Researcher: Linda Geerligs, MSc (PhD student)
Thesis defense: 2014
First promotor: Monicque Lorist, PhD
Funding: GMW-RuG

We all grow older, yet a lot is unknown about the causes behind age-related changes in cognitive functioning. In this thesis, we have investigated how communication between brain areas changes with age and how this affects cognitive functioning. Brain networks consist of different brain areas, which have high connectivity with each other but limited connectivity with other networks. We have shown that these brain networks become less distinct as people age because connectivity within networks is decreasing with age whereas connections between networks are increasing. We found indications that this decrease in connectivity within brain networks is related to a decline in cognitive functioning in older adults. One specific cognitive function was studied in more detail; selective attention. This is the mechanism that allows us to focus attention on the information from the environment that is relevant to us, while ignoring the irrelevant information. Older adults have more trouble ignoring the irrelevant information. We found that the brain can prepare for the upcoming visual information and that this plays an important role in the suppression of irrelevant information. Moreover, we found that older adults are able to compensate for the physical decline in their brain to some extent by recruiting additional brain areas during the selective attention task and by increasing the connectivity between specific brain areas. The insights that stem from this type of fundamental research are important to provide new potential targets for interventions in older adults that will help them maintain their cognitive abilities.

References

• Geerligs L, Renken RJ, Saliasi E, Maurits NM, Lorist MM. A Brain-Wide Study of Age-Related Changes in Functional Connectivity. Cereb Cortex. 2014 Feb 13. PMID: 24532319.
• Geerligs L, Saliasi E, Maurits NM, Renken RJ, Lorist MM. Brain mechanisms underlying the effects of aging on different aspects of selective attention. Neuroimage. 2014 May 1;91:52-62. PMID: 24473095.
• Geerligs L, Saliasi E, Renken RJ, Maurits NM, Lorist MM. Flexible connectivity in the aging brain revealed by task modulations. Hum Brain Mapp. 2014 Aug;35(8):3788-804. PMID: 24382835.
• Geerligs L, Maurits NM, Renken RJ, Lorist MM. Reduced specificity of functional connectivity in the aging brain during task performance. Hum Brain Mapp. 2014 Jan;35(1):319-30. PMID: 22915491.
• Geerligs L, Saliasi E, Maurits NM, Lorist MM. Compensation through increased functional connectivity: neural correlates of inhibition in old and young. J Cogn Neurosci. 2012 Oct;24(10):2057-69. PMID: 22816367.