Ce texte a déjà paru le 26 octobre 2015 sur le site de la Max-Planck Gesellschaft. Nous remercions Jean-Paul Vignal de nous l'avoir signalé. Researchers at Max Planck Institute for Empirical Aesthetics in Frankfurt and of New York University have identified how brain rhythms are used to process music, a finding that also contributes to a better understanding of the auditory system. Furthermore, the study suggests that musical training can enhance the functional role of brain rhythms. (...) The - Sciences du vivant – Nouvel article. (shrink)

It remains a dogma in cognitive neuroscience to separate human attention and memory into distinct modules and processes. Here we propose that brain rhythms reflect the embedded nature of these processes in the human brain, as evident from their shared neural signatures: gamma oscillations (30–90 Hz) reflect sensory information processing and activated neural representations (memory items). The theta rhythm (3–8 Hz) is a pacemaker of explicit control processes (central executive), structuring neural information processing, bit by bit, as (...) reflected in the theta-gamma code. By representing memory items in a sequential and time-compressed manner the theta-gamma code is hypothesized to solve key problems of neural computation: (1) attentional sampling (integrating and segregating information processing), (2) mnemonic updating (implementing Hebbian learning), and (3) predictive coding (advancing information processing ahead of the real time to guide behavior). In this framework, reduced alpha oscillations (8–14 Hz) reflect activated semantic networks, involved in both explicit and implicit mnemonic processes. Linking recent theoretical accounts and empirical insights on neural rhythms to the embedded-process model advances our understanding of the integrated nature of attention and memory – as the bedrock of human cognition. (shrink)

A version of this op-ed appeared in print on May 10, 2015, on page SR9 of the New York edition of The New York Times with the headline : “Rhythms of the Brain”. It is also online here. IN 1890, the American psychologist William James famously likened our conscious experience to the flow of a stream. “A ‘river' or a ‘stream' are the metaphors by which it is most naturally described,” he wrote. “In talking of it hereafter, let's (...) call it the stream of thought, consciousness, or subjective life.” - Biologie – Nouvel article. (shrink)

Respiratory rhythms sustain biological life, governing the homeostatic exchange of oxygen and carbon dioxide. Until recently, however, the influence of breathing on the brain has largely been overlooked. Yet new evidence demonstrates that the act of breathing exerts a substantive, rhythmic influence on perception, emotion, and cognition, largely through the direct modulation of neural oscillations. Here, we synthesize these findings to motivate a new predictive coding model of respiratory brain coupling, in which breathing rhythmically modulates both local (...) and global neural gain, to optimize cognitive and affective processing. Our model further explains how respiratory rhythms interact with the topology of the functional connectome, and we highlight key implications for the computational psychiatry of disordered respiratory and interoceptive inference. (shrink)

Brain Mystique Light and Dark bridges the gap between neuroscience, brain evolution and consciousness by examining scientific models of how the brain becomes conscious. The book argues that the spiritual dimension of life is compatible with scientific naturalism. Not bound by conventional stereotypes, Charles Don Keyes safeguards the unity of brain/mind, synthesized from a wide range of sources, reinterprets the triune brain concept and self-reference models of consciousness.

Gamma rhythms are associated with external and internal sensory processing. Within the conceptual framework of “top-down” and “bottom-up” processing, this suggests that gamma represents a format common to both camps. As these oscillations facilitate communication in the temporal domain, they may represent a mechanism by which top-down and bottom-up processing can interact. A breakdown in this interaction may lead to hallucinations.

The aim of this paper is to present a process-based ontology of art following John Dewey’s concepts of experience and rhythm. I will adopt a pragmatist and embodied point of view within an adverbialist framework. I will defend the idea of an artistic way of experiencing – a subtype of aesthetic experience – as something which allows us to assign the ontological category of art to an object or event. The adverbial features of this artistic way of experiencing will be (...) characterized as being rhythmic in nature. This goal will be achieved in three steps. First, I will explain and elaborate on the concept of adverbialism. Second, the importance of rhythm in experience will be taken into account through a close reading of Dewey’s philosophy and by incorporating the nuances of the Pre-Socratic idea of rhuthmos, as well as some recent findings about brain and bodily oscillations from cognitive science. Third, to conclude I will propose four necessary but not sufficient features of the rhythmic engagement enacted while an artistic way of experiencing takes place: a necessary degree of object or event awareness, a positive feedback dynamic, a loosening of the sense of agency, and being attentionally demanding. (shrink)

