The great debate about free will has taken an interesting turn thanks to a group of scientists from the Center for Mind and Brain at the University of California, Davis.

So forget one's desires or power of choice as the likely explanation behind how we act, our decisions could be predicted on "background noise" – fluctuating electrical activity - in our brains, a new study has found.

"How do we behave independently of cause and effect?

"This shows how arbitrary states in the brain can influence apparently voluntary decisions," said Dr Jesse Bengson, a postdoctoral researcher at the university and lead author on the research.

Nineteen volunteers were asked to sit in front of a screen and focus on a central point while they were monitored by electroencephalography (EEG) machines. They were asked to look either left or right when a cue appeared on the screen in front of them, and then report their decision.

Bengson found that looking at the pattern of brain activity seconds before the cue appeared at random intervals was a good predictor of which way the person would choose to look - rather than be a conscious decision.

"The state of the brain right before presentation of the cue determines whether you will attend to the left or to the right," he said.

In an email to Live Science, Bengson, said: "[Though] purposeful intentions, desires and goals drive our decisions in a linear cause-and-effect kind of way, our finding shows that our decisions are also influenced by neural noise within any given moment.

"This random firing, or noise, may even be the carrier upon which our consciousness rides, in the same way that radio static is used to carry a radio station."

The findings build on a study carried out by Benjamin Libet in the 1970s. He measured the brain waves of people when given a switch and asked to press it. In the same way Libet found there was brain activity before the volunteer took his or her decision.

The difference is Libet had to rely on when volunteers said they made their decision. In the new experiment, Bengson said the random timing of the cues means that "we know people aren't making the decision in advance."

"It inserts a random effect that allows us to be freed from simple cause and effect," he added.

The work, which was funded by the National Institutes of Health, was published online in the Journal of Cognitive Neuroscience.