THE secret world of dreams could soon be cracked open. Brain scanners are already being used to figure out waking thoughts, and now it seems that similar methods can tap into dreams.
To bridge the worlds of sleep and waking, Michael Czisch and Martin Dresler at the Max Planck Institute of Psychiatry in Munich, Germany, and their colleagues turned an array of brain-watching technology on lucid dreamers.
“A lucid dream is simply a dream in which you realise you’re dreaming," says Dresler. Lucid dreamers’ rare ability to “wake up" while remaining in a dream and control their actions — and the dream — makes them an important asset to dream researchers. They are the only people who can reliably communicate in real time what they are dreaming about. Eye movements are the usual means of communication.
After tracking down six people who claimed to be able to have lucid dreams almost nightly, the team used both functional MRI scanning and near-infrared spectroscopy to observe each person's brain activity as they clenched a hand while awake. Then they compared this with the activity associated with imagining clenching the same hand, and clenching it in a lucid dream.
Not that it was easy to tell when the volunteers were dreaming that they were clenching a hand: even when dreaming about it, the lucid dreamers did not clench their own hand in reality. The group used a combination of monitoring methods to check whether the participants were in the rapid eye movement (REM) state of sleep, in which we have most or our dreams. This involved measuring brain activity, tracking eye movements and monitoring the chin muscles, which are paralysed during REM sleep.
At the same time, the team monitored the brain activity of the dreamers using fMRI scanning or near-infrared spectroscopy by turns. Both techniques show which areas of the brain are active by detecting different degrees of blood oxygenation.
To communicate with the researchers, each participant was told to move their eyes from left to right a certain number of times to indicate when they had entered a lucid dream and were intentionally dreaming about clenching a hand.
Because of the difﬁculties involved, the team only managed to study two dreams. In both cases, the brain activity recorded immediately after the volunteers signalled that they were dreaming about hand-clenching proved to be similar to the activity seen when they imagined hand- clenching while awake. Real hand-clenching involved a greater area of activation (Current BioIogy, D01; 10.1016/j.cub.2o11.09.029).
“This provides the first evidence that it may be possible to use brain imaging to read the contents of a person's dream," says Czisch.
Daniel Erlacher at the University of Bern in Switzerland says the study is "a brilliant piece of work... If you can get a detailed reading of brain functions and know what each represents, you can read dreams.”
SOURCE : NEW SCIENTIST MAGAZINE NOVEMBER 2011