Like an MRI, Magnetic Encephalogram (MEG) and Electric Encephalogram (EEG) scanning technology is able to measure brain activity noninvasively. However, unlike an MRI, the speed and fidelity of the EEG/MEG can break down brain activity to the millisecond, providing an almost “real-time” snapshot.
To demonstrate this, here is a video reconstruction of EEG data from a “visual oddball” test conducted by Fred Prior at the Center for Clinical Imaging Research (CCIR) at WashU.
A subject is presented with a visual “oddball” — an image that is very different from an established visual norm. This is an image reconstruction of activated currents beneath the cortical surface of the brain. In the first 25 ms, we see activation in the frontal eye fields of the brain (facing away from the viewer), followed by activity in the visual cortex of the occipital lobe (facing the viewer).
Here is more information on MEG and EEG scan technology and how it will be used in the Human Connectome Project: