London: Researchers have warned that immersion in virtual reality (VR) can cause behavioural changes in consumers that may last even after they leave the virtual environment. The technological capacity for generating virtual worlds from home computers will soon be widely available to the general public, as special head-mounted displays are brought to market that create the illusion of being immersed in virtual three-dimensional worlds. But citing recent studies, Michael Madary and Thomas Metzinger from Johannes Gutenberg University of Mainz in Germany said that VR may create vast opportunities for psychological manipulation - a risk that has received far less attention so far. "These studies suggest that VR poses risks that are novel, that go beyond the risks of traditional psychological experiments in isolated environments, and that go beyond the risks of existing media technology for the general public," the researchers wrote in a recently published article in the journal Frontiers in Robotics and AI. Based on their analysis of the risks, both researchers offered concrete recommendations for the use of VR. For example, in experimental work developing new clinical applications, researchers should be careful not to create false hopes in patients. They should repeatedly remind them of the merely experimental nature of the research. Madary and Metzinger also noted that a code of ethical conduct, however important it may be, can never function as a substitute for ethical reasoning itself on the part of researchers. They warned about content such as violence and pornography, where the advanced technology may increase the risk of psychological trauma. “Users should be clearly informed of these dangers, as well as risks of hallucinations, personality changes, and the powerful unconscious influence of advertising in VR,” they said.