Current biology : CB
April 12, 2021
Karen R Konkoly, Kristoffer Appel, Emma Chabani et al.
126 citations
People who are asleep and having a lucid dream—aware that they are dreaming—can perceive questions from an experimenter and answer them in real time using eye movements and facial muscle contractions. In a study of 36 individuals during REM sleep, including frequent lucid dreamers, a novice, and a patient with narcolepsy, participants performed perceptual analysis of new information, held information in working memory, computed simple answers, and gave volitional replies. Correct answers occurred on 29 occasions across 6 individuals, documented by four independent laboratories. This two-way communication channel allows real-time interrogation of dream cognition and characteristics.
Current biology : CB
December 20, 2021
Aurélie M Stephan, Sandro Lecci, Jacinthe Cataldi et al.
73 citations
Feeling deeply asleep may not align with actual sleep stages. In a study involving 30 participants (20 good sleepers and 10 with sleep misperception), 787 awakenings revealed that good sleepers often perceived their sleep as lightest during the first two hours of NREM sleep, typically seen as the deepest phase. In contrast, those with sleep misperception frequently felt awake and reported lighter REM sleep. High-density EEG data showed that widespread high-frequency power was inversely related to subjective sleep depth, challenging traditional views on deep sleep perception.
Current biology : CB
June 22, 2020
Matthieu Koroma, Célia Lacaux, Thomas Andrillon et al.
34 citations
During REM sleep, the brain flexibly amplifies or suppresses external sounds depending on eye movements. Using EEG to reconstruct speech from brain responses in a multi-talker environment, meaningful speech was amplified over meaningless speech overall. However, at the precise moments of rapid eye movements, meaningful speech was selectively suppressed. This shows that eye movements during REM sleep act as a gate, selectively blocking informative external stimuli while allowing them at other times, resolving a long-standing debate about whether the sleeping brain processes or ignores the outside world.
Current biology : CB
June 9, 2025
Davide Albertini, Maria Del Vecchio, Ivana Sartori et al.
9 citations
Conscious perception of simple touch depends on sustained neural activity in higher-order somatosensory regions, specifically the posterior perisylvian areas. Using human intracortical recordings, tonic responses in these regions showed all-or-nothing patterns at the sensory threshold, remained unchanged whether or not participants reported the stimulus, and most clearly distinguished perceived from non-perceived stimuli. These dynamics may serve as an organizational principle of somatosensory awareness.
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.
Current biology : CB
August 19, 2024
Vincent Courdavault, Nicolas Papon
1 citation
The complete metabolic pathway for the biosynthesis of the psychedelic compound mescaline in the peyote cactus has been deciphered. This discovery suggests that biotechnological strategies could be developed to produce mescaline sustainably, addressing limitations in current knowledge of how medicinal compounds are made in plants.
Current biology : CB
January 5, 2026
Hakan Kucukdereli, Amelia M Douglass
The authors report a mechanism by which the psychedelic drug psilocybin causes acute release of stress hormones, even though it is known to have long-term anti-anxiety effects. This finding suggests that the immediate hormonal stress response may be distinct from the drug's eventual mood benefits.
Current biology : CB
April 21, 2025
Jovin R Jacobs, Adam D Douglass
A tendency to become passive when facing overwhelming challenges is a hallmark of depression. In a zebrafish model of this phenomenon, the antidepressant ketamine promotes long-term improvements in behavioral persistence through a newly discovered mechanism.
Current biology : CB
March 24, 2025
Christopher A Del Negro
Slowly paced breathing, central to practices like yoga and meditation, influences emotions such as anxiety. Neuroscience research in mice has identified a neural circuit connecting the neocortex to the brainstem that modulates breathing and affects anxiety levels.
Current biology : CB
July 2, 2026
Youngjai Park, Younghwa Cha, Hyoungkyu Kim et al.
The human brain's information flow alternates between two dominant modes roughly every 200 milliseconds: a top-down mode where anterior brain regions drive posterior activity, and a bottom-up mode with reverse directionality. These sub-second alternations are most prominent during wakefulness, gradually diminish under anesthesia, and show pathological imbalance in attention-deficit/hyperactivity disorder (ADHD). Simultaneous EEG-fMRI recordings reveal that top-down dynamics coincide with increased activity in higher-order cognitive networks, while bottom-up dynamics correspond to heightened sensory network activity. A connectome-based coupled-oscillator model reproduces these transitions, suggesting they emerge naturally from structural connectivity. Relative phase analysis (RPA) enables tracking these whole-brain dynamics with millisecond precision in real time from electroencephalography.
Current biology : CB
April 20, 2026
Nikhil Bhatla, Kathryn Cheong, Sho Takahashi et al.
After removing the primary visual cortex (V1) in mice, they lose putatively conscious vision only if the dorsolateral geniculate nucleus (dLGN) in the thalamus is also damaged. Suppressing the hippocampus acutely produces blindsight-like behavior, suggesting the hippocampus supports conscious but not unconscious vision in the intact brain. Simultaneous ablation of V1 and the hippocampus causes blindsight-like behavior, while single ablation of either has only minor effects, indicating these two areas can compensate for each other's permanent loss. This reveals a novel form of plasticity supporting conscious vision and positions the hippocampus as a candidate brain area critical for conscious experience.
Current biology : CB
December 1, 2025
Torge Dellert, Henning Balster, Insa Schlossmacher et al.
Conscious auditory perception relies more on sensory brain regions than on widespread fronto-parietal networks. In an fMRI study using a no-report inattentional deafness paradigm, 63 participants performed an auditory distractor task while task-irrelevant sounds were played. Those aware of the sounds showed strong activation in secondary auditory areas (superior temporal gyrus, sulcus, and middle temporal gyrus) and nodes of attention networks. Unaware processing activated only primary auditory regions. Comparing aware and unaware participants, auditory awareness was associated with extensive sensory activation, while fronto-parietal activation was weaker and only detected in Bayesian analysis. This suggests stimulus-specific sensory activity dominates conscious auditory perception.
Current biology : CB
July 12, 2021
Veith Weilnhammer, Merve Fritsch, Meera Chikermane et al.
Inferior frontal cortex plays a causal role in resolving perceptual ambiguities, thereby determining what is consciously experienced. Computational modeling and two fMRI experiments showed that this region detects conflicts caused by ambiguous sensory information. Disrupting inferior frontal cortex activity with transcranial magnetic stimulation slowed the updating of conscious experience in response to such conflicts. These findings indicate that prefrontal cortex is not merely involved in introspection or action but actively contributes to shaping the contents of consciousness.
Current biology : CB
July 26, 2005
John-Dylan Haynes, Geraint Rees
The stream of conscious experience, even when it changes rapidly and spontaneously, can be predicted from brain activity alone. Using binocular rivalry to induce frequent, involuntary shifts in perception without altering what the eyes see, researchers measured brain activity with fMRI. Multivariate pattern analysis of signals from visual cortex accurately tracked participants' reported conscious experience as it fluctuated. Prediction in primary visual cortex relied on eye-based signals, while higher visual areas reflected the color of the percept. Accurate prediction was also possible using signals recorded during stable viewing, showing the method generalizes across conditions and does not depend on motor responses.