IN WHAT'S being claimed as a major breakthrough, scientists have made a direct recording of mirror neurons in the human brain. Mirror neurons, many say, are what make us human. They are the cells in the brain that fire not only when we perform an action but also when we watch someone else perform it. However, there was no proof that mirror neurons existed.

Now, a team at California University has recorded both single cells and multiple cell activity, not only in the motor regions of the brain where mirror neurons were thought to exist but also in regions involved in vision and in memory.

Further, they showed that specific subsets of mirror cells increased their activity during the execution of an action but decreased their activity when an action was only being observed, the 'Current Biology' journal reported.

"We hypothesise that the decreased activity from the cells when observing an ac- tion may be to inhibit the observer from automatical- ly performing that same ac- tion. Furthermore, this sub- set of mirror neurons may help us distinguish actions of other people from our own actions," team leader Roy Mukamel said.

The scientists drew their data from the brains of 21 patients who were being treated at the university's

medical centre for epilepsy and implanted with in- tracranial depth electrodes to identify foci for potential surgical treatment. The ex- periment included three parts -- facial expressions, grasping and a control ex- periment. Activity from 1,177 neurons in patients was recorded as the pa- tients both observed and performed grasping actions and facial gestures. In the observation pha - se, the patients observed various actions presented on a laptop. In the activity phase, the subjects were asked to perform an action based on a visually present- ed word. In the control task, the same words were pre- sented and patients are told not to execute the action.

The scientists found that the neurons fired or showed their greatest activity both

when the individual per- formed a task and when they observed a task, a find- ing that shows that mirror neurons are located in more areas of the human brain than previously thought.

"The study suggests that the distribution of these unique cells linking the ac- tivity of the self with that of others is wider than previ- ously believed," said Itzhak Fried, a team member.