Japanese researchers have reproduced images of things people were looking at by analyzing brain scans, opening the way for people to communicate directly from their mind.
They hope their study, published in the U.S. journal Neuron, will lead to helping people with speech problems or doctors studying mental disorders, although there are privacy issues if it gets to the stage where someone can read a sleeping person's dreams.
"When we want to convey a message, we need to move our body, for example by speaking or by tapping a keyboard," said Yukiyasu Kamitani, the project's head researcher from the Advanced Telecommunications Research Institute International, a private institute based in Kyoto, Japan.
"But if we can get information directly from the brain, it will be possible to communicate directly by imagining what we want to say, without having to move," Kamitani said in a telephone interview with Reuters.
Such technology might one day open the way to communication for people who cannot speak or help visualize hallucinations to assist doctors diagnosing mental disorders, Kamitani added.
When we see, light is converted into electric signals by the retina, at the back of the eye, then processed by the brain's visual cortex.
Researchers from the five institutions involved in the research used a medical brain scanner to look at activity patterns in the visual cortex.
Kamitani's team calibrated a computer program by scanning two volunteers staring at over 400 different still images in black, white and grey.
Then, the volunteers were shown different black-and-white geometric figures and letters of the alphabet.
Their computer program was able to reproduce the figures and letters that the volunteers had seen, although more blurry than the originals.
"In this experiment, we reconstructed images of what people actually saw, but the brain's visual cortex is said to be active even when just imagining something," Kamitani said.
The next step for the team is to study how to visualize images inside people's minds, he said.
"We want to know how our subjective experiences and dreams are expressed inside our brains," Kamitani said, adding that the study might lead to producing images of dreams.
If the team does manage that there were potential privacy issues and strong safeguards would be needed, he said.
"As accuracy rises, it is possible that information that people want to keep private could also be visualized while they are sleeping."
