New York, Sep 5 (IANS): Ever wondered how despite the barrage of visual information on its way, the brain focuses only on important and relevant items? A unique population of shifting neurons in the brain helps it do so, says a study.

The neurons shift in sensitivity toward different colours and directions depending on what is being attended, the findings showed.

“Most of the objects in any given visual scene are not that important, so how does the brain select or attend to important ones?" said study senior author David Freedman, an associate professor of neurobiology at the University of Chicago in the US.

"We have zeroed in on an area of the brain that appears central to this process. It does this in a very flexible way, changing moment by moment depending on what is being looked for," Freedman explained.

The researchers studied the response of individual neurons during a simple task.

They looked at neurons in the lateral intraparietal area (LIP), a region highly interconnected with brain areas involved in vision, motor control and cognitive functions.

As participant monkeys performed the task and looked for a specific combination of colour and motion, LIP neurons became highly active.

They did not respond, however, when the subjects passively viewed the same images without an accompanying task.

When the team further investigated the responses of LIP neurons, they discovered that the neurons possessed a unique characteristic.

Individual neurons shifted their sensitivity to colour and direction toward the relevant colour and motion features for that trial.

"This is the first time that neurons in the brain have been shown to shift their selectivity depending on which features are relevant to solve a task," co-researcher Guilhem Ibos from University of Chicago noted.

The study appeared in the journal Neuron.