Impaired capacity for prospection in the dementias--Theoretical and clinical implications

Prospection, or future thinking, refers to the ability to mentally simulate plausible events at a future point in time and draws heavily upon the capacity to retrieve autobiographical details from the past. This review examines the extent to which prospection is compromised in neurodegenerative disorders with a view to identifying (1) underlying mechanisms of future thinking disruption and (2) the impact of future thinking deficits on everyday adaptive functioning.

PubMed and MEDLINE were searched for peer-reviewed articles published or in press up to 14 October 2014. The key criterion for inclusion was that the primary outcome measure concerned the envisaging of episodic events at a future time point. Search terms of 'future thinking', 'prospection', and 'future simulation' were used in combination with the following terms: 'dementia', 'Mild Cognitive Impairment', 'Alzheimer's disease', 'semantic dementia', 'frontotemporal dementia', 'Parkinson's disease', 'Motor Neuron disease', 'Vascular dementia', and 'Dementia with Lewy bodies' (e.g., 'future thinking' AND 'Alzheimer's disease'). Searches were limited to articles published in English.

A total of nine unique papers were identified in which prospection was the main outcome measure in dementia. Collectively, these studies reveal marked impairments in the ability to simulate personally relevant events at a future time point in dementia syndromes.

Future research investigating the real-world implications of prospection deficits in dementia is crucial to elucidate the interplay between future-oriented thought and everyday adaptive functions such as prospective memory, decision-making, and maintaining a coherent sense of self over time.