I use an MRI scanner to find out about what happens in the brain when people are taking part in my experiments. The scanner is a huge magnet, and when we run scans to measure brain function, the scanner is basically detecting the bloodflow around the brain. It does this by measuring the different properties of oxygen-rich blood and deoxygenated (the opposite of oxygen rich!) blood in the magnetic field.
After we have collected our brain images, we relate the MRI scanner’s measurements to the things that happened in the experiment. We perform statistical tests on the data to find out, for example, which parts of the brain received greater bloodflow during speaking, compared with during listening. The design of the experiment, and the statistical analyses, are really important parts of the process. So even though the MRI is a very powerful tool, its measurements can only be interpreted through careful and thoughtful science!