PLoS ONE
July 23, 2020
Joshua M. Martin, Danyal Wainstein Andriano, Natália Bezerra Mota et al.
41 citations
Dream reports collected after rapid eye movement (REM) sleep are typically longer, more vivid, and more story-like than those from non-REM sleep, but traditional measures may be confounded by report length. By analyzing 133 dream reports from 20 participants as non-semantic directed word graphs, researchers found that REM dream reports have greater connectedness—words recur with longer range—compared to N2 sleep reports. Graph measures predicted dream complexity, with higher connectedness and lower randomness linked to more complex reports. The largest connected component improved models using report length alone for predicting sleep stage and complexity. Graph analysis offers an automated method to complement traditional dream report analysis.
Brain structure & function
April 28, 2026
Saúl Sal-Sarria, Mark Solms, Oliver H Turnbull
The origins of consciousness may lie not in the cerebral cortex but in ancient subcortical systems responsible for affective experience, particularly the ascending arousal networks of the upper brainstem and the periaqueductal gray. These structures sustain wakefulness and imbue it with valence, positioning consciousness as an embodied biological function grounded in feeling rather than higher cognition. From a developmental perspective, these subcortical structures mature relatively early in gestation, suggesting that a primitive form of subjective feeling may emerge during the third trimester, before cortical maturation. This view has ethical implications for debates on fetal pain perception, neonatal care, and treatment of individuals with profound cognitive impairment.
Frontiers in psychology
January 1, 2018
Mark Solms
The article applies the free energy principle to the hard problem of consciousness. It argues that the elemental form of consciousness is affect, located in the upper brainstem via an extended form of homeostasis. This mechanism is formalized as free energy minimization in unpredicted contexts, where decreases in expected uncertainty are felt as pleasure and increases as unpleasure. The work emphasizes why such existential imperatives feel like something to and for an organism.
Journal of integrative neuroscience
June 1, 2014
Mark Solms
A neuropsychoanalytical approach to the hard problem of consciousness prioritizes the subject over objects of consciousness. The subject is the indispensable foundation upon which consciousness of objects is inscribed. Subjective being is not registered in classical exteroceptive modalities; rather, those modalities are registered within subjectivity. Cognitive representations are mental solids embedded in subjectivity, and these solids are no more real than the subjective being they inhabit. Pure subjectivity has content and quality, conventionally described as level of consciousness or wakefulness, but it feels like something to be awake. Affect supplies the subjectivity that underpins all consciousness.