Crowd behaviour challenges our fundamental understanding of social phenomena. Involving complex interactions between multiple temporal and spatial scales of activity, its governing mechanisms defy conventional analysis. Using 1.5 million Twitter messages from the 15M movement in Spain as an example of multitudinous self-organization, we describe the coordination dynamics of the system measuring phase-locking statistics at different frequencies using wavelet transforms, identifying 8 frequency bands of entrained oscillations between 15 geographical nodes. Then we apply maximum entropy inference methods to describe Ising (...) models capturing transient synchrony in our data at each frequency band. The models show that all frequency bands of the system operate near critical points of their parameter space and while fast frequencies present only a few metastable states displaying all-or-none synchronization, slow frequencies present a diversity of metastable states of partial synchronization. Furthermore, describing the state at each frequency band using the energy of the corresponding Ising model, we compute transfer entropy to characterize cross-scale interactions between frequency bands, showing a cascade of upward information flows in which each frequency band influences its contiguous slower bands and downward information flows where slow frequencies modulate distant fast frequencies. (shrink)

Research in basic and clinical neuroscience of music conducted over the past decades has begun to uncover music’s high potential as a tool for rehabilitation. Advances in our understanding of how music engages parallel brain networks underpinning sensory and motor processes, arousal, reward, and affective regulation, have laid a sound neuroscientific foundation for the development of theory-driven music interventions that have been systematically tested in clinical settings. Of particular significance in the context of motor rehabilitation is the notion that (...) musical rhythms can entrain movement patterns in patients with movement-related disorders, serving as a continuous time reference that can help regulate movement timing and pace. To date, a significant number of clinical and experimental studies have tested the application of rhythm- and music-based interventions to improve motor functions following central nervous injury and/or degeneration. The goal of this review is to appraise the current state of knowledge on the effectiveness of music and rhythm to modulate movement spatiotemporal patterns and restore motor function. By organizing and providing a critical appraisal of a large body of research, we hope to provide a revised framework for future research on the effectiveness of rhythm- and music-based interventions to restore and train motor function. (shrink)

Perception of temporal patterns is fundamental to normal hearing, speech, motor control, and music. Certain types of pattern understanding are unique to humans, such as musical rhythm. Although human responses to musical rhythm are universal, there is much we do not understand about how rhythm is processed in the brain. Here, I consider findings from research into basic timing mechanisms and models through to the neuroscience of rhythm and meter. A network of neural areas, including motor regions, is regularly (...) implicated in basic timing as well as processing of musical rhythm. However, fractionating the specific roles of individual areas in this network has remained a challenge. Distinctions in activity patterns appear between "automatic" and "cognitively controlled" timing processes, but the perception of musical rhythm requires features of both automatic and controlled processes. In addition, many experimental manipulations rely on participants directing their attention toward or away from certain stimulus features, and measuring corresponding differences in neural activity. Many temporal features, however, are implicitly processed whether attended to or not, making it difficult to create controlled baseline conditions for experimental comparisons. The variety of stimuli, paradigms, and definitions can further complicate comparisons across domains or methodologies. Despite these challenges, the high level of interest and multitude of methodological approaches from different cognitive domains (including music, language, and motor learning) have yielded new insights and hold promise for future progress. (shrink)

This commentary centres around the system of human visual attention. Although generally supportive of the position advocated in the target article, we suggest that the detailed account overestimates the capacities of active human vision. Limitations of peripheral search and saccadic accuracy are discussed in relation to the division of labour between covert and overt attentional processes.

Introduction. A radical tendency in modern approaches to understanding the mechanisms of the brain is the tendency of some scientists to believe that the brain is a receptor capable of capturing thoughts; the nature of the occurrence of the thoughts themselves, however, is not to be clarified. However, speech expressing thoughts is undoubtedly the result of the work of the brain, so studies of the frequency structure of speech can be the basis for considering the material structure (...) of the brain as a kind of “antenna”. In this approach, the problem of noise protection against the background of the undeniable frequency similarity of speech and music appears to us from somewhat different positions. This study raises the question of how essential the overall height of the musical system is to the perception of music (are there musical systems that are harmful or useful, in terms of their effects on the psyche). This question is also relevant to speech perception.Methodology and sources. The main sources in which the work of the brain and the essence of consciousness are considered from the positions indicated above were for us the work of American and British neurophysiologists and psychiatrists (Sam Parnia, Peter Fenwick). These scientists are studying the phenomena that accompany clinical death, and argue that at these moments the brain functions to the greatest extent as a receiving “antenna”. Assuming that any antenna is to be tuned, we are trying to identify possible ways to “tune” the brain. To do this, we propose to study the frequency characteristics of speech (in the simplest case, when singing vowels in a calm state) for their belonging to a particular musical system, as well as the peculiarities of music perception depending on the musical system (on the height of the note “la”). Varying the frequency characteristics of speech in a particular musical system can be considered, in our opinion, the main way to “tune” the brain. The methodology of the method is based on the use of frequency analysis of sound and the basic provisions of the elementary theory of music.Results and discussion. The main conclusion made by Western psychiatrists is the brain is not an organ of thought, consciousness exists independently from outside, the work of consciousness cannot be explained by the functioning of the brain – it requires a hardware check. If the neural network is an “antenna” that captures thoughts, and its “adjustment” at the physical level can be carried out (and is carried out) through sensory systems (including the hearing organ), the study of the frequency structure of speech will answer a number of important questions, including including related and higher brain functions (insight, creativity). Our experiments (Saint Petersburg Electrotechnical University, FIBS, department of EUT) showed that the influence of the “increased” or “lowered” musical-speech system on brain activity is insignificant. The study revealed the equiprobability of the frequency structure of speech. Since our brain lacks some characteristic set of frequencies – elements of a uniformly temperamental system, it is not necessary to talk about the harmful (or any other noise) effect of the “raised” and “lowered” systems due to deviation from the “internal standard”.Conclusion. In response to the assumptions made by Western experts, we proposed a frequency interpretation of the processes occurring in the brain, which, perhaps, will explain in more detail such phenomena as inspiration, discovery, etc., which occur with minimal activity of consciousness. Despite the limited methods of hardware study of factors that influence the activity of the brain and largely determine its higher functions (for example, creativity), the results of the brain's work in relation to music (both in terms of its creation and in terms of our reaction to it) are quite analyzable, which was shown in this study. The “musicality” of speech is extremely vividly represented in its frequency structure and allows one to reveal, to one degree or another, the features of the brain. (shrink)

Event-related potentials (ERPs) – neglected almost entirely by Wright & Liley – allow objective investigation of information processing in the brain. The application of chaos theory to such an analysis broadens this possibility. Through the use of the point correlation dimension (PD2) accurate dimensional analysis of different Event-Related Potential components such as the P3 wave is possible.

Previous literature on shooting performance neurofeedback training (SP-NFT) to enhance performance usually focused on changes in behavioral indicators, but research on the physiological features of SP-NFT is lacking. To explore the effects of SP-NFT on trainability and neuroplasticity, we conducted a study in which 45 healthy participants were randomly divided into three groups: based on sensory-motor rhythm of C3, Cz and C4 (SMR group), based on alpha rhythm of T3 and T4 (Alpha group), and no NFT (control group). The training (...) was performed for six sessions for 3 weeks. Before and after the SP-NFT, we evaluated changes in shooting performance and resting electroencephalography (EEG) frequency power, participant’s subjective task appraisal, neurofeedback trainability score, and EEG feature. Statistical analysis showed that the shooting performance of the participants in the SMR group improved significantly, the participants in the Alpha group decreased, and that of participants in the control group have no change. Meanwhile, the resting EEG power features of the two NFT groups changed specifically after training. The training process data showed that the training difficulty was significantly lower in the SMR group than in the Alpha group. Both NFT groups could improve the neurofeedback trainability scores and change the feedback features by means of their mind strategy. These results may provide evidence of trainability and neuroplasticity for SP-NFT, suggesting that the SP-NFT is effective in brain regulation and thus provide a potential method to improve shooting performance. (shrink)

