While studying for my D.Phil., I came across a fascinating region of the brain that tracks who you are. It is called the medial prefrontal cortex (or MPFC; image above), and it sits right in front of your brain. Here is one interesting study that highlights its role.
Researchers from Dartmouth college asked people to judge adjectives presented on screen in one of three ways: self (eg. “Does the adjective describe you?”), other (“ Does the adjective describe the current U.S. president?”), or case-judgement (“Is the adjective presented in uppercase?). So a typical participant in their study looked at an adjective like “happy”, and then judged it whether it described them, someone else, or the president.
While people were doing this task, researchers recorded their brain activity using MRI machines. What did they discover? They found that people remembered words from the self-reference condition way more compared to other conditions. That is, if they were asked to think about “happy” in relation to themselves, they were more likely to remember it than in relation to the U.S. president. We’re all somewhat self-centred, aren’t we?
Using fMRI, they found that the medial prefrontal cortex (MPFC) was activated in the self-reference condition compared to the other conditions. However the fun does not end here. Another study found that activity in the MPFC could predict which items would be remembered on a surprise memory test. They could actually look at how active your MPFC is, and then tell you what your scores would be. If you cheated on a memory test, your MPFC may be able to call out your bluff!