August 19, 2013
Computer Reads Thoughts Using MRI Images And An Algorithm
Lee Rannals for redOrbit.com - Your Universe Online
Researchers writing in the journal Neuroimage say they have developed a computer model that can read human thoughts. The scientists from Radbound University Nijmegen in the Netherlands reported that they have successfully created a mathematical model that can analyze MRI images to reconstruct thoughts and decipher letters that test subjects thought about.The team was able to teach a computer model how to analyze MRI images during brain scans to reconstruct an image being viewed by the subject.
MRI scanners have been used in cognition research to help determine which areas of the brain are active while test subjects perform a specific task. The team took this research a step further by using data from the scanner to determine what the subject was looking at.
"After this we did something new," says lead researcher Marcel van Gerven. "We gave the model prior knowledge: we taught it what letters look like. This improved the recognition of the letters enormously. The model compares the letters to determine which one corresponds most exactly with the speckle image, and then pushes the results of the image towards that letter. The result was the actual letter, a true reconstruction."
He said the team's approach is similar to how they believe the brain combines prior knowledge with sensory information.
"For example, you can recognize the lines and curves in this article as letters only after you have learned to read. And this is exactly what we are looking for: models that show what is happening in the brain in a realistic fashion," Gerven added.
The researchers hope to improve the models so that they can be applied to working memory or to subjective experiences such as dreams or visualizations. Sanne Schoenmakers, who is working on a doctoral thesis about decoding thoughts, said they plan to expand their study by working with a more powerful MRI scanner.
"Due to the higher resolution of the scanner, we hope to be able to link the model to more detailed images," Schoenmakers said. "We are currently linking images of letters to 1200 voxels in the brain; with the more powerful scanner we will link images of faces to 15,000 voxels."
The Dutch scientists are not the only ones trying to read minds. A team of Japanese researchers said last year that they have discovered a way to determine what thoughts are going through a person's head while they are dreaming. The team used electroencephalography (EEG) to record brain waves and study changes in activity that could be related to the content of dreams.