1 / 28

Essentials of Electroencephalography Groundwork

Essentials of Electroencephalography Groundwork. Jarrod Blinch May 17 th , 2011 Comprehensive presentation. Overview. Overall goal Physics-EEG interface Potentials Rhythms Fallacies Recording Artifacts Processing…. Overall goal. Connect psychology with physiology

mikel
Download Presentation

Essentials of Electroencephalography Groundwork

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Essentials ofElectroencephalographyGroundwork Jarrod Blinch May 17th, 2011 Comprehensive presentation

  2. Overview • Overall goal • Physics-EEG interface • Potentials • Rhythms • Fallacies • Recording • Artifacts • Processing…

  3. Overall goal • Connect psychology with physiology • EEG has been linked to psychology

  4. Physics-EEG interface

  5. Potentials • Spontaneous • Uncorrelated with the occurrence of an experimental condition • Induced • Correlated with experimental conditions but not strictly phase-locked to its onset • Evoked • Strictly phase-locked to the onset of an experimental condition across trials • Emitted • In response to omitted stimuli

  6. Rhythms

  7. Fallacies • EEG is an epiphenomenon • EEG practice divorced from theory • Artifact-free data • EEG versus MEG • Data reduction

  8. EEG versus MEG • EEG and MEG measure the same dipoles • MEG is more accurate than EEG • Results with one can be checked with the other • MEG is better because it is reference free

  9. Data reduction • EEG is contained in the raw data and nothing is added by computer transformation • Adding more electrodes beyond the standard 10/20 system provides no useful information • New data analysis methods in search of application

  10. Overview • Overall goal • Physics-EEG interface • Potentials • Rhythms • Fallacies • Recording • Artifacts • Processing…

  11. Recording • Clean data • Active and reference electrodes • Noise • Electrodes and impedance • Digitisation • Filtering

  12. Clean data

  13. Active and reference electrodes

  14. Noise • AC line current (60 Hz) • Shielded or use DC • Monitor (60-120 Hz) • Faraday cage • Movement • Relax, drop the jaw • EMG (10-1000 Hz) • EKG (1.0-1.4 Hz) • Pulse-wave • Electrodes • Alpha waves (6-12 Hz) • Skin potentials…

  15. Electrodes and impedance • Why skin impedances below 5 kΩ? • Common-mode rejection • Skin potentials

  16. Digitisation • Amplifier • Gain • Resolution • Nyquist theorem

  17. Filtering • Filters can substantially distort data • Essential to reduce noise • Aliasing, low-pass • Skin potentials, high-pass (.01 Hz)

  18. Artifact rejection

  19. Processing… • Event-related potentials (Tues, May 31st, 2 pm) • Principal component analysis • Independent component analysis (June) • Cortical dynamics (June) Osman & Moore (1993). The locus of dual-task interference: Psychological refractory effects on movement-related brain potentials. Journal of Experimental Psychology: Human Perception and Performance, 19(6), 12-92-1312. - Experiment 1, just 10 pages Luck (1998). Sources of dual-task interference: Evidence from human electrophysiology. Psychological Science, 9(3), 223-227. - Experiment 1, only 3 pages

More Related