The main research focus has been on the technology of computer graphics, in particular real-time global illumination methods, for which an EPSRC Senior Fellowship was held between 1994 and 2004. The major research focus since the 1990s has been immersive virtual reality, mainly concentrating on human factors aspects such as how the sense of presence is maintained, meaning the circumstances under which people will respond realistically in such environments. More recently research has focussed on how virtual reality may be exploited in the fields of psychology and neuroscience, in particular in understanding the mechanisms by which the brain represents the body.
A major contribution has been in a number of novel applications of virtual reality - in particular, to psychotherapy (fear of public speaking, social phobia), social psychology (a reproduction of the Milgram Obedience experiments), and moral psychology (how people respond to moral dilemmas).
Mel Slater has led and currently leads a number of European funded projects on the interdisciplinary theme of virtual environments, neuroscience and psychology.