For the first time in over 15 years, Cathy Hutchinson brought a coffee to her lips and smiled. Cathy had suffered from the paralysing effects of a stroke, but when neurosurgeons implanted tiny recording devices in her brain, she could use her thought patterns to guide a robot arm that delivered her hot drink. This week, it was reported that Jan Scheuermann, who is paralysed from the neck down, could grasp and move a variety of objects by controlling a robotic arm with her mind.
In both cases the implants convert brain signals into digital commands that a robotic device can follow. It’s a remarkable achievement, one that could transform the lives of people debilitated through illness.
Yet it’s still a far cry from the visions of man fused with machine, or cyborgs, that grace computer games or sci-fi. The dream is to create the type of brain augmentations we see in fiction that provide cyborgs with advantages or superhuman powers. But the ones being made in the lab only aim to restore lost functionality – whether it’s brain implants that restore limb control, or cochlear implants for hearing.
Creating implants that improve cognitive capabilities, such as an enhanced vision “gadget” that can be taken from a shelf and plugged into our brain, or implants that can restore or enhance brain function is understandably a much tougher task. But some research groups are being to make some inroads.
For instance, neuroscientists Matti Mintz from Tel Aviv University and Paul Verschure from Universitat Pompeu Fabra in Barcelona, Spain, are trying to develop an implantable chip that can restore lost movement through the ability to learn new motor functions, rather than regaining limb control. Verschure’s team has developed a mathematical model that mimics the flow of signals in the cerebellum, the region of the brain that plays an important role in movement control. The researchers programmed this model onto a circuit and connected it with electrodes to a rat’s brain. If they tried to teach the rat a conditioned motor reflex – to blink its eye when it sensed an air puff – while its cerebellum was “switched off” by being anaesthetised, it couldn’t respond. But when the team switched the chip on, this recorded the signal from the air puff, processed it, and sent electrical impulses to the rat’s motor neurons. The rat blinked, and the effect lasted even after it woke up.
Mind switch
The media proclaimed this achievement as being an “artificial cerebellum“ and a “cyborg rat“. This isn’t quite true: first, the researchers modelled only one specific circuit in the cerebellum; and second, they also stated that the purpose of the device is not to improve a healthy brain, but to help people who have lost motor functions after a stroke.
In September this year, American scientists said they had created a way of enhancing a monkey’s decision making by about 10%. One of the team leaders, Theodore W. Berger, let monkeys play a picture-matching game and recorded their neurons’ activities from the cerebral cortex, where decision-making takes place. They found that the signal pattern differed for correct and incorrect decisions. The team let the monkeys play the same game again, but before a monkey made a decision, they injected the “correct” signal pattern into the brain by sending a sequence of electrical pulses through implanted microelectrodes – much like Morse code. As a result, the monkeys picked the correct picture.
The technique also works on rats, switching their long-term memory on or off, and one day Berger hopes his neuroprosthesis could restore lost memories from people with Alzheimer’s disease. If this works, this could improve the brain’s ability to push short-term memories into the long-term memory – creating humans who remember more than others.
