Overview: Brain responses to a complex story, such as a movie plot, are consistent in children of all ages, but the responses change as a child transitions into an adult.
Researchers have revealed the changes in brain activity underlying how our brains perceive and respond to stories as we grow from infants to adults.
The findings challenge the theory that children’s perceptions are simply a noisier version of adults’ understanding, suggesting instead that children have their own unique way of understanding and interpreting the world.
The ability to perceive and remember the world around us changes radically during the first 20 years of our lives. It is generally accepted that older children and adults can better understand and interpret the world around them and better anticipate future situations, but the changes in brain activity underlying this period of knowledge acquisition are not fully understood.
“In adults, watching a movie triggers synchronized brain responses in different people, reflecting how they perceive, understand and remember the movie,” explains lead author Samantha S. Cohen, postdoctoral scientist, department of psychology, Columbia University, USA.
“While many studies have looked at changes in knowledge during development, there is limited understanding of how internal representations of complex narrative stimuli arise with age, allowing us to understand predictable and naturalistic world events, such as the plot of a Hollywood -movie. “
Analyzing brain responses to complex stories or movies is challenging because there are no models that predict brain-wide responses to these types of stimuli. An alternative, model-free approach is the use of inter-subject correlation (ISC), which measures the similarity of brain responses in a brain region in movie viewers.
The researchers used a large publicly available dataset of functional magnetic resonance imaging (fMRI) brain scans recorded while children and young adults watched a short video animation featuring both social and emotional themes. For the youngest (5-8 years) and oldest (16-19 years) age groups, they measured the ISC for children of the same age and among children of different ages.
They found that the brain’s responses to the film are consistent in children of the same age, but that these responses change as children grow into young adults. In particular, the brain regions used to internally recognize events in the story have shifted from brain regions that track gross narrative information to those that track sensory details and the mental states of characters in the story.
One of the ways to study differences in how children and adults respond to stories is by comparing how they notice and perceive the key events in the film that shape the story. The team asked both children and adults to report where they thought meaningful scene changes were taking place in the story.
They found that children as young as seven organized the story in the same way as adults, but that older children’s brains were better able to anticipate upcoming events in a movie.
Surprisingly, younger children in the hippocampus, an area important for memory formation, responded more strongly to the transitions between events in the story, possibly because they still make sense of events in the world.
“Our results show that brain responses to stories not only become more synchronized in children as they age, but in fact their dynamics and timing change to resemble an adult more,” concludes senior author Christopher Baldassano, assistant professor of psychology, Columbia. university .
“In addition, the study provides the foundation for assessing how children acquire schematic knowledge about the world and learning how to use that knowledge at the right time.”
About this news about neurodevelopmental research
Original research: Open access.
†Developmental changes in story-evoked responses in the neocortex and hippocampusby Christopher Baldassano et al. eLife
Developmental changes in story-evoked responses in the neocortex and hippocampus
How does the representation of naturalistic life events change with age? Here we analyzed fMRI data from 414 children and adolescents (5 – 19 years) while watching a narrative film.
In addition to changes in the degree of inter-subject correlation (ISC) with age in sensory and medial parietal regions, we used a new measure (between-group ISC) to reveal age-related shifts in responses across most of the neocortex. †
Over the course of development, brain responses became more discretized into stable and coherent events and shifted earlier in time to anticipate imminent perceived event transitions, measured behaviorally in an age-matched sample.
However, hippocampal responses to event boundaries declined with age, indicating a shifting division of labor between episodic coding processes and schematic representations of events between the ages of 5 and 19 years.