JMIR Publications

ABSTRACT

Background:

The earliest possible detection of mild cognitive impairment (MCI) is crucial for providing treatment before further cognitive decline occurs. Cognitive challenge tests such as the Loewenstein-Acevedo Scales for Semantic Interference and Learning (LASSI-L™) have demonstrated the ability to identify individuals at higher risk for cognitive deterioration. Further, performance on specific components of the LASSI-L™, particularly proactive interference, has been found to correlate with the presence of critical Alzheimer’s Disease (AD) biomarkers. However, paper and pencil tests require skilled testers and are not practical in many community settings or for large-scale screening in prevention studies. This paper reports on the development and initial validation of a self-administered computerized version of the LASSI, the LASSI-D™.

Objective:

Examine the convergence of the legacy paper LASSI-L and newly developed LASSI-D in healthy individuals and those with amnestic MCI.

Methods:

. A cloud-based software system was developed, using voice recognition technology and an AI generated avatar assessment assistant. English and Spanish versions of the LASSI were created, and participants were assessed with either the LASSI-L™ or LASSI-D™ first, in a sequential assessment study. Participants with amnestic (a)MCI (n=54) or normal cognition (n=58) were also assessed with several cognitive assessments, including traditional measures such as the ADAS-Cog. We examined group differences in performance across the two versions of the LASSI, as well as correlations between LASSI performance and other measures across the two versions.

Results:

Differences between aMCI and NC samples were all statistically significant with large effect sizes (d>.68) across recall and intrusion variables for both versions of the LASSI. There were no statistically significant performance differences in critical variables between paper and computer administration in either NC or aMCI samples, (all p<.13). There were also no differences according to language across versions, and correlations between LASSI variables and other cognitive variables were highly similar across versions. The most predictive LASSI variables in previous studies, Proactive Interference (PI) and Failure to recover from Proactive Interference (frPI), were essentially identical across the versions within each participant group. Critically, PI and frPI scores were identical to those obtained in previous independent studies with the paper version of the LASSI-L™. Classification accuracy was 88% for NC and 78% for aMCI participants.

Conclusions:

The newly developed LASSI-D™ was highly convergent with the legacy paper LASSI-L™. Across all indices of similarity, including sensitivity, criterion validity, classification accuracy, and performance, the two versions converged in both Spanish and English. Future papers will present additional validation data, including correlations with blood-based AD biomarkers and possible alternative forms. Data presented from this study provide convincing evidence of the utility of a fully self-administered computerized cognitive challenge test. Clinical Trial: Not a randomized clinical trial.