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Signal Quality Troubleshooting

Good signal quality is essential for effective neurofeedback training. This guide will help you recognize and fix common signal issues.

🎯 Quick Diagnosis

What You See Likely Cause Quick Fix
Fuzzy/hairy traces Poor electrode contact Add more paste, improve contact
Thick vertical lines 60 Hz electrical noise Move amp away from power, check ground
Flat line Disconnected electrode Check cable connections
Jumpy/spiking Movement or loose electrode Stay still, secure electrode
All traces tiny Scale too high Adjust scaling (F9)

✅ Good Signal vs. ❌ Bad Signal

What Good Signal Looks Like

Characteristics: - Thin, jagged lines (like a seismograph) - Moderate, consistent amplitude - Visible brainwave patterns - Artifact percentage under 10-15% - Stable baseline

Good signal example

If your signal looks like this, you're ready to train!

What Bad Signal Looks Like

Common problems:

1. Fuzzy/Hairy ("Caterpillar")

  • Looks like: Thick, fuzzy, "hairy" traces
  • Cause: 60 Hz electrical interference
  • Fix: See 60 Hz Noise below

Fuzzy signal

2. Flat Line

  • Looks like: Completely flat horizontal line
  • Cause: Electrode disconnected or unplugged
  • Fix: See Flat Line below

3. Jumpy/Spiky

  • Looks like: Big jumps and spikes
  • Cause: Movement, muscle tension, or loose electrode
  • Fix: See Jumpy Signal below

🔧 Common Problems & Solutions

Fuzzy/Hairy Signal

What it means: Poor electrode contact or electrical interference

Fix - Try these in order:

  1. Add more paste:
  2. Insert paste syringe under electrode
  3. Add pea-sized amount

  4. Gently press electrode to work paste in

  5. Improve scalp contact:

  6. Part hair more thoroughly
  7. Make sure electrode touches scalp (not sitting on hair)

  8. Press firmly against scalp

  9. Clean the skin:

  10. Wipe site with NuPrep or alcohol
  11. Let dry completely

  12. Reapply electrode with fresh paste

  13. Check the electrode:

  14. Is it damaged or corroded?
  15. Try a different electrode

If still fuzzy after these steps: Likely electrical noise - see below

60 Hz Noise

What it looks like: Thick, fuzzy trace with vertical lines running through it

What it is: Electrical interference from power sources

Fix - Try these in order:

  1. Move amplifier away from power:
  2. Get amp 2-3 feet from laptop power supply
  3. Move away from phone chargers

  4. Unplug nearby lamps or electronics

  5. Check ground electrode:

  6. Make sure ground is attached (usually to ear or forehead)
  7. Add paste to ground if dry

  8. Ensure good contact

  9. Check ear reference:

  10. Ear clip should have good contact
  11. Add tiny amount of paste to ear clip

  12. Ensure clipped to fleshy part of earlobe

  13. Unplug nearby devices:

  14. Phone chargers
  15. Lamps

  16. Other electronics nearby

  17. Try different outlet:

  18. Plug laptop into different wall outlet
  19. Avoid power strips if possible

Still noisy? Screenshot and send to Slack - may be environmental and we can help remotely.

Flat Line

What it looks like: Completely flat horizontal line (no brainwave activity visible)

What it means: Electrode is disconnected or completely dry

Fix:

  1. Check cable connections:
  2. Is electrode plugged into amplifier?
  3. Is amplifier USB cable connected to computer?

  4. Try unplugging and replugging

  5. Check for paste:

  6. Is electrode completely dry?

  7. Add paste if needed

  8. Try different electrode:

  9. Electrode may be broken

  10. Swap for a spare if available

  11. Check amplifier:

  12. Is it powered on? (some have power switch)
  13. Try different USB port
  14. Restart computer if needed

Jumpy Signal

What it looks like: Signal jumping up and down, big spikes

Causes & fixes:

1. Movement: - Fix: Stay as still as possible during training - Fidgeting is OK, but try not to move head/neck - Make sure wires aren't pulling on electrodes

2. Loose electrode: - Fix: Check that electrode isn't sliding on scalp - Add more paste - Press more firmly - Secure hair away from site

3. Muscle tension: - Fix: Relax jaw and face - Unclench teeth - Let tongue rest on bottom of mouth - Relax shoulders

4. Eye movement (if forehead site): - Fix: Try to keep eyes relatively still - Soft gaze, don't scan rapidly - Blink normally (blinking is OK)

Thick/Spiky Trace

What it looks like: Thick lines with lots of spikes and bursts

Cause: Usually muscle tension (EMG artifact)

Fix:

