By observing the brain activity of individuals while they watched movie clips, neuroscientists have developed the most comprehensive functional map of the brain to date. The analysis, conducted using fMRI and published on November 6 in the Cell Press journal Neuron, illustrates how various brain networks activate when participants view short scenes from an assortment of independent and Hollywood films such as Inception, The Social Network, and Home Alone. The research team identified distinct brain networks that play a role in processing scenes involving people, inanimate objects, action sequences, and dialogue. They further discovered how differing executive networks are utilized during scenes that are either straightforward or challenging to follow.
By observing the brain activity of individuals while they watched movie clips, neuroscientists have developed the most comprehensive functional map of the brain to date. The analysis, conducted using fMRI and published on November 6 in the Cell Press journal Neuron, illustrates how various brain networks activate when participants view short scenes from an assortment of independent and Hollywood films such as Inception, The Social Network, and Home Alone. The research team identified distinct brain networks that play a role in processing scenes involving people, inanimate objects, action sequences, and dialogue. They further discovered how differing executive networks are utilized during scenes that are either straightforward or challenging to follow.
“Our research represents the first attempt to outline the various regions and networks of the brain under natural conditions,” explains Reza Rajimehr, the first author and a neuroscientist at the Massachusetts Institute of Technology (MIT).
The brain consists of multiple interconnected regions forming functional networks that relate to our perception and behavior. Most functional network studies involve fMRI scans conducted while individuals are at rest, but many brain areas may not be fully engaged without external stimuli.
In this investigation, the researchers aimed to see if watching movies during fMRI scanning could shed light on how functional networks in the brain react to complex audio-visual stimuli.
“With resting-state fMRI, there is no active stimulus — people are simply engaged in internal thought, so it’s unclear what triggers these networks,” remarks Rajimehr. “However, with our movie stimulus, we can analyze the response of various brain networks to different elements of the film.”
To map brain activity during movie watching, the researchers utilized a previously gathered fMRI dataset from the Human Connectome Project, which features whole brain scans from 176 young adults while they viewed a total of 60 minutes of short clips from various independent and Hollywood films.
The team averaged the brain activity of all participants and applied machine learning techniques to identify brain networks within the cerebral cortex. Next, they explored how activity in these networks aligned with the movie’s scene-by-scene content, which encompassed humans, animals, objects, music, speech, and narrative.
Their findings identified 24 brain networks correlated with specific sensory or cognitive processing tasks, such as recognizing human faces and bodies, movement, landmarks, human-object interactions, speech, and social dynamics.
Additionally, they observed an inverse relationship between “executive control domains” — regions of the brain responsible for planning, problem-solving, and information prioritization — and areas with more specialized functions. During scenes that were complex or ambiguous, there was increased activity in executive control regions; in contrast, during clearer scenes, areas pertinent to specific functions, such as language processing, were more active.
“Executive control functions are typically engaged during challenging tasks when cognitive demands are high,” Rajimehr states. “It appears that in clearer scenes, for instance during straightforward conversations, the language processing areas are engaged, whereas in complex scenes that involve context, meaning, and ambiguity, the brain shifts to rely on more general executive control domains.”
As the analyses presented in this paper were based on average brain activities, the researchers suggest that future studies could explore how brain network functions vary between individuals, across different age groups, or among those with developmental or psychiatric conditions.
“In upcoming studies, we can analyze individual subject maps, allowing us to connect each person’s unique brain map to their behavioral profiles,” Rajimehr adds. “Currently, we are delving deeper into how specific content in each movie frame stimulates these networks — for instance, examining the semantic and social context, or the relationship between characters and their backgrounds.”
