Washington, Aug 7 - 'That blasted siren. I can't focus.' That reaction to an undesired distraction may signal a person's low working-memory capacity, according to a new study.

Based on a study of 84 students divided into four separate experiments, University of Oregon (UO) researchers found that students with high memory storage capacity were clearly better able to ignore distractions and stay focussed on their assigned tasks.

Principal investigator Edward K. Vogel, a UO professor of psychology, compared working memory to a computer's random-access memory (RAM) rather than the hard drive's size -- the higher the RAM, the better the processing abilities.

With more RAM, he said, students were better able to ignore distractions. This notion surfaced in a 2005 paper in the journal Nature by Vogel and colleagues.

In experiments with some variations in approaches, students' brain activity was monitored using electroencephalography (EEG) while they studied images on a computer screen, recognising a shape with a missing component, and then identifying the object after it moved simply to another location or amid distractions.