BRAIN-COMPUTER INTERFACES (BCI)

1. BRAIN-COMPUTER INTERFACES (BCI) Presentation by Team 1 Bintou Kane Sridevi Puramsetti Raghu Basavaraju Robert Zack 04/18/09 DCS861A

2. Agenda • What is BCI? Why BCI? • BCI Components • Invasive vs. Noninvasive BCI • BCI Benefits/Applications • BCI Challenges • Current trends and Future directions • References

3. What is a BCI? • BCIs Read electrical signals or other manifestations of brain activity and • Translate them into a digital form that computers can understand, process, and • Convert into actions of some kind, such as moving a cursor or turning on a TV.

4. Why BCIs? [1] • The technology holds great promise for people who can’t use their arms or hands normally because they have had spinal cord injuries or suffer from conditions such as amyotrophic lateral sclerosis (ALS) or cerebral palsy. • BCI could help them control computers, wheelchairs, televisions, or other devices with brain activity.

5. The 3 major components of BCIs[4] • Ways of measuring neural signals from the human brain • Methods and algorithms for decoding brain states/intentions from these signals and • Methodology and algorithms for mapping the decoded brain activity to intended behavior or action.

6. Basic Signal-processing blocks of BCIs[5] • Preprocessing: To remove noise and artifacts (mostly related to ocular, muscular, and cardiac activities) to enhance the SNR. • Feature extraction:Performs feature extraction and selection to detect the specific target patterns in brain activity that encode the user’s mental tasks, detect an event-related response, or reflect the subject’s motor intentions. • Classification: Translating or associating these specific features into useful control (command) signals to be sent to an external device.

7. Invasive versus Non-invasive BCI [1] • Invasive techniques: which implant electrodes directly onto a patient’s brain; • Noninvasive techniques: in which medical scanning devices or sensors are mounted on caps or headbands read brain signals.

8. Invasive versus Non-invasive BCI [1] • Noninvasive approaches are less intrusive but can also read brain signals less effectively because the electrodes cannot be located directly on the desired part of the brain. • Invasive techniques, however, require surgery and carry the risk of infection or brain damage. • Noninvasive approaches’ ability to read signals from many points in the brain could help identify a wider range of brain activity. However, processing the large amount of data that neurons in multiple parts of the brain would generate would be difficult for BCI systems.

9. BCI Disciplines [1] • Nanotechnology • Biotechnology • Information technology • Cognitive science • Computer science • Biomedical engineering • Neuroscience • Applied mathematics

10. Benefits of BCI? [2] • BCI might help us better understand how the human brain works in terms of reorganization, learning, memory, attention, thinking, social interaction, motivation etc. • BCI research allows us to develop a new class of bioengineering control devices and robots to provide daily life assistance to handicapped and elderly people. • Several potential applications of BCI hold promise for rehabilitation and improving performance, such as treating emotional disorders (for example, depression or anxiety). • BCI can expand possibilities for advanced human computer interfaces (HCIs), by enhancing the interaction between the brain, the eyes, the body, and a robot or a computer.

11. BCI Potential Applications [1] • Healthcare (Ex: Help disabled People) • Automobile (Ex: Help Drivers/pilots) • Gaming (Ex: Help users manipulate systems) • Biometrics (Ex: Pass-thought authentication) • Unexpected Directions???

12. Carleton University’s proposed BCI-based biometric system [1] Subjects use specific thoughts as passwords (called pass-thoughts).When someone tries to access a protected computer system or building, they think of their pass- thought.A headpiece with electrodes records the brain signals. The system extracts the signal’s features for computer processing,which includes identification of the feature subset that best and most consistently represents the pass-thought.The biometric system then compares the subset to those recorded for authorized users.

13. BCI Systems Challenges [1] • So new, researchers are still learning how to effectively implement it and adapt it to different needs. • Tend to be very expensive, very large, making them impractical. • Complex to use and require the involvement of Experts. • Steep Learning curve for the Users (to learn how to use their thoughts to create the brain signals that generate desired actions) • So new, many companies are not investing the time and money necessary for effective product development. • An issue particularly noninvasive approaches is Signal Accuracy, the ability to accurately capture signals from the brain. • Invasive BCI systems can experience problems with their electrodes since the brain recognizes and tries to remove foreign objects.

14. Current and future trends in noninvasive BCI [2] • Unimodal to multimodal - that is, simultaneous monitoring of brain activity using several devices and combining BCI with multimodal HCIs; • Simple signal-processing tools to more advanced machine learning and multidimensional data mining; • Synchronous binary decision to multidegree control and asynchronous self-paced control; • Open-loop to closed-loop control - neurofeedback combined with multimodal HCI; and • Laboratory tests to practical trials in the noisy real world environment.

15. References • Sixto Ortiz Jr., "Brain-Computer Interfaces: Where Human and Machine Meet," Computer, vol. 40, no. 1, pp. 17-21, Jan., 2007 • Andrzej Cichocki, Yoshikazu Washizawa, Tomasz Rutkowski, Hovagim Bakardjian, Anh-Huy Phan, Seungjin Choi, Hyekyoung Lee, Qibin Zhao, Liqing Zhang, Yuanqing Li, "Noninvasive BCIs: Multiway Signal-Processing Array Decompositions," Computer, vol. 41, no. 10, pp. 34-42, Oct., 2008 • “Conference on Human Factors in Computing Systems CHI '08 extended abstracts on Human factors in computing systems”Florence, Italy WORKSHOP SESSION: Workshops table, Pages 3925-3928, 2008 • 1. F. Babiloni, A. Cichocki, and S. Gao, eds., special issue, “Brain-Computer Interfaces: Towards Practical Implementations and Potential Applications,”ComputationalIntelligence and Neuroscience, 2007; • P. Sajda, K-R. Mueller, and K.V. Shenoy, eds., special issue, “Brain Computer Interfaces,”IEEE Signal Processing Magazine,Jan. 2008. • “ACM SIGACCESS Conference on Assistive Technologies Proceedings of the 9th international ACM SIGACCESS conference on Computers and accessibility”Tempe, Arizona, USA SESSION: Keynote addresss, Pages: 1 – 2, 2007.