Plasticity of the Right-Lateralized Cognitive Reserve Network in Ageing

Méadhbh B. Brosnan, Giorgia Demaria, Anders Petersen, Paul Dockree, Ian Robertson , Iris Wiegand

Research output: Contribution to journalArticleResearchpeer-review

Abstract

Cognitive reserve (CR) is the phenomenon where older adults with more cognitively stimulating environments show less age-related cognitive decline. The right-lateralized fronto-parietal network has been proposed to significantly contribute to CR and visual attention in ageing. In this study we tested whether plasticity of this network may be harnessed in ageing.

We assessed CR and parameters of visual attention capacity in older adults. Transcranial direct current stimulation (tDCS) was employed to increase right fronto-parietal activity during a lateralized whole-report task. At baseline, older adults with greater CR showed a stronger hemifield asymmetry in processing speed towards the left visual-field, indicative of stronger involvement of the right hemisphere in these individuals. Correspondingly, processing speed improved during right prefrontal tDCS. Older adults with lower levels of CR showed tDCS-related improvements in processing speed in the left but not right hemifield: thus tDCS temporarily altered their processing speed asymmetry to resemble that of their high reserve peers.

The finding that stronger right hemisphere involvement is related to CR supports Robertson’s theory. Furthermore, preserved plasticity within the right prefrontal cortex in older adults suggests this is a viable target area to improve visual processing speed, a hallmark of age-related decline.
Original languageEnglish
Article numberbhx085
Pages (from-to)1749-1759
Number of pages11
JournalCerebral Cortex
Volume28
Issue number5
DOIs
Publication statusPublished - 1 May 2018
Externally publishedYes

Keywords

  • ageing
  • cognitive reserve
  • plasticity
  • transcranial direct current stimulation
  • visual attention

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