We all seem to enjoy immersing ourself in fictional worlds, whether your preference is for the technophile’s utopia of Star Trek or a trashy romance novel, there are few among us who don’t enjoy at least a brief sojourn away from reality. We take it for granted that we can separate the two experiences, reality vs fantasy, but how do we really tell the difference? According to an fMRI study published in PLoSone, the key might be in how we judge things to be relevant to ourselves. In real life we interact with people and acquire a large multifaceted body of information about them from where they live to their favourite colour and how they like to have their coffee. In comparison the fiction characters we are likely to encounter we may generally only experience in a very narrow way, in the context of the story.

In this way we can rate how personally relevant a character might be to us, the larger the amount of information we have is interpreted as higher personal relevance and therefore makes them feel more real to us. The researchers in this study presented the participants with a number of short scenarios involving either a fictional character, a friend or relative and finally a famous person who was real but was not known personally such as George Bush. Scenarios would consist of a single sentence relating to a character eg “Someone spoke to George Bush yesterday” this was then judged by the participant to be possible or inpossible.  The brain areas expected to relate to personal relevance (anterior medial prefrontal cortex and the posterior cingulate cortex) where monitored for increases in activity. The brain showed highest activity when the scenarios included personal acquaintances eg their mother, than with fictional characters eg Cinderella, and intermediate activation with famous personalities.

This does of course bring up questions of how we might cope with our fictional worlds becoming ever more detailed and immersive, might we start to blur the line of reality? I suspect not, I doubt this is the whole story reality is seldom that clean cut, but….