Part of brain that filters irrelevant information is found

The part of the brain which filters out irrelevant information has been identified by scientists – with the help of video game-playing monkeys.

Researchers say that an area deep within the brain known as the “pulvinar” regulates messages in the mind, making sure it focuses on people and objects which require our attention.

It is the same principle as a switchboard operator, reports the journal Science, with the pulvinar determining which of the many messages are “put through”.

Dr Yuri Saalmann, from the Princeton Neuroscience Institute (PNI), said without the pulvinar important stimuli such as a bus heading towards us as we cross the street could get lost. The findings could lead to new ways of treating schizophrenia and ADHD.

Dr Saalmann’s team produced neural connection maps using magnetic resonance imaging (MRI), then placed electrodes along the identified communication paths to monitor brain signals of macaque monkeys.

They trained the monkeys to play a video game during which they used visual cues to find a specific shape surrounded by distracting information.

As the macaques focused, Saalmann and his colleagues could see that the pulvinar controlled which parts of the visual cortex sent and received signals.

He said: “A fundamental problem for the brain is that there is too much information in our natural environment for it to be processed in detail at the same time.

“The brain instead selectively focuses on, or attends to, the people and objects most relevant to our behaviour at the time and filters out the rest.

“For instance, as we cross a busy city street, our brain blocks out the bustle of the crowd behind us to concentrate more on an oncoming bus.”