Prior to Participant Arrival

Swap out the amplifier battery with the fully charged battery on the charger
Confirm that headcaps and electrodes are clean and dry
Prepare supplies
- Fill syringes with SignaGel
- Double adhesive collars
- Cable wraps
- External electrodes

When the Participant Arrives

Have the participant read and sign consent form
- Use the correct form depending on whether they want SONA/monetary compensation (and sign consent form as well)
Describe an overview of the procedure and experiments
Ask the participant to complete the STAI questionnaire (or a survey specific to a particular study)
- Put the completed questionnaire in the “completed” folder file
Make sure the participant understands the length of time they will be in the experiment and ask if they’d like to use the restroom
No chewing gum, hair down evenly
Electronics should be left outside the recording chamber
Fill out Excel spreadsheet with participant information, SONA credit/payment information, etc.
Log arrival time in Excel spreadsheet

Participant Preparation

Determining proper head cap size: measure in cm
- Measure head circumference just above the eyebrows and over the inion (the projecting occipital bone at the base of the skull)
  - 54-58 cm: Medium Cap (RED)
  - 56-60 cm: Medium/Large Cap (RED and BLUE)
  - 58-62 cm: Large Cap (BLUE)
Apply external electrodes
- Be sure the electrode collars are not covering the active part of the electrode
- Reference
  - EX1 left mastoid
  - EX2 right mastoid
- Horizontal electroculogram
  - EX3 next to left outer canthus
  - EX4 net to right outer canthus (if applicable)
    - See here for approximate location.
- Vertical electroculogram
  - EX5 and below the left eye
  - EX6 (if applicable) above the the left eye
    - See here for approximate location.
Put on cap
- If the participant requires glasses, have them wear them during cap fitting
- Visually inspect the cap to ensure it is on straight
Determine proper vertex location (i.e., electrode Cz)
- Anterior/posterior - Measure nasion to inion (divide by 2)
- Left/right - measure from left to right preauricular area (divide by 2)
- Double check that the cap is still straight now that you’ve made your adjustments
Ensure that the cap’s tag at the O1, Oz, O2 electrodes is pulled out
Steps for the EEG digitization process can be found at this link: https://docs.google.com/document/d/1xlSQQWCuHG5U2ClRDxCXOOx1W2LTQKZpgBbWgTl5Lck/edit
Apply gel to cap electrode holders
- Build columns of gel: fill from syringe, move hair around
- If participant is bald or has very short hair, start with minimal gel to avoid pooling
Insert electrodes into cap (carefully not to stress electrode leads)
Wrap CMS/DRL three or four times around ribbon cables & EX leads (and secure with cable wrap at nape of neck and below the wraps)
Bring the participant into VERONICA

Electrode Testing

Attach the ribbon cables and EX leads to the amplifier (correctly align the connectors to their respective ports before applying pressure)
Attach the battery to the amplifier and turn on the power
Ensure the amplifier’s solid blue light is on indicating CM in range
Select the Electrode Offset tab in ActiView
- Check all 64 channels and also EX 1-6
- Electrodes should be should be ideally between +/- 20 mV, not bouncing up and down
- If electrode is outside of range:
  - Try adding a bit more gel and parting hair with the syringe
  - Ensure the electrode is firmly in place
  - If many (all) of the electrodes are out of range, check CMS & DRL
  - Select the Monopolar Display tab in ActiView
- Look for channels that are drifting or seem particularly noisy
- Use same techniques above to correct bad channels
- Return to Electrode Offset tab and ensure all electrodes are still in range
Show the participant their alpha waves, EMG, and eye-blinks.
- Use this opportunity to emphasize why being relaxed, comfortable, and still is so important and why they should try to avoid blinking outside of the specified “blink times”
Turn ON and test intercom system
- Turn ON by pressing talk button
- Turn on Monitor Mode on the VERONICA intercom by pressing the Monitor button until you hear a tone
Place the LCD display such that the participant is ~70 cm away and that top of the display is roughly at the eye level of the participant.
Give the participants a few minutes to acclimate to the dim environment inside VERONICA before beginning the first task.
- Do the same whenever you’re transitioning from between bright and dim tasks (e.g., from a paradigm that uses the anaglyph glasses to one that does not)

