The action observation networks (AON) (or the mirror neuron system) are the neural underpinnings of visuomotor integration and play an important role in motor control. Besides, one of the main functions of the human mirror neuron system is recognition of observed actions and the prediction of its outcome through the comparison with the internal mental motor representation. Previous studies focused on the human mirror neurons (MNs) activation during object-oriented movements observation, therefore intransitive movements observation effects on MNs activity remains relatively (...) little-studied. Moreover, the dependence of MNs activation on the biomechanical characteristics of observed movement and their biological plausibility remained highly underexplored. In this study we proposed that naturalness of observed intransitive movement can modulate the MNs activity. Event-related desynchronization (ERD) of sensorimotor electroencephalography (EEG) rhythms, N400 event-related potentials (ERPs) component and corticospinal excitability were investigated in twenty healthy volunteers during observation of simple non-transitive finger flexion that might be either biomechanically natural or unnatural when finger wriggled out toward the dorsal side of palm. We showed that both natural and unnatural movements caused mu/beta-desynchronization, which gradually increased during the flexion phase and returned to baseline while observation of extension. Desynchronization of the mu-rhythm was significantly higher during observation of the natural movements. At the same time, beta-rhythm was not found to be sensitive to the action naturalness. Also, observation of unnatural movements caused an increased amplitude of the N400 component registered in the centro-parietal regions. We suggest that the sensitivity of N400 to intransitive action observation with no explicit semantic context might imply the broader role of N400 sources within AON. Surprisingly, no changes in corticospinal excitability were found. This lack of excitability modulation by action observation could be related with dependence of the M1 activity on the observed movement phase. (shrink)

A paradigm shift in the human chronotoxicity of xenobiotics would study two‐sided desynchronized phenomena of interfacial interactions between cyclic or periodic environmental insults and the endogenous response and recovery profile. These systems‐based networks are under the influence of well‐synchronized biological clocks and their metabolic regulators. This perspective argues in favor of addressing the concept of synchronization in studies involving critical life windows of susceptibility, or circadian rhythms, or 24‐hour (periodic) diurnal rhythms and answering whether these disruptions in synchronization would affect (...) response and recovery or disease phenotypes associated with environmental insults, e.g., xenobiotics. Synchronization or synchrony is defined as the totality of elements that appear during the same time period within a system, including the network of interactions between the system's elements. Desynchronized interfaces during critical life windows or in time‐repeated exposure events would likely lead to initiating a cascade of adverse health effects associated with differentiated disease phenotypes. (shrink)

Event-related desynchronization, as a proxy for mirror neuron activity, has been used as a neurophysiological marker for motor execution after mirror visual feedback. Using EEG, this study investigated ERD upon the immediate effects of single-session MVF in unimanual arm movements compared with the ERD effects occurring without a mirror, in two groups: stroke patients with left hemiplegia and their healthy counterparts. During EEG recordings, each group performed one session of mirror therapy training in three task conditions: with a mirror, (...) with no mirror, and with a covered mirror. An asymmetry index was calculated from the subtraction of the event-related spectrum perturbations between the C3 and C4 electrodes located over the sensorimotor cortices contralateral and ipsilateral to the moved arm. Results of the effect of task versus group in contralateral and ipsilateral motor areas showed that there was a significant effect of task condition at the contralateral motor area in the high beta band at C3. High beta ERD showed that the suppression was greater over the contralateral hemisphere than it was over the ipsilateral hemisphere in both study groups. The magnitude of low beta ERD in patients with stroke was more suppressed in contralesional C3 under the no mirror compared to that of the covered mirror and similarly more suppressed in ipsilesional C4 ERD under the no mirror compared to that of the mirror condition. The correlation analysis revealed that the magnitude of ERSP power correlated significantly with arm severity in the low and high beta bands in patients with stroke, and a higher asymmetry index in the low beta band was associated with higher arm functioning under the no-mirror condition. There was a shift in sensorimotor ERD toward the contralateral hemisphere as induced by MVF accompanying unimanual movement in both stroke patients and healthy controls. The use of ERD in the low beta band as a neurophysiological marker to indicate the relationships between the amount of MVF-induced ERD attenuation and motor severity, and the outcome indicator for improving stroke patients’ neuroplasticity in clinical trials using MVF are warranted to be explored in the future. (shrink)

Due to the individual differences controlling brain-computer interfaces, the applicability and accuracy of BCIs based on motor imagery are limited. To improve the performance of BCIs, this article examined the effect of transcranial electrical stimulation on brain activity during MI. This article designed an experimental paradigm that combines tES and MI and examined the effects of tES based on the measurements of electroencephalogram features in MI processing, including the power spectral density and dynamic event-related desynchronization. Finally, we investigated the (...) effect of tES on the accuracy of MI classification using linear discriminant analysis. The results showed that the ERD of the μ and β rhythms in the left-hand MI task was enhanced after electrical stimulation with a significant effect in the tDCS group. The average classification accuracy of the transcranial alternating current stimulation group and transcranial direct current stimulation group were improved significantly compared to the pre-and pseudo stimulation groups. These findings indicated that tES can improve the performance and applicability of BCI and that tDCS was a potential approach in regulating brain activity and enhancing valid features during noninvasive MI-BCI processing. (shrink)

In the field of psychology, it has been well established that there are two types of motor imagery such as kinesthetic motor imagery (KMI) and visual motor imagery (VMI), and the subjective evaluation for vividness of motor imagery each differs across individuals. This study aimed to examine how the motor imagery ability assessed by the psychological scores is associated with the physiological measure using electroencephalogram (EEG) sensorimotor rhythm during KMI task. First, 20 healthy young individuals evaluated subjectively how vividly they (...) can perform each of KMI and VMI by using the Kinesthetic and Visual Imagery Questionnaire (KVIQ). We assessed their motor imagery abilities by summing each of KMI and VMI scores in KVIQ (KMI total and VMI total ). Second, in physiological experiments, they repeated two strengths (10 and 40% of maximal effort) of isometric voluntary wrist-dorsiflexion. Right after each contraction, they also performed its KMI. The scalp EEGs over the sensorimotor cortex were recorded during the tasks. The EEG power is known to decrease in the alpha-and-beta band (7–35 Hz) from resting state to performing state of voluntary contraction (VC) or motor imagery. This phenomenon is referred to as event-related desynchronization (ERD). For each strength of the tasks, we calculated the maximal peak of ERD during VC, and that during its KMI, and measured the degree of similarity (ERD sim ) between them. The results showed significant negative correlations between KMI total and ERD sim for both strengths ( p total, the smaller the ERD sim ). These findings suggest that in healthy individuals with higher motor imagery ability from a first-person perspective, KMI efficiently engages the shared cortical circuits corresponding with motor execution, including the sensorimotor cortex, with high compliance. (shrink)

