An imaging technique to show brain activation during tasks
Functional magnetic resonance imaging (fMRI) is used to image the parts of the brain that become active during different mental processes.
In medicine, fMRI can be used to map brain functions in patients who are about to undergo neurosurgery to remove a brain tumour or abnormal tissue that causes epileptic seizures. This helps neurosurgeons to minimise the risk of accidentally removing or damaging the parts of the brain involved in functions such as language and memory.
fMRI studies show that different brain areas are specialised for certain functions, often supporting data from previous neurological and psychological studies. For example, the frontal lobe contains areas that plan and control voluntary movements. The frontal lobe also contains areas specialised for complex functions such as making decisions and judgements, which are important for social interactions. fMRI studies show that activity in these areas and their detailed structure is altered in people with autism, but further research is needed to confirm this.
fMRI can also be used to ‘decode’ brain activity. In 2016 researchers at the University of Oregon scanned participants’ brains while they looked at pictures; they then recorded activity in the angular gyrus, which is involved in a number of processes such as attention and visualisation. Researchers then showed the participants different faces while scanning their brains again and were able to construct low-quality copies of what the participants saw by decoding the activity in the angular gyrus. While the images were far from exact copies, traits such as skin colour, whether the face is smiling or not and its general shape were recreated accurately. However, our thoughts are much more complex than this simple mapping of visual images, so we are a long way from decoding the content of minds.Lead image:
Parashkev Nachev/Wellcome Collection CC BY