New York, Jan 22 (IANS): People who are less patient tend to move their eyes with greater speed, says a study.

"It seems that people who make quick movements - at least eye movements - tend to be less willing to wait," said Reza Shadmehr, professor of biomedical engineering and neuroscience at The Johns Hopkins University.

The findings suggest that the weight people give to the passage of time may be a trait consistently used throughout their brains - affecting the speed with which they make movements - as well as the way they make certain decisions.

To understand this, the research team used very simple eye movements - known as saccades - to stand in for other bodily movements.

Saccades are the motions that our eyes make as we focus on one thing and then another.

They are probably the fastest movements of the body as they occur in just milliseconds.
Human saccades are fastest when we are teenagers and slow down as we age, said the study published in the Journal of Neuroscience.

The team first asked healthy volunteers to look at a screen upon which dots would appear one at a time - first on one side of the screen, then on the other, then back again.
A camera recorded their saccades as they looked from one dot to the other.

To determine whether saccade speed correlated with decision-making and impulsivity, the volunteers were told to watch the screen again.

This time, they were given visual commands to look to the right or to the left. When they responded incorrectly, a buzzer sounded.

“When the speed of the volunteers' saccades was compared to their impulsivity during the patience test, there was a strong correlation,” said Shadmehr.

“Some people simply make fast saccades,” he added.

“Our hypothesis is that there may be a fundamental link between the way the nervous system evaluates time and reward in controlling movements and in making decisions,” added Shadmehr.

This might also shed light on why malfunctions in certain areas of the brain make decision-making harder for those with neurological disorders like schizophrenia, or for those who have experienced brain injuries, the study said.