Before applying for the JRA award I knew that becoming a researcher in Psychology was what I wanted to do, but deciding what I wanted to study seemed almost impossible given the sheer number of options available. When I saw that Sussex was offering JRA awards focusing on the causes and cures for Alzheimer’s I jumped at the opportunity, as I felt this would give me a good opportunity to explore a more neuroscience-based research project which greatly interested me. Professor Jenny Rusted was advertising JRAs in the newly established Alzheimer’s Society Doctoral Training Centre and it was with her I worked closely on my application; Prof Rusted was incredibly approachable and supportive throughout the application process, assisting me right from the start.
During the summer I got involved in an ongoing research project aimed at investigating the neural and behavioural consequences of a gene, APOE-E4, widely accepted to be the strongest genetic risk factor for Alzheimer’s disease. I assisted Dr Simon Evans, a postdoctoral fellow in Prof Rusted’s lab, in analysing data and writing a literature review on the use of the subsequent memory paradigm in research examining the neural consequences of ageing and APOE-E4. The subsequent memory paradigm involves participants being incidentally (unintentionally) exposed to words whilst completing an ongoing task in an MRI scanner, followed by a surprise recognition test in which participants indicate whether they had seen the words previously or not. This task is designed to induce episodic memory and activation in the hippocampus, an area implicated in the premature neural ageing seen in carriers of APOE-E4.
The analysis of the data itself proved to be a rewarding experience as it allowed me to gain extremely valuable knowledge with MRI data analysis software such as MATLAB and SPM. Immersing myself in the data for several weeks increased my personal investment in the project and the data itself, this gave me a hunger and excitement that was certainly lacking in my first and second years at university, as I felt I was genuinely contributing to something that would make a difference. Happily, the results of the analysis also proved very interesting; results from the MRI analysis indicated that APOE-E4 carriers were consistently underactivating several regions in the brain, relative to non-carriers, throughout the task. APOE-E4 carriers demonstrated significantly less activation in frontal, temporal, and parietal regions in the brain; these areas have been reported many times before in the literature to exhibit genotype differences with APOE-E4 in a number of cognitive domains. Surprisingly, we were unable to extract any genotype differences in hippocampal activation; this is not unusual – the hippocampus is such a small area in the brain, and so it can be difficult to pull out reliable data. Taken as a whole, the results suggest that APOE-E4 carriers may be more efficiently processing memories and information, as they retained equal memory performance to non-carriers in the face of lesser neural activation.
This post was originally published in Jenny Rusted’s lab group blog in September 2015