Multi-tasking eyes: boon or bane?

New York: Our eyes are drawn to several dimensions of an object - such as colour, texture, and luminance - even when we need to focus on only one of them, says a new research.

In general, this is beneficial as it allows us to combine these measurements (of brightness, hue, texture) to more efficiently identify an object.

It becomes difficult, however, if we need to spot only one aspect of an object.

"Even when we want and need to focus on one dimension of things we come across every day, such as the texture of your cat's fur rather than its lightness, we have difficulty doing so because our eyes want to survey several features at once," said senior study author Michael Landy from New York University.

The study, which appears in the journal Current Biology, points to the ability of our visual system to integrate multiple components of an item while underscoring the difficulty we have in focusing on a particular aspect of it.

Previous studies have shown the human visual system is capable of simultaneously processing several traits of a single object.

Landy and the study's lead author Toni Saarela from the University of Pennsylvania said that the findings point to the challenges faced by medical practitioners and airport screeners, who examine overlapping objects, through x-rays and security scanners readings, possibly outlined by different hues or brightness.

"Our ability to combine dimensions to improve object identification prevents us from ignoring a dimension when that is what our task requires," the researchers said.