What do EEG amplifiers do? Voltage emitted by scalp on the order of microvolts
-EEG amplifiers increase this signal 10^5 for detection and recording
Once EEG recording is digitized, how is it analyzed? Fourier Transform (FT):
• Analyze wave data.
• Converts voltage vs time to intensity vs frequency
• Area under curve = 100%
• Tells the percent of waves at a given frequency
• Easy way to see which frequency ranges predominate in the EEG signal.
What are 3 components of EEG recordings? 1. Brain waves
2. Artifacts
, EEG Questions With Solutions
3. Specific wave patterns
List the different types of brain waves 1. Gamma (>40 Hz)
2. Beta (13-40 Hz)
3. Alpha (8-13 Hz)
4. Theta (>4-8 Hz)
5. Delta (<4 Hz)
Describe the characteristics of gamma waves >40 Hz
- Occur in brain areas active at the same time.
- Binding = unification of awareness.
- Not visible in EEG. Extracted by Fourier analysis.
- Result of thalamocortical loop activity