Cerebral language lateralisation attenuates in old age: evidence from functional transcranial Doppler methods
-
1
University of South Australia, Psychology, Australia
-
2
Flinders University, Australia
-
3
University of South Australia, Australia
-
4
Macquarie University, Australia
Functional magnetic resonance imaging (fMRI) studies over the past decade have reported that the degree of task-related cerebral lateralisation decreases in old age, particularly in those who are cognitively high performing. The recruitment of contralateral regions has been suggested to reflect compensatory mechanisms that support the maintenance of function. We aimed to investigate if we could replicate the age-related compensatory fMRI finding using the functional transcranial Doppler (fTCD) technique. Fifty healthy right-handed individuals (33 female, 17 male) between the ages of 60 and 76 years underwent cognitive testing via the Weschler Abbreviated Intelligence Scale Vocabulary and Matrix sub-tests, and functional TCD testing during a word-generation task. TCD blood flow velocity data was collected from the right and left middle cerebral arteries. This data was averaged relative to stimulus onset (the letter required for the word generation task; 24 trials in total) and an evoked-flow plot for each individual was created. Age was negatively related to the degree of lateralisation (left minus right middle cerebral artery blood flow velocities) (r=-0.45, p=.001), but not to the timing or variability of lateralisation, nor to overall cognitive ability. Age was also associated with an increase in the pulsatility index (vessel resistance) however the negative relationship between age and lateralisation did not change with the addition of pulsatility index into a regression model. Age was not associated with significant change in other resting blood flow velocity measures - mean, max or minimum. Findings suggest that ageing is associated with an attenuation of the left-hemispheric language processing dominance, which can be measured via the fTCD technique and does not appear to be the product of contaminant changes in cerebrovascular integrity. FTCD methods are very well tolerated, portable and inexpensive and have huge potential in psychophysiological research.
Keywords:
Compensation,
cerebrovascular,
TCD,
cognitive ageing
Conference:
XII International Conference on Cognitive Neuroscience (ICON-XII), Brisbane, Queensland, Australia, 27 Jul - 31 Jul, 2014.
Presentation Type:
Poster
Topic:
Cognition and Executive Processes
Citation:
Keage
H,
Churches
O,
Kurylowicz
L,
Flitton
A,
Lavrencic
L,
Hofmann
J,
Kohler
M and
Badcock
N
(2015). Cerebral language lateralisation attenuates in old age: evidence from functional transcranial Doppler methods.
Conference Abstract:
XII International Conference on Cognitive Neuroscience (ICON-XII).
doi: 10.3389/conf.fnhum.2015.217.00266
Copyright:
The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers.
They are made available through the Frontiers publishing platform as a service to conference organizers and presenters.
The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated.
Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed.
For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions.
Received:
19 Feb 2015;
Published Online:
24 Apr 2015.
*
Correspondence:
Dr. Hannah Keage, University of South Australia, Psychology, Adelaide, Australia, hannah.keage@unisa.edu.au