Hull research proves colour is not a black and white issue 

30 November 2011

Scientists at the University of Hull have found that some people have the ability to hallucinate colours at will – even without the help of hypnosis.

Brain activityThe study, published this week in the journal Consciousness and Cognition, was carried out in the Department of Psychology at the University of Hull. It focused on a group of people that had shown themselves to be ‘highly suggestible’ in hypnosis.

The subjects were asked to look at a series of monochrome patterns and to see colour in them. They were tested under hypnosis and without hypnosis and both times reported that they were able to see colours.

Individuals’ reactions to the patterns were also captured using an MRI scanner, which enabled the researchers to monitor differences in brain activity between the suggestible and non-suggestible subjects. The results of the research, showed significant changes in brain activity in areas of the brain responsible for visual perception among the suggestible subjects only.

Professor Giuliana Mazzoni, lead researcher on the project says: “These are very talented people. They can change their perception and experience of the world in ways that the rest of us cannot.”

The ability to change experience at will can be very useful. Research has shown that hypnotic suggestions can be used to block pain and increase the effectiveness of psychotherapy.

It has always been assumed that hypnosis was needed for these effects to occur, but the new study suggests that this is not true. Although hypnosis does seem to heighten the subjects’ ability to see colour, the suggestible subjects were also able to see colours and change their brain activity even without the help of hypnosis.

The MRI scans also showed clearly that although it was not necessary for the subjects to be under hypnosis to be able to perceive colours in the tests, it was evident that hypnosis increased the ability of the subjects to experience these effects.

Dr William McGeown, who also contributed to the study, says: “Many people are afraid of hypnosis, although it appears to be very effective in helping with certain medical interventions, particularly pain control. The work we have been doing shows that certain people may benefit from suggestion without the need for hypnosis.”

The study, which was partially funded by the BBC, used a control group formed of less suggestible people, or people less likely to respond to hypnosis. It was found that this group of people were not able to hallucinate colour and, again, these reported results were supported by MRI scans.


Page last updated by Jonno Witts on 12/1/2011

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Notes to Editors

1. ‘Suggested visual hallucination without hypnosis enhances activity in visual areas of the brain’, by William J. McGeown, Annalena Venneri, Irving Kirsch, Luca Nocetti, Kathrine Roberts, Lisa Foan, and Giuliana Mazzoni, is published online in Consciousness and Cognition. DOI: 10.1016/j.concog.

2. Health research at the University of Hull
Health-related research at the University of Hull ranges from biology and biochemistry to sports science, psychology and medicine. The University heads major UK and EU clinical trials into heart disease, dementia care, obesity and nutrition and is a recognised centre for research into head and neck cancers, medical imaging, respiratory diseases and remote monitoring of health conditions (telehealth).

Health research at the University of Hull is highly translational, with strong links between fundamental scientists and clinicians ensuring maximum impact on treatment and practice. The University has a joint medical school with the University of York. Hull York Medical School (HYMS) works closely with regional NHS trusts and trains 130 new doctors each year.

In the 2008 national Research Assessment Exercise (RAE), 80% of the University’s research across all fields was judged to be of international standard in terms of originality, significance and rigour. The National Student Survey (NSS) consistently ranks the University in the top ten mainstream English Universities.