BCI Basics
A Brain-Computer Interface (BCI) is a device that enables communication without movement. People can communicate via thought alone. Since BCIs do not require movement, they may be the only communication system possible for severely disabled users who cannot speak or use keyboards, mice, or other interfaces.
Most BCI research focuses on helping severely disabled users send messages or commands. But, this is beginning to change. Some companies have begun offering BCI-based games for healthy users, and other groups are developing or discussing BCIs for new purposes and for new users. There may soon be a substantial increase in number of people using BCIs.
There are often a lot of misunderstandings about what BCIs can and cannot do. BCIs do not write to the brain. BCIs do not alter perception or implant thoughts or images. BCIs cannot work from a distance, or without your knowledge. To use a BCI, you must have a sensor of some kind on your head, and you must voluntarily choose to perform certain mental tasks to accomplish goals. For example, the downloads section of this site has videos that show someone moving through a virtual environment by thinking about moving: bci.tugraz.at.
A BCI requires must meet four criteria to be a BCI. First, the device must rely on direct measures of brain activity. A BNCI is a device that can also rely on indirect measures of brain activity. Second, the device must provide feedback to the user. Third, the device must operate in realtime. Fourth, the device must rely on intentional control. That is, the user must choose to perform a mental task, with the goal of sending a message or command, each time s/he wants to use the BCI.
Any BCI or BNCI requires at least 4 components. At least one sensor must detect brain activity. (In a BNCI, the sensor could detect other signals from the body, which might reflect activity from the eyes, heart, muscles, etc.) Next, a signal processing system must translate the resulting signals into messages or commands. Next, this information must be sent to an application on a device, such as a web browser on a monitor or a movement system on a wheelchair. Finally, there must be an application interface or operating environment that determines how these components interact with each other and with the user.
Figure 1 below presents these different components of any BCI or BNCI.
Figure 1: The different components of a BCI or BNCI. This figure is adapted from articles about BCIs (such as Nijholt et al., 2008 or Pfurtscheller et al., 2008), but can apply to BNCIs too if expanded to include signals from the body as well as the brain.
The sections below contain more details about different components of BCIs or BNCIs. These four sections are loosely based on the four components of a BCI. The last section, Standards and Dissemination, is not really a BCI component, but instead discusses important issues related to BCIs. Please see other material in the "About BCIs" Tab to learn more.
Sensors, Signals, and Signal Processing
No matter what the future holds for BNCI, we know that it will involve signals from the brain or body, that these signals will be captured with sensors of some kind, and that those signals will be processed to extract useful information and features. In this website, we will include a wide variety of information related to Sensors, Signals and Signal Processing. This section involves many topics, including: sensors currently in use for BNCI (as mentioned elsewhere on this site, BNCI can include indirect as well as direct signals from the brain); sensors that are currently in development; new areas of research that may yield new sensors; the different signals available from the brain and body which are (or could be) used for BNCI and which sensors can be employed to detect them; the Signal Processing techniques that are typically employed to extract meaning, and in many cases intention, from these signals; and the data fusion techniques necessary to work with multiple signal features or to build hybrid systems that use multiple signals.
Although there are many different choices when developing the Sensors, Signals, and Signal Processing aspect of a BCI or BNCI, here is an example in a common type of BCI. Most BCI systems rely on EEG activity recorded from electrodes placed on the surface of the head. EEG activity can be recorded safely and painlessly, without any surgery, drugs, or risk. However, it takes at least 10 minutes to prepare someone for EEG recording, and getting a good signal requires putting electrode gel on the head, which is inconvenient. Other sensors can also detect the brain's electrical signals, or other types of brain signals, but have various drawbacks such as cost, portability, reliability, invasiveness, or bandwidth. Signal Processing often involves measuring the power in the EEG at certain frequencies. People can learn to control their brain activity at certain frequencies and thereby move a cursor or other device.
Many researchers and developers are excited about "dry" electrodes that could measure electrical signals from the brain or body without electrode gel. This could make BCIs and BNCIs much more practical. In turn, these and other systems based on electrodes could become more helpful to severely disabled users (who will need less assistance preparing their BCI or BNCI) and healthy users (who may be more likely to prefer BCIs and BNCIs over other interfaces).
A report on Sensors, Signals and Signal Processing, written by the consortium, can be downloaded here.
Devices, Applications, and Users
After the signal has been processed, it is only an electronic signal in a computer. The system must then do something with the signal, such as use it to control a device (like a monitor, wheelchair or robot), perhaps via an application running on that device (such as a word processor or internet browser running on a monitor). Early BCI systems could only present simple feedback on a monitor. More advanced systems could allow people to control a much wider variety of applications, and control many different devices. BCIs are no longer limited to monitors. BCIs have been used to control an artificial arm, wheelchair, and several types of mobile robots.
