The LNCD grants share an underlying skeleton: accelerated longitudinal design with each timepoint having distinct visits/sessions: office (“behavioral”), MR (“scan”), and often an EEG or MEG visit.
TODO: order of visits?
SETTING UP FOR THE VISIT
1.Log in to Qualtrics using your account info
2.Locate the Habit survey battery appropriate for your subject (e.g., a Y1 20 yom would receive the “Habit Y1 Adult Battery”)
3.In the drop down menu for the survey, select “Distribute Survey”
4.Select “Personal Links” from the options on the left-hand side
5.Click on the green “Generate Links” button in the top right corner
6.In the drop down menu under “To,” select “New Contact List”
7.Enter the following information in the given field:
a. Email – your email b. First Name – subject’s first initial c. Last Name – subject’s last initial d. External Data Reference – subject’s Luna ID
8. Once you’ve entered the information, click on the green “Create” button
9. Click on the green “Generate Links” button
10. Locate your subject in the downloaded CSV file
11. Navigate to L:\Habit\Behavioral\Qualtrics\Survey_Administration
12. Open the appropriate Habit_Qualtrics_Survey_Links spreadsheet a. Password: lncd2009
13. Enter your subject’s Luna ID, the date of the behavioral visit, and choose the type of battery to be administered from the drop-down tab (e.g., male adult)
14. Copy and paste your subject’s survey link from the CSV file into the Excel spreadshee
* rest
Setup
20-25 minutes
Meeting the subject:
1.Subjects can park at the Medical Arts Garage, 115 Atwood Street or UPMC Presbyterian Garage, located at 255 Lothrop Street 2.Have subject call your office phone once they arrive at the building and meet them in the lobby and walk them up to 1st Floor 3.Parents can either wait in the lobby, or can leave Loeffler but would need to be let back in by one of the RA’s 4.Have subject leave belongings in control room (132) and then bring them into the testing room (134) 5.Administer the pre-scan screen to the subject 6.Have the subject use the restroom and remove any heavy clothing like jackets. They should avoid bringing their cell phone or Apple watch into the shielded room but other metallic objects (belts, etc.) are fine
Setting up the shielded room:
1.Prepare the seven flat external electrodes by placing a washer (two-sided sticky circle) on each, with the blue tab facing down toward the cable. Leave the side that will be adhered to the subject’s skin covered for now 2.Retrieve the A/D box from the control room; it should be plugged into the power supply when not in use so that the battery attached to the bottom of the A/D box can charge. The A/D box receives signals directly from the electrodes and performs analog-to-digital conversion 3. Locate the orange fiber optic cable hanging in the shielded room and plug it into the A/D box. The cable is important and delicate so be careful. Set the A/D box aside for now. The fiber optic cable transmits data from the A/D box to the receiver box outside of the shielded room, which then transmits data to the acquisition computer via a USB cable 4.Prepare the special syringe(s) by filling with SignaGel electrode gel
Fitting the subject with the cap and attaching the external electrodes:
1.Seat the subject in the wooden chair in front of the computer screen 2.Give the participant a rundown of how the visit is going to go: a.First ask the participant if they have had an EEG before b.Regardless of yes or no to previous question explain the set up first:
Script: “So first we will get the cap and electrodes all set up. Set up takes about 20 minutes so you can hang out on your phone during that time. You can also pick out a movie or TV show that you would like to watch while we set you up. The set up consists of us taking measurements of your head so we know which size cap will work best. During the scan we use what are called external electrodes which are little stickers that go on different parts of your face to measure your muscle movement. So if you blink, yawn, etc. we understand what it means in the data. After that we will get the cap on and make sure that it is nice and centered on your head. Then we will fill the cap up with gel and plug in the electrodes. Once the cap is all set up and good to go you will complete the EEG which takes about 45-50 minutes. You will do some eye tracking games, the button glove task, and a couple auditory tasks where you will sit back and listen to some sounds. After those tasks we will come in and get you all unhooked. We will get you a towel and you can use the bathroom sinks to hopefully get most of the gel out of your hair (you may need to go home and take a shower to get it all out. After that we will have just a couple post-scan questions for you and then we will get you paid and get you out of here. Do you have any questions?”
