Vieillissement normal et cognition

Abstract

Le vieillissement normal est accompagné de modifications du fonctionnement cognitif. Les plus fréquentes touchent la mémoire, l’attention ou les habiletés visuospatiales. Des facteurs généraux et des facteurs spécifiques expliquent ces changements indicateurs du vieillissement cérébral. Ils ne sont cependant pas obligatoires, mais dépendent des réserves en ressources cognitives que les individus possèdent, et de la façon dont ils continuent à les entretenir et à les exploiter. Le cerveau est en effet un organe qui s’adapte si on le met dans de bonnes conditions. Il est donc possible de retarder les effets du vieillissement et, dans certains cas, de les moduler.

It is now well documented that normal aging modifies the cognitive functioning and most observations suggest that cognition evolves in the direction of deterioration. The more frequently impaired functions are memory, attention and visual-spatial abilities. On the other hand, some abilities seem to increase, such as vocabulary. Considering the aging effect on cognition, questions remain regarding directionality, universality and reversibility. A great variability in aged related impacts is observed among subjects and among cognitive domains. Some individuals evolved more rapidly than others. Some cognitive functions are more affected by aging than others. General and specific factors are hypothesized to explain the aged related cognitive decline. Among them, educational level, health, cognitive style, life style, personality, are likely to modulate the aged related cognitive evolution by influencing attentional resources and cerebral plasticity. Cognitive resources are essential to develop adaptative strategies. During the life span, resources are activated and increased by learning and training. Considering the role of cognitive resources, successful aging is dependent on several conditions : absence of disease leading to a loss of autonomy, maintenance of cognitive and physical activities, and active and social engaged lifestyle.