A pilot study of a test for visual recognition memory in adults with moderate to severe intellectual disability

Objective assessment of memory functioning is an important part of evaluation for Dementia of Alzheimer Type (DAT). The revised Picture Recognition Memory Test (r-PRMT) is a test for visual recognition memory to assess memory functioning of persons with intellectual disabilities (ID), specifically targeting moderate to severe ID. A pilot study was performed to investigate whether the r-PRMT could differentiate DAT-related memory decline from pre-existing poor memory functioning of persons with moderate to severe ID. The r-PRMT scores were compared between 26 participants with DAT and moderate to severe ID and 33 controls with similar levels of ID. The results revealed that the controls with DS showed uniformly high scores in contrast to those with DAT on the r-PRMT and the score distributions of two groups were distinctly different with no overlap. On the other hand, the controls with non-DS etiologies scored much lower with a wider score spread, resulting in significant overlap with the score distribution of the participants with DAT. In conclusion, the r-PRMT may be effective in identifying persons with DAT among persons with moderate to severe ID from DS. However, the r-PRMT may result in a high false positive error rate in discriminating those with DAT among persons with moderate to severe ID from non-DS etiologies, if the judgment is based on a single point assessment.