Professor Ian Deary, Director of The Centre for Cognitive Ageing and Cognitive Epidemiology at Edinburgh University, presents this lecture on healthy cognitive ageing and principally, the research carried out on the Lothian birth cohorts of 1921 and 1936. He talks about the Scottish Mental Surveys of 1932 and 1947, the Murray House Test No.12 and how Scotland is unique in having twice measured the IQ of the entire nation. Professor Deary's lecture looks at four different areas that might be helpful in learning how we best can optimally cognitively age. These areas are lifestyle factors, biomedical factors, brain imaging and genetics.