Some 20 years ago Todd and colleagues proposed that rhythm perception is mediated by the conjunction of a sensory representation of the auditory input and a motor representation of the body (Todd, 1994a, 1995 ), and that a sense of motion from sound is mediated by the vestibular system (Todd, 1992a, 1993b ). These ideas were developed into a sensory-motor theory of rhythm and beat induction (Todd et al., 1999 ). A neurological substrate was proposed which might form the biological (...) basis of the theory (Todd et al., 2002 ). The theory was implemented as a computational model and a number of experiments conducted to test it. In the following time there have been several key developments. One is the demonstration that the vestibular system is primal to rhythm perception, and in related work several experiments have provided further evidence that rhythm perception is body dependent. Another is independent advances in imaging, which have revealed the brain areas associated with both vestibular processing and rhythm perception. A third is the finding that vestibular receptors contribute to auditory evoked potentials (Todd et al., 2014a, b ). These behavioral and neurobiological developments demand a theoretical overview which could provide a new synthesis over the domain of rhythm perception. In this paper we suggest four propositions as the basis for such a synthesis. (1) Rhythm perception is a form of vestibular perception; (2) Rhythm perception evokes both external and internal guidance of somatotopic representations; (3) A link from the limbic system to the internal guidance pathway mediates the “dance habit”; (4) The vestibular reward mechanism is innate. The new synthesis provides an explanation for a number of phenomena not often considered by rhythm researchers. We discuss these along with possible computational implementations and alternative models and propose a number of new directions for future research. (shrink)

Training can influence behavioral performance and lead to brain reorganization. In particular, training in one modality, for example, auditory, can improve performance in another modality, for example, visual. Previous research suggests that one of the mechanisms behind this phenomenon could be the cross-modal recruitment of the sensory areas, for example, the auditory cortex. Studying expert musicians offers a chance to explore this process. Rhythm is an aspect of music that can be presented in various modalities. We designed an fMRI (...) experiment in which professional pianists and non-musicians discriminated between two sequences of rhythms presented auditorily or visually. Behavioral results showed that musicians performed in both visual and auditory rhythmic tasks better than non-musicians. We found no significant between-group differences in fMRI activations within the auditory cortex. However, we observed that musicians had increased activation in the right Inferior Parietal Lobe when compared to non-musicians. We conclude that the musicians’ superior visual rhythm discrimination is not related to cross-modal recruitment of the auditory cortex; instead, it could be related to activation in higher-level, multimodal areas in the cortex. (shrink)

Music uses the evolutionarily unique temporal sensitivity of the auditory system and its tight coupling to the motor system to create a common neurophysiological clock between individuals that facilitates action coordination. We propose that this shared common clock arises from entrainment to musical rhythms, the process by which partners' brains and bodies become temporally aligned to the same rhythmic pulse.

The EEG activity recorded from the human sensorimotor cortical area exhibits rhythmic activity covering a broad range of frequencies, including alpha, mu, beta, and gamma (40-Hz) rhythms. This commentary elaborates on connections between these sensorimotor rhythms and Nunez's neocortical dynamic theory.

In chronic schizophrenic patients with both positive and negative symptoms (see Table 1), interhemispheric connections at the high frequency beta2-rhythm are absent during cognitive tasks, in contrast to normal controls, who have many interhemispheric connections at this frequency in the same situation. Connectivity is a fundamental brain feature, evidently greatly promoted by the NMDA system. It is a more reliable measure of brain function than the spectral power of this rhythm.

Mental fatigue (MF) jeopardizes performance and safety through a variety of cognitive impairments and according to the complexity loss theory, should represent “complexity loss” in electroencephalogram (EEG). However, the studies are few and inconsistent concerning the relationship between MF and loss of complexity, probably because of the susceptibility of brain waves to noise. In this study, MF was induced in thirteen male college students by a simulated flight task. Before and at the end of the task, spontaneous EEG and (...) auditory steady-state response (ASSR) were recorded and instantaneous frequency variation (IFV) in alpha rhythm was extracted and analyzed by multiscale entropy (MSE) analysis. The results show that there were significant differences in IFV in alpha rhythm either from spontaneous EEG or from ASSR for all subjects. Therefore, the proposed method can be effective in revealing the complexity loss caused by MF in spontaneous EEG and ASSR, which may serve as a promising analyzing method to mark mild mental impairments. (shrink)

A cross-species perspective can extend and provide testable predictions for Savage et al.'s framework. Rhythm and melody, I argue, could bootstrap each other in the evolution of musicality. Isochrony may function as a temporal grid to support rehearsing and learning modulated, pitched vocalizations. Once this melodic plasticity is acquired, focus can shift back to refining rhythm processing and beat induction.

Lewis emphasizes the role of theta oscillations in emergent coupling among neural subsystems during emotionally relevant tasks or situations. Here I present some recent data on the relationship of rhythmic neuronal discharge in the supramammillary nucleus and the large-scale theta oscillations in the limbic system which provide support to many of his ideas regarding vertical integration in dynamic systems.

