ABSTRACT
Alterations in cognitive functioning in the absence of dementia have long been considered a normal aspect of ageing related to the changes in brain. Aecting, principally episodic verbal memory, such changes are generally distinguished from neurodegenerative disorders by their far slower progression, their lesser impact on ability to perform activities of daily living and the relative sparing of linguistic and visuospatial functions. Increased interest in the nature and long-term prognosis of ageing-related modications in cognitive performance has now led to the question as to what extent they may be considered ‘normal’. e past 50 years have seen numerous attempts to dene these subclinical alterations in cognitive functioning and to establish their aetiology with greater precision than the general notion of ‘ageing brain changes’ to which they have formerly been attributed.