The potential benefits of priming intermittent theta burst stimulation with continuous theta burst stimulation have not been examined in regard to sensorimotor oscillatory activities recorded in electroencephalography. The objective of this study was to investigate the modulatory effect of priming iTBS delivered to the motor cortex on movement-related and mirror visual feedback -induced sensorimotor event-related desynchronization, compared with iTBS alone, on healthy adults. Twenty participants were randomly allocated into Group 1: priming iTBS—cTBS followed by iTBS, and Group 2: non-priming (...) iTBS—sham cTBS followed by iTBS. The stimulation was delivered to the right primary motor cortex daily for 4 consecutive days. EEG was measured before and after 4 sessions of stimulation. Movement-related ERD was evaluated during left-index finger tapping and MVF-induced sensorimotor ERD was evaluated by comparing the difference between right-index finger tapping with and without MVF. After stimulation, both protocols increased movement-related ERD and MVF-induced sensorimotor ERD in high mu and low beta bands, indicated by significant time effects. A significant interaction effect favoring Group 1 in enhancing movement-related ERD was observed in the high mu band [F = 4.47, p = 0.049], compared with Group 2. Our experiment suggests that among healthy adults priming iTBS with cTBS delivered to the motor cortex yields similar effects with iTBS alone on enhancing ERD induced by MVF-based observation, while movement-related ERD was more enhanced in the priming iTBS condition, specifically in the high mu band. (shrink)

Autism spectrum disorders (ASD) are thought to result in part from altered cortical excitatory-inhibitory balance; this pathophysiology may impact the generation of oscillations on EEG. We investigated premotor-parietal cortical physiology associated with praxis, which has strong theoretical and empirical associations with ASD symptomatology. 25 children with high-functioning ASD (HFA) and 33 controls performed a praxis task involving the pantomiming of tool use, while EEG was recorded. We assessed task-related modulation of signal power in alpha and beta frequency bands. Compared with (...) controls, subjects with HFA showed 27% less left central (motor/premotor) beta (18-22 Hz) event-related desynchronization (ERD) (p = 0.030), as well as 24% less left parietal alpha (7-13 Hz) ERD (p = 0.046). Within the HFA group, blunting of central ERD attenuation was associated with impairments in clinical measures of praxis imitation (r = -0.4; p = 0.04) and increased autism severity (r = 0.48; p = 0.016). The modulation of central beta activity is associated, among other things, with motor imagery, which may be necessary for imitation. Impaired imitation has been associated with core features of ASD. Altered modulation of oscillatory activity may be mechanistically involved in those aspects of motor network function that relate to the core symptoms of ASD. (shrink)

Knowledge of the input-output characteristics of various neuronal types is a necessary first step toward an understanding of cellular events related to waking and sleep. In spite of the oversimplification involved, the dichotomy in terms of type I (long-axoned, output) neurons and type II (short-axoned, local) interneurons is helpful in functionally delineating the neuronal circuits involved in the genesis and epiphenomena of waking and sleep states. The possibility is envisaged that cortical interneurons, which are particularly related to higher neuronal activity (...) and have been found in previous experiments to be more active during sleep than during wakefulness, might be involved in complex integrative processes occurring during certain sleep stages. Electrophysiological criteria for the identification of output cells and interneurons are developed, with emphasis on various possibilities and difficulties involved in recognizing interneurons of the mammalian brain. The high-frequency repetitive activity of interneurons is discussed, together with various possibilities of error to be avoided when interpreting data from bursting cells. Data first show opposite changes in spontaneous and evoked discharges of identified output cells versus putative interneurons recorded from motor and parietal association cortical areas in behaving monkeys and cats during wakefulness (W) compared to sleep with synchronized EEG activity (S): significantly increased rates of spontaneous firing, enhanced antidromic or synaptic responsiveness, associated with shorter periods of inhibition in type I (pyramidal tract, cortico-thalamic and cortico-pontine) cells during W versus significantly decreased frequencies of spontaneous discharge and depression of synaptically elicited reponses of type II cells during W compared to S. These findings are partly explained on the basis of recent iontophoretic studies showing that acetylcholine, viewed as a synaptic transmitter of the arousal system, excites output-type neurons and inhibits high-frequency bursting cells. Comparing W and S to the deepest stage of sleep with desynchronized EEG activity (D) in type I and type II cells revealed that: (a) the increased firing rates of output cells in D, over those in W and S, is substantially due to a tonic excitation during this state, and rapid eye movements (REMs) only contribute to the further increase of discharge frequencies; (b) in contrast, the increased rates of discharge in interneurons during D is entirely ascribable to REM-related firing. On the basis of experiments reporting that increased duration of D has beneficial effects upon retention of information acquired during W, the suggestion is made that increased firing rates of association cortical interneurons during REM epochs of D sleep are an important factor in maintaining the soundness of a memory trace. (shrink)

Peter Goldie’s account of grief as a narrative process that unfolds over time allow us to address the structure of self-understanding in the experience of loss. Taking up the Goldie’s idea that narrativity plays a crucial role in grief, I will argue that the experience of desynchronization and an altered relation to language disrupt even of our ability to compose narratives and to think narratively. Further, I will argue that Goldie’s account of grief as a narratively structured process focus (...) on the process having come to an end. By contrast, I will propose the idea that grief can be understood as an open-ended rehearsal of our capacity to be alone in the company of an absent other. This makes grief a relational activity that differs from composing narratives about one’s past and about one’s process of grieving. Thus, grief is not primarily a process of recollecting our past narratively; rather, it can be seen as a dedicational activity which involves a future-oriented and open-ended rehearsal of relatedness despite irrevocable absence. (shrink)

