Brain damage
Researchers have used various means to explore the brain regions that are associated with idiom comprehension. The investigations involve examining brain damage patients, and conducting transcranial magnetic stimulation (rTMS) and functional magnetic resonance imaging (fMRI) studies. Brain damages in the patients were mostly caused by strokes or traumatic accidents. rTMS causes temporary cerebral lesion, and thereby impairs the target area’s functioning. fMRI measures brain activity by detecting changes in blood flow. The areas that have been studied include the right hemisphere, left hemisphere, and prefrontal cortex.