Imma Perfetto
Cosmos science journalist
Researchers studying how the brain responds to watching movies are now able to show it’s anything but a mindless way to wind down at the end of a busy week.
Scientists mapped the brains of participants who watched clips from cinematic favourites like Inception (2010), The Empire Strikes Back (1980), and Home Alone (1990) to identify the different brain networks involved in processing different types of scenes.
The work helps characterise the organisation of the cerebral cortex – the outermost layer of the brain, responsible for sensory and cognitive processing – which the researchers say is… “a fundamental step in understanding how different kinds of information are processed in the brain.”
The findings showed heightened activity in brain regions with specific functions, like language processing, occur during more easily understood scenes.
But when the movie’s content was ambiguous or difficult to follow, there was more activity in “executive control domains” – brain regions that enable people to plan, solve problems, and prioritise information.
“Executive control domains are usually active in difficult tasks when the cognitive load is high,” says neuroscientist Reza Rajimehr of Massachusetts Institute of Technology (MIT) in the US, first author of the paper published in the journal Neuron.
“It looks like when the movie scenes are quite easily comprehendible, for example if there’s a clear conversation going on, the language areas are active, but in situations where there is a complex scene involving context, semantics, and ambiguity, more cognitive effort is required, and so the brain switches over to using general executive control domains.”
Rajimehr and his team used freely available functional magnetic resonance imaging (fMRI) data collected by the Human Connectome Project (HCP).
fMRI detects the increases in blood flow that occur when regions of the brain are in use. These whole brain scans were taken while 176 young adult participants watched 60 minutes’ of short clips from a range of independent and Hollywood films.
“Our work is the first attempt to get a layout of different areas and networks of the brain during naturalistic conditions,” says Rajimehr.
“With resting-state fMRI, there is no stimulus – people are just thinking internally, so you don’t know what has activated these networks.
“But with our movie stimulus, we can go back and figure out how different brain networks are responding to different aspects of the movie.”
They averaged the brain activity across all participants and used machine learning techniques to identify brain networks within the cerebral cortex.
They then analysed how activity within these different networks related to the movie’s scene-by-scene content, including people, animals, objects, music, speech, and narrative.
“Now, we’re studying in more depth how specific content in each movie frame drives these networks—for example, the semantic and social context, or the relationship between people and the background scene,” says Rajimehr.
