Controlled and automatic memory processing in Alzheimer’s disease

Over the last two decades studies of patients with Alzheimer’s disease (AD) have made a significant contribution in helping to elucidate the neurological and cognitive bases for controlled and automatic forms of retrieval from long-term memory. These studies show that AD patients demonstrate severe deficits on tasks that involve controlled processes. In contrast, their performance on tasks involving automatic processes is more variable. This article reviews experimental studies that have revealed dissociations between controlled and automatic memory processing in AD, and discusses evidence from functional neuroimaging studies which indicate that different forms of retrieval represent distinct aspects of brain activity. Attention is given to the assumption that memory retrieval reflects the operation of a single form of processing (automatic or controlled). The implications of adopting this assumption are discussed within the context of contemporary theoretical perspectives, and recent attempts to understand memory processing in AD and normal ageing by using the process-dissociation approach to memory are described. Finally, the importance of understanding the status of controlled and automatic memory processing for the diagnosis and management of AD is considered