Learning to control brain activity can improve visual sensitivity
Researchers say training human volunteers to control their own brain activity in precise areas of the brain can enhance fundamental aspects of their visual sensitivity.
This non-invasive 'neurofeedback' approach could one day be used to improve brain function in patients with abnormal patterns of activity, for example stroke patients.
Researchers at the Wellcome Trust Centre for Neuroimaging at UCL used non-invasive, real-time brain imaging that enabled participants to watch their own brain activity on a screen, a technique known as neurofeedback. During the training phase, they were asked to try and increase activity in the area of the brain that processes visual information, the visual cortex, by imagining images and observing how their brains responded.
After the training phase, the participants' visual perception was tested using a new task that required them to detect very subtle changes in the contrast of an image. When they were asked to repeat this task whilst clamping brain activity in the visual cortex at high levels, they found that those who had successfully learned to control their brain activity could improve their ability to detect even very small changes in contrast.
This improved performance was only observed when participants were exercising control of their brain activity.
"We've shown that we can train people to manipulate their own brain activity and improve their visual sensitivity, without surgery and without drugs," said lead author Dr Frank Scharnowski, who is now based at the University of Geneva.