New York, Oct 25 (IANS): Engaging brain areas linked to so-called "off-task" mental activities such as mind-wandering and looking back at good times can actually boost performance on some challenging mental tasks, new research reveals.

The prevailing view is that activating brain regions referred to as the default network impairs performance on attention-demanding tasks because this network is associated with behaviours such as mind-wandering.

Like if you start thinking about what you did last weekend while taking notes during a lecture, for example, your note-taking and ability to keep up will suffer.

"Our study is the first to demonstrate the opposite - that engaging the default network can also improve performance," said Nathan Spreng, neuroscientist at Cornell University.

Spreng and his team developed a new approach in which off-task processes such as reminiscing can support rather than conflict with the aims of the experimental task.

While undergoing brain scanning, 36 young adults viewed sets of famous and anonymous faces in sequence and were asked to identify whether the current face matched the one presented two faces back.

The team found participants were faster and more accurate when matching famous faces than when matching anonymous faces.

This better short-term memory performance was associated with greater activity in the default network.

"The results show that activity in the default brain regions can support performance on goal-directed tasks when task demands align with processes supported by the default network," Spreng added.

The paper was published in the Journal of Neuroscience.