psychology, University of Texas at Austin, Austin, TX, USA
2 Department of Kinesiology and Health Education, University of Texas at Austin, Austin, TX, USA
3 Imaging Research Center, University of Texas at Austin, Austin, TX, USA


© 2014 Steward et al.

open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International Public License (CC-BY 4.0), a copy of which is available at: https://creativecommons.org/licenses/by/4.0/legalcode. This license permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

* Address correspondence to this author at the Department of Psychology, The University of Texas at Austin, 108 East Dean Keeton, Stop A8000, Austin, TX 78712, USA; Tel: +1 512 232 0863; Fax: +1 512 471 6175; Email: haley@austin.utexas.edu


Abstract

Objective:

Arterial stiffness is associated with cognitive decline and may serve as an early marker of brain vulnerability. In search of potential early intervention targets, the present study examined the neural correlates of working memory in relation to arterial stiffness in middle-aged, cognitively healthy adults.

Methods:

Twenty-eight adults, ages 40- 60 years, completed a 2-Back verbal working memory task during fMRI. Arterial stiffness was measured using the 􀀁- stiffness index via simultaneous ultrasound and applanation tonometry on the carotid artery. Mean task-related activation intensity was determined for 12 a priori regions of interest (ROI). Statistical analyses included partial correlations, controlling for hypertension status and antihypertensive medication. Results: Arterial stiffness was correlated negatively with task-related activation in 3 ROIs: left precentral gyrus/BA 6 (r=-0.64, p<0.001), left precentral/middle frontal gyrus (r=-0.62, p=0.001) and left superior parietal lobule/BA 7 (r=-0.48, p=0.013). There was also a negative association between arterial stiffness and task-related activation in the right superior frontal gyrus/BA 6 (r=-0.45, p=0.023).

Conclusions:

Greater arterial stiffness was significantly associated with decreased task-related brain activation during a verbal working memory task, possibly reflecting increased vulnerability for cognitive impairment. Arterial stiffness should be investigated further as an early marker of cognitive risk and a potential target for early intervention.

Keywords: Arterial stiffness, β-stiffness index, working memory, fMRI, BOLD, middle-aged adults, aging.