Psychology research offers details on how

As soon as a person walks off the street and into a restaurant – to take just one example – the brain mentally begins a new “chapter” of the day, a shift that causes a significant shift in brain activity. Changes like this happen throughout the day, as people experience new environments, like going out to lunch, attending their child’s soccer game, or settling in for an evening of watching TV.

But what determines how the brain divides the day into individual events that we can understand and remember separately? This is what an article in the newspaper Current biology aimed to find out.

The research team, led by Christopher Baldassano, associate professor of psychology, and Alexandra De Soares, then a member of his laboratory, came up with some interesting results.

The researchers wanted to better understand what causes the brain to form a boundary around the events we experience, thereby recording them as a new “chapter” of the day. One possibility is that the new chapters are caused entirely by big changes in a person’s environment, like how entering a restaurant takes them from outside to inside.

Another possibility, however, is that new chapters are driven by internal scripts that our brains write based on past experiences, and that even major environmental changes could be ignored by our brains if they are not related to our current priorities and objectives.

To test their hypothesis, the researchers developed a set of 16 audio stories, each lasting approximately three to four minutes. Each story took place in one of four locations (a restaurant, an airport, a grocery store, and a conference room) and dealt with one of four social situations (a breakup, a proposal, a business deal, and a meet cute).

Researchers have found that how the brain divides an experience into individual events depends on what the person is currently interested in and what they are paying attention to. When listening to a story about a proposal in a restaurant, for example, the subjects’ prefrontal cortex typically organizes the story into events related to the proposal, leading (hopefully) to the final “yes.”

But the researchers found that they could force the prefrontal cortex to organize the story in a different way if they asked study participants to focus on the events related to the couple’s dinner orders. For study participants who were asked to focus on these details, moments like ordering food became critical new chapters in the story.

“We wanted to challenge the theory that sudden changes in brain activity when we start a new chapter in our day are only caused by sudden changes in the world, that the brain doesn’t ‘do’ anything. interesting when it creates new phenomena chapters, it’s just passively reacting to a change in sensory input,” Baldassano said.

“Our research has found that this is not the case: the brain, in fact, actively organizes our life experiences into chunks that are meaningful to us.”

The researchers measured where the brain created new chapters both by examining MRI scans of the brain to identify new brain activity and, in a separate group of participants, by asking them to press a button to indicate when they were thinking of a new part of the chapter. the story had begun.

They found that the brain divided stories into separate chapters based on the perspective they were told to tune into – and this didn’t just apply to the restaurant proposal scenario: a person hearing a story about a breakup in a restaurant. the airport could, if prompted to pay attention to the details of the airport experience, record new chapters as they passed through security and arrived at their gate.

Meanwhile, a person who hears the story of someone entering into a business transaction while shopping might be prompted either to record the new stages of the business transaction as new chapters or to adapt mainly during the phases of his races.

The details that study participants were asked to pay attention to influenced what their brains perceived as a new chapter in the story.

In the future, researchers hope to study the impact of expectations on long-term memory. As part of this study, the researchers also asked each participant to tell them everything they remembered about each story. They are still analyzing the data to understand how the perspective they were asked to take when listening to the story changes the way they remember it.

More broadly, this study is part of an ongoing effort in the field to build a comprehensive theory of how real-life experiences are divided into memories of events. The results indicate that prior knowledge and expectations are a key ingredient in the functioning of this cognitive system.

Baldassano described the work as a passion project.

“Tracking patterns of brain activity over time is a major challenge that requires the use of complex analysis tools,” he said.

“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.”