1. A Short Introduction to
BRAIN COMPUTER INTERFACE

2. Outline
• Definitions
• History
• Types
• EEG
• Commercialization
• Outlook
• Hands on!

3. Definitions
• Brain–computer interface (BCI)
• A direct communication pathway between
the brain and an external device
• A.K.A.
– mind-machine interface (MMI)
– direct neural interface
– brain–machine interface (BMI)

4. Current BCI Systems

5. History
• Hans Berger
– First EEG recording in 1924
– Find oscillation activity: alpha wave (8-12Hz)

6. History
• Animal Study
– 1970s University of Washington School of
Medicine in Seattle
– 1980s Johns Hopkins University

7. Types
• Invasive
– Put the whole module into the brain
• Partially Invasive
– Attach sensors on the surface of the brain
• Non-invasive
– Leave everything outside of the skull

8. Invasive BCI
• Sci-Fi
– “Plug in” to human central
neural system
– Qualia: subjective feelings
• Real world
– Vision
• William Dobelle
– Movement
• Robotic arms

9. Partially Invasive BCI
• Electrode on the brain surface
– Better signals
– Lower risks

10. Non-Invasive BCI
• EEG
– the electrical activity along
the scalp
• MEG
– the magnetic fields
produced by brain
• MRI
– Use nuclear magnetic
resonance (NMR) to image
nuclei of atoms inside the
body

11. MRI
• Magnetic resonance imaging
– uses a powerful magnetic field to systematically
alter the alignment of this magnetization
– causes the nuclei to produce a rotating magnetic
field which can be detected

12. MEG
• Magnetoencephalography
– Record magnetic fields produced by electrical
currents occurring naturally in the brain
– SQUIDs (superconducting quantum interference
devices)

13. EEG
• Electroencephalography
– the most studied
– fine temporal resolution
– ease of use
– portability
– low set-up cost

14. EEG Measurement
• Measure the “wave” generated by the brain

15. Brain Waves
• Different Brain waves
腦波種類 腦波頻率 心理及活動狀態
Delta 0.1Hz ~ 3Hz 深度睡眠、無意識狀態
Theta 4Hz ~ 7Hz 想像力活躍的狀態，幻想、回想，以及作夢
安靜、清醒、放鬆的狀態，但沒有到昏昏欲睡
Alpha 8Hz ~ 12Hz
的程度
Low Beta 12Hz ~ 15Hz 放鬆，但是注意力集中
Midrange Beta 16Hz ~ 20Hz 思考中，並且意識到自身和環境的變化
High Beta 21Hz ~ 30Hz 警戒、焦慮的狀態

16. Brain Waves
• Different Brain waves
Delta
Theta
Alpha
Beta

17. Commercialization
• BrainGate
– Cyberkinetics
– Neural Signals
• For PC users
– Neural Impulse Actuator (April, 2008)
– Emotiv Systems (December, 2009)
– NeuroSky (2009-)

18. Current BCI Systems

19. Toward a Natural User Interface
• Signal Acquisition
– Non-intrusive
• Signal Processing
– Convert what we measured to bits and bytes
• Translation
– Convert intention to action

20. Challenges of BCI to NUI
• Lost in Translation
1. What is in your mind?
2. How is your brain work?
3. What are the corresponding EEG patterns?
Brain Activity
EEG Thoughts

21. Outlook
• Artificial Sensory Channel
– Hearing
– Vision
– Motion
– Neural disorder control
• Portable, non-invasive BCI is not yet intuitive
– Need to solve translation problems

22. Tan Le from Emotive System
• Tan Le 展示一個影響深遠
應用程式，只需要運用意
念和一點專注力，這令人
耳目一新的電腦界面可以
透過頭戴式耳機來解讀使
用者的大腦電波，從而控
制虛擬物件和家電用品
http://www.youtube.com/watch?v=fVhggGSjXVg

23. Hands On: Neurosky
• Mindset / Mindwave
http://www.youtube.com/watch?v=CV411vt_51w

24. Necomimi from Neurowear
• Time Magazine 2011
– Best Invention of the Year
http://www.youtube.com/watch?v=w06zvM2x_lw

25. THANK YOU!