London, October 18 : Children exposed to black-and-white films and television programmes are more likely to dream in greyscale throughout their lives, say researchers.
Eva Murzyn from the University of Dundee, UK, asked 60 subjects, half of whom were under 25 and half over 55, to answer a questionnaire on the colour of their dreams and their childhood exposure to film and TV.
She also asked the participants to record different aspects of their dreams in a diary every morning.
The researcher revealed that her approach to studying the colour of dreams was a combination of the study methods used from 1915 through to the 1950s, and those used since the 60s.
She pointed out that the studies conducted up to the 50s suggested that the vast majority of dreams were in black and white, while later results suggested that up to 83 per cent of dreams contained some colour.
According to her, differences between the studies prevented the researchers from drawing any firm conclusions, and such differences could have been due to the transition between black-and-white film and TV and widespread Technicolor in the 60s.
While the later studies asked subjects to complete dream diaries as soon as they awoke, said the researcher, the earlier research used questionnaires completed in the middle of the day, because of which the subjects might have simply forgotten colour elements to their dreams and assumed they were greyscale.
Eva said that she incorporated both methods into one study so as to lay the debate to rest.
She revealed that her study showed that there was no significant difference between results drawn from the questionnaires and the dream diaries, indicating that the previous studies were comparable.
With a view to determining whether an early exposure to black-and-white TV could still have a lasting effect on her subjects' dreams 40 years later, she analysed her own data.
The researcher observed that only 4.4 per cent of the under-25s' dreams were black and white. The over-55s who had had access to colour TV and film during their childhood also reported a very low proportion of just 7.3 per cent.
However, the over-55 participants, who had only had access to black-and-white media, reported dreaming in black and white roughly a quarter of the time.
"There could be a critical period in our childhood when watching films has a big impact on the way dreams are formed," New Scientist magazine quoted Eva as saying.
She said that one reason for that impact could be the heightening of their attention and emotional engagement while watching TV or films, which probably leaft a deeper imprint on their mind.
She, however, admitted that it was yet to be determined whether dreams were actually in black-and-white, or whether media exposure somehow alters the way the mind reconstructs the dreams once we wake.
An article on the study has been published in the journal Consciousness and Cognition.