The scientists believe that regardless of whether we are asleep or awake, our brains use the same mental circuits to interpret images . They are currently trying to find ways of using this technology for treating psychiatric patients with hallucinations.

Senior author, Yukiyasu Kamitani of Japan’s ATR Computational Laboratories in Kyoto, together with colleagues from the Nara Institute of Science and Technology and the National Institute of Information and Communications Technology explained that their breakthrough follows recent research advances in decoding the brain signals that interpret what we see while we are awake.

fMRI scans can reveal the visual images we have in our brains while we are dreaming, researchers from Japan reported in the journal Science. Put simply, they have found a way of seeing our dreams.

Co-author, Yukiyasu Kamitani believes it is mind reading in the sense that some data are gleaned regarding the subjective state of their participants. He stressed though, that the performance of their current method has a long way to go before he would call it proper “mind reading” in the sense of having accurate details of the dreamer’s thoughts.

In this study, the team asked three volunteers to sleep inside fMRI (functional magnetic resonance imaging) machines.

What is the difference between MRI and fMRI? – MRI is a scanning device that sees what the inside of the brain is like, while fMRI can observe what the brain is doing. It is a bit like the difference between a photograph and a video, one sees functioning while the other one does not. For example, fMRI observes changes in blood flow in the brain. Put simply, MRI looks at the brain for what it is while fMRI looks at what the brain is doing (its function). MRI scans image anatomical structure whereas FMRI image metabolic function.

They looked at the participants’ brain activities while they were in a state of light sleep and compared what they found to when they looked at pictures of cars, streets and other everyday things while awake.

The participants were woken up from their sleep and asked to describe what they saw just before waking up. The authors said that most of them would describe a house, or street or some everyday scene.

After a total of 200 awakenings, the scientists found that their computer process was approximately 60% accurate – it was predicting what the sleepers were seeing just before waking up 60% of the time.

This suggest that parts of the brain work in the same way when we are either awake or asleep and seeing images.

Examining people while in the REM (rapid eye movement) phase of deep dreams has proven much more difficult. Scanning machines are noisy and not too comfortable – people cannot stay in them for hours on end. The team says they plan to use their technology to observe volunteers during REM.