By Stephen Beech via SWNS
Our brains divide the day into “chapters” to help us cope with day-to-day life, according to new research.
The moment a person steps off the street and into a restaurant, for example, the brain mentally starts a new “chapter” of the day – a change that causes a big shift in cerebral activity, say scientists.
They explained that similar shifts happen throughout the day as people encounter new environments, such as going out for lunch, attending a football match, or settling down for a night watching telly.
An American research team wanted to better understand what prompts the brain to form a boundary around the events we encounter, effectively registering it as a new “chapter” in the day.
They believe that one possibility is that new chapters are entirely caused by big changes in a person’s surroundings, such as how walking into a restaurant takes them from outdoors to indoors.
But another possibility is that the new chapters are prompted by “internal scripts” that our brain writes based on past experience, and that even big environmental changes might be ignored by our brain if they are not related to our current priorities and goals.
To test their hypothesis, the team developed a set of 16 audio narratives, each about three to four minutes long.
Each narrative took place in one of four locations – a restaurant, an airport, a grocery store, and a lecture hall – and dealt with one of four social situations: a break-up, a proposal, a business deal, and an amusing first encounter between romantic partners.
The team’s findings, published in the journal Current Biology, suggest that the way the brain divides up an experience into individual events depends on what a person currently cares about and is paying attention to.
For example, when listening to a story about a marriage proposal at a restaurant, participants’ prefrontal cortex would usually organize the story into events related to the proposal.
However, the researchers also found that they could force the prefrontal cortex to organize the story in a different way if they instead asked study participants to focus on the events related to the dinner orders of the couple.
For study participants who were told to focus on those details, moments such as ordering dishes became critical new chapters in the story.
Study leader Professor Christopher Baldassano, of Columbia University in New York, said: “We wanted to challenge the theory that the sudden shifts in brain activity when we start a new chapter of our day are only being caused by sudden shifts in the world – that the brain isn’t really ‘doing’ anything interesting when it creates new chapters, it’s just responding passively to a change in sensory inputs.
“Our research found that isn’t the case: the brain is, in fact, actively organizing our life experiences into chunks that are meaningful to us.”
The Columbia team measured where the brain created new chapters both by looking at MRI scans to identify fresh brain activity, and, in a separate group of participants, by asking them to press a button to indicate when they thought a new part of the story had begun.
They found that the brain divided stories into separate chapters depending on the perspective they were told to be attuned to and it didn’t just apply to the proposal-in-a-restaurant scenario.
A person hearing a story about a break-up in an airport could if prompted to pay attention to details of the airport experience, register new chapters as they went through security and arrived at their gate.
The team also found that a person who heard a story about someone closing a business deal while grocery shopping could be prompted to register either the new steps of the business deal as new chapters or to be attuned primarily to the phases of grocery shopping instead.
Baldassano said the details that the study participants were prompted to pay attention to influenced what their brains perceived as a new chapter in the story.
Now the team hopes to investigate the impact that expectations have on long-term memory.
They asked each participant in the “chapters” study to tell them everything they remembered about each story.
The researchers are currently analyzing the data to understand how the perspective they were asked to adopt while listening to the story changes the way they remember it.
Baldassano added: “Tracking activity patterns in the brain over time is a big challenge that requires using complex analysis tools.
“Using meaningful stories and mathematical models to discover something new about cognition is exactly the kind of unconventional research in my lab that I am most proud of and excited about.”
