Among your memory’s biggest challenges is remembering what actually happened, versus what you imagined – that’s especially hard with some people I know. That ability, according to a new study, is linked to the presence of a small fold; even more interesting, some people have and some people don’t have this fold – a finding that could help researchers better understand how memory works, as well as treat diseases such as schizophrenia, where the line between reality and imagination is blurred out.

Researchers used MRI scans to look into the brains of a large number of adults; in particular, they looked for the paracingulate sulcus (PCS), a fold located on the front of the brain. There’s a lot of variability in this fold in different people: some have it clearly marked out and distinctive, while in others it is just barely visible.

The participants in the study saw well-known word pairs (“Jekyll and Hyde”) and some half pairs (“Jekyll and ?”). If they only saw a half of pair, they were asked to imagine the other halfAfter each pair or half pair, either the participant or the experimenter said the whole pair aloud. After they saw all the pairs, they were asked some questions, such as ‘Did you see both words of the pair, or just one?’, and the people who didn’t have a clear fold did worse on both questions – remembering if something was real or imgaginary , but they felt just as confident as their counterparts. This is consistent with other studies, which have shown that people with schizophrenia frequently have smaller or no PCS, suggesting a connection between this structure and keeping track of reality.

However, the study only shows clearly that PCS and reality monitoring are linked, not that its absence (for example) meant the total lack of such a capacity. Still, future studies in this direction will definitely point out exactly how tight this bond is.

Via 80 Beats