Philosophical Transactions of the Royal Society B Biological Sciences
October 11, 2016
Anil K. Seth, Karl Friston
936 citations
Interoception—the perception of internal bodily states—is being reconceptualized through the lens of hierarchical inference in the brain. Bodily states are regulated by autonomic reflexes enslaved by descending predictions from deep generative models of our internal and external environment. This re-conceptualization, termed interoceptive inference, illuminates issues in cognitive and clinical neuroscience, including experiences of selfhood and emotion. The review contextualizes interoception in active Bayesian inference, highlighting its enactivist aspects, the role of uncertainty or precision in neuromodulation, implications for the functional anatomy of the emotional brain, and the role of interoception in shaping a sense of embodied self and feelings. Links are drawn between homeostasis, allostasis, cybernetic predictive control, and predictive processing. The explanatory scope ranges from autism and depression to consciousness.
Philosophical Transactions of the Royal Society B Biological Sciences
July 23, 2012
Ronald S. Duman, Nanxin Li
361 citations
Stress and antidepressant treatments have opposing effects on neurotrophic factors like brain-derived neurotrophic factor in brain regions such as the hippocampus and prefrontal cortex (PFC). Stress reduces these factors, leading to decreased neurogenesis, dendrite length, and spine density, which may contribute to the reduced brain volume seen in depressed patients. Antidepressant treatments can block or reverse this atrophy. A novel rapid-acting antidepressant, ketamine, an NMDA receptor antagonist, rapidly induces synaptogenesis and spine formation in the PFC by stimulating the mammalian target of the rapamycin signaling pathway and increasing synaptic protein synthesis. These effects reverse chronic stress-induced PFC neuron atrophy and correspond to rapid behavioral actions in depression models, identifying new cellular targets for rapid antidepressant actions without ketamine's side effects.
Philosophical Transactions of the Royal Society B Biological Sciences
November 29, 1998
M. E. Raichle
130 citations
A brain-imaging strategy isolates neural correlates of consciousness by examining a cognitive skill—generating verbs for visually presented nouns—before and after practice. Marked qualitative differences in neural circuitry appear between naive and practised states, including both increases and decreases from baseline brain activity.
Philosophical Transactions of the Royal Society B Biological Sciences
March 17, 2014
Randolph Blake, Jan Brascamp, David J. Heeger
102 citations
Binocular rivalry, a phenomenon where perception alternates between two incompatible images presented to each eye, has been used to study the neural correlates of conscious vision. This essay critically examines four key questions about its usefulness: what comparison condition is appropriate, how to separate abolished awareness from inattention, whether findings from rivalry generalize to other perceptual phenomena, and whether neural activity linked to rivalry truly constitutes a neural correlate of consciousness. The authors arrive at skeptical answers to these questions but suggest that a more nuanced use of binocular rivalry can still provide insights into neural dynamics and components of consciousness, including those involved in perceptual decision-making.
Philosophical Transactions of the Royal Society B Biological Sciences
December 13, 2020
Jennifer Windt
56 citations
The conventional view that sleep and wakefulness mark a sharp divide in conscious experience is challenged by recent research showing that mind wandering occupies much of waking life and that dreaming resembles intensified mind wandering. This suggests a continuum of spontaneous experience spanning both states. A conceptual framework distinguishing subtypes of spontaneous thoughts and experiences independently of behavioral state is proposed and applied to findings from dream and mind-wandering research. The argument holds that assessing the relationship between spontaneous experience and sleep or wakefulness requires looking beyond dreams to include dreamless sleep-related experiences. Considering the full range of spontaneous thoughts and experiences reveals variation both within and across behavioral states, undermining the coarse-grained distinction between sleep and waking and their assumed link to conscious states.
Philosophical Transactions of the Royal Society B Biological Sciences
December 13, 2020
Madeleine E. Gross, Anna Smith, Yvette M. Graveline et al.
37 citations
People spend much of their lives engaged in stimulus-independent thoughts (SITs), such as dreaming and waking thoughts not tied to immediate surroundings, which can feel similar to stimulus-dependent thoughts (SDTs) driven by external input. Using a 7-day smartphone-based experience-sampling procedure where participants reported whether their current thoughts were stimulus dependent or independent and rated qualitative aspects like topic jumping, the results show substantial distinctiveness among dreaming, waking SITs, and SDTs, with significant differences between at least two of the three mental states across every measured variable.
Philosophical Transactions of the Royal Society B Biological Sciences
December 13, 2020
Caitlin Mills, Andre Zamani, Rebecca White et al.
27 citations
Abrupt transitions in thought content occur at surprising times but lead to unsurprising content, while wayward transitions occur at surprising times and also lead to surprising content. The authors distinguish these two types using probabilistic and predictive processing concepts, employing transition and occurrence probability metrics. They discuss how these transitions may contribute to mental function and their possible neural implementation.
Philosophical Transactions of the Royal Society B Biological Sciences
December 13, 2020
Flavie Waters, Joseph M Barnby, Jan Dirk Blom
26 citations
Hallucinations, mental imagery, and dreams share a common feature: they are perceptions that occur without matching external stimulation. Historically, medical and psychological sciences have studied these experiences separately, but this review examines their similarities and differences in phenomenology and brain function to unite them within a single framework. Using Edmund Parish's historical work alongside current cognitive, clinical, and computational research, the authors consider how different perspectives can be reconciled to generate new hypotheses for future investigation.
Philosophical Transactions of the Royal Society B Biological Sciences
October 21, 2024
Stefanie Enriquez‐geppert, Jaroslav Krc, Fiachra O'Higgins et al.
5 citations
Executive function deficits, common in psychiatric disorders, may be linked to diminished neural plasticity. A pioneering study tested the feasibility and preliminary efficacy of combining psilocybin with frontal-midline theta neurofeedback (NF) to improve executive functions. Thirty-seven participants were randomized into an experimental group (18) receiving three microdose sessions followed by three psilocybin-assisted NF sessions, and a passive control group (19). NF learning showed a statistical trend for increased frontal-midline theta with a large effect size.
Philosophical Transactions of the Royal Society B Biological Sciences
July 9, 2026
Andrew P. Maurer, Sara Burke, Mary A. Peterson et al.
The brain generates meaning not from isolated regions but as an emergent property of large-scale recurrently connected networks, with the hippocampus playing a central role. The authors propose five principles: network-level emergence, reentrant processing, dynamic stability, grounding and multi-level integration, and context-dependency. They argue that meaning arises from coordinated activity across distributed hubs, bidirectional hippocampal-cortical loops that inform perception with prior experience, attractor-like states that balance stability and flexibility, and the linking of embodied sensorimotor experiences with abstract concepts. The hippocampus dynamically modulates meaning based on task demands, prior knowledge, and emotional states, transforming sensory input into coherent, context-rich meaning across the lifespan.