G.BHADRA

1

CONTENTS

INTRODUCTION THE HUMAN BRAIN ELECTROENCEPHALOGRAPHY BCI APPROACHES HARDWARE & SOFTAWARE REQUIRED HOW BCI WORKS BCI FEEDBACK DRAWBACKS & INNOVATORS APPLICATIONS CONCLUSION

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BRAIN COMPUTER INTERFACE 2

INTRODUCTION

THE BRAIN COMPUTER INTERFACE. BCI Systems are systemsthat uses Brain signals (Electrical,Magnetic , Metabolic) to Control external devices such as computers, switches, wheelchairs,or neuroprosthesses . Various Techniques used:FMRI, MEG, PET, SPECT, Optical brain imaging , singleNeuron recording (with micro-Electrodes) & ElectroEnce –phaloGraphy (EEG).

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BRAIN COMPUTER INTERFACE 3

THE HUMAN BRAIN

MAJOR PART OF BRAIN WHICH SUPPORTS BCI

Brain divided in 4 parts: Cerebral Cortex Cerebellum Brain stem Hypothalamus & Thalamus

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BRAIN COMPUTER INTERFACE 4 Fig 3: Human Brain

ELECTROENCEPHALOGRAPHY(EEG)

CONCEPT OF EEG PROPERTIES OF EEG:

RYTHMIC BRAIN ACTIVITY, COMMON EEG FREQUENCY RANGES, EVENT RELATED POTENTIALS (ERP`S), EVENT RELATED DESYNCHRO- NIZATION (ERD) EVENT RELATED SYNCHRINIZATION (ERS)

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BRAIN COMPUTER INTERFACE 5

Fig 4 : EEG frequency

BCI APPROACHES

TWO DIFFERENT BCI APPROACHES :

PATTERN RECOGNITION APPROACH BASED ON MENTAL TASK .

OPERANT CONDITIONING APPROACH BASED ON SELF REGULATION OF EEG .

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BRAIN COMPUTER INTERFACE 6

HARDWARE REQUIREMENTS

ELECTROENCEPHALO PROCESSOR MODEL H11 (EEPH11) EEG DEVICE ELECTRODE CAP EEG AMPLIFIERE FIBRE OPTIC CABLE COMPUTER OR SUBJECT SCREEN

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BRAIN COMPUTER INTERFACE 7

SOFTWARE REQUIREMENTS

EEP H11 SERVER

ABI LEARNING PROGRAME

ABI ONLINE PROGRAME

ABI VISUALIZATION PROGRAME

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BRAIN COMPUTER INTERFACE 8

HOW BCI WORKS

IT HAS SIX STAGES: GENERATION OF SIGNALS FROM BRAIN

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BRAIN COMPUTER INTERFACE 9

HOW BCI WORKS

MEASUREMENT OF EEG, PREPROCESSING, FEATURE EXTRACTION, CLASSIFICATION, DEVICE CONTROL.

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BRAIN COMPUTER INTERFACE 10

BCI FEEDBACK

BIOFEEDBACK IN GENERAL

EEG BIOFEEDBACK

FEEDBACKS IN BCI

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BRAIN COMPUTER INTERFACE 11Fig 6 : BCI Feedback

BCI FEEDBACKS

EFFECT OF FFEDBACK : BENEFICIAL FEEDBACK.

FURNISHES BENEFICIAL MOTIVATION. ENSURES ATTENTION TO THE TASK BY MAINTAINING

SUBJECT`S INTEREST. IMPROVES PERFORMANCE BY RAPID REACTION TO

WRONG CLASSIFICATION. HARMFUL FEEDBACK.

FEEDBACK STIMULUS MIGHT PREVENT CONCENTRATION ON INTERNAL STATES.

FALSE CLASSIFICATION CAN ELICIT FRUSTRATION & THUS AFFECT THE EEG RESPONSE.

VISUAL FEEDBACK STIMULUS AFFECT ALPHA RHYTHM .

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BRAIN COMPUTER INTERFACE 12

BCI DRAWBACKS

THE DRAWBACKS OF BCI : THE BRAIN IS INCREDIBLY COMPLEX,

THE SIGNAL IS WEAK & PRONE TO INTERFENCE,

THE EQUIPMENTS IS LESS THAN PORTABLE,

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BRAIN COMPUTER INTERFACE 13

BCI INNOVATORS

PIONEERS NASA CYBERKINETICS NEUROTECHNOLOGY SYSTEM, JAPANESE REASERCH TEAM

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BRAIN COMPUTER INTERFACE 14

APPLICATIONS OF BCI

CONTROL A ROBOT

PLAYING GAMES

FOR PHYSICALLY WEAK PERSONS TO HANDLE THE COMPUTER

CURSOR CONTROL

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BRAIN COMPUTER INTERFACE 15

CONCLUSION

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BRAIN COMPUTER INTERFACE 16

In this work EEG-based brain computer interface systems were reviewed and compared. Experiments lasting five days with three subjects were done with the new Adaptive Brain Interface system.

The comparison of the BCI systems, especially their training duration and performance, proved to be difficult. This was because the results were reported differently in most of the papers. Reporting the experiments and results should be standardized.