lesion

tissue destruction or damage (brain lesions)

EEG

an amplified recording of electrical waves sweeping across the brain's surface. These waves are measured by placing electrodes on the scalp.

PET (positron emission tomography)

a technique for detecting brain activity that displays where a radioactive form of glucose goes while the brain performs a given task

MRI (magnetic resonance imaging)

a technique that uses magnetic fields and radio waves to produce computer-generated images of soft tissue. MRI scans show brain anatomy (size and shape)

fMRI (functional MRI)

a technique for revealing blood flow and, therefore, brain activity by comparing successive MRI scans. fMRI scans show brain function as well as structure.