Biology subjects

Palmieri, J.

Publications and source records attributed to Palmieri, J..

3 recordsLinked to original sources

bioRxiv2025

Nightly dynamics of emotional content in dreams

Emotional processing is a crucial adaptive function. Research suggests that sleep, particularly rapid eye movement (REM) sleep, may have a role in processing the emotional load of past events. Notably, dream experiences may offer insight into this nighttime process. Some studies have reported increased emotionality in dreams as the night progresses, possibly reflecting ongoing emotional processing in the sleeping brain. However, findings on how dream affect evolves throughout the night remain mixed. In this study, we investigated how emotional intensity in conscious experiences during sleep changes across the night and sleep stages. Participants (Nsubjects = 20) were subjected to a multiple awakening paradigm, where they were awakened 4-5 times throughout the night and asked to recall their dreams (Ndreams = 61). Additionally, they rated the emotional intensity of their experiences using a structured cued questionnaire. Emotional intensity in dreams increased significantly throughout the night, with late-night dreams being more emotional than dreams collected during earlier sleep. Contrary to our expectation, this increase was not driven by dream reports obtained from REM sleep awakenings. Moreover, late- night dream reports were also significantly longer than those from early sleep, yet the length of the dream reports did not correlate with their emotional intensity. This suggests that the emotionality of dreams is not directly linked to the ability to recall the dream or its narrative complexity. Instead, it could be driven by emotional processes occurring independently throughout the night, or by other factors that regulate our access to dream experiences and their emotional content.

neuroscience↗

bioRxiv2025

Incorporation of complex narratives into dreaming

Reactivation of waking neuronal activity during sleep holds a functional role in memory consolidation. Reprocessing of daytime memory in dreams might aid later memory performance in a similar way. Numerous findings hint at a link between dreaming and sleep-dependent memory processing, however, studies investigating day-residue incorporation in dreaming led to mixed results so far. In this study, we used a naturalistic learning paradigm aimed at biasing dream content by manipulating pre-sleep experience. Participants listened to one of four different audiobooks while falling asleep and were awoken several times during the night to report their dreams. Afterwards, we tested how well they remembered the content of the audiobook. We then asked three blind raters to guess, based solely on anonymized dream reports, which audiobook someone had listened to before experiencing a dream. Our findings show that dreams across the whole night and from both NREM and REM awakenings contain specific information about the content of narratives studied before sleep. Moreover, participants with stronger incorporation of the audiobook in their dreams showed a tendency to recognize more audiobook content across the sleep period. Together, these findings suggest that salient day-time experiences resurface in dreams and that content selected for consolidation during sleep is more strongly incorporated.

neuroscience↗

bioRxiv2023

Daytime experiences shape neural activity and dream content in the sleeping brain

Dreams incorporate recent experiences, and memory-related brain activity is reactivated during sleep, suggesting that dreaming, memory consolidation and reactivation are tightly linked. We devised a paradigm to investigate whether memory reprocessing during sleep contributes to dreaming. Participants listened to different audiobooks before falling asleep, introducing dissimilar experiences to be processed at night. We show that audiobook content was reprocessed at the neural level using multivariate pattern analyses. Brain activity during rapid eye movement sleep, particularly in the beta range, carried information about the audiobook. While the amount of neural reinstatement did not correlate with memory retention, global beta power during REM sleep was associated with better memory performance. Moreover, blind raters could determine which audiobook participants had studied based on dream reports. Participants who dreamt of the audiobook also showed stronger neural reinstatement. Reprocessing of pre-sleep experiences during sleep may thus shape our brain activity, our dreams, and our memories.

neuroscience↗