passingham started by investigating each area of the frontal lobes in macaques, and his earlier findings were summarized in his seminal book ‘the frontal lobes and voluntary action’ (1993). when brain imaging became available for studies of the human brain, passingham was amongst the first to use it. he carried out pet studies from 1988 at the hammersmith hospital and fmri studies from 1995 at the wellcome trust centre for neuroimaging (ucl), where he was among the founding principal investigators of the centre. thus, for much of his career he had a research group working in oxford with macaques and rtms in humans, and a group working with brain imaging of humans in london.