NUNZIUM

Memory is a fascinating and complex aspect of human cognition. Imagine you're trying to recall where you placed your keys, and you're confident they're on the dining room table. However, upon checking, you will find them on the side table by the front door. You're not alone in experiencing such a memory mishap. Recent research reveals that our expectations can significantly influence our short-term and long-term memories. Short-term memory (STM) lasts briefly (seconds to minutes) and stores information like the car's colour that drove by or the name of a person you've just met. Long-term memory (LTM), on the other hand, can last for years or even a lifetime, enabling us to recall childhood memories or recognize a friend we haven't seen in years. While it is known that expectations can influence the formation of false memories in LTM, a series of experiments have shown that STM is also susceptible to such illusions.

These experiments involved memory displays containing actual and mirrored letters (pseudo-letters). Participants were asked to remember and later report the letters they saw. By focusing on high-confidence errors, researchers found that participants were more likely to report seeing an actual letter when a pseudo-letter was shown, and this tendency increased over time. These results suggest that prior expectations about the likely appearance of letters, based on lifelong learning and development, can shape the content of STM. Another set of studies investigated the role of world knowledge in generating illusory memories in STM. Participants were shown faces combined with roles (e.g., professor, drug dealer, artist). After a 20-minute delay, they were more likely to attribute criminal labels to faces with stereotypically black features incorrectly. This result suggests that internal biases and expectations can shape memory content. Additionally, research on cultural experiences with music revealed that participants made erroneous responses about musical mode and tonality just one second after hearing a sequence of tones. These findings indicate that world knowledge alone can influence illusory memories in STM.

So, why is it important to understand the role of expectations in memory formation? First, it highlights that our memories are not infallible, even when they seem highly reliable. This fact has implications for everyday life. We should be cautious when relying solely on our memories, especially in high-stakes situations. Second, the influence of expectations on memory formation can impact human behaviour and relationships. For example, the incorrect labelling of faces based on stereotypes can contribute to prejudiced attitudes and discriminatory behaviour. Understanding the role of expectations in memory can help us become more aware of our biases and work towards addressing them. Finally, these findings support the predictive processing view of memory formation, which posits that all memory stages involve integrating bottom-up input with top-down predictions. It means that our prior expectations can shape our memory traces, making our recollections more adaptive, efficient, and prone to errors. Memory is a dynamic and intricate process influenced by our expectations and world knowledge. The research presented here highlights the susceptibility of both short-term and long-term memory to illusions. It emphasizes the importance of understanding the factors that shape our memories. By becoming more aware of the role of expectations in memory formation, we can better understand human cognition, behaviour, and relationships, ultimately leading to a more nuanced view of the world around us.