Share this article You are free to share this article under the Attribution 4.0 International license. New research suggests that every time we access information, the way we remember it can influence how the brain represents it the next time. We tend to think of memory as something stored in the brain, ready to be retrieved when we need it. But remembering can be much more dynamic than that. “Our memory is far from simply a fixed resource that we consult when necessary,” says Marc Coutanche of Rice University. “It is dynamic and adaptive. Memory retrieval actively updates our memories rather than simply ‘replaying’ them.” Coutanche, who recently joined Rice as an associate professor of psychological sciences, and fourth-year doctoral student Amy Qi explored whether the way people access information leaves a trace that can be detected the next time they retrieve it. Their findings were published in the Journal of Cognitive Neuroscience. Think about remembering your dog. You could focus on a specific detail, such as the pattern of their coat. Another time, you might just think of him as a dog. Or you could think about your broader role as part of your family. Coutanche and Qi wanted to know if those different ways of accessing information could affect what happens in the brain later. To find out, participants learned pairs of unknown Dutch words and pictures while undergoing functional magnetic resonance imaging (fMRI). The researchers then asked them to remember the objects in different ways, focusing on a specific feature, a broader category, or a theme. When the participants were tested again, they were equally good at remembering the information regardless of how they had previously thought about it. But his brain activity told a different story. “What I find most interesting is that we showed that a memory appears to contain a trace of how it was used before,” Qi says. “Memory-related neural activity not only reflected what participants were doing at that moment, but also something about how that memory had been accessed before.” The researchers found that thinking about objects by category made the neural patterns associated with different objects more similar in areas involved in visual processing. Meanwhile, focusing on an individual object made their neural pattern more distinctive in an area involved in word processing. The findings contribute to a growing understanding of memory as something that can change as we use it, rather than a fixed record that is simply stored and reproduced. The study also demonstrates how computational tools can reveal aspects of memory that behavior alone may not show. Coutanche and Qi combined fMRI with machine learning techniques to look for subtle patterns in brain activity. These methods allowed them to detect how information had been previously accessed in areas such as the hippocampus and visual cortex, even though the participants obtained similar results on memory tests. “Without looking at subtle patterns of activity with techniques like this, we might have missed the findings entirely,” Coutanche says. “Computational methods like this allow us to detect and understand subtle patterns of activity in a way that provides real information about how the brain remembers.” Source: Rice University
