Scientists at Columbia University have discovered that the human brain breaks experiences into discrete “chapters” rather than consolidating changes in the environment. In a new paper published in Current Biology, researchers show how goals, together with attention, shape memory and a person’s interpretation of events.
This study, led by associate professor Christopher Baldassano and former lab member Alexandra De Soares, explored the cognitive mechanism through which a brain categorizes experience. Traditionally, it was understood to be the result of environmental changes. For example, entering a restaurant triggered these mental divisions. Researchers, on the other hand, have a different view, arguing that this is essentially driven by internal priorities and attentional focus.
They created 16 audio narratives of three to four minutes in length set up in diverse locations such as restaurants or airports and centred on different kinds of social contexts such as proposals, breakups or romantic spying. As participants listened to the stories, their brain activity was recorded during MRI scans. The results indicated how participants structured their stories into chapters differed widely based on their attention. For example, as listeners focused on a marriage proposal during a dinner scenario, the brain organized the events before the proposal as different chapters. When, however, told to track the order of the meal prepared by the couple, it marked these as new important moments.
The brain is not passively reacting to the environment. Instead, it is proactively organizing life experiences into coherent chunks. When participants perceived a shift in the narrative, they marked new chapters with button presses, further confirming the role of attentional focus in memory formation. In the present analysis, the focus was to gain better insight into the interplay of expectation and prior knowledge that affects long-term memory retention. This work marks an important step towards the understanding of the cognitive systems that decide upon how everyday experience gets parcelled up into memorable events.
Enthusiastic about his participation in this project, Baldassano was interested in the effort of studying activity in the brain and making use of mathematical models to reveal the hidden patterns within cognition. These investigations further expand a growing volume of literature on the development of memory, strongly underlining how complexly interconnected attention and context are to this process.