Morten L Kringelbach

Psychedelics are serotonergic drugs that profoundly alter consciousness, yet their neural mechanisms are not fully understood. A popular theory, RElaxed Beliefs Under pSychedelics (REBUS), posits that psychedelics flatten the hierarchy of information flow in the brain. Here, we investigate hierarchy based on the imbalance between sending and receiving brain signals, as determined by directed functional connectivity. We measure directed functional hierarchy in a magnetoencephalography (MEG) dataset of 16 healthy human participants who were administered a psychedelic dose (75 micrograms, intravenous) of lysergic acid diethylamide (LSD) under four different conditions. LSD diminishes the asymmetry of directed connectivity when averaged across time. Additionally, we demonstrate that machine learning classifiers distinguish between LSD and placebo more accurately when trained on one of our hierarchy metrics than when trained on traditional measures of functional connectivity. Taken together, these results indicate that LSD weakens the hierarchy of directed connectivity in the brain by increasing the balance between senders and receivers of neural signals.

“Supporting human flourishing” is a goal of governments and societies, yet the construct may appear hard to define. We discuss the emerging science of pleasure and flourishing, insights into the brain mechanisms of meaning making and thriving, and the potential for interdisciplinary studies to advance this promising scientific field.

Cognitive aging is characterized by the gradual decline of a number of abilities, such as attention, executive functioning, and memory. Research on memory aging has reported age-related deficits in short-term (STM), long-term (LTM), and working memory (WM) and linked these to structural and functional changes in the brain that occur with aging. However, only a few studies have drawn direct comparisons between these memory subsystems in the auditory domain. In this study, we assessed auditory STM, LTM, and WM abilities of young (under 25 years of age) and older (over 60 years of age) adults using musical and numerical tasks. In addition, we measured musical training history and tested its modulating effects on auditory memory performance. Overall, we found that older adults underperformed in specific memory tasks, such as STM related to discrimination of rhythmic sequences, LTM associated with …

A fundamental topological principle is that the container always shapes the content. In neuroscience, this translates into how the brain anatomy shapes brain dynamics. From neuroanatomy, the topology of the mammalian brain can be approximated by local connectivity, accurately described by an exponential distance rule (EDR). The compact, folded geometry of the cortex is shaped by this local connectivity and the geometric harmonic modes can reconstruct much of the functional dynamics. However, this ignores the fundamental role of the rare long-range cortical connections, crucial for improving information processing in the mammalian brain, but not captured by local cortical folding and geometry. Here we show the superiority of harmonics mode combining rare long-range with EDR (EDR+LR) in capturing functional dynamics (specifically long-range functional connectivity and task-evoked brain activity) compared to geometry and EDR representations. Importantly, the orchestration of dynamics is carried out by a more efficient manifold made up of a low number of fundamental EDR+LR modes. Our results show the importance of long-range connectivity for capturing the complexity of functional brain activity through a low-dimensional manifold shaped by fundamental EDR+LR modes.

The human brain is a complex system, whose activity exhibits flexible and continuous reorganisation across space and time. The decomposition of whole-brain recordings into harmonic modes has revealed a repertoire of gradient-like activity patterns associated with distinct brain functions. However, the way these activity patterns are expressed over time with their changes in various brain states remains unclear. Here, we investigate healthy participants taking the serotonergic psychedelic N, N-Dimethyltryptamine (DMT) with the Harmonic Decomposition of Spacetime (HADES) framework that can characterise how different harmonic modes defined in space are expressed over time. HADES demonstrates significant decreases in contributions across most low-frequency harmonic modes in the DMT-induced brain state. When normalizing the contributions by condition (DMT and non-DMT), we detect a decrease …

Methods:We recruited first-time pregnant women at the end of the second trimester with a complaint of poor sleep. Participants in the music group received standard sleep hygiene advice and were instructed to listen to music daily at bedtime for four weeks. They could choose among six sleep playlists of different genres. Participants randomised to the sleep hygiene group received standard sleep hygiene alone. Primary outcomes were sleep quality measured with the Pittsburgh Sleep Quality Index (PSQI) and insomnia severity measured with the Insomnia Severity Index.Results:Among the 98 participants receiving the online intervention 31 participants in the music group (62%) and 40 participants in the sleep hygiene group (80%) completed the post-measurements. Both groups experienced improved sleep quality during the intervention period (PSQI change-2.10, 95% CI-3.27 to-0.93, p< 0.001) with no significant difference between the groups. Similarly, insomnia symptoms were reduced (ISI change-3.42, 95% CI-5.02 to-1.83, p< 0.001) with no significant difference in the effect. There was a significant difference in the compliance between the groups, with 42% of participants in the music group not implementing the sleep hygiene advice.Discussion:Sleep quality and insomnia severity can be improved in pregnant women with relatively simple interventions like music listening and sleep hygiene advice. These results are in line with previous research, but larger trials are recommended to support introduction into clinical practice.

Maternal prenatal distress (PD), frequently defined as in utero prenatal stress exposure (PSE) to the developing fetus, influences the developing brain and numerous associations between PSE and brain structure have been described both in neonates and in older children. Previous studies addressing PSE-linked alterations in neonates’ brain activity have focused on connectivity analyses from predefined seed regions, but the effects of PSE at the level of distributed functional networks remains unclear. In this study, we investigated the impact of prenatal distress on the spatial and temporal properties of functional networks detected in functional MRI data from 20 naturally sleeping, term-born (age 25.85 ± 7.72 days, 11 males), healthy neonates. First, we performed group level independent component analysis (GICA) to evaluate an association between PD and the identified functional networks. Second, we …

The brain is able to sustain many different states as shown by the daily natural transitions between wakefulness and sleep. Yet, the underlying complex dynamics of these brain states are essentially in non-equilibrium. Here, we develop a thermodynamical formalism based on the off-equilibrium extension of the fluctuation-dissipation theorem (FDT) together with a whole-brain model. This allows us to investigate the non-equilibrium dynamics of different brain states and more specifically to apply this formalism to wakefulness and deep sleep brain states. We show that the off-equilibrium thermodynamical signatures of brain states are significantly different in terms of the overall level of differential and integral violation of FDT. Furthermore, the framework allows for a detailed understanding of how different brain regions and networks are contributing to the off-equilibrium signatures in different brain states. Overall, this framework shows great promise for characterising and differentiating any brain state in health and disease.