Running Experiments

On the display and acquisition computers:
- Turn off the WiFi
- Pause Dropbox
- Close all unnecessary programs
Create an EEG file in ActiView
- Press Start File
- Press OK on popup window
- Enter filename
- At this point the file has been created, but it is NOT recording
Prepare to run the paradigm in PsychoPy
- Be sure to enter the participant’s “p” number as it is saved in the EEG file
Recording EEG data - START
- Most of our experiments will automatically trigger the ActiView system to being recording. When PsychoPy begins the experiment you should confirm in the ActiView window that the button above the Pause button has turned from red to green and displays SAVING
- Note: If you are running an experiment that does not automatically trigger EEG recording (unlikely), you would press the Pause button to begin recording
Recording EEG data – STOP
- Most of our experiments will automatically pause EEG data recording when the experiment is over. However, you still need to terminate the session (i.e., close the file)
- Press the Stop button
Remember to check in on the participant via the intercom between experiments and to make sure they know what is expected of them for the next experiment

After Experimental Session Is Complete

Take picture of participant with the cap on (if they’d like one)
- Remember to email this picture and a screenshot of their EEG to the participant
Carefully remove all of the EX electrodes and cap
Give the participant paper towels and allow them to clean up
On the display and acquisition computers:
- Turn on the WiFi
- Unpause Dropbox
Debrief the participant
- Tell them the goal of the studies that were run and give them the opportunity to ask any questions that they have
Log the completion time in the Excel spreadsheet and if SONA credit it being used to compensate the participant, document the credit earned and which class they would like it applied to
Compensate the participant (and have them sign the Payment Verification form)
Note: Email Prof. Engell if we are low on any forms or subject payment funds (< $80)
Mount the KPNL_Participant_Info.dmg virtual drive
- Enter your handwritten run sheet and notes into the Excel file
- Keep the run sheet in the lab folder
- Save the Excel file
- Unmount the KPNL_Participant_Info.dmg virtual drive
Turn OFF the intercoms (pressing and holding the volume button down for 3 seconds), lights, and fan in VERONICA

Cleaning Up

Carefully remove all of the electrodes from the cap
- Take extreme care to not stress the electrode leads
Never bend the electrode lead where it meets the electrode
- Electrodes should never come into contact with any metal surfaces (e.g., the sink!)
Ensure that the amplifiers are turned off and disconnected from the battery
Wash CMS/DRL and EX electrodes
- Follow the same procedures as used for the cap electrodes (see below)
Wash cap electrodes
- Swirl electrodes in a half bucket of cold water
- After ~45 sec feel for slipperiness to indicate if gel has been washed off
- Change the water intermittently and continue until electrodes no longer feel slippery
- Hang ribbons from the rack and spread out the electrodes to dry on the “wee-wee pad”
Wash cap
- Use the sprayer to wash the gel out of each of the electrode holders
The sprayer can make a mess, so keep the water pressure relatively low and wear the brain apron!
- Wash in warm soapy (use a small amount of Ivory liquid soap) water in bucket
- Wash so there is not gel in the fabric
Be careful to excessively stretch the fabric during cleaning
- Once clean, rinse the cap in clean water
- Place the clean cap on one of the plastic cap racks to dry
Do not pull the cap down over the rack or stretch it in any way
- If another participant is scheduled for the same day it is important to speed up drying of the cap. To do so,
Remove as much water as possible by towel drying (do not stretch the cap)
Turn on and direct the fan at the drying rack

Table of Contents

Prior to Participant Arrival

When the Participant Arrives

Participant Preparation

Electrode Testing

Running Experiments

After Experimental Session Is Complete

Cleaning Up