An exploratory study of the effects of spatial working-memory load on prefrontal activation in low- and high-performing elderly

Older adults show more bilateral prefrontal activation during cognitive performance than younger adults, who typically show unilateral activation. This over-recruitment has been interpreted as compensation for declining structure and function of the brain. Here we examined how the relationship betwe...

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Main Authors: Anouk eVermeij, Arenda H.E.A. van Beek, Babette L.R. Reijs, Jurgen A.H.R. Claassen, Roy P.C. Kessels
Format: Article
Language:English
Published: Frontiers Media S.A. 2014-11-01
Series:Frontiers in Aging Neuroscience
Subjects:
Online Access:http://journal.frontiersin.org/Journal/10.3389/fnagi.2014.00303/full
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author Anouk eVermeij
Anouk eVermeij
Arenda H.E.A. van Beek
Babette L.R. Reijs
Jurgen A.H.R. Claassen
Jurgen A.H.R. Claassen
Roy P.C. Kessels
Roy P.C. Kessels
Roy P.C. Kessels
author_facet Anouk eVermeij
Anouk eVermeij
Arenda H.E.A. van Beek
Babette L.R. Reijs
Jurgen A.H.R. Claassen
Jurgen A.H.R. Claassen
Roy P.C. Kessels
Roy P.C. Kessels
Roy P.C. Kessels
author_sort Anouk eVermeij
collection DOAJ
description Older adults show more bilateral prefrontal activation during cognitive performance than younger adults, who typically show unilateral activation. This over-recruitment has been interpreted as compensation for declining structure and function of the brain. Here we examined how the relationship between behavioral performance and prefrontal activation is modulated by different levels of working-memory load. Eighteen healthy older adults (70.8 ± 5.0 years; MMSE 29.3 ± 0.9) performed a spatial working-memory task (n-back). Oxygenated ([O2Hb]) and deoxygenated ([HHb]) hemoglobin concentration changes were registered by two functional Near-Infrared Spectroscopy (fNIRS) channels located over the left and right prefrontal cortex. Increased working-memory load resulted in worse performance compared to the control condition. [O2Hb] increased with rising working-memory load in both fNIRS channels. Based on the performance in the high working-memory load condition, the group was divided into low and high performers. A significant interaction effect of performance level and hemisphere on [O2Hb] increase was found, indicating that high performers were better able to keep the right prefrontal cortex engaged under high cognitive demand. Furthermore, in the low performers group, individuals with a larger decline in task performance from the control to the high working-memory load condition had a larger bilateral increase of [O2Hb]. The high performers did not show a correlation between performance decline and working-memory load related prefrontal activation changes. Thus, additional bilateral prefrontal activation in low performers did not necessarily result in better cognitive performance. Our study showed that bilateral prefrontal activation may not always be successfully compensatory. Individual behavioral performance should be taken into account to be able to distinguish successful and unsuccessful compensation or declined neural efficiency.
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spelling doaj.art-bbb82b0512704da9a72c03777e6594f42022-12-21T22:59:19ZengFrontiers Media S.A.Frontiers in Aging Neuroscience1663-43652014-11-01610.3389/fnagi.2014.0030397549An exploratory study of the effects of spatial working-memory load on prefrontal activation in low- and high-performing elderlyAnouk eVermeij0Anouk eVermeij1Arenda H.E.A. van Beek2Babette L.R. Reijs3Jurgen A.H.R. Claassen4Jurgen A.H.R. Claassen5Roy P.C. Kessels6Roy P.C. Kessels7Roy P.C. Kessels8Radboud University NijmegenRadboud University Medical CenterRadboud University Medical CenterMaastricht UniversityRadboud University NijmegenRadboud University Medical CenterRadboud University NijmegenRadboud University Medical CenterRadboud University Medical CenterOlder adults show more bilateral prefrontal activation during cognitive performance than younger adults, who typically show unilateral activation. This over-recruitment has been interpreted as compensation for declining structure and function of the brain. Here we examined how the relationship between behavioral performance and prefrontal activation is modulated by different levels of working-memory load. Eighteen healthy older adults (70.8 ± 5.0 years; MMSE 29.3 ± 0.9) performed a spatial working-memory task (n-back). Oxygenated ([O2Hb]) and deoxygenated ([HHb]) hemoglobin concentration changes were registered by two functional Near-Infrared Spectroscopy (fNIRS) channels located over the left and right prefrontal cortex. Increased working-memory load resulted in worse performance compared to the control condition. [O2Hb] increased with rising working-memory load in both fNIRS channels. Based on the performance in the high working-memory load condition, the group was divided into low and high performers. A significant interaction effect of performance level and hemisphere on [O2Hb] increase was found, indicating that high performers were better able to keep the right prefrontal cortex engaged under high cognitive demand. Furthermore, in the low performers group, individuals with a larger decline in task performance from the control to the high working-memory load condition had a larger bilateral increase of [O2Hb]. The high performers did not show a correlation between performance decline and working-memory load related prefrontal activation changes. Thus, additional bilateral prefrontal activation in low performers did not necessarily result in better cognitive performance. Our study showed that bilateral prefrontal activation may not always be successfully compensatory. Individual behavioral performance should be taken into account to be able to distinguish successful and unsuccessful compensation or declined neural efficiency.http://journal.frontiersin.org/Journal/10.3389/fnagi.2014.00303/fullPrefrontal Cortexworking memorycognitive agingHaroldBOLDfunctional near-infrared spectroscopy
spellingShingle Anouk eVermeij
Anouk eVermeij
Arenda H.E.A. van Beek
Babette L.R. Reijs
Jurgen A.H.R. Claassen
Jurgen A.H.R. Claassen
Roy P.C. Kessels
Roy P.C. Kessels
Roy P.C. Kessels
An exploratory study of the effects of spatial working-memory load on prefrontal activation in low- and high-performing elderly
Frontiers in Aging Neuroscience
Prefrontal Cortex
working memory
cognitive aging
Harold
BOLD
functional near-infrared spectroscopy
title An exploratory study of the effects of spatial working-memory load on prefrontal activation in low- and high-performing elderly
title_full An exploratory study of the effects of spatial working-memory load on prefrontal activation in low- and high-performing elderly
title_fullStr An exploratory study of the effects of spatial working-memory load on prefrontal activation in low- and high-performing elderly
title_full_unstemmed An exploratory study of the effects of spatial working-memory load on prefrontal activation in low- and high-performing elderly
title_short An exploratory study of the effects of spatial working-memory load on prefrontal activation in low- and high-performing elderly
title_sort exploratory study of the effects of spatial working memory load on prefrontal activation in low and high performing elderly
topic Prefrontal Cortex
working memory
cognitive aging
Harold
BOLD
functional near-infrared spectroscopy
url http://journal.frontiersin.org/Journal/10.3389/fnagi.2014.00303/full
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