John Gallacher is Professor of Cognitive Health at Oxford University and Director of Dementias Platform UK (DPUK), a MRC-funded public-private partnership focused on accelerating research into the early detection and treatment of dementia. An expert on brain health and the use of big data in medical research, Professor Gallacher holds a visiting professorship at Imperial College London and an honorary professorship at the University of Hong Kong. He is the Principal Investigator for the Caerphilly Prospective Study (CaPS).