How Intention and Emotion Shape Memory?
Interest in memory and sleep dates back to ancient times. More than 2,000 years ago, Plato and Aristotle laid the foundations for understanding memory with their theories. For example, Aristotle’s De Somno et Vigilia argued that sleep is essential for the recovery of both body and mind, and Hippocrates also brought attention to the importance of sleep for health. However, interest in the topic has not faded, as shown by a study published in early October. According to the study, people have more control over their memories than they often realize.
The study, “Top-down instruction outweighs emotional salience: nocturnal sleep physiology indicates selective memory consolidation,” was conducted by Laura B. F. Kurdziel, Carie Fiedler, Alex Gajewski, and Caroline Pongratz from the Laboratory of Social Cognition and Affective Neuroscience, Department of Psychology, Merrimack College, North Andover, MA, United States. We spoke with Laura B. F. Kurdziel, the study’s corresponding author.
Remember or Forget?
In the study, researchers investigated how intentional memory instructions (remember vs. forget) and emotional content (negative vs. neutral words) interact to shape memory, as well as whether sleep influences this process.
The research consisted of two studies. The first was an online experiment, in which behavioral data were collected remotely from 45 participants. The second was an in-lab replication with 53 participants, bringing the total to 98. In the laboratory study, participants’ brain activity during sleep was recorded using a wearable EEG headband that they could wear at home. In both studies, participants viewed 100 words, half negative and half neutral. After each word, they were instructed to either remember or forget it. Immediately afterward, participants performed a recognition task with 100 words, half previously seen, half new. Twelve hours later, the test was repeated.
The results show that the intention to remember has a stronger effect on memory than emotion alone. As the corresponding author, Ph.D. Kurdziel highlighted several key findings. Instructions to remember led to better memory than emotional content alone. Emotion increased recognition, especially when paired with a “remember” cue, but it also led to more false memories, particularly for negative words. Sleep did not improve memory performance overall, but brain activity during sleep predicted what was remembered or forgotten. This suggests that we have more control over what we remember than we think, and that the quality of sleep physiology—not just sleep itself—is what truly shapes memory.
“I need to remember this.”
It was often said that studying before going to bed helps you remember better. How could this finding help students and others who study before sleep?
Laura B. F. Kurdzie: It’s true that studying before sleep can help—but what you focus on matters. Our results suggest that intentionally deciding to remember something is more powerful than just feeling that it’s important or emotional. So, students might benefit from actively tagging information they want to remember—even silently saying “I need to remember this”—right before bed. And while sleep is important, it’s the specific brain activity during sleep—like sleep spindles and REM theta—that determines what gets consolidated. So, getting quality sleep, not just sleep quantity, is key.
Can this help neuroscience in further research, and what benefits might result from it?
Laura B. F. Kurdzie: Definitely. This study helps clarify how emotion, intention, and sleep physiology interact, which is a fundamental question in neuroscience. It bridges cognitive psychology, sleep research, and emotional memory, offering insight into how memory is selectively formed.
Potential benefits include: Improving memory strategies in education and training. Developing sleep-based interventions for conditions like PTSD, where emotional memories are difficult to regulate. Advancing our understanding of how forgetting can be adaptive and possibly even harnessed.
What additional research is needed?
Laura B. F. Kurdzie: Future research could explore how individual differences—such as anxiety, emotional reactivity, or sleep quality—modulate these effects. Examine real-world relevance, such as how these mechanisms apply to memories of emotionally charged events like trauma. Investigate whether targeted interventions (e.g., enhancing spindles) could help improve selective memory in educational or clinical settings.
Memory shapes what we focus on, how we feel, and even how we sleep. Even deciding to memorize key information before bed, perhaps by silently marking important material, can help. And this study, one of the first of its kind, bridges ancient wisdom and modern neuroscience.
Image: Tips for forming smart sleeping habits during university, Torontomu.ca