Dynamic systems theory offers conceptual andmathematical tools for describing the performance ofneural systems at very different levels oforganization. Three aspects of the dynamic paradigmare discussed, namely neural rhythms, neural andmental development, and macroscopic brain theories andmodels.

Brain states, which correlate with specific motor, cognitive, and emotional states, may be monitored with noninvasive techniques such as electroencephalography and magnetoencephalography that measure macroscopic cortical activity manifested as oscillatory network dynamics. These rhythmic cortical signatures provide insight into the neuronal activity used to identify pathological cortical function in numerous neurological and psychiatric conditions. Sensory and transcranial stimulation, entraining the brain with specific brain rhythms, can effectively induce desired brain states correlated with such cortical (...) class='Hi'>rhythms. Because brain states have distinct neural correlates, it may be possible to induce a desired brain state by replicating these neural correlates through stimulation. To do so, we propose recording brain waves from a “donor” in a particular brain state using EEG/MEG to extract cortical signatures of the brain state. These cortical signatures would then be inverted and used to entrain the brain of a “recipient” via sensory or transcranial stimulation. We propose that brain states may thus be transferred between people by acquiring an associated cortical signature from a donor, which, following processing, may be applied to a recipient through sensory or transcranial stimulation. This technique may provide a novel and effective neuromodulation approach to the noninvasive, non-pharmacological treatment of a variety of psychiatric and neurological disorders for which current treatments are mostly limited to pharmacotherapeutic interventions. (shrink)

We investigate the long-term evolution of degree-degree correlations (assortativity) in functional brain networks from epilepsy patients. Functional networks are derived from continuous multi-day, multi-channel electroencephalographic data, which capture a wide range of physiological and pathophysiological activities. In contrast to previous studies which all reported functional brain networks to be assortative on average, even in case of various neurological and neurodegenerative disorders, we observe large fluctuations in time-resolved degree-degree correlations ranging from assortative to dissortative mixing. Moreover, in some patients (...) these fluctuations exhibit some periodic temporal structure which can be attributed, to a large extent, to daily rhythms. Relevant aspects of the epileptic process, particularly possible pre-seizure alterations, contribute marginally to the observed long-term fluctuations. Nevertheless, our findings suggest that physiological and pathophysiological activity may modify functional brain networks in a different and process-specific way. We evaluate factors that possibly influence the long-term evolution of degree-degree correlations. (shrink)

Besides the pure pleasure of watching a dance performance, dance as a whole-body movement is becoming increasingly popular for health-related interventions. However, the science-based evidence for improvements in health or well-being through dance is still ambiguous and little is known about the underlying neurophysiological mechanisms. This may be partly related to the fact that previous studies mostly examined the neurophysiological effects of imagination and observation of dance rather than the physical execution itself. The objective of this pilot study was to (...) investigate acute effects of a physically executed dance with its different components (recalling the choreography and physical activity to music) on the electrical brain activity and its functional connectivity using electroencephalographic (EEG) analysis. Eleven dance-inexperienced female participants first learned a Modern Jazz Dance (MJD) choreography over three weeks (1 h sessions per week). Afterwards, the acute effects on the EEG brain activity were compared between four different test conditions: physically executing the MJD choreography with music, physically executing the choreography without music, imaging the choreography with music, and imaging the choreography without music. Every participant passed each test condition in a randomized order within a single day. EEG rest-measurements were conducted before and after each test condition. Considering time effects thephysically executed dance without musicrevealed in brain activity analysis most increases in alpha frequency and in functional connectivity analysis in all frequency bands. In comparison,physically executed dance with musicas well asimagined dance with musicled to fewer increases andimagined dance without musicprovoked noteworthy brain activity and connectivity decreases at all frequency bands. Differences between the test conditions were found in alpha and beta frequency betweenthe physically executed danceandthe imagined dance without musicas well as between thephysically executed dance withandwithout musicin the alpha frequency. The study highlights different effects of a physically executed dance compared to an imagined dance on many brain areas for all measured frequency bands. These findings provide first insights into the still widely unexplored field of neurological effects of dance and encourages further research in this direction. (shrink)

