The Ultimate Brainwave Recording Rig Cheat Sheet: Setting Up Your EEG System

Introduction

A brainwave recording rig (electroencephalography or EEG system) captures electrical activity produced by brain neurons through electrodes placed on the scalp. These systems range from clinical-grade medical equipment to consumer-grade headsets, enabling applications from neuroscience research and medical diagnostics to neurofeedback, brain-computer interfaces (BCIs), and personal brain monitoring. This cheat sheet covers essential components, setup procedures, and best practices for capturing quality EEG data.

Core Components of an EEG Recording Rig

EEG Hardware Components

• Electrodes: Sensors placed on scalp to detect electrical activity
• Amplifier: Strengthens weak brain signals (microvolts to volts)
• Analog-to-Digital Converter (ADC): Transforms analog signals to digital data
• Reference & Ground: Critical for signal isolation and noise reduction
• Headcap/Mounting System: Secures electrode placement
• Impedance Checker: Verifies electrode contact quality
• Data Acquisition Device: Physical hardware for signal processing/transfer
• Computer/Recording Device: Stores and processes EEG data

Software Components

• Acquisition Software: Controls recording parameters and data collection
• Signal Processing Software: Filters, cleans, and analyzes raw EEG
• Visualization Tools: Displays brainwave activity in real-time
• Storage System: Archives recorded data securely
• Analysis Software: Processes data for research or clinical interpretation

EEG System Types Comparison

Electrode Systems & Placement

International 10-20 System

• Standard mapping system for electrode placement
• Based on skull landmarks (nasion, inion, preauricular points)
• Positions named by brain region letters and numbers
  • F (Frontal), T (Temporal), C (Central), P (Parietal), O (Occipital)
  • Even numbers = right hemisphere, Odd numbers = left hemisphere, z = midline

Common Montages

• Full Cap: Complete coverage (21+ electrodes)
• Clinical Standard: 19 electrodes plus ground and reference
• Research-Focused: Selected regions based on study objectives
• Minimal Montage: 2-8 electrodes for specific application (e.g., meditation, sleep)

Electrode Types

• Wet Electrodes:
  • Silver/Silver Chloride (Ag/AgCl) with conductive gel/paste
  • Highest signal quality, standard for clinical use
  • Requires skin preparation and cleanup
• Dry Electrodes:
  • No gel required, often spring-loaded or pin-based
  • Faster setup, more comfortable for extended wear
  • Generally higher impedance, more motion artifacts
• Semi-Dry:
  • Pre-gelled or saline-based
  • Balance between signal quality and convenience

Step-by-Step Setup Process

1. Preparation

   • Select appropriate room (quiet, minimal electrical interference)
   • Prepare all equipment and consumables
   • Have subject seated comfortably in non-metal chair
   • Remove subject’s earrings, hair accessories, glasses if possible

2. Measurement & Marking

   • Measure nasion to inion and preauricular points
   • Mark Cz (center point) if using 10-20 system
   • Mark additional electrode positions if needed

3. Skin Preparation (for wet electrodes)

   • Clean electrode sites with alcohol swab
   • Gently abrade skin with prep gel/NuPrep
   • Dry area completely before electrode placement

4. Electrode Application

   • Apply cap if using full headcap system
   • Apply conductive gel/paste to electrode cups
   • Place individual electrodes in marked positions
   • Secure with tape or elastic bands if needed
   • Connect reference and ground electrodes first

5. Impedance Check

   • Verify all electrodes have impedance <5kΩ for research (10kΩ acceptable for some applications)
   • Re-prep sites with high impedance
   • Document final impedance values

6. System Configuration

   • Connect electrode leads to amplifier
   • Set appropriate gain and sampling rate
   • Configure filters (typical: high-pass 0.1-1Hz, low-pass 30-100Hz, notch 50/60Hz)
   • Set data storage parameters and file naming

7. Baseline Recording

   • Record 1-2 minutes eyes closed
   • Record 1-2 minutes eyes open
   • Verify signal quality across all channels

8. Main Recording Session

   • Begin recording with timestamp or event marker
   • Monitor impedance periodically during long sessions
   • Use event markers for significant activities/stimuli
   • Minimize subject movement and external interference

9. Shutdown & Cleanup

   • Save all data with proper metadata
   • Gently remove electrodes and cap
   • Clean equipment according to manufacturer guidelines
   • Help subject clean gel from hair/skin