Despite its complex experiential structure, the phenomenon of grief following bereavement has not been a major topic of phenomenological research. The paper investigates its basic structures, elaborating as its core characteristic a conflict between a presentifying and a ‘de-presentifying’ intention: In grief, the subject experiences a fundamental ambiguity between presence and absence of the deceased, between the present and the past, indeed between two worlds he lives in. This phenomenological structure will be analyzed under several aspects: regarding bodily experience, as (...) disruption of a shared intercorporeality; as a loss of the shared world and shared habitualities, leaving the bereaved person with ubiquitous indications of absence and with a contraction of their own self; regarding temporality, as a separation of two strands of time, namely a still ongoing past and an alienated present which become more and more desynchronized; finally, as an “as-if presence” of the deceased which the bereaved continue to feel and sometimes to perceive, leading to a cognitive-affective conflict between two experienced realities. The transforming process of grief is then analyzed as a gradual adjustment to the loss, finally enabling a re-integration of the conflicting realities. This is achieved through an incorporation and identification with the deceased on the one hand, and through various forms of representation on the other hand, in particular by recollection and symbolization. (shrink)

In “Melancholia, temporal disruption, and the torment of being both unable to live and unable to die”, I discuss the way in which the temporal desynchronization of melancholia can disrupt the melancholic’s relation to their own death and, on a Heideggerian interpretation, the meaning and significance of their life. In their thoughtful commentaries, Kevin Aho and Gareth Owen draw out some important points for further elaboration and clarification, the most pressing of which invoke Heidegger’s interpretation of time and the (...) radical temporalities of fundamental attunements. As Aho anticipates, this is the conception of time that underpins my interpretation of melancholia and, because this is important... (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Philosophy, Psychiatry, & Psychology 12.3 (2005) 195-198 [Access article in PDF] Implicit and Explicit Temporality Thomas Fuchs Keywords implicit/explicit temporality, embodiment, intersubjectivity, desynchronization, melancholia, schizophrenia Since Minkowski (1970), Strauss (1966), v. Gebsattel (1954), and Tellenbach (1980), temporality has been a main subject of phenomenological psychiatry. Drawing on philosophical concepts of Bergson, Husserl, and Heidegger, these authors have analyzed psychopathologic deviations of time experience, mainly from an individual point (...) of view, for example, as a slowing down or inhibition of lived time in depression or obsessive–compulsive disorder. Their analyses are still most valuable today, but may be carried further by introducing concepts such as embodied and intersubjective temporality into psychopathology. Martin Wyllie (2005), by opening up a wide scope of temporal phenomena and related concepts, makes a laudable effort to contribute to such a progress.In my commentary, I would like to propose a distinction that is suggested by much of Wyllie's analysis and may shed further light on psychopathology, namely between implicit and explicit temporality. If we look at a child while obliviously playing with his toys, lost to the world, we may assume that there is no sense of the time passing. Lived time runs with the movement of life, implicit in the child's experience of being engaged in his play and directed toward his goals. It "unfolds through the processes of bodily activity" (Wyllie 2005). Future and past do not stand out against the pure presence of "becoming." This implicit mode of temporality is retrieved every time that we are absorbed in what we are doing, and may even reach the climax of "flow experiences" (Csikszentmihalyi 1988) where the sense of time is lost in unimpeded, fluent performance.However, this changes when a gap arises between need and satisfaction, desire and fulfillment, or plan and execution. Now the future appears as a "not yet" or "yet to come," experienced as the temporality of awaiting, striving, or longing for. Time is felt as passing by and refusing the desired fulfillment; it becomes conscious or explicit. A similar gap arises between the present and something irretrievably lost, bringing the past to consciousness as a "no more." Again time is experienced explicitly, but now as moving on relentlessly and separating us from the lost object. The gap to the past may not be bridged any more: this is the temporality of missing or mourning. In both cases, explicit time arises as a negation of implicit or lived time (here my use of the term is a bit divergent from Wyllie's); it is experienced as a "not yet" or "no more," often with a component of displeasure or suffering (Fuchs 2001a, 2003)."Implicit" versus "explicit time" thus come near to another distinction well known in phenomenology, namely between the "lived" and [End Page 195] the "corporal body" (Leib versus Koerper). The first term refers to the body functioning in the tacit mode, as the medium of everyday performance. The second term points to the body as turning into the object of attention, for example, when it puts up resistance to our purposes, or is used as an instrument deliberately (Fuchs 2001b). In fact, implicit temporality and tacit performance of the body are nearly synonymous: Lived time may be regarded as a function of the lived body, opened up by its potentiality and capability. The more we are engaged in our tasks, the more we forget time as well as the body; we are, as it were, "inside time." On the other hand, in explicit temporality the body often appears in the corporal or explicit mode as well. For example, when falling ill, we experience our body no more as a tacit medium but rather as an object or obstacle, while we notice the slowing down of time and may even feel excluded from the movement of life. Thus, embodiment and temporality have a parallel background–foreground structure.I now try to carry these considerations further by including the intersubjective dimension of time. In an earlier paper, I describe the attunement of the living being to its environment as a continuous synchronization on the biological as... (shrink)

Motor imagery is often used inducing changes in electroencephalographic (EEG) signals for imagery-based brain-computer interfacing (BCI). A BCI is a device translating brain signals into control signals providing severely motor-impaired persons with an additional, non-muscular channel for communication and control. In the last years, there is increasing interest using BCIs also for healthy people in terms of enhancement or gaming. Most studies focusing on improving signal processing feature extraction and classification methods, but the performance of a BCI can also be (...) improved by optimizing the user’s control strategies, e.g., using more vivid and engaging mental tasks for control. We used multichannel EEG to investigate neural correlates of a sports imagery task (playing tennis) compared to a simple motor imagery task (squeezing a ball). To enhance the vividness of both tasks participants performed a short physical exercise between two imagery sessions. EEG was recorded from 60 closely spaced electrodes placed over frontal, central, and parietal areas of 30 healthy volunteers divided in two groups. Whereas Group 1 (EG) performed a physical exercise between the two imagery sessions, Group 2 (CG) watched a landscape movie without physical activity. Spatiotemporal event-related desynchronization (ERD) and event-related synchronization (ERS) patterns during motor imagery (MI) tasks were evaluated. The results of the EG showed significant stronger ERD patterns in the alpha frequency band (8–13 Hz) during MI of tennis after training. Our results are in evidence with previous findings that MI in combination with motor execution has beneficial effects. We conclude that sports MI combined with an interactive game environment could be a future promising task in motor learning and rehabilitation improving motor functions in late therapy processes or support neuroplasticity. (shrink)

