PHASE SYNCHRONIZATION OF NEURONAL NOISE IN MOUSE HIPPOCAMPAL EPILEPTIFORM DYNAMICS

Organized brain activity is the result of dynamical, segregated neuronal signals that may be used to investigate synchronization effects using sophisticated neuroengineering techniques. Phase synchrony analysis, in particular, has emerged as a promising methodology to study transient and frequency-specific coupling effects across multi-site signals. In this study, we investigated phase synchronization in intracellular recordings of interictal and ictal epileptiform events recorded from pairs of cells in the whole (intact) mouse hippocampus. In particular, we focused our analysis on the background noise-like activity (NLA), previously reported to exhibit complex neurodynamical properties. Our results show evidence for increased linear and nonlinear phase coupling in NLA across three frequency bands [theta (4–10 Hz), beta (12–30 Hz) and gamma (30–80 Hz)] in the ictal compared to interictal state dynamics. We also present qualitative and statistical evidence for increased phase synchronization in the theta, beta and gamma frequency bands from paired recordings of ictal NLA. Overall, our results validate the use of background NLA in the neurodynamical study of epileptiform transitions and suggest that what is considered "neuronal noise" is amenable to synchronization effects in the spatiotemporal domain.

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Bilateral Gamma/Delta Transcranial Alternating Current Stimulation Affects Interhemispheric Speech Sound Integration

Journal of Cognitive Neuroscience ◽

10.1162/jocn_a_01498 ◽

2020 ◽

Vol 32 (7) ◽

pp. 1242-1250 ◽

Cited By ~ 1

Author(s):

Basil C. Preisig ◽

Matthias J. Sjerps ◽

Alexis Hervais-Adelman ◽

Anne Kösem ◽

Peter Hagoort ◽

...

Keyword(s):

Auditory Cortex ◽

Phase Synchronization ◽

Speech Sound ◽

Alternating Current ◽

Phase Lag ◽

Disruptive Effect ◽

Phase Coupling ◽

Gamma Frequency ◽

Transcranial Alternating Current Stimulation ◽

Speech Cues

Perceiving speech requires the integration of different speech cues, that is, formants. When the speech signal is split so that different cues are presented to the right and left ear (dichotic listening), comprehension requires the integration of binaural information. Based on prior electrophysiological evidence, we hypothesized that the integration of dichotically presented speech cues is enabled by interhemispheric phase synchronization between primary and secondary auditory cortex in the gamma frequency band. We tested this hypothesis by applying transcranial alternating current stimulation (TACS) bilaterally above the superior temporal lobe to induce or disrupt interhemispheric gamma-phase coupling. In contrast to initial predictions, we found that gamma TACS applied in-phase above the two hemispheres (interhemispheric lag 0°) perturbs interhemispheric integration of speech cues, possibly because the applied stimulation perturbs an inherent phase lag between the left and right auditory cortex. We also observed this disruptive effect when applying antiphasic delta TACS (interhemispheric lag 180°). We conclude that interhemispheric phase coupling plays a functional role in interhemispheric speech integration. The direction of this effect may depend on the stimulation frequency.

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Stimulus-induced visual cortical networks are recapitulated by spontaneous local and interareal synchronization

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1513773113 ◽

2016 ◽

Vol 113 (5) ◽

pp. E606-E615 ◽

Cited By ~ 35

Author(s):

Christopher M. Lewis ◽

Conrado A. Bosman ◽

Thilo Womelsdorf ◽

Pascal Fries

Keyword(s):

Phase Synchronization ◽

Brain Activity ◽

Brain Organization ◽

Neuronal Synchronization ◽

Gamma Frequency ◽

Dorsal Aspect ◽

Visual Areas ◽

Multiple Levels ◽

Visual Cortical ◽

Signal Correlation

Intrinsic covariation of brain activity has been studied across many levels of brain organization. Between visual areas, neuronal activity covaries primarily among portions with similar retinotopic selectivity. We hypothesized that spontaneous interareal coactivation is subserved by neuronal synchronization. We performed simultaneous high-density electrocorticographic recordings across the dorsal aspect of several visual areas in one hemisphere in each of two awake monkeys to investigate spatial patterns of local and interareal synchronization. We show that stimulation-induced patterns of interareal coactivation were reactivated in the absence of stimulation for the visual quadrant covered. Reactivation occurred through both interareal cofluctuation of local activity and interareal phase synchronization. Furthermore, the trial-by-trial covariance of the induced responses recapitulated the pattern of interareal coupling observed during stimulation, i.e., the signal correlation. Reactivation-related synchronization showed distinct peaks in the theta, alpha, and gamma frequency bands. During passive states, this rhythmic reactivation was augmented by specific patterns of arrhythmic correspondence. These results suggest that networks of intrinsic covariation observed at multiple levels and with several recording techniques are related to synchronization and that behavioral state may affect the structure of intrinsic dynamics.

