New Delhi, Aug 5 (PTI) Neuroscientists have found no direct link between brain activity preceding one's action and the intention to perform the action, and say that the classical Libet paradigm may not be suitable for knowing if we have free will in making decisions.

In the 1970-1980s, the American neuroscientist Benjamin Libet, considered a pioneer in the field of human consciousness, showed that 0.5-1.5 seconds before conscious awareness of the intention to perform a movement, the brain emitted electroencephalogram (EEG) activity predicting this movement.

Also Read | Imran Khan Arrested: Master Graff Watch Led to Conviction of Former Pakistan PM in Toshakhana Case.

The results were concluded to mean that the brain made a decision and sent a readiness potential before the person realised it, and that our actions were nothing more than a result of an unconscious physiological process in the brain.

The researchers at the National Research University Higher School of Economics, Moscow, Russia, questioned this experimental paradigm and in their new study confirmed that the time of intention awareness in Libet's experiments was determined incorrectly.

Also Read | Amrit Bharat Station Scheme: PM Narendra Modi to Lay Foundation Stone for Redevelopment of 508 Railway Stations Across India Today.

Further, EEG activity, or the brain signal indicating the readiness of a decision, recorded by Libet before the decision was made, actually had no direct link to this decision, they said in their study published in the journal Neuropsychologia.

In Libet's original experiment, the subjects were asked to occasionally bend their wrists and at the same time remember the moment when they felt ready to perform this action.

The time of intention awareness was recorded from the words of the subjects themselves - they observed a point that moved along the screen-dial, similar to a clock hand, and indicated the position of the point when they felt the desire to bend their hand. The moment of the final decision was determined by the exact reading of the sensor attached to the wrist of the subjects.

In this study, the neuroscientists repeated the experiment with two groups of subjects, adding small changes to the task in one of the groups. Using behavioural reports and hypersensitive EEG techniques, the scientists investigated the correlation between the time of intention awareness and the time of final decision.

They found that the time of awareness can be influenced by experimental procedures: for example, without certain training, the subjects were barely able to determine their intentions, and the traditional Libet paradigm pushed them to the feeling that they can determine the moment of decision-making and intention.

Apparently, the instruction itself in the Libet task made the participants feel that the intention should emerge long before the final decision is made, the researchers said.

Confirming the absence of a correlation between the brain signal and decision-making, they said that the sense of intention emerged in the subjects at different points in time, whereas the readiness potential was always registered at about the same time.

Thus, they said, the readiness potential may reflect the general dynamics of the decision-making process about making a move, but it did not mean that the intention to act has already been generated.

"It appears that the classical Libet paradigm is not suitable for answering the question of whether we have free will while making decisions. We need to come up with a new approach to this extremely interesting scientific puzzle," said Dmitry Bredikhin, study author.

(The above story is verified and authored by Press Trust of India (PTI) staff. PTI, India’s premier news agency, employs more than 400 journalists and 500 stringers to cover almost every district and small town in India.. The views appearing in the above post do not reflect the opinions of LatestLY)