Alex's brain scan in the film is referred to as an "MRI." This imaging modality is commonly used on athletes who need to have the extent of tissue damage visualized by a radiologist. Alex was studied with "fMRI" or functional MRI, which follows localized blood flow in the range of seconds which increases with increased neural activity. The interpretation presented in the film suggests Alex had a decreased response to fearful stimuli (pictures of sinking ships, knives, etc.) since there doesn't appear to be increased activity in the amygdala as compared to other subjects considered to be "normal."