The predictable rhythmic structure is important to most ecologically relevant sounds for humans, such as is found in the rhythm of speech or music. This study addressed the question of how rhythmic predictions are maintained in the auditory system when there are multiple perceptual interpretations occurring simultaneously and emanating from the same sound source. We recorded the electroencephalogram (EEG) while presenting participants with a tone sequence that had two different tone feature patterns, one based on the sequential rhythmic variation in (...) tone duration and the other on sequential rhythmic variation in tone intensity. Participants were presented with the same sound sequences and were instructed to listen for the intensity pattern (ignore fluctuations in duration) and press a response key to detected pattern deviants (attend intensity pattern task); to listen to the duration pattern (ignore fluctuations in intensity) and make a button press to duration pattern deviants (attend duration pattern task), and to watch a movie and ignore the sounds presented to their ears (attend visual task). Both intensity and duration patterns occurred predictably 85% of the time, thus the key question involved evaluating how the brain treated the irrelevant feature patterns (standards and deviants) while performing an auditory or visual task. We expected that task-based feature patterns would have a more robust brain response to attended standards and deviants than the unattended feature patterns. Instead, we found that the neural entrainment to the rhythm of the standard attended patterns had similar power to the standard of the unattended feature patterns. In addition, the infrequent pattern deviants elicited the event-related brain potential called the mismatch negativity component (MMN). The MMN elicited by task-based feature pattern deviants had a similar amplitude to MMNs elicited by unattended pattern deviants that were unattended because they were not the target pattern or because the participant ignored the sounds and watched a movie. Thus, these results demonstrate that the brain tracks multiple predictions about the complexities in sound streams and can automatically track and detect deviations with respect to these predictions. This capability would be useful for switching attention rapidly among multiple objects in a busy auditory scene. (shrink)

Leibniz, Husserl and the Brain is about the structural relations between phenomenological and neurophysiological aspects of perception, consciousness and time. Its focus lies with auditory perception, since nearly all perceived qualities in hearing - such as pitch, rhythm and the localization or origin of a sound - are most intimately related to temporal patterns and regularities. Here striking analogies are shown between the structural features of perceptual states, as dealt with in philosophical phenomenology, and of their physical counterparts, as (...) dealt with in neurophysiology. Accordingly, the comprehensive and consolidating references to the work of Leibniz and Husserl are not for philological reasons, but, rather, to work towards philosophical orientation in a conceptual maze. They allow for a fresh view on several issues in contemporary philosophy of mind and also in psychophysics - in particular, on the transition from unconscious to conscious states and on the constitution of time consciousness. (shrink)

Long-term potentiation (LTP) is operationally defined as a long-lasting increase in synaptic efficacy following high-frequency stimulation of afferent fibers. Since the first full description of the phenomenon in 1973, exploration of the mechanisms underlying LTP induction has been one of the most active areas of research in neuroscience. Of principal interest to those who study LTP, particularly in the mammalian hippocampus, is its presumed role in the establishment of stable memories, a role consistent with descriptions of memory formation. Other characteristics (...) of LTP, including its rapid induction, persistence, and correlation with natural brain rhythms, provide circumstantial support for this connection to memory storage. Nonetheless, there is little empirical evidence that directly links LTP to the storage of memories. In this target article we review a range of cellular and behavioral characteristics of LTP and evaluate whether they are consistent with the purported role of hippocampal LTP in memory formation. We suggest that much of the present focus on LTP reflects a preconception that LTP is a learning mechanism, although the empirical evidence often suggests that LTP is unsuitable for such a role. As an alternative to serving as a memory storage device, we propose that LTP may serve as a neural equivalent to an arousal or attention device in the brain. Accordingly, LTP may increase in a nonspecific way the effective salience of discrete external stimuli and may thereby facilitate the induction of memories at distant synapses. Other hypotheses regarding the functional utility of this intensely studied mechanism are conceivable; the intent of this target article is not to promote a single hypothesis but rather to stimulate discussion about the neural mechanisms underlying memory storage and to appraise whether LTP can be considered a viable candidate for such a mechanism. (shrink)

