The mock scanner simulates the scanning environment so that participants can experience what being in the scanner is like and learn how still they need to stay.
When using the MRI scanner to take images of the brain, it is of vital importance that participants keep their head (and body) as still as possible. Any head movement can affect the images and, thus, the precious data that allows us to answer our research questions. In the scanner, we ask participants to avoid making any head movements, even those as small as 1mm. As you might imagine, it can be tricky to stay this still for several minutes at a time. Indeed, most people need to learn what a tiny movement like that even feels like, and how to perform tasks and push buttons without moving too much. In addition, the scanning environment – which is both constrained and noisy – can take a bit of getting used to. This is particularly true for children, for whom the scanner can appear (and sound) a bit daunting.
Here in the Bangor Imaging Centre, we use the mock scanner for three reasons. First, the mock scanner can be used to simulate what a real MRI/fMRI scan sounds and feels like. A session in the mock scanner allows children, and participants with sound sensitivities or mild claustrophobia, to acclimate to and become more comfortable in the MRI environment. Second, participants can learn how much movement is “too much” and directly observe their own head motion while practicing in-scanner tasks. Third, we can collect behavioural measures (and detailed head-motion information) from participants in a scanner-like environment. This can be important in developing tasks that will actually work in the scanner, but also for collecting detailed behavioural data on tasks where the scanner environment may affect performance. Many tasks are a bit harder to do when lying on your back in a small, noisy tube while also focusing on not moving!
Our mock scanner was purchased from Psychology Software tools with the support of a Royal Society Research grant. It is equipped with a sound system to play scanner sounds and MoTrak, a software which allows fine-grained head motion tracking. A 10 – 20 minute session in the mock scanner can make all the difference in helping participants be more comfortable, and stay still enough, during the “real” scan.
