How to run: cerebReachComp
Special consideration
This experiment is part of the cerebellar battery run in 2022-2023. For controls and patients, it is in the FIRST session. This is after cerebReachAdapt so you do not need to re-deliver general instructions on how to reach.
In this battery, participants come in for multiple sessions and do multiple experiments in a row. As such, this is a bare bones document on how to run the experiment. Procedures for consent, hearing screening, awareness surveys, general equipment set up, and payment are not included in this document. See the documents below for how these procedures are implemented in this multi-study session:
- Protocol for cerebellar battery: controls
- For patients
What's special about this experiment
This is a reaching experiment, with a separate interface computer.
The lights should be OFF for this experiment so the participant can only see the cursor, not their actual hand.
Prepping for participant
These should not have any occasion to change between studies, but it is good to check anyway. Note that you should run these checks on the REACHING computer which is on the cart (not Quiberon).
Check sampling rate of tablet:
- Click on Windows start button
- In the search at the bottom, type in Wacom tablet properties, and click on it when it appears
- Double click on the Intuos4 XL under "Device"
- Make sure it is in to be in "Recognition Data" mode
Check refresh rate of monitor:
- Click on the Windows Start button
- Type in settings, click when it appears
- Go to System > Display > Advanced Display Settings
- There should be two monitors in the dropdown to choose your display. Select Display 2: VG248
- The refresh rate is at the bottom. It should be 144.001 Hz
Pre-experiment instructions
Start the experiment by typing in run_cerebReachComp_expt and hitting enter. Enter the required responses. Then place the pen on the tablet.
General instructions (not needed if running after cerebReachAdapt)
Tell the participant:
“The point of this experiment is to better understand how the brain controls reaching movements. We will be measuring how accurately you can reach to targets in different locations. Your data will be used as a normative baseline for future comparisons with neurological patients. So, please try your best to pay attention and follow all instructions.”
“In this experiment, you will be playing a game where you’ll be trying to make quick and accurate reaches to different target locations. For each trial, you will move the cursor to a home location in the center, which will be indicated with a circle. Then you'll make a quick reach to a target that appears somewhere on the screen. You should reach as quickly and accurately as you can, and slice through the targets rather than stopping at the target”
“Please take some time now to adjust the seat height and scoot in close to the work station. You will be making many reaches towards the edges of the tablet, and I want you to be able to do that without moving any parts of your body other than your arm. Keep the same posture throughout the experiment, and rest your other hand in your lap. Be sure to not swirl around in the chair.”
You will hold this pen at the red base with your dominant hand – maintain the same grip throughout the experiment. (demonstrate)
There are no pre-planned breaks, but if you need to rest for a bit, just wait before moving the cursor to the center for the next trial.
“Do you have any questions?”
“I’ll give you a minute to get comfortable before turning out the lights.”
After they are comfortable, turn off the lights, then press SPACE to start the experiment
Baseline phase
Tell the participant: “Move your hand into the start circle and wait for the target to appear. Once the target appears, reach in a smooth motion to hit the target. Make sure that you slice through the target without stopping. You will see a cursor representing your hand position during the reach.”
“The knock just means you reached far enough, but it doesn’t mean that you hit the target.”
Throughout the experiment, you should monitor how they are performing their reaches. You may have to issue corrections. Common issues:
-
When they get “Too Slow” message: “The too slow message means that you did not move fast enough for a valid trial. Remember to slice through the targets with your hand.” This is related to movement time, not reaction time
- When they get "Too Fast" message: Try to make a smooth sweeping movement through the target.
-
If participant gets “slice through the target" message: “Remember to move accurately through the target in a quick, straight line.”
- If they are picking up paddle: Please don’t pick up the paddle and just slide it along the table.
No feedback + jump
Instructions will appear on the screen for the participant. In this phase, they will continue reaching in a smooth motion to hit the target. They will not see the cursor representing their hand position and the target may move.
Participants may anticipate the jump by starting slow and get messages about their movement speed. Encourage them to keep moving in one smooth sweep.
If Matlab crashes during the experiment
There is no restart script. This is a relatively short experiment, and can be restarted if necessary.