Publications - Memory, Sleep and Dreams

  • Zebrafish automatic monitoring system for conditioning and behavioral analysis. Scientific Reports

    Here, a fully automatic conditioning and detailed analysis of zebrafish behavior is presented.
  • Cyclic alternation of quiet and active sleep states in the octopus. iScience

    These results suggest that cephalopods have an ultradian sleep cycle analogous to that of amniotes
  • Zebrafish tracking using YOLOv2 and Kalman filter. Scientific Reports

    The results of the algorithm show adequate performances in the trajectories of groups of zebrafish that exhibited rapid movements
  • The entropic tongue: Disorganization of natural language under LSD. Consciousness and Cognition

    We investigated the hypothesis that language produced under the effects of lysergic acid diethylamide (LSD) should exhibit increased entropy and reduced semantic coherence.
  • Dreaming during the Covid-19 pandemic: Computational assessment of dream reports reveals mental suffering related to fear of contagion. PLoS One

    These results corroborate the hypothesis that pandemic dreams reflect mental suffering, fear of contagion, and important changes in daily habits that directly impact socialization.
  • Selective Inhibition of Mirror Invariance for Letters Consolidated by Sleep Doubles Reading Fluency. Current Biology

    Mirror invariance is a visual mechanism that emerges early in human development and that enables a prompt recognition of mirror images.
  • The dream of God: how do religion and science see lucid dreaming and other conscious states during sleep? Frontiers in Psychology

    Teachings from religious traditions around the world offer important insights for scientific researchers today who want to understand the full range of LD phenomenology as it has emerged through history.
  • The history of writing reflects the effects of education on discourse structure: implications for literacy, orality, psychosis and the axial age. Trends In Neuroscience And Education

    The educational pathways of oral and literate traditions are structurally divergent, with a decreasing range of recurrence in the former, and an increasing range of recurrence in the latter. Education is seemingly the driving force underlying discourse maturation
  • Structural differences between REM and non-REM dream reports assessed by graph analysis

    These results indicate that dream reports sampled after REM awakening have on average a larger connectedness compared to those sampled after N2 (i.e. words recur with a longer range), a difference which appears to be related to underlying differences in dream...
  • Verbal Short-Term Memory Underlies Typical Development of “Thought Organization” Measured as Speech Connectedness

    Here we set out to test a longitudinal sample (6–8 years old, n =45, followed for 2 years) to verify whether the LSC is predictive of various memory measures, and whether such relations can explain the correlation with reading.
  • Portable devices to induce lucid dreams — are they reliable?

    One of the main current challenges in lucid dreaming (LD) research is to develop a simple and reliable way to induce it (Stumbrys et al., 2012). This is because, for most people, LD is very pleasurable but also very rare (LaBerge and...
  • Criticality between Cortical States

    Here, using both new and publicly available data, we test independent signatures of criticality and show that a phase transition occurs in an intermediate value of spiking variability, in both anesthetized and freely moving animals.
  • Hippocampal functional organization: a microstructure of the place cell network encoding space

    Here, we show that in animals confined to a small part of a maze, principal cells in the CA1/CA3 subfields of the dorsal hippocampus immunoreactive (IR) for Zif268 adhere to a ‘cluster-type’ organization.
  • REHAB FUN: an assistive technology in neurological motor disorders rehabilitation of children with cerebral palsy

    We measured attention levels, errors, and time. The REHAB FUN has been shown to be a motivating tool for patients, and through the data acquired, the specialists can direct the treatment in an individualized way so that there are greater effectiveness and...
  • Computational fluid dynamic analysis of physical forces playing a role in brain organoid cultures in two different multiplex platforms

    Here we used computational fluid dynamics (CFD) to simulate two multiplex culture conditions: steering plates on an orbital shaker and the use of a previously described bioreactor.
  • The maturation of speech structure in psychosis is resistant to formal education

    Here we report that a graph-theoretical computational analysis of verbal reports from subjects spanning 6 decades of age and 2 decades of education reveals asymptotic changes over time that depend more on education than age. In typical subjects, short-range recurrence and lexical...
  • Computational models of memory consolidation and long-term synaptic plasticity during sleep

    Research on the neurobiology of sleep and the mechanisms of long-term synaptic plasticity has provided data in support of various theories of how brain activity during sleep affects long-term synaptic plasticity.
  • Non-visual exploration of novel objects increases the levels of plasticity factors in the rat primary visual cortex

    Our results suggest that non-visual exploration induces the activation of immediate-early genes in V1 cortex, which is suggestive of cross-modal processing in this area. Besides, the increase in the number of neurons labeled with pCaKMII may signal a condition promoting synaptic...
  • Recording Day and Night: Advice for New Investigators in the Sleep and Memory Field

