A new tool for brain research

Physicists and neuroscientists from The University of Nottingham and University of Birmingham have unlocked one of the mysteries of the human brain, thanks to new research using functional Magnetic Resonance Imaging (fMRI) and electroencephalography (EEG). The work will enable neuroscientists to map a kind of brain function that up to now could not be studied, allowing a more accurate exploration of how both healthy and diseased brains work. Functional MRI is commonly used to study how the brain works, by providing spatial maps of where in the brain external stimuli, such as pictures and sounds, are processed. The fMRI scan does this by detecting indirect changes in the brain's blood flow in response to changes in electrical signalling during the stimulus. A signal change that happens after the stimulus has stopped is also observed with the fMRI scan. This is called the post-stimulus signal and up until now it has not been used to study how the brain works because its origin was uncertain. In novel experiments, the research team has now combined fMRI techniques with EEG, which measures electrical activity in the brain, to show that the post-stimulus signal also actually reflects changes in brain signalling.