The architecture of brain, consciousness, and behavioral processes is shown to be formally similar in that all three may be conceived and depicted as Petri net patterned processes structured by a series of elements occurring or becoming active in stochastic succession, in parallel, with different rhythms of temporal iteration, and with a distinct qualitative manifestation in the spatiotemporal domain. A patterned process theory is derived from the isomorphic features of the models and contrasted with connectionist, dynamic system notions. (...) This empirically derived formulation is considered to be optimally compatible with the dual aspect theory in that the foundation of the diverse aspects would be a highly structured and dynamic process, the psychophysical neutral “ground” of mind and matter posed (but not properly determined) by dual aspect and neutral monist theories. It is methodologically sound to approach each one of these processes with specific tools and to establish concurrences in real time between them at the organismic level of analysis. Such intra‐level and inter‐perspective correlations could eventually constitute psychophysical bridge‐laws. A mature psychology of consciousness is necessary to situate and verify the bridges required by a genuine mind‐body science. (shrink)

Introduction to mind and brain -- The science and philosophy of mind -- A brief look into brain structure and function -- States of mind -- Signatures of consciousness -- Rhythms of the brain -- Brain synchrony, coherence, and resonance -- Networks of the brain -- Introduction to the hard problem -- Multiscale speculations on the hard problem -- Glossary.

Circadian rhythms in the sleep/wake cycle, along with a range of physiological measures, are severely disrupted in individuals with major depressive disorder (MDD). Moreover, several central circadian genes have been implicated as potential genetic factors underlying the illness through candidate gene studies and some genome wide association studies. However, investigations into the molecular underpinnings of circadian disturbances in the human brain have been quite challenging. In their recent publication, Li and colleagues have used a novel approach to determine (...) the rhythmic patterns of circadian gene expression in several regions of the human brain, and how these patterns are disrupted in MDD. Their findings demonstrate that in healthy subjects, several brain regions outside the suprachiasmatic nucleus (the master clock) exhibit diurnal gene expression patterns that are disrupted in the brains of MDD subjects. These findings will provide the foundation for future studies of gene‐specific drug targets, and biomarkers for the disease. (shrink)

Based on the theoretical analysis of self-consciousness concepts, we hypothesized that the spatio-temporal pattern of functional connectivity within the default-mode network (DMN) should persist unchanged across a variety of different cognitive tasks or acts, thus being task-unrelated. This supposition is in contrast with current understanding that DMN activated when the subjects are resting and deactivated during any attention-demanding cognitive tasks. To test our proposal, we used, in retrospect, the results from our two early studies ([Fingelkurts, 1998] and [Fingelkurts et al., (...) 2003]). In both studies for the majority of experimental trails we indeed found a constellation of operationally synchronized cortical areas (indexed as DMN) that was persistent across all studied experimental conditions in all subjects. Furthermore, we found three major elements comprising this DMN: two symmetrical occipito-parieto-temporal and one frontal spatio-temporal patterns. This new data directly supports the notion that DMN has a specific functional connotation – it provides neurophysiologic basis for self-processing operations, namely first-person perspective taking and an experience of agency. (shrink)

BackgroundPrevious studies suggested a circadian variation of migraine attack onset, although, with contradictory results – possibly because of the existence of migraine subgroups with different circadian attack onset peaks. Migraine is primarily a brain disorder, and if the diversity in daily distribution of migraine attack onset reflects an important aspect of migraine, it may also associate with interictal brain activity. Our goal was to assess brain activity differences in episodic migraine subgroups who were classified according to their (...) typical circadian peak of attack onset.MethodsTwo fMRI studies were conducted with migraine without aura patients (n= 31 in Study 1,n= 48 in Study 2). Among them, three subgroups emerged with typical Morning, Evening, and Varying start of attack onset. Whole brain activity was compared between the groups in an implicit emotional processing fMRI task, comparing fearful, sad, and happy facial stimuli to neutral ones.ResultsIn both studies, significantly increased neural activation was detected to fearful (but not sad or happy) faces. In Study 1, the Evening start group showed increased activation compared to the Morning start group in regions involved in emotional, self-referential (left posterior cingulate gyrus, right precuneus), pain (including left middle cingulate, left postcentral, left supramarginal gyri, right Rolandic operculum) and sensory (including bilateral superior temporal gyrus, right Heschl’s gyrus) processing. While in Study 2, the Morning start group showed increased activation compared to the Varying start group at a nominally significant level in regions with pain (right precentral gyrus, right supplementary motor area) and sensory processing (bilateral paracentral lobule) functions.ConclusionOur fMRI studies suggest that different circadian attack onset peaks are associated with interictal brain activity differences indicating heterogeneity within migraine patients and alterations in sensitivity to threatening fearful stimuli. Circadian variation of migraine attack onset may be an important characteristic to address in future studies and migraine prophylaxis. (shrink)