Brain-Computer Interfaces: Exploring EEG and SSVEP Technologies for Enhanced Communication
Brain-computer interfaces (BCIs) leverage electroencephalography (EEG) to measure electrical activity in the brain through electrodes placed on the scalp. These systems can translate brain signals into commands, facilitating communication without physical interaction. Current BCIs can transfer information at rates of 10-25 bits/min, relying on adaptive feedback mechanisms. Notable methods include the P300 and steady-state visually evoked potential (SSVEP), which utilize brain responses to specific stimuli. This technology opens new avenues for individuals with mobility challenges, enhancing their quality of life.
Brain-Computer Interfaces: Exploring EEG and SSVEP Technologies for Enhanced Communication
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Presentation Transcript
Billy Vermillion Brain-Computer Interfacing
EEG • Electroencephalography • A test to measure the electrical activity of the brain. • Brain cells communicate by producing tiny electrical signals, called impulses. • Flat metal disks called electrodes are placed all over your scalp. • Held in place with a sticky paste or specially designed helmet. • Connected by wires to a recording machine. • The recording machine filters the signals into patterns that can be seen on a computer.
Brain-Computer Interface (BCI) • Current BCIs have maximum information transfer rates up to 10-25bits/min • A BCI depends on feedback and adaptation of brain activity based on that feedback • Operation depends on the interaction of two adaptive controllers: • The user’s brain • Which produces the signals measured by the BCI • The BCI itself • Which translates these signals in specific commands
BCI BCI2000: A General-Purpose Brain-Computer Interface (BCI) System GerwinSchalk*, Member, IEEE, Dennis J. McFarland, ThiloHinterberger, NielsBirbaumer, and Jonathan R.Wolpaw
P300 • Infrequent or particularly significant auditory, visual, or somatosensory stimuli • Interspersed with frequent or routine stimuli • Evoke in the EEG over parietal cortex a positive peak at about 300ms latency • Only the choice desired by the user evokes a large P300 potential • Requires no initial user training • P300 is a typical, or native, response to a desired choice
Steady-State Visually Evoked Potential (SSVEP) • Natural responses to visual stimulation at specific frequencies • When the retina is excited by a visual stimulus ranging from 3.5 Hz to 75 Hz, the brain generates electrical activity at the same (or multiples of) frequency of the visual stimulus. • Used widely with research regarding vision • Excellent signal-to-noise ratioand relative immunity to artifacts. • SSVEP's also provide a means to characterize preferred frequencies of neocortical dynamic processes.
SSVEP http://www.youtube.com/watch?v=9afbMN1lPZE Design and Implementation of a Brain-Computer Interface With High Transfer Rates Ming Cheng*, XiaorongGao, ShangkaiGao, Senior Member, IEEE, and DingfengXu
Combination http://futuristicnews.com/wp-content/uploads/2012/10/mind-controlled-leg-robotics-EEG-2.jpg
Signals http://scienceblogs.com/thoughtfulanimal/wp-content/blogs.dir/351/files/2012/04/i-7cb3dec9973ac6a5143c37eb9efce18b-motor%20somato.jpg http://www.brain.riken.jp/bsi-news/bsinews34/files/research0103-big.jpg
fMRI http://scienceblogs.com/developingintelligence/wp-content/blogs.dir/411/files/2012/04/i-8df6cca3f243ab02d498057e053ff30b-fmri_image.jpg
http://mialab.mrn.org/software/fit/images/fmri_fmri_fusion.jpghttp://mialab.mrn.org/software/fit/images/fmri_fmri_fusion.jpg