3.Use the tape measure to determine the circumference of the subject’s head, using the nasion (intersection of the frontal bone and two nasal bones) and inion (the most prominent projection of the occipital bone at the posteroinferior part of the skull) as anterior and posterior landmarks, respectively; this will determine the size of the EEG cap to use
a. Cap size is given as a range (e.g., 54-58cm) and can be found on the tag inside the cap b. If the subject is between sizes, try the smaller size first; the cap should be snug against the subject’s head but not uncomfortably tight c.Record the head circumference and cap size used on the run sheet d.Script: “First we are going to measure your head to make sure we have a cap that fits nicely for you.”
4.Try the cap on the subject to ensure it’s a good fit, then remove it for now
a. Let the participant know that if the cap is too tight we can try a larger size, or if the chin strap is uncomfortable we can always put a paper towel underneath to try to cushion it.
5.Use the alcohol prep pads to clean off the areas of skin where the external electrodes will be attached (behind the ears, on either side of the eyes, above and below the right eye, and the bridge of the nose)
Script: “Next we are going to have you use this alcohol wipe to wipe down a couple spots on your face to help the external electrodes stick better”
6. Attach the external reference electrodes (1-6):
7. Script: “Next we are just going to start placing the external electrode stickers on the places you just wiped down”
a. Use the syringe to place a small amount of gel in the recessed area of the electrodes; the gel should be flush with the surface of the electrode
b. Peel off the covers of the washers and place the sticky sides down against the **mastoid bones** behind the subject’s left **(EXG1)** and right **(EXG2)** ears
i. The wires of the electrodes are very sensitive, so always hold the electrode by the plastic casing when peeling off the sticker backing
ii. The electrodes should be placed in approximately the same spot on each side
c. Place the **HEOG electrodes (3 and 4)** on either side of the subject’s left (3) and right (4) eyes, roughly in line with but not touching the corners of the eyes
i.These will measure horizontal eye movements and are critical for the MGS task
d. Place the VEOG electrodes (5 and 6) above (5) and below (6) the subject’s right eye, roughly in line with the pupil
i.These will measure vertical eye movements
8. Place the cap back on the subject:
a. Place the front of the cap along the subject’s forehead and ask them to hold it there
b. Stretch the cap around the back of their head, doing your best to get all of the electrode holders flat against the scalp
c. Pull the small tag on the back seam of the cap down so that it’s outside of the cap and not interfering with any of the electrode holders
d. **Script:** “Now we are going to get the cap back on for you”
i. Ask subject if cap still fits okay
9. Adjust the cap so that the Cz channel is in the center of the scalp:
a. Use the measuring tape to measure across the subject’s head from left to right using the pre-auricular points as landmarks; Cz should be in the center. Adjust the cap if it is not b. Use the measuring tape to measure across the subject’s head from front to back using the nasion and inion as landmarks; Cz should be in the center. Adjust the cap if it is not c. Visually inspect the channels along the midline to ensure they are roughly in line with the subject’s nose. Adjust the cap if they are not. You may need to measure for Cz again if you make any drastic adjustments
10. Fasten the cap’s chin strap around the subject’s chin, moving their hair out of the way if necessary
a.The chin strap will be uncomfortable at first, but the subject will acclimate to it after some time; however, if they find it particularly bothersome, you can place a paper towel between the subject’s chin and the strap (per Pete, although it seems counterintuitive to stick more stuff in there, it actually helps)
11.Make sure any electrode wires are out of the way, and then have the subject scoot their chair up to the computer desk so that the arms of the chair are against the edge of the table (they may do this later but it’s easier at this point, before they have a bunch of additional wires on their head)
Filling the electrode holders in the cap with gel and inserting the electrodes into the cap: 1.Script: “Next we are going to start filling up the cap with gel. We will be using these plastic syringes. You will feel us go down to the top of your scalp and swirl our way back up as we fill them with gel. The syringes are plastic so they shouldn’t hurt but if we are scratching the top of your head please let us know.” 2. Place the syringe inside one of the channels and swirl it around a few times to move hair out the way, until you make contact with the scalp 3.Press the holder around the channel down firmly against the subject’s scalp and begin filling the channel with gel by pressing down on the syringe, moving the syringe tip up and out of the channel as you go
