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Information for Participants

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Read what to expect before, during & after your NIRS session.

Before NIRS Appointment

Measure Head

nirs cap

Before your scheduled NIRS session, you will be asked to measure your or your child's head using measuring tape. We need this measurement to choose the correct NIRS cap size so that it is not too tight or too loose. We need this information at least one day before your appointment, so let us know as soon as you can. Please watch our instructional video on how to properly measure your head.

Dress Comfortably

NIRS does not have clothing restrictions like MRI scans, so feel free to wear any kind of outfit you like. If your study does have specific clothing guidelines (eg. exercise studies) the research coordinator will let you know ahead of time. For those with long hair, leave your hair down without braids or ponytails if possible. If you will have a MRI scan on the same day, then wear clothes that are comfortable that do NOT contain any metal (no jewelry, hair accessories, buckles/belts). Glasses are fine to use with NIRS, but you will not be able to use them in the MRI scanner. Please let your research coordinator know the prescription ahead of time so they can prepare MRI-safe glasses or use contact lenses instead.

Watch this 5-minute video about NIRS (fNIRS Lab Aachen University)

During NIRS Appointment

Cap Set-Up & Signal Optimization

Before the NIRS scan, we will need to place the cap on your head. The cap contains light sources and detectors that are placed around the head. It is not painful and we can adjust the cap to alleviate any discomfort. Putting on the cap only takes a minute. Once the cap is on, we will need to run a signal optimization to make sure the sources and detectors have a strong signal. Since light needs to shine into the head from the scalp, we may need to adjust the optodes by using a q-tip to push hair or wires out of the way. In cases when hair is very thick or dark, we may use gel. The gel is water-based so it is not sticky and dries out quickly so you won't even know it was there at the end of the session.


Once we have a good signal, it's time to start the NIRS scan. Each study has different tasks for their scan. Common examples include playing games on the computer or having a conversation with someone else. We even have a project where participants ride a bike outside while getting a scan! Your study's research coordinator should have already provided you with details on what to expect during the NIRS scan. Most scans last about 20-40 minutes, but may be shorter or longer depending on the project.

After NIRS Appointment

Participants’ Next Steps

After your session, a researcher will take you or your child to their next study agenda item. This could be a MRI scan, answering questionnaires or other study-specific activities. Or NIRS may be the last thing you need to do for the study appointment and you will be given information about compensation and next steps. We greatly appreciate your participation!

Researchers’ Next Steps

Once we have your NIRS data, researchers will analyze it and compare results with all participants to answer research questions. Our goal is to publish these results so they are available to you and the public. This important contribution to science and knowledge is not possible without you, our research participants and their families!