PhD ceremony Ms. L. Geerligs: Images of healthy aging: functional brain networks and selective attention

PhD ceremony: Ms. L. Geerligs

Dissertation: Images of healthy aging: functional brain networks and selective attention

Promotor(s): prof. M.M. Lorist, prof. N.M. Maurits

Faculty: Behavioural and Social Sciences

All of us are growing older; still 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 areas are organized into networks composed of brain areas with high interconnectivity, 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 using recruiting additional brain areas during the selective attention task and by increasing the connectivity between specific brain areas. The insight that stem from this type of fundamental research is important to provide new potential targets for interventions in older adults that will help them to maintain their cognitive functions.