When I'm asked to perform or at least to monitor or co-interpret fMRI results for a variety of reasons, it's because the neurosurgeon, typically, has concerns as to whether the area of the brain that is affected by a tumor, epilepsy or any part of the brain that is to be resected, if that resection will result in some kind of debilitating impairment. A lack of motor skills, a loss of speech or a loss of memory, those are really the three areas that I focus on.
Using fMRI we perform a series of tasks. I will have a patient move their finger so I can see how the left or the right side of the brain, what we call "lights up" when they are performing that task.
Another task that we can perform is asking a patient to read a sentence or listen to speech so that we can determine how, for example, the posterior temporal lobe, the receptive language area, is functioning. Any area that is activated typically should not be resected. That's the reason why we do functional MRIs for a patient leading up to their surgery.
