Working memory function and dysfunction in Alzheimer's disease
The average age of the population of Western Europe is increasing to the extent that within a decade, people of retirement age may well be in the majority. With this will come an increase in the number of people suffering from cognitive changes with age, and as sequellae to the dementias. Cognitive Neuroscience has, and will have a crucial role to play in developing an understanding of these cognitive changes to assist with early detection, with evaluation of therapies, and with the management of cognitive impairments to extend independent living. The societal importance is complemented by the scientific importance of understanding the links between cognitive function and brain organisation, using a combination of behavioural experimental techniques and methods for exploring the neuroanatomical correlates of cognitive operations. This presentation will first review research examining the changes in cognitive functions that are associated with old age and with the early stages of Alzheimer’s disease (AD), set in the context of working memory. The discussion then will focus on recent research showing how the ability to perform a memory task and a perceptuo motor task, or two memory tasks concurrently is specifically impaired in Alzheimer’s patients while being less evident in healthy ageing. The effects appear to be specific dual task demands, and not to differences in baseline levels of single task performance or overall task demand. Results will be interpreted as indicating a dual task co- ordination function within the healthy brain that shows a specific deterioration in AD. Implications for detection and management of the cognitive impairments observed will be discussed.