    The investigation of the sleep-dependent mechanisms of memory processing and consolidation is largely based on the electrophysiological recording of action potentials (spikes), local field potentials (LFPs), and muscle activity from freely behaving rodents.
  • Post-class naps boost declarative learning in a naturalistic school setting

    Here we assessed the effect of post-class naps on the retention of Science and History curricular contents presented by the regular class teacher to 24 students from 5th grade. Retention was repeatedly measured 3–4 days after content learning, with weekly group randomization...
  • Memory corticalization triggered by REM sleep: mechanisms of cellular and systems consolidation

    This article reviews the plasticity mechanisms triggered by REM sleep, with a focus on the emerging role of kinases and immediate-early genes for the progressive corticalization of hippocampus-dependent memories.
  • Speech structure links the neural and socio-behavioural correlates of psychotic disorders

    We found a canonical correlation linking speech connectedness and i) functional as well as developmentally relevant structural brain markers (degree centrality from resting state functional imaging and cortical gyrification index) ii) psychometric evaluation of thought disorder iii) aspects of cognitive performance (processing...
  • The interpretation of dream meaning: Resolving ambiguity using Latent Semantic Analysis in a small corpus of text

    Computer-based dreams content analysis relies on word frequencies within predefined categories in order to identify different elements in text.
  • Short term changes in the proteome of human cerebral organoids induced by 5-MeO-DMT

    Here we used shotgun mass spectrometry to explore proteomic differences induced by 5-methoxy-N,N-dimethyltryptamine (5-MeO-DMT) on human cerebral organoids. Out of the 6,728 identified proteins, 934 were found differentially expressed in 5-MeO-DMT-treated cerebral organoids.
  • Sleep, Synaptic Plasticity, and Memory

    The mechanisms underlying the intimate connection between sleep and learning are becoming increasingly clear.
  • Electrophysiological evidence that the retrosplenial cortex displays a strong and specific activation phased with hippocampal theta during paradoxical (REM) sleep

    It is widely accepted that cortical neurons are similarly more activated during waking and paradoxical sleep (PS, aka REM) than during slow wave sleep (SWS).
  • Dopamine Modulates Delta-Gamma Phase-Amplitude Coupling in the Prefrontal Cortex of Behaving Rats

    Dopamine release and phase-amplitude cross-frequency coupling (CFC) have independently been implicated in prefrontal cortex (PFC) functioning.
  • Thought disorder measured as random speech structure classifies negative symptoms and schizophrenia diagnosis 6 months in advance

    This analysis relies mostly on connectedness, a structural feature of speech that is anti-correlated with negative symptoms.
  • Coupled variability in primary sensory areas and the hippocampus during spontaneous activity

    The cerebral cortex is an anatomically divided and functionally specialized structure. It includes distinct areas, which work on different states over time.
  • Physiology and assessment as low-hanging fruit for education overhaul

    Physiology and assessment constitute major bottlenecks of school learning among students with low socioeconomic status.
  • Machine Learning Algorithms for Automatic Classification of Marmoset Vocalizations

    In this work, we consider seven different classification algorithms with the goal of finding a robust classifier that can be successfully trained on small datasets.
  • A Naturalistic Assessment of the Organization of Children’s Memories Predicts Cognitive Functioning and Reading Ability

    To explore the relationship between memory and early school performance, we used graph theory to investigate memory reports from 76 children aged 6–8 years. The reports comprised autobiographical memories of events days to years past, and memories of novel images reported immediately...
  • Novel Virtual Environment for Alternative Treatment of Children with Cerebral Palsy

    In this paper, we describe a virtual environment for patients to engage in a playful therapeutic game for neuropsychomotor rehabilitation, based on the experience of the occupational therapy program of the Nucleus for Integrated Medical Assistance (NAMI) at the University of Fortaleza,...
  • Computational Tracking of Mental Health in Youth: Latin American Contributions to a Low-Cost and Effective Solution for Early Psychiatric Diagnosis

    Here, we briefly introduce the problem by reviewing the scarce epidemiological data from Latin America regarding the onset of mental disorders, and discussing the difficulties associated with early diagnosis.
  • Repertoires of Spike Avalanches Are Modulated by Behavior and Novelty

    Esse artigo mostra em ratos que avalanches neuronais variam através do ciclo sono vigília e refletem em alguma medida os comportamentos dos animais. Detectamos a existência de repertórios complexos de padrões de ativação entre neurônios (avalanches) que são construídas na vigília e...
  • Motor Coordination Correlates with Academic Achievement and Cognitive Function in Children

    The relationship between exercise and cognition is an important topic of research that only recently began to unravel.
  • Psychosis and the Control of Lucid Dreaming

    Dreaming and psychosis share important features, such as intrinsic sense perceptions independent of external stimulation, and a general lack of criticism that is associated with reduced frontal cerebral activity.
  • The brave new brain world

    This perspective article discusses current neuroscience topics of utmost interest including the conquest of aging, evidence-based education, the epidemic of psychiatric medication, the prohibition of certain drugs, the resurgence of depth psychology (e.g. psychoanalysis) and the mechanisms underlying consciousness.
  • Can vocal conditioning trigger a semiotic ratchet in marmosets?

