One potential way of tackling this question is by non-invasively studying the brains of human participants while they watch movies. This is a useful approach because movies simulate information present in our everyday lives and require us to integrate information in order to comprehend the movie narrative. Under the Marie Skłodowska Curie fellowship, I developed a novel method for studying brain activity evoked by movie watching, which sheds light on the way our brains incorporate the ongoing stream of experiences with our prior knowledge to make sense of evolving events.
My novel approach for studying naturalistic integration of information takes inspiration from the vast knowledge gained in the field of spatial navigation in rodents. While a rat is navigating a maze, its brain “replays” the route travelled so far, to help the rat keep track of its position. My findings from movie-watching data indicate that the human brain uses a similar mechanism to keep track of evolving experiences and interpret them. To illustrate this, let’s consider the well-known sentence “We will always have Paris” from the movie “Casablanca”. To understand the meaning of this sentence while we perceive it, our brains must integrate this sentence with relevant information displayed throughout the movie (e.g. that the protagonists first fell in love in Paris and must now separate). Indeed, I found that at the end of each movie scene, the brain replays information from past scenes. But, significantly, out of the vast information conveyed to us during the movie, only information that is directly relevant to the current scene is replayed at the end of this scene (e.g. to understand the “Casablanca” example given above, the brain does not need to replay irrelevant information, such as that the male protagonist had letters of transit obtained from murdered German couriers). This suggests that the human brain can selectively replay relevant past information in order to interpret ongoing experiences.
