The Visual Image Simple Recognition Test, a language-minimized recognition test: Psychometric and clinical evaluation in Alzheimer's disease

Background Episodic memory tests in Alzheimer's disease (AD) often depend on verbal recall or drawing. Objective To develop Visual Image Simple Recognition Test (VISRET) and evaluate its psychometric and clinical performance. Methods We studied 149 individuals (healthy participants [HP] = 62; AD = 53; patients with aphasia [AP] = 34). We assessed reliability (split-half Spearman–Brown [SB]), known-groups validity with age-adjusted models and age-stratified analyses, and a Bayesian logistic model (AD versus HP). A Bayesian linear model produced a composite Memory Score and highest posterior density (HPD)-based cut-offs using HP alone, subsequently evaluated by five-fold cross-validation. Convergent and discriminant validity were assessed by correlating VISRET with established neuropsychological tests in non-aphasic AD. Results Internal consistency was good in AD (SB = 0.87) and acceptable when pooled within-group (SB = 0.84). AD–HP discrimination was large, persisting after age adjustment, within age strata, and following aphasic AD exclusion. The Bayesian model showed excellent discrimination (posterior-mean AUC = 0.99, 95% HPD = 0.97–0.99). AP differed from HP but with trivial absolute differences (total 39.6 versus 39.4; false recognitions 0.1 versus 0.3). In non-aphasic AD, VISRET total correlated with an established episodic memory test (ρ=0.60) but demonstrated weak or near-zero correlations with non-memory domains (e.g., nonverbal reasoning, ρ=0.02). Cross-validated, HP-derived Memory-Score cut-offs achieved mean AUC = 0.98; at the 95%-HPD threshold, sensitivity = 0.87 and specificity = 0.95; at 99%-HPD, sensitivity = 0.74 and specificity = 0.98. Conclusions VISRET is a brief, language-minimized recognition test facilitating AD-related memory impairment detection, with minimal practical impact of aphasia. The HP-derived Memory Score and cut-offs demonstrated stable cross-validation, suggesting potential clinical utility pending replication and external validation.