To study the relationships between age-related differences in MRI metrics and genetic and lifestyle risk factors of LOAD as well as differences in episodic memory performance, we also acquired the following information (Table 1): Genetic risk was assessed by carriage of the Apolipoprotein-E (APOE) ε4 allele49,50 and separately by a positive family history of a first grade relative with dementia of the Alzheimer’s, Lewy body or vascular type. The gene discussed is APOE; the disease is dementia.