In a magnetic resonance imaging (MRI) scan, we can observe anatomical features of each person's brain. Some examples of MRI scans obtained from healthy volunteers can be seen here.

We are especially interested in the cortex that surrounds the Sylvian fissure, because this tissue in the left hemisphere is particularly important for language (you can select Sylvian fissure from the pull-down structure menu in the previous link).

Below you can see outlined some of the important structures that we measure in each hemisphere in the areas surrounding the Sylvian fissure. A. Frontal structures pars triangularis (PTR), solid line, and pars opercularis (OP), large dashed line, and posterior structure Heschl’s gyrus (HG). B. Posterior structures planum temporale (PT) and planum parietale (PP).