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.
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
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
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
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
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
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
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.