Yen Ying Lim

Previous research using the Online Repeatable Cognitive Assessment Language Learning Test (ORCA-LLT) has demonstrated its utility in detecting differences in learning between groups of cognitively normal older adults who had abnormal levels of the beta-amyloid protein and cognitively normal older adults with normal levels of beta-amyloid. These changes can be detected using the ORCA battery in a much shorter period of time than existing screening tools. This led to the hypothesis that deficits in learning may be one of the earliest cognitive abnormalities of Alzheimer’s disease. 

We have now challenged this even further by examining rates of learning in cognitively normal, amyloid negative individuals who are APOE ε4 carriers and non-carriers. Using the ORCA-LLT, we found that even those who are amyloid negative, ε4 carriers showed a substantially lower rate of learning that matched ε4 non-carriers. These results provide the first evidence that subtle cognitive abnormalities can be detected even prior to individuals reaching accepted thresholds of amyloid abnormality.

We hope to use these high frequency modes of cognitive testing to detect extremely subtle signs of memory and thinking changes in a much shorter amount of time in individuals who have an elevated risk for Alzheimer's disease dementia than can be detected using standard paper and pencil neuropsychological assessments.

Lim, Yen Ying, Baker, Jenalle E, Bruns, Loren, Mills, Andrea, Fowler, Christopher, Fripp, Jurgen, Rainey-Smith, Stephanie R, Ames, David, Masters, Colin L, & Maruff, Paul. (2020). Association of deficits in short-term learning and Aβ and hippocampal volume in cognitively normal adults. Neurology, 95(18), e2577–e2585. https://doi.org/10.1212/WNL.0000000000010728

Lim, Yen Ying, Baker, Jenalle E, Mills, Andrea, Bruns, Loren, Fowler, Christopher, Fripp, Jurgen, Rainey‐Smith, Stephanie R, Ames, David, Masters, Colin L, & Maruff, Paul. (2021). Learning deficit in cognitively normal APOE ε4 carriers with LOW β‐amyloid. Alzheimer's & Dementia : Diagnosis, Assessment & Disease Monitoring, 13(1). https://doi.org/10.1002/dad2.12136

At the time of award, Dr Lim was a Senior Research Fellow and Head of the Cognitive Health and Ageing Outcomes (CHAOS) laboratory at the Melbourne Dementia Research Centre, Florey Institute of Neuroscience and Mental Health and the University of Melbourne.