Japanese boffins say they can tell what you are dreaming about by analysing magnetic resonance imager (MRI) scans.

Researchers at Kyoto’s ATR Computational Neuroscience Laboratories published their breakthrough findings in Science magazine in a paper titled Neural Decoding of Visual Imagery During Sleep.

The boffins used electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) scanners to detect which areas of the subject’s brain were most active in the first (non-REM) stages of sleep, before waking them up to ask what they had been dreaming about.

By linking the brain-mapping data with these verbal reports, the boffins were apparently then able to build an algorithm capable of predicting with 60 per cent accuracy the content of dreams.

The abstract of the research describes the results as follows:

Decoding models trained on stimulus-induced brain activity in visual cortical areas showed accurate classification, detection, and identification of contents. Our findings demonstrate that specific visual experience during sleep is represented by brain activity patterns shared by stimulus perception, providing a means to uncover subjective contents of dreaming using objective neural measurement.

"We have concluded that we successfully decoded some kinds of dreams with a distinctively high success rate," said senior researcher Yukiyasu Kamitani told AFP.

"Dreams have fascinated people since ancient times, but their function and meaning has remained closed. I believe this result was a key step towards reading dreams more precisely."

At present, the system is apparently limited to detecting only very basic classes of objects which the dreamers visualise – “building”, “food”, “car” and so on – and it cannot be applied generically to all subjects but must be specifically crafted for each dreamer.

However, plans are afoot to further refine the dream-reader, as well as extend it to map smells, emotions and entire stories, and possibly in time plumb the depths of REM sleep. ®