Investigating neurophysiological changes in ageing and their relation to recognition memory using advanced MRI

Abstract

It is believed that with ageing comes a decline in many cognitive processes, rangingfrom memory, language and executive function to response inhibition andmotor and visual processes. However, memory has attracted much attention andis of particular interest in ageing research. This is because it is a form of cognitionthat probably suffers the clearest decline with age, and can have a detrimentaleffect on day-to-day living. Additionally, as people are living longer these problemsare affecting an increasing number of people and has therefore become anissue of concern. It is believed that these declines stem from neurophysiologicalchanges that occur alongside ageing. It can be seen that research into this area is ofparticular importance to better understand the healthy ageing brain, and how illnessessuch as Alzheimers disease differ from this normal progression. The focusof this PhD project addresses this issue by exploring healthy age-related declinesin recognition memory and their neural correlates, using brain imaging techniquesto investigate underlying changes in brain structure. Novel recognition memorytasks were developed (Chapter 4) to tap underlying processes supporting scenerecognition (recollection and familiarity), and were run alongside selected cognitivetasks taken from existing standardised batteries (Chapter 5). In additionto these behavioural measures, MR imaging datasets were collected relating tostructural (Chapter 6), perfusion and functional (Chapter 7) as well as diffusion(Chapter 8) measures of the brain. The relationships between these imaging measureswere investigated in Chapter 9, in addition to looking at how they relatedindividually to a measure of recollection memory when accounting for the influenceeach imaging measure had on the others. Overall, age effects were found forthe novel recognition memory tasks, in particular showing a significant decline inrecollection performance with age. This was associated with a number of neurophysiologicalmeasures (functional, perfusion, diffusion and volume) which alsoshowed age-related changes. After taking into account the relative contribution ofthese measures to task performance, no single imaging measure was found to bea significant predictor of recollection performance.

Date of Award	1 Aug 2014
Original language	English
Awarding Institution	The University of Manchester
Supervisor	Laura Parkes (Supervisor), Geoff Parker (Supervisor) & Daniela Montaldi (Supervisor)