Gallery Game: Smartphone-based Assessment of Long-Term Memory in Adults at Risk of Alzheimer’s Disease

Abstract

Gallery Game, deployed within the Mezurio smartphone app, targets the processes of episodic memory first vulnerable to neurofibrillary tau-related degeneration in Alzheimer’s Disease, prioritising both perirhinal and entorhinal cortex/hippocampal demands. Thirty-five healthy adults (aged 40-59 years), biased towards those at elevated familial risk of dementia, completed daily Gallery Game tasks for a month. Assessments consisted of cross-modal paired-associate learning, with subsequent tests of recognition and recall following delays ranging from one to 13 days. There was a non-linear decline in memory retention with increasing delays between learning and test, with significant forgetting first reported following delays of three and five days for paired-associate recall and recognition respectively, supporting the need for ecologically valid measures of longer-term memory. Gallery Game outcomes correlated as expected with established neuropsychological memory assessments, confirming the validity of this digital assessment of episodic memory. In addition, there was preliminary support for utilising the perirhinal-dependent pattern of semantic errors during object recognition as a marker of early impairment, justifying ongoing validation against traditional biomarkers of Alzheimer’s disease.