Personality and everyday experiences shape the structure of dreams

Dreams have traditionally been considered by neuroscience as a unique model for studying consciousness and the functions of sleep. Despite the fact that the content of nighttime dreams is often associated with emotional regulation, learning processes, and memory consolidation, the question of how much stable individual personality traits determine the semantic structure of dreams has remained open. A team of researchers led by Giulio Bernardi from the IMT Graduate School of Advanced Studies (Lucca, Italy) has presented the results of a large-scale longitudinal project that sheds light on the mechanisms underlying the formation of these subjective experiences.

Over a four-year period (2020-2024), researchers collected and organized dream reports and daydream experiences from 207 adult participants. The total data set consisted of 3,366 records, supplemented with demographic, cognitive, and psychometric measures, as well as sleep quality data.

To process this vast amount of unstructured information, the researchers employed an innovative approach: a combination of hypothetical semantic measurement analysis using large language models and data-driven lexical analysis. An article published in the journal Communications Psychology, based on the results of the study, confirms that the content of dreams is the result of a complex interaction between stable personality characteristics and current daily experiences.

The study found that dreams are not simply a reproduction of the events of the previous day. Rather, they are a “hyperassociative” reinterpretation of past experiences and future expectations. During sleep, the brain extracts fragments of reality and reorganizes them into new narrative scenarios that may appear paradoxical but still maintain an internal logic.

The key factors determining the “architecture” of dreams, scientists include:

• Individual traits: a person’s attitude to dreams themselves, a tendency to mind-wandering, and the subjective quality of sleep.
• External stress: an analysis of an independent set of data collected during the lockdown of 2020 demonstrated that large—scale external shocks lead to natural changes in the semantics of dreams – an increase in the intensity of emotions and an increase in the frequency of stories associated with limitations. Over time, as the situation normalized, the content of the dreams also returned to their usual patterns.

The data obtained allow us to bridge the gap between fundamental research on dreams and cognitive neuroscience. The method developed by the authors for quantifying the semantic structure of dreams provides a basis for testing new hypotheses about the functions of sleep, including its role in memory consolidation and emotional regulation.

The work of Giulio Bernardi and his colleagues proves that dreams are not random “noise” of the brain, but a dynamic process that reflects the unique cognitive profile of each individual. Further research in this area will help us better understand how sleep mechanisms support mental health and adaptation to changing environmental conditions.