    The complexity of human communication has often been taken as evidence that our language reflects a true evolutionary leap, bearing little resemblance to any other animal communication system.
  • Automated analysis of free speech predicts psychosis onset in high-risk youths

    Psychiatry lacks the objective clinical tests routinely used in ther specializations. Novel computerized methods to characterize complex behaviors such as speech could be used to identify and predict sychiatric illness in individuals.
  • D2 dopamine receptor regulation of learning, sleep and plasticity

    Dopamine and sleep have been independently linked with hippocampus-dependent learning.
  • The Psychedelic State Induced by Ayahuasca Modulates the Activity and Connectivity of the Default Mode Network

    The experiences induced by psychedelics share a wide variety of subjective features, related to the complex changes in perception and cognition induced by this class of drugs.
  • Synaptic Homeostasis and Restructuring across the Sleep-Wake Cycle

    Sleep is critical for hippocampus-dependent memory consolidation. However, the underlying mechanisms of synaptic plasticity are poorly understood. The central controversy is on whether long-term potentiation (LTP) takes a role during sleep and which would be its specific effect on memory....
  • Experience-dependent upregulation of multiple plasticity factors in the hippocampus during early REM sleep

    Sleep is beneficial to learning, but the underlying mechanisms remain controversial. The synaptic homeostasis hypothesis (SHY) proposes that the cognitive function of sleep is related to a generalized rescaling of synaptic weights to intermediate levels, due to a passive downregulation of plasticity...
  • The onset of data-driven mental archeology

    How did human consciousness arise, in comparison with that of apes?
  • Graph analysis of verbal fluency test discriminate between patients with Alzheimer’s disease, Mild Cognitive Impairment and normal elderly controls

    This study reports a graph analysis of data generated by the semantic verbal fluency test by cognitively healthy elderly (NC), patients with Mild Cognitive Impairment – subtypes amnestic (aMCI) and amnestic multiple domain (a+mdMCI) - and patients with Alzheimer’s disease (AD).
  • Naps in school can enhance the duration of declarative memories learned by adolescents

    Here we set out to evaluate the influence of daytime naps on the duration of declarative memories learned in school by students of 10–15 years old.
  • Efeitos da administração aguda de quetamina sobre as oscilações eletrofisiológicas da região ca1 hipocampal

  • An investigation of Hebbian phase sequences as assembly graphs

    We investigated action potentials recorded from the adult rat hippocampus and neocortex before, during and after novel object exploration (experimental periods).
  • Undersampled Critical Branching Processes on Small-World and Random Networks Fail to Reproduce the Statistics of Spike Avalanches

    We conclude that undersampled branching-process-like models in these topologies fail to reproduce the statistics of spike avalanches.
  • Neuroscience and education: prime time to build the bridge

    We discuss four specific cases in which neuroscience synergizes with other disciplines to serve education, ranging from very general physiological aspects of human learning such as nutrition, exercise and sleep, to brain architectures that shape the way we acquire language and reading,...
  • Increase in Hippocampal Theta Oscillations during Spatial Decision Making.

    In this study, we investigated to what extent spatial decision making modulates hippocampal theta oscillations when controlling for variations in locomotion speed.
  • Sleep and school education

    Here we review the biological and psychological phenomena underlying the cognitive role of sleep, present the few published studies on sleep and learning that have been performed in schools, and discuss potential applications of sleep to the school setting. Translational research on...
  • Graph analysis of dream reports is especially informative about psychosis

    Dream reports are substantially more informative about the mental state of psychotic subjects than waking reports.
  • Dream characteristics in a Brazilian sample: an online survey focusing on lucid dreaming.

    During sleep, humans experience the offline images and sensations that we call dreams, which are typically emotional and lacking in rational judgment of their bizarreness.
  • Detecting cell assemblies in large neuronal populations

    Here we review three linear methods for the detection of cellassemblies in large neuronal populations that rely on principal and independent component analysis.
  • Ketamine alters oscillatory coupling in the hippocampus

    Network interactions that underlie cognitively relevant oscillatory coupling in the hippocampus are altered upon NMDA receptor blockade by ketamine, a pharmacological model of schizophrenia.
  • Análise de grafos aplicada a relatos de sonhos: ferramenta diagnóstica objetiva e diferencial para psicose esquizofrênica e bipolar.