The article examines the concept of utopia in its post-Marxist context. Since the 1970s—against the backdrop of the failures of May 68, the self-exposures of the USSR, and the decline of the workers’ movement, as well as in accordance with the immanent history of the logic of the history of philosophy itself—the concept of utopia has been running through new areas of meaning and is extremely dialectical in two modes: temporal and ontological. The first transforms utopia from never-being into “past”, (...) the second provides two inversions, considering it as 1) a dystopia, the other of utopia, which is declared to be the hidden truth of utopia; and — when it is fundamentally possible according to its own concept — 2) as impossible, in connection with which utopia and its concept return to the discourse as a kind of empty place around which modern pessimism circles, correctly believing that the future is unimaginable. The time of ends, from the end of the grand narratives of disappointed radicals (Lyotard) to the end of politics (see Rancière’s analysis), is, however, picked up by Marcuse, who suggests considering utopia as ahistorical. The author introduces this strange ahistorical or even anti-historicalism as historical, relying on the conceptualized phenomenon of the desynchronization of the “base” (the development of productive forces to the degree necessary for social revolution) and the “superstructure”, which runs into a limit, since it cannot represent the restrained base, which has broken out of the formational “scientific” logic. When Marcuse writes that a utopia in the strict sense can now be called a project that violates the laws of nature, he means the “impossible” into which utopia turns after the catastrophes of the 20th century, betraying the truth of its concept contained in the simple possibility of another world. More than 50 years after “The End of Utopia” and almost 30 years after the ontological turn in philosophy, we can say that utopia is still unimaginable — in the strict sense is what violates the laws of logic. This thesis opens up the possibilities of a new dialectic and its alliance with transcendentalism, which the author considers as a critique of plastic reason in the spirit of Malabou, constructing time and time again the assumptions-concepts that it needs and which are “practically necessary” according to Kant. (shrink)

Melancholia is an attunement of despair and despondency that can involve radical disruptions to temporal experience. In this article, I extrapolate from the existing analyses of melancholic time to examine some of the important existential implications of these temporal disruptions. In particular, I focus on the way in which the desynchronization of melancholic time can complicate the melancholic’s relation to death and, consequently, to the meaning and significance of their life. Drawing on Heidegger’s distinction between death and demise, I (...) argue that melancholic time leaves the melancholic in an impossible state of existing, where they are both unable to live and unable to die. Turning to the role of the physician, I consider the significant role that clinical interventions might have in resynchronizing the melancholic with time and examine these ideas further through a case study on physician-assisted suicide. In so doing, I demonstrate that the desynchronization of melancholic time should indeed be understood as a matter of life and death. (shrink)

While robot-assisted arm and hand training after stroke allows for intensive task-oriented practice, it has provided only limited additional benefit over dose-matched physiotherapy up to now. These rehabilitation devices are possibly too supportive during the exercises. Neurophysiological signals might be one way of avoiding slacking and providing robotic support only when the brain is particularly responsive to peripheral input. We tested the feasibility of three-dimensional robotic assistance for reach-to-grasp movements with a multi-joint exoskeleton during motor imagery-related desynchronization of sensorimotor (...) oscillations in the β-band only. We also registered task-related network changes of cortical functional connectivity by electroencephalography via the imaginary part of the coherence function. Healthy subjects and stroke survivors showed similar patterns – but different aptitudes – of controlling the robotic movement. All participants in this pilot study with nine healthy subjects and two stroke patients achieved their maximum performance during the early stages of the task. Robotic control was significantly higher and less variable when proprioceptive feedback was provided in addition to visual feedback, i.e. when the orthosis was actually attached to the subject’s arm during the task. A distributed cortical network of task-related coherent activity in the θ-band showed significant differences between healthy subjects and stroke patients as well as between early and late periods of the task. Brain-robot interfaces may successfully link three-dimensional robotic training to the participants’ efforts and allow for task-oriented practice of activities of daily living with a physiologically controlled multi-joint exoskeleton. Changes of cortical physiology during the task might also help to make subject-specific adjustments of task difficulty and guide adjunct interventions to facilitate motor learning for functional restoration. (shrink)

Everyday conversation requires listeners to quickly recognize verbal actions, so-called speech acts, from the underspecified linguistic code and prepare a relevant response within the tight time constraints of turn-taking. The goal of this study was to determine the time-course of speech act recognition by investigating oscillatory EEG activity during comprehension of spoken dialog. Participants listened to short, spoken dialogs with target utterances that delivered three distinct speech acts (Answers, Declinations, Pre-offers). The targets were identical across conditions at lexico-syntactic and phonetic/prosodic (...) levels but differed in the pragmatic interpretation of the speech act performed. Speech act comprehension was associated with reduced power in the alpha/beta bands just prior to Declination speech acts, relative to Answers and Pre-offers. In addition, we observed reduced power in the theta band during the beginning of Declinations, relative to Answers. Based on the role of alpha and beta desynchronization in anticipatory processes, the results are taken to indicate that anticipation plays a role in speech act recognition. Anticipation of speech acts could be critical for efficient turn-taking, allowing interactants to quickly recognize speech acts and respond within the tight time frame characteristic of conversation. The results show that anticipatory processes can be triggered by the characteristics of the interaction, including the speech act type. (shrink)