a. The goal is to create a “column” of gel inside the channel that is making good contact with the subject’s scalp b. The channel should be about 75-95% filled with gel; it’s important not to overfill the channel, as this may cause the gel to squidge out around the holder on the interior side of the cap and start running down the scalp, resulting in signal carry-over (vs. localization) c. If you get some extra gel on the exterior of the cap, scoop it up with the side of the syringe tip and wipe it off on a paper towel
4. Repeat this process until all of the channels have been filled with gel; it helps to fill the channels in “rows” to minimize the chance of skipping over any o them 5.Once the channels have been filled with gel, begin plugging the ribbon cables of electrodes into their respective locations on the cap
a. Electrode names reflect location: i. Odd numbers are on the subject’s left ii. Even numbers are on the subject’s right iii. “Z” is along the midline iv. C = Central; F = Frontal; P = Parietal; T = Temporal; O = Occipital v. Larger numbers are farther from the midline
b. The electrodes should easily “snap” into the holders; if they don’t snap, you may need to add some extra gel to the channel to make sure the electrode is seated properly c. As you plug in the electrodes, try to keep the electrode wires organized (i.e. angled backward) so that they can easily be gathered at the back of the subject’s head and the ribbons can be plugged into the A/D box d. The two grounding electrodes (CMS and DRL) are located on individual wires and can be plugged into the cap last e. Attach the remaining external electrode (7):
i. Repeat the process of filling each recess in the electrode with gel and removing the sticker backing for the remaining five electrodes ii. Place **electrode 7** on the bridge of the nose and tape it down with a bit of medical tape, as it has a tendency to slide off iii. When attaching the electrodes, make sure all of the wires are organized neatly (i.e., angled down and backward) and that neither the electrodes themselves or the wires are interfering with the subject’s vision
Setting up the A/D box:
1.Organize the cables to be plugged into the box:
a. Gather the four bands of ribbon cables at the back of the subject’s head and stack them in the order in which they will be plugged into the A/D box, from A-D, with A on the bottom and D at the top b. Remove the plastic covers from the ends of the ribbons and set aside c. Gather the individual electrode wires and wrap this bundle around the four ribbons; this helps stabilize the cables as well as reduces noise by allowing the opposing magnetic fields to cancel d. Wrap a couple of black velcro bands around the entire bundle for extra support
2. Position the green swivel chair behind the subject’s chair, with the backs of the chairs touching one another 3. Drape the bundle of cables over the back of the swivel chair, leaving some slack on the other side in case the subject moves their head forward. Tape the bundle to the back of the swivel chair 4. Place the A/D box on the seat of the swivel chair and plug the cables into the appropriate spots
Troubleshooting the electrode connections:
1. In the control room, visually inspect the channels using the ActiView705 software 2. If there is global, high-frequency noise, this indicates that there is not a closed circuit inside the shielded room; ensure that the subject’s feet are flat on the floor, they do not have a cell phone with them, the fan is unplugged, etc. 3. Note down any individual channels that look noisy; usually filling the channels with a little extra gel will be sufficient to fix this. You can also use the prep gel to clean out tricky channels with a q-tip and then add more gel. 4. If you are having problems getting a good signal from CMS and DRL (either indicated by a blinking blue light on the A/D box, or a solid blue blue light but noisy channels):
a. Tear off a few inches of medical tape and pull the tape taut across the two channels; fasten the tape on either side. This can help put a little pressure on the electrode holders and get them closer to/flatter against the scalp b. If the pressure from the medical tape is not sufficient, tear off a piece of the stretchy coband tape that is long enough to wrap around the subject’s entire head at least once or twice; wrap the tape turban-style around their forehead and the back of the head, placing the tape over top of CMS and DRL at the back
General data collection instructions:
1. Click start (»>) 2. Start the file 3. Insert the file name three times 4. Unpause the recording (the tasks will do this automatically) 5. Stop the recording at the end of each task (if the task does not trigger this automatically); open a new file for the next task by repeating the steps above
Running the scan:
1. EOG calibration
a. On the acquisition computer, create a file named [Luna]_[Date]_eyecal b. On the presentation computer, open the eeg eye_cal application on the desktop c. Enter [Luna]_[Date] in the subject ID field d. Let the subject know that they will see a series of dots appear on the screen; they should look at each dot until a new one appears e. Press the space bar to begin the task; this should also trigger the acquisition software to begin recording