An interdisciplinary research project, based on a European inquiry, has just shown that the age people retire from working life has an impact on cerebral ageing. The longer a person remains active the less they will be subject to the loss of cognitive functions, and the opposite is true. This is a research project whose results could influence political decisions and which thus needs to be handled with care.

Chance sometimes deals you a lucky hand. In 2004, Stéphane Adam, a neuropsychology researcher, was in the middle of polishing the final pages of his thesis, on improving the quality of life for people affected by Alzheimer’s disease. The door to his office was open. Sergio Perelman, a HEC Management School-ULg economist, lost in the psychology building, asked him for help in finding a researcher who was interested in the research field of ageing. The subject grabbed the neuropsychologist’s attention. Pereleman for his part manages the French Speaking Community of Belgium’s role in the SHARE enquiry. An enquiry funded by the European Commission carried out on over 44,000 people aged over 50 in 14 different countries; this is a vast project which allows many different problematics to be tackled. Levels of income, health problems, the composition of the family, retirement, extra-professional activities, and two tests on memory and attention span. Two tests which explain the presence of the economist in the psychology department’s corridors.  What to do with such data? Stéphane Adam thus talked to him about cognitive reserve, a relatively recent concept which he focused on in his thesis. This reserve is the accumulation of all the activities carried out over the course of a lifetime. It enables the effects of the reduction of cognitive functioning, which progressively sets in over the years, to be compensated. It also has a beneficial impact against certain diseases which affect cognition, such as Alzheimer’s disease. ‘There are even cases of patients who contract Alzheimer’s disease but the illness is only diagnosed during a post-mortem examination of the brain. It wasn’t revealed whilst they were alive because the cerebral characteristics of the disease did not affect their day to day lives.’

The meeting between Sergio Perelman, Stéphane Adam, and Eric Bonsang, who was to join the project, marked the being of a long saga. Meetings were set up, the project was thought through and little by little led to a new and original starting problematic. ‘The majority of studies carried out since the 1990s look at activities carried out by the population before the age of 60, and the impact of these activities on mental health and the functioning of memory. The underlying conclusion of these studies is that it is necessary to begin studying as early as possible and to remain active all life long. Our initial question was different: never mind a  person’s past, never mind their current extra-professional activities. If the person continues being active at the age of 60 (professional and leisure activities) what will be the impact on their cognition and their future in the years to come?’

The chicken or the egg?