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Title: Visuo-spatial processing in ageing : neuropsychological and neuroimaging correlates
Authors: Lai, Che-Ying
Issue Date: 2016
Publisher: Newcastle University
Abstract: The relationship between cognitive decline in ageing and changes in associated brain areas is attracting research interest. Growing evidence suggests that in some individuals, recruitment of resources from additional brain areas can act as a buffer against declining cognitive function. However, most research has focused on language while evidence from the visuo-spatial domain is lacking. Categorical and coordinate visuo-spatial relations are known to elicit a marked hemispheric specialisation effect and were therefore utilised to investigate cognitive scaffolding in visuo-spatial processing in healthy ageing. Two visuo-spatial short-term memory (VSSTM) tasks, the CATCOORD task and the dot-cross task, were first administered to young adults (n=164) to observe categorical and coordinate performance. Hemispheric lateralisation effects were found in the dot-cross task but not the CATCOORD task. Neuroimaging results revealed similar bilateral activation when processing categorical or coordinate spatial judgments. Stronger frontal activation was observed when processing difficult coordinate, but not categorical, change trials in the dot-cross task. Seventy-one middle-aged (age between 45-59) and older adults (age above 60) undertook a battery of neuropsychological tests. Some of the older participants (n=38) were recruited to the neuroimaging component of the study. Participants were separated into higher- and lower-performance groups. Neuropsychological results showed widespread correlations between different neuropsychological tests in the lower- rather than the higher-performance group. The young group involved fewer brain regions than the old groups. Within the older participants, the higher performance group activated regions stronger than the lower performance group. In addition, the old-higher performance group showed stronger frontal activations than the young and old-lower groups when processing difficult trials. Older people showed slower behavioural performance than young people however, no significant difference was observed between the old-higher and old-lower group. A number of interesting findings have been identified to further our understanding of cognitive ageing and scaffolding mechanisms.
Description: PhD Thesis
Appears in Collections:Institute of Neuroscience

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