Performance and intrusion errors on challenging cognitive assessments associate with subjective cognitive decline

Abstract

AbstractBackgroundSubjective cognitive decline (SCD) in ostensibly cognitively normal older adults has been proposed to reflect preclinical Alzheimer’s disease (AD). Yet traditional neuropsychological tests have inconsistently linked SCD and cognitive performance, possibly reflecting the lack of sensitivity and specificity in such tests to capture subtle cognitive changes. Indeed, novel cognitive tests as well as intrusion errors appear to be more closely associated with preclinical AD biomarkers. However, there is limited investigation into the association of SCD with these cognitive outcomes. This study examines SCD in relation to the main outcomes and intrusion errors on two novel challenging cognitive tasks, and a traditional neuropsychological test.Method94 healthy older adults with a mean age of 73 years (SD=7.36), and education of 17 years (SD=2.34) were recruited for this study. Participants completed three SCD questionnaires regarding common cognitive difficulties in memory, language, attention and executive functioning. A single factor score was derived as main outcome for SCD. Cognitive assessment included the Loewenstein‐Acevedo Scale for Semantic Interference and Learning (LASSI‐L), the Face‐Name Associative Memory Exam (FNAME) task, and the Selective Reminding Test (SRT). Main outcomes for each measure included: SRT (total and delayed recall and intrusion errors); LASSI‐L (recovery from semantic interference, percentage of intrusions errors, total semantically related intrusions (SRI) and competing item intrusions (CII)); FNAME (total names recalled, SRI and CII). Demographically adjusted linear regressions were conducted to examine the unique contribution of performance and intrusion errors on each measure to SCD.ResultBoth FNAME names recall (β=‐.24, p=.027) and SRI (β=.25, p=.015) were independently associated with SCD, while overall intrusions and CII were not (p>.05). The LASSI‐L overall intrusions (β=‐ .30, p=.009) and CII (β=‐ .29, p=.014) were also associated with SCD, while SRI and recovery from semantic interference were not. (p>.05). No SRT outcomes were associated with SCD (p>.05)ConclusionSCD appears to capture subtle changes on sensitive cognitive measures proposed to be indicative of preclinical AD. Results support the use of both main outcomes and intrusion errors on these cognitive tests, as they may each reveal sensitive information regarding various mechanisms that can breakdown in early AD.