Training human volunteers to control their own brain
activity in precise areas of the brain can enhance
fundamental aspects of their visual sensitivity,
according to a new study in the Journal of
Neuroscience.
Brain scan showing activity pre- and post-training
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.
Lead author Dr Frank Scharnowski, who is now based
at the University of Geneva, explains: “We’ve shown
that we can train people to manipulate their own
brain activity and improve their visual sensitivity,
without surgery and without drugs".
In the past, researchers have used recordings of
electrical activity in the brain to train people to
get better at various tasks, including decreased
reaction times, altered emotional responses and even
enhanced musical performance.
In this study, the researchers used functional
magnetic resonance imaging (fMRI) to provide the
volunteers with real-time feedback on brain activity.
The advantage of this technique is that you can see
exactly where in the brain the training is having an
effect, so you can target the training to particular
brain areas that are responsible for specific tasks.
“The next step is to test this approach in the
clinic to see whether we can offer any benefit to
patients, for example to stroke patients who may
have problems with perception, even though there is
no damage to their vision,” adds Dr Scharnowski.
The study was funded by the Wellcome Trust, Swiss
National Science Foundation and the European Union.
For more information
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