Mark Prigg
Scientists have used brain scanners to detect and reconstruct the faces that people are thinking of, effectively reading their minds.
Researchers use fMRI scans to successfully identify the faces people were looking at.
They say the discovery could allow witnesses to create e-fits simply by thinking about a criminal’s face – and could even help reconstruct dreams.
Researchers showed participants a series of pictures of faces (left) and them monitored their brain activity with an fMRI scanner before reconstructing the images (right)
HOW THEY DID IT
Researchers showed six subjects 300 different ‘training’ faces while undergoing fMRI scans.
They used the data to create a sort of statistical library of how those brains responded to individual faces.
They then showed the six subjects new sets of faces while they were undergoing scans.
Using that fMRI data alone, researchers used their statistical library to reconstruct the faces their subjects were viewing.
Researchers say the accuracy of these facial reconstructions will increase with time and he envisions they can be used as a research tool, for instance in studying how autistic children respond to faces.
It builds on previous experiments where researchers were able to work out whether people were looking at beach or city scenes from scans.
Using only data from an fMRI scan, researchers led by a Yale University undergraduate have accurately reconstructed images of human faces as viewed by other people.
‘It is a form of mind reading,’ said Marvin Chun, professor of psychology, cognitive science and neurobiology and an author of the paper in the journal Neuroimage.
The increased level of sophistication of fMRI scans has already enabled scientists to use data from brain scans taken as individuals view scenes and predict whether a subject was, for instance, viewing a beach or city scene, an animal or a building.
‘But they can only tell you they are viewing an animal or a building, not what animal or building,’ Chun said.
‘This is a different level of sophistication.’
One of Chun’s students, Alan S. Cowen, wanted to know whether it would be possible to reconstruct a human face from patterns of brain activity.
The researchers say they were able to reconstruct the faces because we process far more information about faces that other images we see
The team say their research could one day be used by police to create more accurate photofits from witnesses.
The task was daunting, the team said, because faces are more similar to each other than buildings.
Also large areas of the brain are recruited in the processing of human faces, a testament to its importance in survival.
‘We perceive faces in a much greater level of detail than we perceive other things,’ Cowen said.
‘You can even imagine, way down the road, a witness to a crime might want to come in and reconstruct a suspect’s face.’
The reconstructed images were good enough for the researchers to work out which face was being looked at from a selection of 600
Working with funding from the Yale Provost’s office, Cowen and post doctoral researcher Brice Kuhl, now an assistant professor at New York University,
The team showed six subjects 300 different ‘training” faces while undergoing fMRI scans.
They used the data to create a sort of statistical library of how those brains responded to individual faces.
They then showed the six subjects new sets of faces while they were undergoing scans.
spot the face: Researchers used fMRI scans to work out which faces subjects were looking at
Taking that fMRI data alone, researchers used their statistical library to reconstruct the faces their subjects were viewing.
Cowen said the accuracy of these facial reconstructions will increase with time and he envisions they can be used as a research tool, for instance in studying how autistic children respond to faces.
Chun said the study shows the value of funding research ambitions of Yale undergraduates.
‘I would never have received external funding for this, it was too novel,’ Chun said.
The team wrote that their discovery could also be used in other areas – and even reconstructing dreams.
‘This methodology not only represents a novel and promising approach for investigating face perception, but also suggests avenues for reconstructing ‘offline’ visual experiences—including dreams, memories, and imagination—which are chiefly represented in higher-level cortical areas.’