  1. Relax your jaw:
  2. Unclench teeth
  3. Let mouth hang slightly open

  4. Tongue rests on bottom of mouth

  5. Relax your face:

  6. Unfurrow brow
  7. Release facial tension

  8. Soft eyes

  9. Check electrode location:

  10. Is it on a muscle? (forehead, temple)
  11. If on forehead, EMG is more common

  12. May need to just work with it

  13. Stay warm:

  14. If you're cold and shivering, that creates muscle artifact
  15. Get a blanket!

🔍 Troubleshooting Process

Step-by-Step System Check

If signal is bad, work through this checklist:

  1. Check connections:
  2. All electrodes plugged into amplifier?
  3. Amplifier USB connected?

  4. No loose cables?

  5. Check electrodes:

  6. Electrode touching scalp (not hair)?
  7. Adequate paste?
  8. Firmly pressed to skin?

  9. Ear clips attached to earlobes?

  10. Check environment:

  11. Amplifier away from power sources?
  12. No phone chargers nearby?

  13. Ground electrode connected?

  14. Check client:

  15. Sitting still?
  16. Jaw relaxed?
  17. Face relaxed?

  18. Not too cold?

  19. Still bad?

  20. Take screenshot
  21. Send to coach via Slack
  22. We can usually diagnose remotely!

📸 Sending Screenshots to Coach

For faster help, include a good screenshot:

What to Capture

Show: - The EEG traces (all channels visible) - The raw signal window (if relevant) - Any error messages - Which electrode is problematic

How to Screenshot

Windows: 1. Press Windows + Shift + S 2. Drag to select area 3. Image copies to clipboard 4. Paste in Slack (Ctrl + V)

Mac: 1. Press Cmd + Shift + 4 2. Drag to select area 3. Image saves to desktop 4. Upload to Slack

Phone: - Just snap a photo of the screen! - Quick and works great for most issues

⚙️ Advanced Fixes

If Nothing Else Works

Try these:

  1. Different USB port:
  2. Some ports have better power/grounding

  3. Try USB 2.0 vs 3.0

  4. Restart everything:

  5. Close EEGer
  6. Unplug amplifier
  7. Restart computer

  8. Reconnect and try again

  9. Different location:

  10. Sometimes room has bad electrical environment

  11. Try training in different room

  12. Contact coach:

  13. May be amplifier issue
  14. May need equipment swap
  15. We'll troubleshoot remotely

✅ Prevention Tips

Before Each Session

Prep checklist: 1. ✅ Clean scalp sites (alcohol or NuPrep) 2. ✅ Part hair thoroughly 3. ✅ Use adequate paste (pea-sized per electrode) 4. ✅ Press electrodes firmly 5. ✅ Check all connections 6. ✅ Verify signal BEFORE starting training

Spending 2 extra minutes on setup prevents interrupting your session later!

During Training

Stay still: - Fidgeting is OK - Small adjustments are fine - Just don't move your head dramatically or pull on wires

Keep warm: - Shivering creates muscle artifact - Use a blanket if needed

Relax: - Jaw unclenched - Face relaxed - Shoulders down

🆘 When to Contact Your Coach

Before Starting

If signal is bad BEFORE you begin training: 1. Try the quick fixes above 2. If still bad after 5-10 minutes of troubleshooting 3. Screenshot and post in Slack 4. We can usually help quickly!

Don't train with bad signal - it's not effective and may give false feedback.

During Training

If signal degrades during session: 1. Pause (press F6) 2. Check electrode (probably just needs more paste) 3. Add paste, improve contact 4. Resume (press F5)

If it keeps happening: - Something is loose - Screenshot and send to coach - May need to end session early and troubleshoot

🎯 Signal Quality Goals

Acceptable for Training

Minimum standards: - Artifact percentage under 20% (ideally under 10%) - No flat lines - Traces are visible and responsive - Can see brainwave patterns

Not perfect? That's OK! Some artifact is normal. We just want "good enough" for the training to work.

When Good Enough is Good Enough

You don't need perfect signal!

Train if: - Most traces look decent - Only minor fuzziness - Occasional jumps (not constant) - Can see game responding to brain state

Don't train if: - Completely flat lines - Can't see any brainwave patterns - Game doesn't respond at all - Artifact percentage consistently over 30%

💡 Pro Tips

Tip 1: The Paste is Your Friend

When in doubt, add more paste.

Most signal issues = poor contact = need more paste!

Tip 2: Hair Management is Critical

Especially for: - Thick hair - Curly hair - Long hair - Lots of hair product residue

Use a comb to part hair at electrode sites. Makes a huge difference!

Tip 3: Consistency Helps

Once you find good positions and technique: - Use same spots each time - Same amount of paste - Same setup routine

You'll get faster and signal quality will improve!

Tip 4: Environment Matters

Best setup: - Away from kitchen (appliances cause interference) - Not right next to TV or stereo - Dedicated training spot - Comfortable seating

Most signal issues are simple fixes! Add paste, improve contact, move away from power sources. When in doubt, screenshot and send to your coach - we can usually tell immediately what's wrong. 📊✨