Female sex steroids can affect the motor system, modulating motor cortex excitability as well as performance in dexterity and coordination tasks. However, it has not yet been explored whether FSS affects the cognitive components of motor behavior. Mu is a sensorimotor rhythm observed by electroencephalography in alpha and beta frequency bands in practices such as motor imagery and action observation. This rhythm represents a window for studying the activity of neural circuits involved in motor cognition. Herein we investigated whether the (...) alpha-mu and beta-mu power in the sensorimotor region and the alpha and beta power over frontal, parietal, and occipital regions are modulated differently in the menstrual, follicular, and luteal phases of menstrual cycles in right-handed dominant women. To do so, these women underwent MI and AO in the three menstrual cycle phases. The spectral activity of the cortical regions for the alpha and beta bands were compared between phases of the menstrual cycle and a correlation analysis was also performed in relation to estrogen and progesterone levels. For the hypothesis-based approach, beta-mu event-related desynchronization was significantly stronger in the C3 channel in the follicular phase than in the menstrual and luteal phases. For the data-driven approach, beta ERD during MI was higher in the follicular phase than in the menstrual and luteal phases in the frontal region. These findings suggest the effect of FSS on executive movement control. No effect of menstrual cycle phases was observed in cortical areas investigated during OA, but alpha and beta bands correlated positively with the follicular phase plasma estradiol level. Thus, the attenuation of alpha and beta bands referring to mirror neuron activities appears to be associated with inhibition of cortical activity when estradiol levels are lower, improving cognitive processing of motor action. (shrink)

Time is an essential feature in bipolar disorder (BP). Manic and depressed BP patients perceive the speed of time as either too fast or too slow. The present article combines theoretical and empirical approaches to integrate phenomenological, psychological, and neuroscientific accounts of abnormal time perception in BP. Phenomenology distinguishes between perception of inner time, ie, self-time, and outer time, ie, world-time, that desynchronize or dissociate from each other in BP: inner time speed is abnormally slow (as in depression) or fast (...) (as in mania) and, by taking on the role as default-mode function, impacts and modulates the perception of outer time speed in an opposite way, ie, as too fast in depression and too slow in mania. Complementing, psychological investigation show opposite results in time perception, ie, time estimation and reproduction, in manic and depressed BP. Neuronally, time speed can be indexed by neuronal variability, ie, SD. Our own empirical data show opposite changes in manic and depressed BP (and major depressive disorder [MDD]) with abnormal SD balance, ie, SD ratio, between somatomotor and sensory networks that can be associated with inner and outer time. Taken together, our combined theoretical-empirical approach demonstrates that desynchronization or dissociation between inner and outer time in BP can be traced to opposite neuronal variability patterns in somatomotor and sensory networks. This opens the door for individualized therapeutic “normalization” of neuronal variability pattern in somatomotor and sensory networks by stimulation with TMS and/or tDCS. (shrink)

Dr. Vukov analyzing patients with disorders of consciousness, proposed that medical well-regarded policy recommendations cannot be justified by looking solely to patients’ actual levels of consciousness (minimally conscious state – MCS versus vegetative state – VS), but that they can be justified by looking to patients’ potential for consciousness. One objective way to estimate this potential (actual physical possibility) is to consider a neurophysiologically informed strategy. Ideally such strategy would utilize objective brain activity markers of consciousness/unconsciousness. The Operational Architectonics (OA) (...) theory of brain-mind functioning is an example of such a strategy. Besides being mathematically simple, neurophysiologically accurate, and compatible with the cognitive/phenomenal perspectives on consciousness, application of OA strategy to quantitative EEG analysis of patients in VS and MCS revealed that the absence of consciousness in VS is paralleled by impairment of overall EEG operational architecture. Specifically, neuronal assemblies become smaller, their life span shortened, and they became highly unstable and functionally disconnected (desynchronized). At the same time, fluctuating (minimal) awareness in patients in MCS was paralleled by partial restoration of EEG operational architecture (increased size, life span, and stability of neuronal assemblies, together with an increased number and strength of functional connections among them), approaching the level found in healthy fully conscious participants. Moreover OA strategy to EEG analysis allowed predicting the emergence of consciousness in VS patients after six years following the brain trauma. Therefore, the OA methodology could reliably predict which patients may regain consciousness, and thus determine which patients may have the potential for consciousness. (shrink)

We show that dynamical clustering, where a system segregates into distinguishable subsets of synchronized elements, and chimera states, where differentiated subsets of synchronized and desynchronized elements coexist, can emerge in networks of globally coupled robust-chaos oscillators. We describe the collective behavior of a model of globally coupled robust-chaos maps in terms of statistical quantities and characterize clusters, chimera states, synchronization, and incoherence on the space of parameters of the system. We employ the analogy between the local dynamics of a system (...) of globally coupled maps with the response dynamics of a single driven map. We interpret the occurrence of clusters and chimeras in a globally coupled system of robust-chaos maps in terms of windows of periodicity and multistability induced by a drive on the local robust-chaos map. Our results show that robust-chaos dynamics does not limit the formation of cluster and chimera states in networks of coupled systems, as it had been previously conjectured. (shrink)

Objective: Atypical patterns of language lateralization due to early reorganizational processes constitute a challenge in the pre-surgical evaluation of patients with pharmaco-resistant epilepsy. There is no consensus on an optimal analysis method used for the identification of language dominance in MEG. This study examines the concordance between MEG source localization of beta power desynchronization and fMRI with regard to lateralization and localization of expressive and receptive language areas using a visual verb generation task.Methods: Twenty-five patients with pharmaco-resistant epilepsy, including (...) six patients with atypical language lateralization, and ten right-handed controls obtained MEG and fMRI language assessment. Fourteen patients additionally underwent the Wada test. We analyzed MEG beta power desynchronization in sensor (controls) and source space (patients and controls). Beta power decrease between 13 and 35 Hz was localized applying Dynamic Imaging of Coherent Sources Beamformer technique. Statistical inferences were grounded on cluster-based permutation testing for single subjects.Results: Event-related desynchronization of beta power in MEG was seen within the language-dominant frontal and temporal lobe and within the premotor cortex. Our analysis pipeline consistently yielded left language dominance with high laterality indices in controls. Language lateralization in MEG and Wada test agreed in all 14 patients for inferior frontal, temporal and pari... (shrink)

