Journal article
Modulating perceptual complexity and load reveals degradation of the visual working memory network in ageing
NeuroImage (Orlando, Fla.), Vol.157, pp.464-475
08/15/2017
DOI: 10.1016/j.neuroimage.2017.06.019
PMID: 28627364
Abstract
Previous neuroimaging studies have reported a posterior to anterior shift of activation in ageing (PASA). Here, we explore the nature of this shift by modulating load (1,2 or 3 items) and perceptual complexity in two variants of a visual working memory task (VWM): a 'simple' color and a 'complex' shape change detection task. Functional near-infrared spectroscopy (fNIRS) was used to record changes in activation in younger (N=24) and older adults (N=24). Older adults exhibited PASA by showing lesser activation in the posterior cortex and greater activation in the anterior cortex when compared to younger adults. Further, they showed reduced accuracy at loads 2 and 3 for the simple task and across all loads for the complex task. Activation in the posterior and anterior cortices was modulated differently for younger and older adults. In older adults, increasing load in the simple task was accompanied by decreasing activation in the posterior cortex and lack of modulation in the anterior cortex, suggesting the inability to encode and/or maintain representations without much aid from higher-order centres. In the complex task, older adults recruited verbal working memory areas in the posterior cortex, suggesting that they used adaptive strategies such as labelling the shape stimuli. This was accompanied by reduced activation in the anterior cortex reflecting the inability to exert top-down modulation to typical VWM areas in the posterior cortex to improve behavioral performance.
Details
- Title: Subtitle
- Modulating perceptual complexity and load reveals degradation of the visual working memory network in ageing
- Creators
- Sobanawartiny Wijeakumar - University of East Anglia, School of Psychology, Norwich NR4 7TJ, United Kingdom. Electronic address: S.Wijeakumar@uea.ac.ukVincent A Magnotta - University of Iowa, Department of Radiology, Iowa City, IA 52242, USAJohn P Spencer - University of East Anglia, School of Psychology, Norwich NR4 7TJ, United Kingdom
- Resource Type
- Journal article
- Publication Details
- NeuroImage (Orlando, Fla.), Vol.157, pp.464-475
- Publisher
- United States
- DOI
- 10.1016/j.neuroimage.2017.06.019
- PMID
- 28627364
- ISSN
- 1053-8119
- eISSN
- 1095-9572
- Language
- English
- Date published
- 08/15/2017
- Academic Unit
- Roy J. Carver Department of Biomedical Engineering; Radiology; Psychiatry; Psychological and Brain Sciences; Iowa Neuroscience Institute
- Record Identifier
- 9984051789702771
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