Multivariate imaging of knowledge and memory in youth and ageing

As people age, their ability to form new memories of events - to encode episodic memories - declines. This project uses advanced behavioural and functional magnetic resonance (fMRI) brain imaging methods to investigate this decline. It examines proposed age differences in the interplay between knowledge and memory that may reflect fundamental lifespan shifts in neural architecture. Despite their greater knowledge base, older adults are less able than young adults to access and use this knowledge to encode memories. In youth, both memory encoding and access to knowledge are supported by the left inferior frontal gyrus, part of a cognitive control network. One goal of the project is to examine how controlled access to knowledge contributes to memory and is supported by these brain networks. A second is to explore how controlled access to knowledge differs with age. A third is to test the proposal that impaired memory encoding in older people reflects reduced left inferior frontal gyrus function and altered interactions between cognitive control and memory brain networks. The results will help to test wider theories of cognitive and brain ageing that explain cognitive decline in terms of either a loss of specialised network architecture or a compensatory shift to rely on different brain networks. To test these theories the PhD student will learn and employ several advanced brain imaging design and multivariate analysis techniques: to quantify different knowledge representations involved in memory encoding (representational similarity analysis), to test for compensation by measuring the information carried by brain regions that are activated more in older people (multivariate Bayesian analysis), and to assess the integrity of functional brain networks and their interplay during memory encoding. This foundational research will improve understanding of memory difficulties in healthy older people.