EEGs were analyzed to investigate the effect of experiences in listening to preferred music in dancers and non-dancers. Participants passively listened to instrumental music of their preferred genre for 2 min, alternate genres, and silence. Both groups showed increased activity for their preferred music compared to non-preferred music in the gamma, beta, and alpha frequency bands. The results suggest all participants' conscious recognition of and affective responses to their familiar music, appreciation of the tempo embedded in their preferred music and (...) emotional arousal, and enhanced attention mechanism for cognitive operations such as memory retrieval. The observed alpha activity is considered in the framework of the alpha functional inhibition hypothesis, in that years of experience listening to their favorite type of music may have honed the cerebral responses to achieve efficient cortical processes. Analyses of the electroencephalogram activity over 100s-long music pieces revealed a difference between dancers and non-dancers in the magnitude of an initial alpha event-related desynchronization and the later development of an alpha event-related synchronization for their preferred music. Dancers exhibited augmented alpha ERD, as well as augmented and uninterrupted alpha ERS over the remaining 80s. This augmentation in dancers is hypothesized to be derived from creative cognition or motor imagery operations developed through their dance experiences. (shrink)

The hypnosis technique is currently used in the medical field and influences directly the patient's state of relaxation, perception of the body and its visual imagination. There is evidence to suggest that hypnosis state may help patients to better achieve the task of motor imagination, which is central in rehabilitation protocols after a stroke. However, the hypnosis technique could also alter the activity in motor cortex. To the best of our knowledge, the impact of hypnosis on the EEG signal during (...) a movement or an imagined movement is poorly investigated. In particular, how event-related desynchronization (ERD) and event-related synchronization (ERS) patterns would be modulated for different motor tasks may provide a better understanding of the potential benefits of hypnosis for stroke rehabilitation. To investigate this purpose, we recorded EEG signals from 23 healthy volunteers who performed real movements and motor imageries in closed eye condition. Our results suggest that the state of hypnosis changes the sensorimotor beta rhythm during the ERD phase but maintains the ERS phase in the mu and beta frequency band suggesting a different activation of the motor cortex in the hypnotized state. (shrink)

The process of urban landmark-based navigation has proven to be difficult to study in a rigorous fashion, primarily due to confounding variables and the problem of obtaining reliable data in real-world contexts. The development of high-resolution, immersive virtual reality technologies has opened exciting new possibilities for gathering data on human wayfinding that could not otherwise be readily obtained. We developed a research platform using a virtual environment and electroencephalography to better understand the neural processes associated with landmark usage and recognition (...) during urban navigation tasks. By adjusting the architectural parameters of different buildings in this virtual environment, we isolated and tested specific design features to determine whether or not they served as a target for landmarking. EEG theta band event-related synchronization/desynchronization over posterior scalp areas was evaluated at the time when participants observed each target building along a predetermined self-paced route. A multi-level linear model was used to investigate the effects of salient architectural features on posterior scalp areas. Our results support the conclusion that highly salient architectural features—those that contrast sharply with the surrounding environment—are more likely to attract visual attention, remain in short-term memory, and activate brain regions associated with wayfinding compared with non-salient buildings. After establishing this main aggregate effect, we evaluated specific salient architectural features and neural correlates of navigation processing. The buildings that most strongly associated extended gaze time, location recall accuracy, and changes in theta-band neural patterns with landmarking in our study were those that incorporated rotational twist designs and natural elements such as trees and gardens. Other building features, such as unusual façade patterns or building heights, were to a lesser extent also associated with landmarking. (shrink)

Healthcare workers who are on the front line of coronavirus disease 2019 and are also undergoing shift schedules face long work hours with few pauses, experience desynchronization of their circadian rhythm, and an imbalance between work hours effort and reward in saving lives, resulting in an impact on work capacity, aggravated by the lack of personal protective equipment, few resources and precarious infrastructure, and fear of contracting the virus and contaminating family members. Some consequences are sleep deprivation, chronic insomnia, (...) stress-related sleep disorders, and post-traumatic stress disorder. These sleep alterations critically affect mental health, precipitating or perpetuating anxiety, stress, and depression, resulting in the inability to regulate positive and negative emotions. Pre-existing sleep disorders are an important risk factor for the development and maintenance of PSTD when individuals are exposed to an important stressor such as a COVID-19 pandemic. At the same time, how an individual regulates the emotion associated with worries during daytime functioning impacts nighttime sleep, precipitating and perpetuating difficulties in sleeping. All of these changes in sleep and emotional regulation also alter the immune system. Sleep deprivation is commonly associated with chronic inflammatory diseases, due to the desynchronizations in circadian rhythms, causing possible psychophysiological disorders and impaired neuroimmune-endocrine homeostasis. From this perspective, we clarify in this article how sleep disorders affect the immune system and emotional regulation, explaining their phenomenological and neurobiological mechanisms, and discussing elements of cognitive and behavioral coping for health professionals to adopt and manage a healthier sleep pattern in the COVID-19 outbreak. (shrink)

BackgroundTo probe the functional role of brain oscillations, transcranial alternating current stimulation has proven to be a useful neuroscientific tool. Because of the excessive tACS-caused artifact at the stimulation frequency in electroencephalography signals, tACS + EEG studies have been mostly limited to compare brain activity between recordings before and after concurrent tACS. Critically, attempts to suppress the artifact in the data cannot assure that the entire artifact is removed while brain activity is preserved. The current study aims to evaluate the (...) feasibility of specific artifact correction techniques to clean tACS-contaminated EEG data.New MethodIn the first experiment, we used a phantom head to have full control over the signal to be analyzed. Driving pre-recorded human brain-oscillation signals through a dipolar current source within the phantom, we simultaneously applied tACS and compared the performance of different artifact-correction techniques: sine subtraction, template subtraction, and signal-space projection. In the second experiment, we combined tACS and EEG on one human subject to demonstrate the best-performing data-correction approach in a proof of principle.ResultsThe tACS artifact was highly attenuated by SSP in the phantom and the human EEG; thus, we were able to recover the amplitude and phase of the oscillatory activity. In the human experiment, event-related desynchronization could be restored after correcting the artifact.Comparison With Existing MethodsThe best results were achieved with SSP, which outperformed sine subtraction and template subtraction.ConclusionOur results demonstrate the feasibility of SSP by applying it to a phantom measurement with pre-recorded signal and one human tACS + EEG dataset. For a full validation of SSP, more data are needed. (shrink)

