BRAIN COMPUTER INTERFACE

A Short Introduction to

Outline

• Definitions

• History

• Types

• EEG

• Commercialization

• Outlook

• Hands on!

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)

Current BCI Systems

History

• Hans Berger

– First EEG recording in 1924

– Find oscillation activity: alpha wave (8-12Hz)

History

• Animal Study

– 1970s University of Washington School of Medicine in Seattle

– 1980s Johns Hopkins University

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

Invasive BCI

• Sci-Fi

– “Plug in” to human central neural system

– Qualia: subjective feelings

• Real world

– Vision

• William Dobelle

– Movement

• Robotic arms

Partially Invasive BCI

• Electrode on the brain surface

– Better signals

– Lower risks

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

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

MEG

• Magnetoencephalography

– Record magnetic fields produced by electrical currents occurring naturally in the brain

– SQUIDs (superconducting quantum interference devices)

EEG

• Electroencephalography

– the most studied

– fine temporal resolution

– ease of use

– portability

– low set-up cost

EEG Measurement

• Measure the “wave” generated by the brain

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

Alpha 8Hz ~ 12Hz 安靜、清醒、放鬆的狀態，但沒有到昏昏欲睡的程度

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

Brain Waves

• Different Brain waves

Delta

Theta

Alpha

Beta

Commercialization

• BrainGate

– Cyberkinetics

– Neural Signals

• For PC users

– Neural Impulse Actuator (April, 2008)

– Emotiv Systems (December, 2009)

– NeuroSky (2009-)

Current BCI Systems

Toward a Natural User Interface

• Signal Acquisition

– Non-intrusive

• Signal Processing

– Convert what we measured to bits and bytes

• Translation

– Convert intention to action

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?

EEG

Brain Activity

Thoughts

Outlook

• Artificial Sensory Channel

– Hearing

– Vision

– Motion

– Neural disorder control

• Portable, non-invasive BCI is not yet intuitive

– Need to solve translation problems

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

Hands On: Neurosky

• Mindset / Mindwave

http://www.youtube.com/watch?v=CV411vt_51w

Necomimi from Neurowear

• Time Magazine 2011

– Best Invention of the Year

http://www.youtube.com/watch?v=w06zvM2x_lw

THANK YOU!