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Brain Implant That Decodes Intention Will Let Us Probe Free Will

Posted: Jun 4, 2015 at 12:02 am   /   by   /   comments (0)

Imagine a world where you think of something and it happens. For instance, what if the moment you realise you want a cup of tea, the kettle starts boiling?

That reality is on the cards, now that a brain implant has been developed that can decode a person’s intentions. It has already allowed a man paralysed from the neck down to control a robotic arm with unprecedented fluidity.

But the implications go far beyond prosthetics. By placing an implant in the area of the brain responsible for intentions, scientists are investigating whether brain activity can give away future decisions – before a person is even aware of making them. Such a result may even alter our understanding of free will.


Fluid movement

“These are exciting times,” says Pedro Lopes, who works at the human-computer interaction lab at Hasso Plattner Institute in Potsdam, Germany. “These developments give us a glimpse of an exciting future where devices will understand our intentions as a means of adapting to our plans.”

The implant was designed for Erik Sorto, who was left unable to move his limbs after a spinal cord injury 12 years ago. The idea was to give him the ability to move a stand-alone robotic arm by recording the activity in his posterior parietal cortex – a part of the brain used in planning movements.

“We thought this would allow us to decode brain activity associated with the overall goal of a movement – for example, ‘I want to pick up that cup’,” Richard Andersen at the California Institute of Technology in Pasadena told delegates at the NeuroGaming Conference in San Francisco earlier this month.

Two tiny electrodes implanted in Sorto’s posterior parietal cortex were able to record the activity of hundreds of individual neurons. After some training, a computer could match patterns of activity with Sorto’s intended movement. Once this neuronal information had been collected, a computer translated Sorto’s intentions into movements of a robotic arm. This enabled him to control the speed and trajectory of the arm, so he could shake hands with people, play rock, paper, scissors and swig a beer at his own pace.

Desires laid bare

The breakthrough raises the tantalising possibility of using other intentions decoded from brain activity to control our environment. For example, could we identify the pattern that corresponds to the thought of wanting to watch a film, then have that switch on the television?

To investigate the feasibility, Andersen’s team had a person with a similar implant to Sorto’s play a version of the prisoner’s dilemma, where players can either collaborate or double-cross one another. The team was able to predict the volunteer’s decision based on the neural activity the implant recorded. This showed that more abstract decisions such as, in this case, the intention to snitch on a hypothetical partner, can indeed be decoded from the posterior parietal cortex.

Ori Cohen from the Advanced Virtuality Lab at the Interdisciplinary Center in Herzliya, Israel, says that using abstract commands for brain-computer interfacesMovie Camera is a promising idea. “After all, this is how we control our body – we have a goal such as getting coffee and our brain kick-starts a range of processes involving complex geometrical computations in order to achieve it,” he says.

Eventually, he believes that a person with paralysis could imagine themselves making a cup of coffee and have a humanoid robot automatically carry out the action. He is hopeful that such approaches could one day be achieved using non-invasive techniques, such as recording brain activity with an EEG headset, rather than having to embed electrodes in the brain.


Probing free will

Others are not so sure. “It’s hard to get really high-quality brain signals with non-invasive technology,” says Jörn Diedrichsen, a neuroscientist at University College London. He thinks this might be off-putting to those who have no medical need to link up with their environment. “You have to ask whether you’d want to have invasive surgery to not have to press a button on a remote control,” he says. “It might be technically possible in five to 10 years, but would you do it?”

The most intriguing aspect of Andersen’s work, he says, is that we are now able for the first time to record the brain activity underlying intentions while asking about a person’s conscious experience. For example, Andersen’s team has already started to repeat classic free will experiments in which researchers try to use brain activity to predict a person’s decisions before they are consciously aware of making any.

“We will be able to look carefully into big philosophical questions of whether a person’s future decisions can be decoded from their neural activity before the individual is aware of having formed them – and what that all means for our ideas on free will,” says Diedrichsen. “It really captures the imagination.”