Rusted, J. 1 , Broulidakis, J. 1 , Dowell, N. 2 & Ruest, T. 1
1 Sussex University, Brighton BN1 9QH, UK
2 Brighton and Sussex Medical School, Brighton, UK.
The APOE e4 genotype is associated with higher risk for cognitive impairment and dementia in older adulthood. In younger adults, however, a number of studies report carriers of this allele perform better on cognitive tasks than their age-matched non-e4 peers. We present behavioural and structural imaging data to explore differences between healthy e4 carriers and their non-e4 counterparts. First we examine structural MR imaging data, to examine whether there are subtle differences in normal appearing brain tissue that might produce cognitive benefits in e4 carriers. Second, we collected verbal fluency data, using switching and clustering indices, to distinguish any strategy differences that may account for a previously reported advantage of e4 over non-e4 carriers on this task. Behavioural results suggest e4 carriers may use more effective cognitive strategies; structural imaging data identified higher density white matter in e4 carriers, suggesting also greater neural efficiency. We discuss the impllications of these findings in relation to the APOE genotype effects observed in older adults.