37 The MAPP Room Memory Task: Examining Contextual Memory Using a Novel Computerized Task in Cognitively-Unimpaired Individuals with Autosomal Dominant Alzheimer’s Disease from the Colombia-Boston Biomarker Study

Abstract

Objective:Contextual memory, which refers to the ability to remember spatial or temporal circumstances related to an event, is affected early in Alzheimer’s Disease (AD). Computerized cognitive tasks have been suggested to be an ecological way to assess memory, but there are few studies that utilize these tools. Studying contextual memory via a computerized task in a Colombian kindred with autosomal dominant AD due to the Presenilin-1 (PSEN1) E280A mutation and a well-characterized disease progression may help us understand contextual memory changes in the preclinical AD stage. In this study we investigated whether a novel computerized task examining contextual memory can help identify those at increased risk for dementia.Participants and Methods:A group of 31 non-carriers (mean age=38.97±6.11; mean education=11.45±4.34) and 15 cognitively unimpaired PSEN1E280A mutation carriers from the Colombia-Boston (COLBOS) Biomarker Study (mean age=35.67±5.50), mean education=10.60±3.83) performed the “MAPP Room Memory Task” on a computer. As part of this task, participants are asked to remember ten rooms and the specific location of a few objects for later recall. During the immediate recall phase, participants are asked to recognize the objects presented in each room (Immediate Object Recognition) and their location (Immediate Object Placement). During the subsequent delay phase of the task, participants are asked to select the correct room in which an object was first presented (Delayed Room Recognition) and place the objects previously seen in each room (Delayed Object Placement). We conducted Mann Whitney U tests to analyze differences between groups and Spearman Rho correlations to examine associations among the Room Memory Task performance, age, education, and Mini Mental State Examination (MMSE).Results:There were no differences in age or education between carriers and non-carriers (p>0.05, for both). Carriers had worse Delayed Room Recognition than non-carriers (Carriers mean score=0.893±0.18, non-carriers mean score=0.987±0.05; U=168.0, p=0.02), while there were no differences in the other task conditions (all p>0.05). In carriers, education was positively associated with Immediate Object Placement (rs=0.61, p=0.02), Delayed Object Placement (rs=0.76, p=0.001), and Delayed Room Recognition (rs=0.68, p=0.006). There were no significant associations between Room Memory Task conditions and age or MMSE scores in carriers. Further, no significant associations were observed between Room Memory Task performance, and age, education or MMSE scores in non-carriers.Conclusions:Our preliminary findings show that the MAPP Room Memory Task, in particular the Delayed Room Recognition condition, may be helpful to discriminate those at increased risk of dementia. Future studies with larger samples using the Room Memory Task and AD-related biomarkers are needed to examine whether this task can be sensitive to early preclinical changes associated with AD and can potentially help track disease progression in those at risk.