Signal Quality Troubleshooting

Brainwave Frequency Bands & Their Significance

Common EEG Artifacts & Filtering

Physiological Artifacts

• Eye Blinks/Movements: Large amplitude deflections (±50-200 μV)
  • Solution: EOG recording, ICA decomposition, blink detection algorithms
• Muscle Activity (EMG): High-frequency (>30Hz) irregular spikes
  • Solution: Low-pass filter, ask subject to relax, ICA decomposition
• Heart Activity (EKG/ECG): Regular pulses matching heartbeat
  • Solution: ECG recording for removal, ICA decomposition
• Sweat/Skin Potentials: Very slow baseline drift
  • Solution: High-pass filter (>0.5Hz), room temperature control

Environmental/Technical Artifacts

• Line Noise (50/60Hz): Regular oscillation matching power frequency
  • Solution: Notch filter, better grounding, move power cables away
• Electrode Pop: Sudden jump in baseline
  • Solution: Secure electrode, replace if damaged
• Cable Movement: Irregular sharp deflections
  • Solution: Secure cables, use shielded cables, minimize movement
• Common Mode Interference: Affects all channels similarly
  • Solution: Check reference electrode, use driven right leg circuit if available

Data Processing Workflow

1. Pre-Processing

   • Import raw data into analysis software
   • Apply bandpass filtering (typically 0.5-45Hz)
   • Apply notch filter (50/60Hz) if needed
   • Segment data into relevant epochs
   • Identify and mark artifacts

2. Artifact Rejection/Correction

   • Automated detection of eye blinks, muscle activity
   • Manual inspection and marking of artifacts
   • ICA decomposition for artifact removal
   • Channel interpolation for bad channels

3. Feature Extraction

   • Power spectral density (PSD) analysis
   • Event-related potential (ERP) averaging
   • Time-frequency analysis
   • Coherence and connectivity measures

4. Analysis Methods

   • Quantitative EEG (qEEG) metrics
   • Statistical comparison to normative databases
   • Machine learning classification
   • Source localization (if sufficient electrodes)

Best Practices for Research-Quality Recordings

• Environment Control

  • Use electrically shielded room if possible
  • Turn off fluorescent lights, dimmers, electronics
  • Use dedicated power circuit for EEG equipment
  • Maintain consistent temperature (sweat affects impedance)

• Subject Preparation

  • Request clean, dry hair without products
  • Ask subject to avoid caffeine before recording
  • Explain procedure thoroughly to reduce anxiety
  • Position subject comfortably to minimize movement

• Technical Optimization

  • Use highest practical sampling rate (minimum 2x highest frequency of interest)
  • Record at 24-bit depth when possible
  • Document exact electrode positions
  • Include calibration signal at beginning of recording

• Quality Assurance

  • Take photos of electrode placement
  • Document impedance values before and after
  • Regular equipment maintenance and calibration
  • Create standard operating procedures for consistency

Equipment Care & Maintenance

• Electrodes

  • Rinse thoroughly after each use
  • Store dry electrodes in proper containers
  • Check for corrosion or damage regularly
  • Replace Ag/AgCl electrodes when chlorided surface wears off

• Caps/Headsets

  • Clean with manufacturer-recommended solution
  • Air dry completely before storage
  • Store shaped to prevent deformation
  • Check for wear on straps and fasteners

• Amplifiers/Equipment

  • Calibrate according to manufacturer schedule
  • Keep firmware/software updated
  • Store in dry, temperature-controlled environment
  • Use surge protectors for all components

Resources for Further Learning

Books

• Niedermeyer’s Electroencephalography by Schomer and Lopes da Silva
• Introduction to Quantitative EEG and Neurofeedback by Evans and Abarbanel
• Clinical Neurophysiology by Daube and Rubin

Online Courses

• EEGLAB Workshop Series
• Neuroscience Online (University of Texas)
• Coursera’s Medical Neuroscience

Software Tools

• Free/Open Source: EEGLAB (MATLAB), MNE (Python), BrainVision Analyzer (free viewer)
• Commercial: NeuroGuide, BESA, Brain Products Analyzer

Communities

• Society for Neuroscience
• International Society for Neuronal Regulation
• American Clinical Neurophysiology Society
• OpenBCI Community

Remember that quality EEG recording requires practice and patience. Start with simple setups and gradually work toward more complex configurations as you gain experience. Proper documentation of your recording parameters and setup will ensure reproducibility and reliability of your brainwave data.