Current biology : CB
May 5, 2025
Pavlos I Topalidis, Gianpaolo Demarchi, Lisa Reisinger et al.
1 citation
During sleep, the brain retains the ability to preactivate representations of specific sound features, such as tone frequency, but loses the capacity to track higher-order statistical associations between sounds. Using EEG and MEG with multivariate pattern analysis, the study compared brain responses to predictable and random tone sequences during wakefulness and sleep. Feature-specific responses to subtle tone changes were present in N1 and N2 sleep, though weaker than when awake. The brain preactivated feature-specific representations during sleep, but tracking of statistical associations between tones occurred only during wakefulness. This suggests that while some automatic predictive processing of low-level features persists, higher-order anticipation of patterns is disrupted when consciousness fades.
Frontiers in Neuroscience
January 1, 2026
Sabrina Diny, Fabian Schmidt, Andreas Wutz et al.
Mental disorders are a growing challenge for health care systems, and mind-body interventions like mindfulness and relaxation are widely used but their mechanisms are poorly understood. This study protocol describes a planned investigation of regulation during brief mindfulness and relaxation exercises in adults with depression and adults with ADHD. Magnetoencephalography will be combined with heart and breathing measures to capture brain-body interactions during three conditions: mindfulness (body scan), relaxation (safe place imagery), and an auditory control (podcast). Subjective stress and relaxation ratings will be collected. The study aims to advance understanding of how brief mind-body interventions work, supporting future personalized applications.
Proceedings of the National Academy of Sciences of the United States of America
March 31, 2020
Gaëtan Sanchez, Thomas Hartmann, Marco Fuscà et al.
Neural activity in primary sensory regions not directly relevant to a task can predict conscious perception of near-threshold stimulation in a different sensory modality. Using magnetoencephalography and multivariate decoding analysis across tactile, visual, and auditory tasks, supramodal spatiotemporal patterns were identified that predicted conscious perception. These patterns included activity in visual cortex predicting conscious perception of auditory stimuli. The findings were replicated in a control experiment and were independent of the type of report (button press or withholding a button press). The results suggest a common signature of conscious access across sensory modalities, involving temporally late and widespread broadcasting of neural representations.
Neuroimage
June 1, 2016
Lorenzo Magazzini, Philipp Ruhnau, Nathan Weisz
The partial awareness hypothesis proposes that people can become conscious of distinct properties of an object independently, from low-level features to complex forms. In a visual word masking experiment adjusted to each participant's perception threshold, participants perceived individual letters but not whole words in about half of trials, corresponding to partial awareness. Magnetoencephalography (MEG) recordings showed that partial awareness, compared to no awareness, involved suppression of alpha oscillations in left temporal and parietal cortices. Functional connectivity analysis revealed strong connections between the temporal seed and other language network regions. The findings suggest that engagement of language regions, indexed by alpha power suppression, establishes and maintains conscious representations of pre-lexical units.
Scientific Reports
February 11, 2016
Julia Natascha Frey, Philipp Ruhnau, Sabine Leske et al.
Conscious perception of a faint touch depends not only on brain activity in the sensory cortex but also on the state of larger brain networks just before the stimulus arrives. In a magnetoencephalography study, participants performed a near-threshold tactile detection task. Before correctly detected stimuli, alpha and beta power were reduced in the somatosensory region opposite the stimulated hand, and event-related responses were stronger afterward. Graph analysis revealed that the right primary somatosensory cortex showed increased integration in the theta band and decreased integration in the beta band before detection. These findings suggest that a reduction of irrelevant functional connections helps tune neural pathways for conscious perception.
Cerebral cortex (New York, N.Y. : 1991)
December 1, 2015
Sabine Leske, Philipp Ruhnau, Julia Frey et al.
Brain regions crucial for hearing a faint sound are already coupled before the sound arrives, forming pre-established pathways that influence whether the sound is consciously perceived. Using magnetoencephalography and graph theory, the study found that in a near-threshold auditory task, the left auditory cortex behaved like a hub and was more integrated into the brain's functional network prior to conscious perception, while right auditory regions were decoupled from non-auditory areas. Local excitability, measured by decreased alpha power in the auditory cortex, also increased before conscious percepts. These connectivity and excitability states were largely independent of each other.