Rethinking Behavioral and Psychological Symptoms of Dementia in Severe Alzheimer's Disease: From Intentional Explanation to an Ecological, Body-Environment Framework.

In contemporary dementia care, behavioral and psychological symptoms of dementia (BPSD) are often understood as expressions of the person's intentions or needs. This paper examines the limits of understanding BPSD as "expressions of intention" in severe Alzheimer's disease. It argues that while desires may still be preserved, the formation and maintenance of beliefs-an essential constituent of intentions in the standard desire-belief model-are likely to be severely compromised. As a result, many behavioral and perceptual symptoms closely related to basic activities of daily living cannot be adequately explained within an intention-based framework. As a complementary framework to existing dementia care theories, this paper proposes a reconceptualization of BPSD as arising from the interaction between embodied procedural memory and environmental affordances. Many BPSD are better understood not as expressions of intention, but as the outcome of situational and non-selective reactivation of fragments of relatively preserved procedural memory in response to the structure of the immediate environment. This reconceptualization extends the focus of care practice beyond the interpretation of the presumed meanings or intentions underlying BPSD and highlights the importance of modifying care environments in ways that appropriately support or constrain the reactivation of procedural memory.