"It was one of the weirdest sensations I have ever felt." This is how Stephen Dunne, director of neuroscience research at Starlab in Barcelona, described his first experience of transcranial magnetic stimulation (TMS). This new brain stimulation method can, among other things, produce involuntary muscle movements. Dunne used the technology to send a signal to his brain directing his arm to move.
It’s just one of the extraordinary things Irishman Stephen Dunne and his research team have been up to.
Starlab made the headlines in 2014 when the lab achieved the first known realisation of brain-to-brain (B2B) communication. In this instance, it involved a process they developed known as transcranial current stimulation (TCS). Two subjects, one located in India and the other in France, established internet-mediated B2B communication through a combination of Starlab's brain computer interface (BCI) technology with the aforementioned TMS. It allowed them to induce the conscious perception of light flashes sent from one brain to the other. "It seems almost trivial in terms of what was communicated," says Dunne. "Still it was B2B communication nonetheless." Modesty from an Irishman spearheading mind control – one of science fiction's favourite themes.
Fiction it is no more. The successful transmission of those light pulses, trivial or otherwise, signals the dawn of a new age in B2B communication research.
The underlying technology has already been used effectively in a number of clinical settings. “It has been used to stimulate the motor cortex in post-stroke patients,” says Dunne. “It has also proven useful in helping treat traumatic brain injury by promoting recovery in damaged neurons.”
TCS has also been found to help in the treatment of depression, addiction, Dyscalculia (the numerical equivalent of dyslexia) and general cognitive enhancement.
Animal neurophysiology
Research in this field dates back to the 1970s. Back then though, it was all batteries and wet sponges. In recent years, B2B communication has developed rapidly, particularly for research that doesn’t begin with human subjects.
"Animal experimentation is a necessary step before the technology can be translated to human clinical trials," says Mikhail A Lebedev, senior research scientist at the Centre for Neuroengineering at the Department of Neurobiology at Duke University Medical Centre in North Carolina. "Before we implant any electrodes into the human brain, we need to thoroughly test them out first on animals.
“We can implant electrodes directly into animals’ brains and record from many neurons simultaneously. Recording this way gives us an opportunity to accurately decode brain signals. So, for example, we can decode signals that represent movements. If an animal wants to move an arm, we can record from the neurons that represent arm movements and transform the activity of the neurons to the coordinates of the arm.
“We have been doing our research for over 10 years and have achieved multiple successes. We have demonstrated that monkeys can control the movements of artificial arms by their brain activity alone – one arm or even two simultaneously.”
Lebedev has also been able to successfully realise one animal sending messages to the thoughts of another.
“This research was outlined in three papers, one published a year ago and the other two this year,” he says. “We connected two rats together. The task was simple: one rat received a stimulus which told it to press a right or left lever and then we recorded brain activity from this rat and transmitted it to the brain of another. We used electrical stimulation of the nervous tissue as the method of signal delivery.”
The team at Duke decided to make things even more interesting by introducing a feedback link from the receiver rat to the transmitter rat. “If the receiver rat still performed their task correctly, the first rat was given an additional reward. This encouraged the first rat to ‘think clearly’ and transmit signals very precisely.”
“Brain-nets”
Researchers at Duke decided to experiment with more than two animals, thereby creating a ‘brain network’.
“Our next project tested the possibility of interconnecting several animal brains to create a network that could perform computations,” he says. “We connected the brains of up to four rats to test some simple computational operations: synchronisation of responses to an input, stimulus recognition, and memory. Based on these results, we expect to build much more sophisticated brain-nets in the future.
Synchronisation
Human B2B communication is moving slower than animal-based research because of the risks associated with invasive surgery. At present most B2B communication among the human populous is of the non-invasive variety and so is limited in terms of what can be tested. As one commentator put it, the work from Starlab is impressive but is essentially a “circus trick” at this point.
Still Dunne and his team are looking at other ways the technology could be used, like controlled synchronisation. “People often say that when musicians are really locked in with each other, they start to feel like they are in sync,” he says. “Some research has shown that musicians’ movements do in fact begin to synchronise. It might not be obvious to the eye. We suspect there might be some neural synchronisation as well.
“We now have the tools to read and write to the brain,” he says. “So why not start thinking about things like synchrony and resonance? What happens if I measure the peak frequency and phase of your brain waves in a certain band and then stimulate someone else’s brain in the same area at that frequency and phase? Are there behavioural consequences to this type of physiological synchrony?”
Synchronisation could be extended to more than two people. BMIs could be used to create brain networks with multiple people experiencing the same transmissions. To return to the musical analogy, could this technology become the instrumental equivalent of autotune, where a band might only need one good musician – whose creative brain waves are being transmitted to everyone else in the band – for them all to seemingly perform well together live? It’s probably not that simple.
Social neuroscience
B2B communication, like that being done at Starlab, is a very direct form of interaction, independent of our sensory nervous system. Normally our brain interacts with the outside world through our motor system and sees and feels the affects of its actions through the sensory nervous system. B2B communication is short-cutting all of that and bypassing the peripheral nervous system.
But when these systems are all working together a natural form of B2B communication happens anyway, without the need for BCIs, TCS, or ay other acronym you can think of.
Studying the behaviour of the brain in social/group settings is part of a hot, new interdisciplinary field known as social neuroscience, which attempts to understand what part biological systems play in influencing social processes and behaviours. "If you have a group of people, all with brain computer interfaces interacting in a conversation, you can look at brain activity levels and take measurements of interaction between the users," explains Dr Tomas Ward from the Dept of Electronic Engineering at NUI Maynooth.
“When two people are having a really good, stimulating conversation, each knows when to stop talking and when to start listening,” says Ward. “Maybe we’ll reciprocate each other’s body language, maybe even give a little nod in appropriate ways at the right times.” These processes have always been considered social. But the measurements are now being extended into the brain.
“Social neuroscience asks how brains can become coupled through our sensory and motor systems,” he says.
“Human beings are social animals, very tuned into observing others. There is something known as the mirror neuron system, a part of our brains that reflects when we observe someone else doing something. It triggers something to make us think as if we’re doing it ourselves. If you observe someone kicking a ball, there are parts of your brain that will light up with you kicking a ball. Observation and our sensory system are both very important for driving brain dynamics.”