Auditory scene analysis is critical for complex auditory processing. We study auditory segregation from the neural network perspective, and develop a framework for primitive auditory scene analysis. The architecture is a laterally coupled two‐dimensional network of relaxation oscillators with a global inhibitor. One dimension represents time and another one represents frequency. We show that this architecture, plus systematic delay lines, can in real time group auditory features into a stream by phase synchrony and segregate different streams by desynchronization. The (...) network demonstrates a set of psychological phenomena regarding primitive auditory scene analysis, including dependency on frequency proximity and the rate of presentation, sequential capturing, and competition among different perceptual organizations. We offer a neurocomputational theory—shifting synchronization theory—for explaining how auditory segregation might be achieved in the brain, and the psychological phenomenon of stream segregation. Possible extensions of the model are discussed. (shrink)

The chronologic age classically used in demography is often unable to give useful information about which exact stage in development or aging processes has reached an organism. Hence, we propose here to explain in some applications for what reason the chronologic age fails in explaining totally the observed state of an organism, which leads to propose a new notion, the biological age. This biological age is essentially determined by the number of divisions before the Hayflick’s limit the tissue or mitochondrion (...) in a critical organ (in the sense where its loss causes the death of the whole organism) has already used for its development and adult phases. We give a precise definition of the biological age of an organ based on the Hayflick’s limit of its cells and we introduce a desynchronization index (the cell entropy) for some critical tissues or membranes, which are mainly skin, intestinal endothelium, alveoli epithelium and mitochondrial inner membrane. In these actively metabolising interface tissues or membranes, there is a rapid turnover of cells, of their cytoplasmic constituents such as proteins, and of membrane lipids. The boundaries corresponding to these tissues, cells or membranes have vital functions of interface with the environment (protection, homeothermy, nutrition and respiration) and have a rapid turnover (the total cell renewal time is in mice equal to 3 weeks for the skin, 1.5 day for the intestine, 4 months for the alveolae and 11 days for mitochondrial inner membrane) conditioning their biological age. The biological age of a tissue is made of two major components: (1) first, its embryonic age based on the distance (in number of divisions) between the birth date of its first differentiated cell and the time until it reaches its final boundary at the end of its development and (2) second, its adult age whose complement until its death is just the lapse of time made of the sum of remaining cell cycle durations authorized by its Hayflick’s limit. From this definition, we calculate the global biological lifespan of an organism and revisit notions like demographic survival curves, duration and synchrony of cell cycles, living boundaries from proto-cells to organs, and embryonic and adult phases duration. (shrink)

Introduction: Advantageous effects of biological motion detection, a low-perceptual mechanism that allows the rapid recognition and understanding of spatiotemporal characteristics of movement via salient kinematics information, can be amplified when combined with motor imagery, i.e., the mental simulation of motor acts. According to Jeannerod’s neurostimulation theory, asynchronous firing and reduction of mu and beta rhythm oscillations, referred to as suppression over the sensorimotor area, are sensitive to both MI and action observation of BM. Yet, not many studies investigated the use (...) of BM stimuli using combined AO-MI tasks. In this study, we assessed the neural response in the form of event-related synchronization and desynchronization patterns following the observation of point-light-walkers and concordant MI, as compared to MI alone.Methods: Twenty right-handed healthy participants accomplished the experimental task by observing BM stimuli and subsequently performing the same movement using kinesthetic MI. We recorded an electroencephalogram with 32 channels and performed time-frequency analysis on alpha and beta frequency bands during the MI task. A two-way repeated-measures ANOVA was performed to test statistical significance among conditions and electrodes of interest.Results: The results revealed significant ERD/S patterns in the alpha frequency band between conditions and electrode positions. Post hoc comparisons showed significant differences between condition 1 and condition 3 over the left primary motor cortex. For the beta band, a significantly less difference in ERD patterns was detected only between condition 3 and condition 4.Discussion: Our results confirmed that the observation of BM combined with MI elicits a neural suppression, although just in the case of jumping. This is in line with previous findings of AO and MI eliciting a neural suppression for simulated whole-body movements. In the last years, increasing evidence started to support the integration of AOMI training as an adjuvant neurorehabilitation tool in Parkinson’s disease.Conclusion: We concluded that using BM stimuli in AOMI training could be promising, as it promotes attention to kinematic features and imitative motor learning. (shrink)

In the context of a parametric theory (with the time being a dynamical variable) we consider here the coupling between the quantum vacuum and the background gravitation that pervades the universe (unavoidable because of the universality and long range of gravity). We show that this coupling, combined with the fourth Heisenberg relation, would break the parametric invariance of the gravitational equations, introducing thus a difference between the marches of the atomic and the astronomical clocks. More precisely, they would be progressively (...) and adiabatically desynchronized with respect to one another in such a way that the latter would lag behind the former. This would produce a discrepancy between gravitational theory and observations, which use astronomical and atomic time respectively. It turns out that this result, surprising at it might be, is fully compatible with current physics, since it does not conflict with any known physical law or principle. We argue that this phenomenon must be studied, since it could have cosmological consequences. (shrink)

For scene analysis, it is important to ask the question of how synchronized population codes – the basic representation employed in the target article – are generated. Recent computational advances have resolved the critical challenges of rapid synchronization with local coupling and rapid desynchronization. The synchronized codes make real contributions to tackling the problem of scene analysis.

Graphical AbstractThe variable photoperiods of Northern latitudes challenge the entrainment capacity of the circadian pacemaker, which evolved under constant photoperiods in Equatorial regions. Entrainment to the erratic photoperiods facilitated by artificial light presents an additional challenge. Metabolic dysfunction and obesity are potential consequences of such desynchronization of circadian and environmental rhythms.

