Comparing different tests to detect early manifestation of prospective memory decline in aging

Time-Based and Event-Based Prospective Memory in Mild Cognitive Impairment and Alzheimer's Disease Patients: A Systematic Review and Meta-analysis

Prospective memory (PM) is the ability to remember to perform planned actions in a future moment and it is of fundamental importance for an independent and autonomous lifestyle from development to late adulthood. Deficits in episodic memory and executive functions, which are involved in PM are characteristic features of mild cognitive impairment (MCI) and Alzheimer's disease (AD). Considering that the number of older adults is drastically increasing over the next decades, it is of great interest to understand how PM decline in healthy older adults and patients with different degree of cognitive decline. The present meta-analysis included 46 studies investigating PM performance in AD patients (17 studies) and people with MCI (24 studies); 5 studies included both clinical conditions in the same article. The 46 studies contributed a total of 63 independent samples and 129 effect sizes from 4668 participants (2115 patients and 2553 controls). Unlike previous reviews of the literature, our results with a larger and updated sample of studies confirmed lower PM abilities in AD compared to MCI and controls, although we did not observe conclusive differences between event-based and time-based PM in patients. Surprisingly, PM deficits shown by MCI and AD patients have decreased across years, in parallel to a reduction of the evidence of publication bias and an increase in the number of observations per task. We propose the use of more reliable research designs as one plausible explanation for the reduction of PM impairments.

Factor Structure of the Memory for Intentions Test (MIsT): A Conceptual Replication in Older Adults and People with HIV Disease

OBJECTIVE

The Memory for Intentions Test (MIsT) is a clinical measure of prospective memory that has strong evidence for convergent, discriminative, and ecological validity. This study uses a conceptual replication design to evaluate the latent structure of the MIsT in two parallel samples who commonly experience prospective memory deficits: older adults and people living with HIV disease.

PARTICIPANTS AND METHODS

Study participants included 303 people with HIV disease (ages 18-67) and 267 community-dwelling older adults (ages 50-91). Confirmatory factor analyses of the MIsT were conducted separately in each sample. We evaluated a one-factor model, as well as three two-factor models with the MIsT items loading onto each factor based on cue type, delay interval, or response modality.

RESULTS

The one-factor model provided the best (and most parsimonious) fit to the data in both study samples. All two-factor models also demonstrated good fit statistics, although correlations between the two factors in each model were high and none of the two-factor models provided a significantly better fit than the one-factor model.

CONCLUSIONS

Results of this conceptual replication study provide support for a robust factor structure of the MIsT across older adults and people with HIV disease. A total score for the MIsT provides the most parsimonious solution, although available evidence and theory also support the potential use of subscales (e.g., cue type). Future studies of the MIsT would be useful to determine its psychometrics in different clinical populations and across demographic factors (e.g., race/ethnicity).

Prospective memory impairment in neurological disorders: implications and management

Prospective memory is a core neurocognitive ability that refers to memory for future intentions, such as remembering to take medications and to switch off appliances. Any breakdown in prospective memory, therefore, has serious implications for the ability to function independently in everyday life. In many neurological disorders, including Parkinson disease and dementia, prospective memory deficits are common even in the earliest stages and typically become more severe with disease progression. Consequently, clinical assessment of prospective memory is of critical importance. This article provides an overview of the various manifestations and neural bases of prospective memory deficits. To facilitate clinical decision-making, validated measures of this construct are identified and their suitability for clinical practice is discussed, focusing in particular on clinical sensitivity and psychometric properties. The article concludes by reviewing the approaches that can be used to rehabilitate different types of prospective memory impairment, and algorithms to guide the evaluation and treatment of these impairments are provided.