PATTERN SEPARATION ABILITY RESULTS BETWEEN YOUNG ADULT APOLIPOPROTEIN E4 ALLELE CARRIERS AND NONCARRIERS

Abstract

The second leading risk factor for Alzheimer’s behind aging is the apolipoprotein e4 allele. This allele has been found to have slight differences in the cognitive abilities of aging populations regardless of the presence or lack of cognitive impairments. Older adult carriers tend to present better memory function than noncarriers of the e4 allele. A similar study looking at fMRI imaging in young adults reveals that neural activity in e4 noncarriers was slightly more demanding than in e4 carriers. Researchers in the current study recruited 51 graduate and undergraduate students at the University of Arizona to participate in a pattern separation task that tests the ability of working memory and recognition. Blood spot or saliva samples were collected from each participant to determine their apolipoprotein e4 status. Recognition results produced a main effect of scene condition—it was easier to recognize previously seen objects on white backgrounds than any other scene condition. Pattern separation results produced a main effect of scene condition as well—it was easier to identify objects depicted on white backgrounds than any other scene condition. Error Difference Score results produced a main effect of scene condition—repeated and novel scenes induced more errors to be made than white scene conditions. A surprising error score result of white scene condition found participants tended to incorrectly identify similar objects as “different” more often than on other scene conditions. There were no interactions between apolipoprotein status and scene condition. Further studies with more sensitive measures are needed to confirm or deny any differences in young adult apolipoprotein e4 carriers and noncarriers.