Electroencephalography has contributed greatly to the advancement of neuroscience. Now this powerful technology is on its way to the consumer market.
Charles Xavier, also known as Professor X, is oneof the most powerful mutants from the comicbook 'X-Men'. He can read and control minds, just by using his brain. It may not yet be possible to take over someone's body using telepathy, but you can do some pretty impressive things with brain-computer interfaces, and they may soon be hitting the consumer market.
Electroencephalography (EEG) is a technique used for measuring voltage changes resulting from ionic current flows occurring inside the brain's neurons. EEG belongs to a larger group of electrobiological measurement techniques, which have been in use for both research and medical purposes for decades.
Besides EEG, this group includes electrocardiography (ECG/EKG) for heart electrical measurement, electromyography (EMG) for muscular contraction measurement, electrooptigraphy (EOG) for corneo-retinal measurement, as well as electrogastrography (EGG) for stomach electrical measurement.
According to Professor Howard Bowman from the University of Birmingham School of Psychology, who studies cognitive phenomena using EEG and Neural Modelling, 'EEG picks up the electrical fields set up when a large population of neurons that are physically similarly oriented relative to an electrode, become active together. This creates a large enough electrical field that it can be detected on the scalp.'
The actual electrical fields measured by EEG are extremely weak, typically on the scale of tens of microvolts. To make the most out of these weak signals, medical-grade EEG units typically use conductive gels applied to the scalp and active electrodes, which amplify the signal at the electrode level. Medical grade EEGs also employ a relatively large number of electrodes (up to 256), which can be complex and expensive, but allows for a much better spatial resolution.
A history of brainwaves
The first EEG was tested on a human subject in 1924 by German neurologist Hans Berger, who followed the pioneering work of Richard Caton in the UK and others going back to the 19th and even 18th centuries.
Berger performed the first human EEG examination during a neurosurgical operation on a 17-year-old boy. In his early testing, Berger observed that different brainwaves correlate to different states of consciousness. Brain activity changes in a consistent and recognisable way when the general status of the subject changes, for example from a relaxation state to an alert state. It took several more years for researchers to identify the different range of frequencies of brainwaves ranging from about 0.5 to 100Hz.
Since its development in the first half of the 20th century, EEG greatly contributed to the advancement of neuroscience as well as to everyday neurological practice. It is used to: diagnose epilepsy for seizure prediction; develop biomarkers for a spectrum of brain disorders including Alzheimer's and depression; and diagnose sleep disorders, coma and even brain death. Now this unique and powerful technology is on its way to the consumer market.
There are several manufacturers of consumer EEG, and they have different approaches in bringing brain-computer interfaces to the general public and a different vision for the use of the technology. NeuroSky, for example, is one of the oldest and largest consumer EEG manufacturers. The company has its roots early in the last decade, when academics from Korea who were working with BCI technology decided to create a prototype mind-controlled remote control car. The car was based on a simple RadioShack-type RF-controlled car, and a rather complex and cumbersome looking headset that used both EEG and EOG sensors. The player's eyes controlled the left and right movements of the car using left and right glances. Forward and reverse movement was done by moving the eyes up and down respectively. The speed of the car was based on the concentration level of the player (measured using EEG).
The initial idea of the NeuroSky's founders was to launch a small toy company based on this technology. However, once the executive team was formed in Silicon Valley, the decision was made to become a more general biosensor/algorithm company in order to reach a broader audience. Indeed, in the past decade the company worked mostly with OEMs, developers and research institutions to deploy its technology into their own products.
In 2010, NeuroSky also released a commercial product called MindWave. According to Greg Hyver, general manager at Mind Business Group at NeuroSky: 'MindWave incorporates NeuroSky's EEG biosensor module called ThinkGear. It is a three-input sensor; two of them are contained in an ear clip and the third as the active (EEG) channel at the user's forehead. The active channel picks up the EEG and the noise (ambient, physical) and transmits this raw EEG signal to the ThinkGear sensor that executes noise filtering and signal amplification'.
The amplified signal is sent to a platform (there are both PC/Mac versions and a mobile version) which interprets the raw brainwave data to create real-time mental state interpretation (attention, meditation, mental effort etc.). From this point on developers can use this data to create different applications which can be downloaded from the company's app store (currently over 30 exist, including games, stress reduction and meditation apps).
