Published: 2019-08-27 11:30 | Updated: 2019-09-02 08:25

New thesis: Multimodal imaging: Functional, structural, and molecular brain correlates of cognitive aging

Hi Bárbara Avelar Pereira, PhD-student at the Division of Aging Research Center. On 16 September you will defend your thesis ”Multimodal imaging: Functional, structural, and molecular brain correlates of cognitive aging”, what's the main focus of the thesis?

Bild på Bárbara Avelar Pereira, ARC.

In my thesis, I used various neuroimaging techniques to investigate the role of aging on brain integrity and how this relates to cognitive performance. As we grow older, many of our cognitive abilities decline; this means that we perform a little worse in tasks evaluating, for example, memory or processing speed. We know that cognitive decline is associated with changes in the brain, but how the two relate to each other is still unclear. Different brain changes are also likely to be interrelated, which adds to this complexity.

Which are the most important results? 

A primary focus in my thesis was functional connectivity, a measure of how well different brain areas communicate with each other, but we also investigated changes in white-matter integrity and molecular properties. We found that functional connectivity is reliably linked to performance in different cognitive tasks, and is also related to other measures of brain integrity, such as iron load and white-matter integrity. For example, iron content was associated with worse functional connectivity in a brain area called the striatum, and dopamine was also linked to iron in this brain region. We also showed that functional connectivity varies depending on age and mental state, which has implications for aging research, since it suggests that scanning sessions during rest do not provide a complete picture of brain dynamics. In general, our results show that the way in which alterations in different brain measures relate to each other is complex and multifaceted and this is reflected in cognition as well.

How can this new knowledge contribute to the improvement of people’s health?

It is hard to say what the immediate gains might be. Basic science tries to further our understanding of a given phenomenon, so it focuses less on potential practical implications, and more on the questions themselves. In this case, the main goal is to contribute to a better understanding of how the brain relates to cognition in aging. We hope that this knowledge can help to differentiate normal age-related changes from those that are pathological, such as in the case of dementia. This will also contribute to the development of better intervention programs and diagnostic tools. Only by doing that, we can hope to detect early signs of brain pathology and either prevent further degeneration or, perhaps, even improve brain functioning.

What’s in the future for you? Will you keep on conducting research?

After a sunny vacation in the Maldives, I will continue working at KI but also apply for other positions. I plan to keep conducting work on this line of research, focusing on brain connectivity and other measures of brain integrity in relation to cognition and aging.