Using delay differential equations to study mathematical models of Parkinson's disease and Huntington's disease is important to show how important it is for synchronization between basal ganglia loops to work together. We used the delay circuit RLC (resistor, inductor, capacitor) model to show how the direct pathway and the indirect pathway in the basal ganglia excite and inhibit the motor cortex, respectively. A term has been added to the mathematical model without time delay in the case of the hyperdirect pathway. (...) It is proposed to add a non-linear term to adjust the synchronization. We studied Hopf bifurcation conditions for the proposed models. The desynchronization of response times between the direct pathway and the indirect pathway leads to different symptoms of Parkinson's disease. Tremor appears when the response time in the indirect pathway increases at rest. The simulation confirmed that tremor occurs and the motor cortex is in an inhibited state. The direct pathway can increase the time delay in the dopaminergic pathway, which significantly increases the activity of the motor cortex. The hyperdirect pathway regulates the activity of the motor cortex. The simulation showed bradykinesia occurs when we switch from one movement to another that is less exciting for the motor cortex. A decrease of GABA in the striatum or delayed excitation of the substantia nigra from the subthalamus may be a major cause of Parkinson's disease. An increase in the response time delay in one of the pathways results in the chaotic movement characteristic of Huntington's disease. (shrink)

It follows from the temporal nature of mind—the main concern of this essay—that mind functions are not localized in brain space.“ Time is extendedness, probably of the mind itself”, concludes Saint Augustine in Book XI of his Confessions (26.33), and, in our days, this extendedness can be made visible through an oscilloscopic “line” or trace of slow potentials. These graded, additive (not all-or-none) autorhythmic and seemingly self-generating potentials are primary events recorded at synapses. Autorhythmic brain structures (Zabara, 1973) appear to (...) be the source of time frames, while a change in time frames (as reflected in the EEG) leads to synchronization and desynchronization of brain structures respectively. Synchronization forms a homogeneous time domain, such as obtained during rhythmic exercises, chanting, listening to music and mental processes that are the hallmark of religious practices (Rogers, 1973). Desynchronization of brain structures on the other hand marks a functional independence of neuronal elements with each element available for separate channels of data processing, for example, during hallucinogenic drug-induced central sympathetic arousal, that is, a waking dream state (Fischer, 1979). (shrink)

The aim of this paper is to study the temporal de-synchronization that occurs, within the European Union (EU), between technological innovations in Artificial Intelligence and its legal regulations. To do that, I base on a thesis formulated by Hartmut Rosa, a German sociologist close to the Critical Theory of society, according to which the temporal structures of politics are no longer compatible with the pace of change in some others social spheres. This produces a new form of social pathology, which (...) Rosa calls "risks of de-synchronisation", and whose most worrying effect must be sought in the displacement of decision-making processes from the political sphere to faster areas of society, fundamentally the market. To analyze this problem, I first reconstruct the thesis of desynchronization as a social pathology derived from acceleration. Then, I map the AI legislation process at EU level. Finally, I defend the thesis that this legislative process, which is certainly very admirable, has consistently come too late. El objetivo de este trabajo es estudiar el desajuste temporal que se produce, dentro de la Unión Europea (UE), entre las innovaciones tecnológicas en materia de Inteligencia Artificial y sus regulaciones jurídicas. Para ello se parte de una tesis formulada por Hartmut Rosa, sociólogo alemán cercano a la Teoría Crítica de la sociedad, de acuerdo con la cual las estructuras temporales de la política no resultan hoy ya compatibles con el ritmo de cambio de algunas esferas sociales. Esto produce una nueva forma de patología social, que Rosa denomina “riesgos de la desincronización”, y cuyo efecto más preocupante hay que buscar en el desplazamiento de los procesos de toma de decisiones desde el ámbito de la política hacia otros ámbitos de la sociedad más rápidos, fundamentalmente el mercado. Para analizar esta problemática se reconstruye, en primer lugar, la tesis de la desincronización como patología social derivada de la aceleración. Tras ello, se hace un mapeo del proceso de legislación en materia de IA a nivel de la UE. Por último, se defiende la tesis de que este proceso legislativo, ciertamente muy admirable, ha llegado sistemáticamente tarde. (shrink)

Extant research on design thinking is subjective and limited. This manuscript combines protocol analysis and electroencephalogram to read design thoughts in the core design activities of concept generation phase. The results suggest that alpha band power had event related synchronization in the scenario task and divergent thinking occupies a dominant position. However, it had event related desynchronization in analogy and inference activities, etc., and it is stronger for mental pressure and exercised cognitive processing. In addition, the parietooccipital area differs (...) significantly from other brain areas in most design activities. This study explores the relationship of different design thinking and EEG data, which is innovative and professional in the field of design, providing a more objective data basis and evaluation method for future applied research and diverse educational practices. (shrink)

ABSTRACTThe political impact of “social acceleration” has recently attracted much attention in sociology and political theory. The concept, however, has remained entirely unexplored in the discipline of history. Although numerous British historians have noted the prominent position of acceleration in the late‐Victorian and Edwardian imagination, these observations have never expanded beyond the realm of rhetorical flourish. The present paper attempts to build a two‐way interdisciplinary bridge between British political history and the theories of social acceleration that have been posited in (...) the social sciences, arguing that both British political historians and acceleration theorists have much to gain from further dialogue. (shrink)

Our primary goal was to develop and validate a task that could provide evidence about how humans learn praxis gestures, such as those involving the use of tools. To that end, we created a video-based task in which subjects view a model performing novel, meaningless one-handed actions with kinematics similar to praxis gestures. Subjects then imitated the movements with their right hand. Trials were repeated 6 times to examine practice effects. EEG was recorded during the task. As a control, subjects (...) watched videos of a model performing a well-established (over learned) tool-use gesture. These gestures were also imitated 6 times. Demonstrating convergent validity, EEG measures of task-related cortical activation were similar in topography and frequency between the novel gesture task and the overlearned, praxis gesture task. As in studies assessing motor skill learning with simpler tasks, cortical activation during novel gesture learning decreased as the same gestures were repeated. In the control condition, repetition of overlearned tool-use gestures were also associated with reductions in activation, though to a lesser degree. Given that even overlearned, praxis gestures show constriction of EEG activity with repetition, it is possible that that attentional effects drive some of the repetition effects seen in EEG measures of activation during novel gesture repetition. (shrink)