For a long time, research has suggested that our physiological traits are directly linked to what we are watching or listening to. Whether it be a heart-racing horror or mindless-but-entertaining comedy, our heart rates change and our breathing differs according to our brain activity while watching, and that phenomenon is the same for those watching around us. But now, a new study has found something extremely strange – our heart rates sync up with others watching or listening to the same thing, even when doing so at completely different times and in different places.
“There's a lot of literature demonstrating that people synchronize their physiology with each other. But the premise is that somehow you're interacting and physically present the same place,” says co-senior author Lucas Parra, a professor at City College of New York, in a statement.
“What we have found is that the phenomenon is much broader, and that simply following a story and processing stimulus will cause similar fluctuations in people’s heart rates. It's the cognitive function that drives your heart rate up or down.”
The results were published in Cell Reports by the City College of New York, supported by the Paris Brain Institute and Inserm.
To try to understand how cognition affects our heart rates, the researchers set up four experiments. First, 27 healthy volunteers listened to an audiobook and their heart rates were measured by an electrocardiogram (ECG). Throughout the story’s twists and turns, the subjects’ heart rates changed accordingly, and often in the same points throughout. Most of the subjects had heart rates that correlated with one another, indicating the story was directly changing their physiology and the differing plot points had the same effect.
Much research to date assumed this effect was an emotional response – scary stories frighten us, likely raising our heart rates. So, the researchers set out to identify whether this was emotional, by showing them a standard instructional video. In accordance with the first experiment, their heart rates changed at similar points despite having almost no emotional interest in the video, but this effect only happened when they were paying attention. When the researchers distracted the participants, their heart rates did not fluctuate in the same way.
In another experiment, the researchers found that those paying the most attention (measured by how well they could answer questions about the narrative) had the most synchronization between heart fluctuations. Finally, they repeated the first experiment but with participants who had lower degrees of consciousness, such as those in a vegetive state. They discovered that these people had less synchronization compared to healthy people, and in cases where their consciousness recovered six months later, their heart rates became more correlated with others.
These experiments suggest that cognition in reaction to a visual and auditory stimulus has a direct link to heart rate and breathing rates and that similar stimuli will elicit the same response in people, even when they are not together. Even more so, it shows just how connected our bodies and brains are in terms of cognition.
“This study is still very preliminary, but you can imagine this being an easy test that could be implemented to measure brain function,” Jacobo Sitt, co-author of the study, says.
“It doesn’t require a lot of equipment. It even could be performed in an ambulance on the way to the hospital.”
So, even if you are enjoying a movie alone, your body is still feeling almost exactly the same way as many others who have and will watch it, all experiencing it in the same way. Touching, really.