Using Cognitive Reserve to Create Norms for the TMA-93 (Relational Binding of Images)

Abstract

Background: TMA-93 examines relational binding using images. Biomarker validation has demonstrated that it is discriminative for diagnosing early AD. The effect of cognitive reserve on TMA-93 performance remains unexplored and could improve the interpretative framework for using the test. Objective: To study the effect of cognitive reserve on TMA-93 performance and to provide new norms for the test that include its measurement. Methods: Cognitively unimpaired people aged 55 and over were systematically recruited for this cross-sectional normative study in southern Spain. Age, sex, and scores on the Cognitive Reserve Questionnaire (CRQ; maximum score: 25 points) were collected, and the TMA-93 was administered (maximum score: 30 points). Percentile-based reference data that captured combinations of socio-demographics variables with significant effect on TMA-93 performance were calculated. Results: 902 participants (62.5% female; age: median = 68, IQR = 61–75, range = 55–90) were included. CRQ total scores were globally low (median = 8, IQR = 5–13, range = 0–24). Cognitive reserve, including modifiable items as reading activity and intellectual gaming activity, and age mainly supported the TMA-93 total score variance. Sex seemed to have some influence in the elderly. TMA-93 total scores medians began to drop from 70–75 years old. Higher total score on the CRQ and, possibly, female sex determined a gentler slope. New norms based on these variables showed wide variations in scores for the 5th and 10th percentiles. Conclusion: Visual relational binding ability depends on cognitive reserve, including modifiable items. The age-related binding deficit is buffered by higher cognitive reserve and, at older ages, by female sex.