Virtual Reality in Brain-Computer Interface Research

F. Lee 1, R. Scherer 2, H. Bischof 1, G. Pfurtscheller 2

1) Institute for Computer Graphics and Vision2) Institute for Human-Computer Interfaces

Outline Overview of Brain Computer

Interface (BCI) Problems in BCI research Studierstube combined with BCI Experiments Further work

Brain Computer Interface A Brain-Computer Interface is a

communication system that do not depend on peripheral nerves and muscles

Applications: Patient with severe movement disorders:

Control external devices (neuroprosthesis, wheelchair) by mental focus

Entertainment (games) Military Use (fighter pilots)

Graz BCI system Graz-BCI system based on classification

of motor imagery related brain activity changes in ongoing EEG Electrodes placed on the scalp Movement imagination (left hand, right

hand, foot or tongue)

Homunculus

Primary Somato Sensory Cortex

Primary Motor Cortex

Motor execution vs. Movement imagination

Imagination

Execution

Subject g3, 16-20 Hz Subject f7, 20-24 Hz

ERD ERS500mstime

Simplified model of the BCI system

Problems in BCI Research Time-consuming training

Which kind of movement imagination is better?

Impact of visual stimulus on the motor cortex activity and resulting EEG Can lead to deterioration of motor

imagery related EEG pattern Correct visual feedback should help user

to get more control on the own brain activity

Goal Design an accurate BCI system

which needs only few training sessions Investigation of different classification

methods Presentation of „better“ visual

feedback Studierstube (stereoscopic 3-D scene, tracking)

BCI combined with Studierstube

Experiments Rotate the cube by mental focus

Observation of Movement

•Feature extraction: adaptive autoregressive parameter•Feature mapping: PCA•Feedback: rotation, size, color of cube

Further work

Virtual flat Navigastion: e.g

moving into bathroom

Thank you for your attention