    Dissertação apresentada ao curso de Pós-Graduação em Neurociências da Universidade Federal do Rio Grande do Norte, como requisito parcial para a obtenção do Grau de Mestre.
  • On High-Frequency Field Oscillations (>100 Hz) and the Spectral Leakage of Spiking Activity

    Our results argue against the idea that all high-frequency LFP activity stems from spike contamination and suggest avoiding defining brain rhythms solely based on frequency range.
  • Differential roles of the dorsal hippocampal regions in the acquisition of spatial and temporal aspects of episodic-like memory

  • Noradrenergic Control of Gene Expression and Long-Term Neuronal Adaptation Evoked by Learned Vocalizations in Songbirds

  • Diferenças Cognitivas entre Homens e Mulheres na Produçao de Associações Livres de Palavras.

  • Comparação entre Sonhos e Psicose: do processamento de memórias aos déficits cognitivos

  • Long-term decrease in immediate early gene expression after electroconvulsive seizures

  • Statistical characterization of an ensemble of functional neural networks

  • Semiotic evolution of toolmaking: the role of symbols for work towards delayed reward.

  • Free secretory component and lactoferrin of human milk inhibit the adhesion of enterotoxigenic Escherichia coli

  • Brain gene regulation by territorial singing in freely ranging songbirds

  • ZENK protein regulation by song in the brain of songbirds

  • Noradrenergic system of the zebra finch brain: Immunocytochemical study of dopamine-?-hydroxylase

  • Toward a Song CodeEvidence for a Syllabic Representation in the Canary Brain

  • An automated system for the mapping and quantitative analysis of immunocytochemistry of an inducible nuclear protein

  • Brain Gene Expression During REM Sleep Depends on Prior Waking Experience

  • Behaviourally driven gene expression reveals song nuclei in hummingbird brain.

  • Gene Expression and Synaptic Plasticity in the Auditory Forebrain of Songbirds.

  • Induction of hippocampal long-term potentiation during waking leads to increased extra-hippocampal zif-268 expression during ensuing rapid-eye-movement sleep.

  • Multielectrode recordings: the next steps.

  • Light-induced Egr-1 expression in the striate cortex of the opossum.

  • Sonho, memória e o reencontro de Freud com o cérebro

  • Long-Lasting Novelty-Induced Neuronal Reverberation during Slow-Wave Sleep in Multiple Forebrain Areas

  • Reverberation, storage, and postsynaptic propagation of memories during sleep

  • Global Forebrain Dynamics Predict Rat Behavioral States and Their Transitions.

  • Seeking the neural code

  • Dopaminergic Control of Sleep-Wake States

  • Processing of tactile information by the hippocampus

  • Novel experience induces persistent sleep-dependent plasticity in the cortex but not in the hippocampus

  • Neuronal Activity in the Primary Somatosensory Thalamocortical Loop Is Modulated by Reward Contingency during Tactile Discrimination

  • Symbols are not uniquely human

  • Baseline hippocampal theta ocscillation speeds correlate with rate of operant task acquisition

  • Downscale or emboss synapses during sleep.

  • Persistent Hyperdopaminergia Decreases the Peak Frequency of Hippocampal Theta Oscillations during Quiet Waking and REM Sleep.

  • A Ocorrência de Sonhos Antecipatórios é Proporcional à Crença em sua Eficácia.

  • Activation of frontal neocortical areas by vocal production in marmosets.

  • Spike Avalanches Exhibit Universal Dynamics across the Sleep-Wake Cycle.

    A unique scale-invariant regime of spike avalanches across all major behaviors.
  • Different kinds of subjective experience during lucid dreaming may have different neural substrates.

  • Sleep and plasticity.

  • Comprehensive Analysis of Tissue Preservation and Recording Quality from Chronic Multielectrode Implants.

  • Theta Phase Modulates Multiple Layer-Specific Oscillations in the CA1 Region.

    The phase of the hippocampal theta rhythm modulates the amplitude of multiple layer-specific oscillations in CA1.
  • Cross-modal responses in the primary visual cortex encode complex objects and correlate with tactile discrimination

    The primary visual cortex can engage in meaningful tactile processing depending on task demand.
  • Seeing with the eyes shut: Neural basis of enhanced imagery following ayahuasca ingestion.

  • In vivo photorelease of GABA in the mouse cortex.

  • Neuronal Assembly Detection and Cell Membership Specification by Principal Component Analysis.

    Here we describe a principal component-based method that is able to (1) identify all cell assemblies present in the neuronal population investigated, (2) determine the number of neurons involved in ensemble activity, (3) specify the precise identity of the neurons pertaining to ...
  • Speech Graphs Provide a Quantitative Measure of Thought Disorder in Psychosis

    Psychosis has various causes, including mania and schizophrenia. Since the differential diagnosis of psychosis is exclusively based on subjective assessments of oral interviews with patients, an objective quantification of the speech disturbances that characterize mania and schizophrenia is in order. In principle, such quantification...
  • Improvement in physiological and psychological parameters after 6 months of yoga practice.pdf