Similar to NeuroSky is Toronto-based startup InteraXon. The company was formed in 2007 by neuroscientist Ariel Garten and her two co-founders Trevor Coleman and Chris Aimone. Garten was working on EEG technology about a decade before in the university lab and by her own account was 'blown away by the fact that she was essentially controlling the world with her mind'. She wanted consumers to know about the technology so InteraXon was formed.
Garten's team started by making a technology that allowed a user to perform actions with their mind such as controlling lights, sound and physical objects. These early successes gave the team the confidence to develop their first commercial EEG unit called Muse. InteraXon decided to raise the money for Muse through a crowdfunding campaign, and on October 2012 the company was able to raise nearly double its $150,000 goal on Indiegogo.
Garten says: 'Muse uses clinical EEG sensors to measure the electrical activity across a range of frequencies naturally produced by the brain. These measurements are then transmitted via Bluetooth to mobile devices which, with the use an app called Calm, allow users to look at the balance of the different frequencies emitted by their brain and see how that balance changes over time, both in real-time and post-session'.
Like NeuroSky, InteraXon offers an API to developers so that they will be able to create their own applications based on the Muse hardware. The headset uses seven electrodes, four of which are EEG channels and the other three are used for referencing and reducing electrical noise. The electrodes cover the most important hairless areas of the scalp, as reading EEG through hair is quite challenging without specialised wet electrodes that can be both uncomfortable and messy according to Garten.
One of the most recent additions to the growing consumer EEG market is Paris-based startup myBrain Technologies. Similar to InteraXon, Yohan Attal and Thibaud Dumas, the founders of myBrain, realised the untapped potential of EEG during their academic research. The two decided to work together with the Brain and Spine Institute (ICM) in Paris to create a neurofeedback headset called melomind.
The melomind headset uses four electrodes (two channels in parietal regions and two electrodes for reference and noise cancelling) and transmits the data they collect to a mobile application. Unlike some of the other companies in this new market, myBrain's approach with its melomind headset is specific to stress management and the use of neuro- feedback based around music.
Yohan Attal, myBrain Technologies CEO says: 'The user's brain activity is represented by a music which will be modulated by his/her own brainwaves as they change during the relaxation session. The audio environment responds to your relaxation level, which means that what you hear depends on how relaxed you are, or not. This is neurofeedback: the music is the feedback, so you can actually be conscious of what is happening in your brain by listening to the music.'
OpenBCI goes one step further than NeuroSky and InteraXon and is actively working on developing an open-source EEG platform that people can adapt and change on both the hardware and the software level. They're all about creating an open-source brain-computer interface.
Like InteraXon, OpenBCI also has its roots as a crowdfunding project. Back in 2013 founder Joel Murphy partnered with Conor Russomanno to launch a Kickstarter campaign to fund the development of the project, which became OpenBCI. It eventually raised over $215k - more than twice its initial goal.
Unlike the rest of the companies mentioned, OpenBCI sells a platform and not a product. It allows a user to attach several types of electrodes (sold separately) for measuring different parts of the body including EEG, ECG and EMG and in the future possibly also sensors for galvanic skin response (GSR) and even things like blood pressure.
What separates OpenBCI from other EEG manufacturers, apart from the open-source approach, is the company's target audience, which includes researchers, individuals and companies looking for a more DIY approach to the brain-computer interface problem.
Murphy says: 'People right now are doing mainly research with OpenBCI. We have seen people use our tech to control a computer keyboard (as a communication tool for people with ALS), control video game avatars as well as robotics (an arm and other machines). There is even a group at the Burke rehabilitation hospital that is currently evaluating our tech for use in tele-health uses'. Murphy agrees that although at the moment consumers are not the main target audience for OpenBCI, it is possible that OEMs will embrace the technology and create consumer products.
Whether or not EEG devices will become as widespread as other existing and upcoming wearables depends on our ability to make the technology transparent and flexible enough to be integrated into everyday items such as caps, helmets and glasses. However, no matter how they will look, consumer brain-computer interfaces will form part of our near future.