Semantic Intrusion Error Ratio Distinguishes Between Cognitively Impaired and Cognitively Intact African American Older Adults.

Abstract

Semantic intrusion errors on memory tests may represent very early cognitive changes associated with elevated Alzheimer's disease pathology within the brain, including amyloid-β (Aβ). Subscales that measure proactive semantic interference (PSI) and intrusions related to PSI on the Loewenstein Acevedo Scales of Semantic Interference and Learning (LASSI-L) have been associated with high levels of brain amyloid load, structural changes on brain MRI in Hispanic and non-Hispanic groups. It is presently unknown whether intrusion errors or other measures of the LASSI-L can differentiate between African-American (AA) older adults diagnosed with amnestic mild cognitive impairment (aMCI) or classified as cognitively normal (CN). This study examined the extent to which a high percentage of semantic intrusion errors on LASSI-L subscales susceptible to PSI and other LASSI-L measures could differentiate between AA aMCI and CN groups. Forty-eight AA older adults were recruited (27 CN and 21 aMCI) and received a through clinical and neuropsychological evaluation. The LASSI-L was administered independent of diagnostic classification. With and without statistical adjustment for literacy, AA aMCI participants scored lower on all LASSI-L measures. ROC analyses revealed an area under the curve exceeding 90% and correctly classified 86% of AA aMCI with 82% specificity for AA CN participants. Percentage of intrusion errors on the LASSI-L subscales susceptible to PSI differentiated AA aMCI from AA CN. This adds to emerging evidence indicating that the LASSI-L may be culturally appropriate and can differentiate between aMCI and CN in diverse ethnic/cultural groups.