Establishing Normal Cognitive Test Scores for Adults Using a Voice-Enabled Digital Testing Platform Across the Lifespan

Registry record from ClinicalTrials.gov (NCT07763392). This is a study registration, not published results. Lead sponsor: The Neurology Center of Southern California. Recruitment status: RECRUITING. Study type: OBSERVATIONAL. Enrollment: 1000 participants (ESTIMATED). Conditions: Cognition, Cognition Disorders, Cognition - Other, Dementia, Alzheimer Disease, Memory, Neurocognition. Interventions: DIAGNOSTIC_TEST: Voice-based Cognitive Testing. Primary outcome measures: Development of normative reference values , 30 minutes. Brief summary: Participants enrolled in this study will complete a single-session, non-invasive, computerized cognitive assessment administered through a secure, web-based digital platform. The purpose of the study is to establish normative cognitive performance data from healthy adults aged 18-100 years and develop age-, sex-, and education-adjusted reference values for the digital assessment platform. This is an observational study and does not involve any therapeutic intervention, investigational treatment, or alteration of routine medical care. Following electronic informed consent, participants will complete a standardized screening questionnaire to determine eligibility. The questionnaire collects demographic information, education, English language proficiency, medical and neurological history, psychiatric history, medication use, substance use, sleep history, and self-reported cognitive concerns. Standardized mood screening instruments (PHQ-9 and GAD-7) are also administered. Individuals meeting predefined exclusion criteria that could significantly influence cognitive performance will not be included in the normative dataset. Eligible participants will then complete a digital cognitive assessment battery using standardized visual and auditory instructions. The platform utilizes automated voice-recognition technology to capture spoken responses and standardized algorithms to score performance, eliminating the need for examiner scoring and ensuring consistent administration across participants. Total study participation, including consent, screening, and testing, is approximately 30 to 45 minutes. The cognitive battery evaluates multiple cognitive domains commonly assessed during neuropsychological examinations. Language abilities are assessed through phonemic and semantic verbal fluency tasks, measuring the ability to rapidly generate words within specified categories. Confrontation naming is evaluated using digitally presented images that participants identify verbally. Learning and memory are assessed through immediate and delayed verbal recall tasks, including recognition memory measures. Attention and working memory are evaluated using forward and backward digit span tasks. Executive functioning and attention are further assessed using a brief computerized problem-solving task. Equivalent alternate versions of selected tasks may be administered to minimize practice effects while measuring the same cognitive domains. All assessments are brief, non-invasive, and completed using spoken responses. The platform automatically records participant responses, response timing, and scoring metrics. Voice recordings are collected solely to support automated scoring and quality assurance. All electronic data are transmitted using encrypted connections and stored within HIPAA-aligned cloud infrastructure. Personally identifiable information is stored separately from cognitive performance data using unique study identification numbers, and only authorized study personnel have access to identifiable information. De-identified data will be used to generate normative reference values. A subset of approximately 100 participants may be invited to complete a second assessment 2-4 weeks after the initial visit to evaluate test-retest reliability. Participation in this follow-up assessment is voluntary. Participants will not receive diagnostic results or individualized interpretations of their performance because the study is intended solely to establish normative reference data. If responses on the PHQ-9 suggest potential acute self-harm risk, the platform will provide crisis resources and notify the study team in accordance with the study safety procedures. The primary outcome of the study is the development of age-, sex-, and education-adjusted normative reference values for the digital cognitive assessment platform, supporting standardized interpretation of future assessments in clinical and research settings.