EEG (Electroencephalography)
A non-invasive neuroimaging technique that records electrical activity in the brain using electrodes placed on the scalp.
EEG (Electroencephalography)
Electroencephalography (EEG) is a fundamental neuroscience technique that captures the brain's electrical patterns through an array of electrodes placed on the scalp. This technology has revolutionized our understanding of brain activity and continues to be a crucial tool in both research and clinical settings.
Basic Principles
The human brain generates continuous electrical activity through the communication between neurons. This activity produces different types of brain waves:
- Beta waves (13-30 Hz): Associated with active thinking and focus
- Alpha waves (8-13 Hz): Present during relaxation
- Theta waves (4-8 Hz): Common during drowsiness
- Delta waves (0.5-4 Hz): Predominant during deep sleep
Technical Implementation
Recording System
- Electrodes (typically 16-256 channels)
- Amplification system
- Signal processing equipment
- Recording software
The placement of electrodes follows the standardized 10-20 System, ensuring consistency across recordings and laboratories.
Clinical Applications
EEG serves crucial roles in various medical contexts:
- Epilepsy diagnosis and monitoring
- Sleep disorders assessment
- Brain injury evaluation
- Coma monitoring
- Brain death determination
Research Applications
In research settings, EEG enables investigation of:
- Cognitive processing
- Neural oscillations
- Brain-computer interfaces
- Consciousness states
- Mental disorders patterns
Advantages and Limitations
Advantages
- Excellent temporal resolution
- Non-invasive
- Relatively low cost
- Portable technology
- Real-time monitoring capability
Limitations
- Limited spatial resolution
- Difficulty measuring deep brain structures
- Susceptibility to electrical interference
- Complex signal interpretation
Modern Developments
Recent advances have integrated EEG with:
- Machine learning algorithms
- Virtual reality systems
- Mobile health applications
- Neurofeedback therapy
Future Directions
Emerging trends include:
- Development of dry electrodes
- Wireless systems
- Integration with artificial intelligence
- Combined EEG-fMRI approaches
- Consumer-grade applications
The continued evolution of EEG technology promises new insights into brain function and expanded clinical applications, maintaining its position as a cornerstone of neurological research and diagnosis.