As BCIs are developed that can control a wider range of devices and applications, different users may become interested in BCIs and BNCIs. For example, until recently, very few people in the gaming community were interested in playing games with a BCI or BNCI. Today, however, a few companies sell such systems to play games. Some of the videos under the "About BCIs" tab show people controlling a game or other application in a complex virtual environment with a BCI.
A report on Application Scenarios and User Groups, written by the consortium, can be downloaded here.
Application Interfaces and Environments
This component refers to the way that the BNCI system communicates with itself and the user. How does the user know if s/he accomplished a task with a BNCI? How does s/he understand the state of the system, such as which choices are available and how to choose one of them? In a well designed interface, interaction with the system seems easy, natural, and intuitive. It should be easy for a user to understand how to accomplish a goal. Interfaces in BCI systems can draw on the same principles that help lead to good environments with other interfaces, such as this web page, a word processing program, or another assistive technology for disabled users.
Research in Human Computer Interaction (HCI) has shown that well designed, user centred interfaces yield many benefits, but many fundamental design principles in HCI are still ignored in the BNCI community. For instance, non ALS users often have to behave as ALS patients (no movement, no blinking, etc.) to interact through BNCI. Principles in assistive technology (AT) design are often ignored in BNCI research. On the contrary, in user centred interface design, the focus is on multimodal natural and intuitive interaction, using for instance verbal and non verbal communication channels besides keyboard and mouse. The development of successful BNCI’s may therefore benefit from the many fundamental design and validation principles from the HCI community.
Important current issues are first the integration of BNCIs in multimodal interfaces so that users can interact, in an intuitive and natural way, using BNCI as one of the communication channels and second to make the BCI more robust using techniques from Artificial Intelligence. This could be useful in situations such as flying, driving, cell phone use, surgery, space applications, or gaming. In these settings, users experience “situational disability”, when their hands and voices are busy or temporary unavailable. This website will provide objective views and feedback from stakeholders with relevant experience and different views.
A report on Application Interfaces and Environments, written by the consortium, can be downloaded here.
Standards and Dissemination
Of course, this is not really a component of a BCI in the same way as a sensor or output device. But, establishing standards, and disseminating these standards and BCI research, is a major issue we need to address. Today, there are no established guidelines that define what a BCI is, or set standards for the different parts of a BCI. Future BNCI will work to develop guidelines and standards, and work toward extablishing a body of experts that can make relevant decisions. Please also see the new website bcistandards.org and the TOBI project at http://www.tobi-project.org/.
A report on (Re)Defining BCIs, written by the consortium, can be downloaded here.
Dissemination (that is, telling people about BCIs) occurs through many channels: academic conferences and workshops, journals, and books. Unfortunately, these mechanisms focus only on other experts. One goal of Future BNCI is to help make BCIs accessible and understandable to other groups, such as doctors, therapists, younger students, journalists, and the public at large. This website is one step in that effort.
The following material may help people learn about BCI Basics. All of this material is directed toward people who do not have a background in BCI research. The presentations are based on professional talks that introduced BCIs to audiences of intelligent professionals and laypeople. The news story was from a popular CBS news program. The chapters are from books about BCIs that will be published soon. The chapters have some similar material at first, and then explore some different directions later.
Click for a .pdf file with an introduction to BCI systems.
(To watch the videos from this presentation please go to the videos section.)
Graimann, B., Allison, B.Z., and Pfurtscheller, G. An introduction to brain – computer interface (BCI) systems, In: Brain-Computer Interfaces: Revolutionizing Human-Computer Interaction, editors: Graimann, B., Allison, B.Z., & Pfurtscheller, G. Springer Publishing. (in press).
This book is available through this link
Tan, D. and Nijholt, A. Brain-Computer Interfaces and Human-Computer Interaction, In: Brain-Computer Interfaces: Applying our Minds to Human-Computer Interaction, editors: Tan, D. S. and Nijholt, A. Springer Publishing. (in press)
This book is available through this link
Click here for the table of contents of this book.
Click here for an article in the journal "Neuroethics" that we published in 2011. This article contains results of a survey that FBNCI conducted at the 2010 International BCI Conference in Asilomar, California. Because this article was published in an open access journal, you are welcome to share it freely. We produced several other journal and conference papers, which are noted in the roadmap.
Click here for the slides of a TEDx talk from 29 April 2012 (excluding one video that was part of the talk). The talk was titled BCIs: Emerging Technology, Emerging Issues. The TEDx staff are editing the video, and it should be available online soon.
