Study describes rotating waves in brain that help one focus after brief distraction

New Delhi, Nov 3 (PTI) A study has described a brain process involving circling waves coordinated by neurons in the prefrontal cortex, which helps pay attention, in aiding one to get back to the task at hand following a distracted spell.

Researchers from the US' Massachusetts Institute of Technology (MIT) analysed electrical activity in the prefrontal cortex -- a brain region known to help with higher-level functions, including paying attention -- of monkeys.

Findings published in the Journal of Cognitive Neuroscience showed a rotating wave in the brain highly coordinated by neurons in the cortex to put one's thought processes back on track.

"The rotating waves act like herders that steer the cortex back to the correct computational path," senior author Earl K. Miller, professor at MIT's The Picower Institute and department of brain and cognitive sciences, said.

Miller added that the circling seemed to represent the recovery of the monkeys' activity state following a distraction.

Monkeys were asked to perform a visual task, but at times experienced one of two kinds of distractions as they tried to remember an object they saw, the researchers explained.

The distractions affected the animals' performance in terms of either making mistakes or slowing down their reaction time when required to act on the designated task, the team said.

In cases where the animals did not make a mistake while distracted, the researchers observed "a complete circle, indicating the recovery was complete".

In cases where mistakes were made, the path of the circling brain wave fell short of making a full circle by an angle of 30 degrees on average, they said.

The trajectory of the wave during errant sessions also showed a slower speed, which could explain the lack of recovery from distraction, they added.

Further, the animals were found to be better at recovering if more time passed between the start of a distraction spell and an individual feeling that they need to get back to the task at hand, the team said.

They explained that the brain needed that time to come full circle mathematically and get back on track behaviourally.

The authors wrote, "Cortical activity shows the ability to recover from distractions. We analysed neural activity from the pFC (prefrontal cortex) of monkeys performing working memory tasks with mid-memory delay distractions (a cued gaze shift or an irrelevant visual input)." "After (a) distraction, there were state-space rotational dynamics that returned spiking to population patterns similar to those predisruption," they said.

"Rotations were fuller when the task was performed correctly versus when errors were made," the team added. PTI KRS KRS KSS KSS