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Stimulus induced visual cortical networks are recapitulated by spontaneous local and inter-areal synchronization

10.1101/021055 ◽

2015 ◽

Author(s):

Christopher Lewis ◽

Conrado Bosmann ◽

Thilo Womelsdorf ◽

Pascal Fries

Keyword(s):

Phase Synchronization ◽

Brain Activity ◽

Brain Organization ◽

Neuronal Synchronization ◽

Gamma Frequency ◽

Co Activation ◽

Visual Areas ◽

Multiple Levels ◽

Visual Cortical ◽

Signal Correlation

Intrinsic covariation of brain activity has been studied across many levels of brain organization. Between visual areas, neuronal activity covaries primarily among portions with similar retinotopic selectivity. We hypothesized that spontaneous inter-areal co-activation is subserved by neuronal synchronization. We performed simultaneous high-density electrocorticographic recordings across several visual areas in awake monkeys to investigate spatial patterns of local and inter-areal synchronization. We show that stimulation-induced patterns of inter-areal co-activation were reactivated in the absence of stimulation. Reactivation occurred through both, inter-areal co-fluctuation of local activity and inter-areal phase synchronization. Furthermore, the trial-by-trial covariance of the induced responses recapitulated the pattern of inter-areal coupling observed during stimulation, i.e. the signal correlation. Reactivation-related synchronization showed distinct peaks in the theta, alpha and gamma frequency bands. During passive states, this rhythmic reactivation was augmented by specific patterns of arrhythmic correspondence. These results suggest that networks of intrinsic covariation observed at multiple levels and with several recording techniques are related to synchronization and that behavioral state may affect the structure of intrinsic dynamics.

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Modifications in the Topological Structure of EEG Functional Connectivity Networks during Listening Tonal and Atonal Concert Music in Musicians and Non-Musicians

Brain Sciences ◽

10.3390/brainsci11020159 ◽

2021 ◽

Vol 11 (2) ◽

pp. 159

Author(s):

Almudena González ◽

Manuel Santapau ◽

Antoni Gamundí ◽

Ernesto Pereda ◽

Julián J. González

Keyword(s):

Topological Structure ◽

Phase Synchronization ◽

Random Network ◽

Small World ◽

Surrogate Data ◽

Musical Structure ◽

Beta Band ◽

Tonal Music ◽

Frequency Bands ◽

Concert Music

The present work aims to demonstrate the hypothesis that atonal music modifies the topological structure of electroencephalographic (EEG) connectivity networks in relation to tonal music. To this, EEG monopolar records were taken in musicians and non-musicians while listening to tonal, atonal, and pink noise sound excerpts. EEG functional connectivities (FC) among channels assessed by a phase synchronization index previously thresholded using surrogate data test were computed. Sound effects, on the topological structure of graph-based networks assembled with the EEG-FCs at different frequency-bands, were analyzed throughout graph metric and network-based statistic (NBS). Local and global efficiency normalized (vs. random-network) measurements (NLE|NGE) assessing network information exchanges were able to discriminate both music styles irrespective of groups and frequency-bands. During tonal audition, NLE and NGE values in the beta-band network get close to that of a small-world network, while during atonal and even more during noise its structure moved away from small-world. These effects were attributed to the different timbre characteristics (sounds spectral centroid and entropy) and different musical structure. Results from networks topographic maps for strength and NLE of the nodes, and for FC subnets obtained from the NBS, allowed discriminating the musical styles and verifying the different strength, NLE, and FC of musicians compared to non-musicians.

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In your phase: neural phase synchronisation underlies visual imagery of faces

Scientific Reports ◽

10.1038/s41598-021-81336-y ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Andrés Canales-Johnson ◽

Renzo C. Lanfranco ◽

Juan Pablo Morales ◽

David Martínez-Pernía ◽

Joaquín Valdés ◽

...

Keyword(s):

Long Range ◽

Visual Imagery ◽

Brain Activity ◽

Neural Connectivity ◽

Frequency Range ◽

Subjective Impression ◽

Gamma Frequency ◽

Gamma Range ◽

Theta Frequency ◽

Socially Relevant

AbstractMental imagery is the process through which we retrieve and recombine information from our memory to elicit the subjective impression of “seeing with the mind’s eye”. In the social domain, we imagine other individuals while recalling our encounters with them or modelling alternative social interactions in future. Many studies using imaging and neurophysiological techniques have shown several similarities in brain activity between visual imagery and visual perception, and have identified frontoparietal, occipital and temporal neural components of visual imagery. However, the neural connectivity between these regions during visual imagery of socially relevant stimuli has not been studied. Here we used electroencephalography to investigate neural connectivity and its dynamics between frontal, parietal, occipital and temporal electrodes during visual imagery of faces. We found that voluntary visual imagery of faces is associated with long-range phase synchronisation in the gamma frequency range between frontoparietal electrode pairs and between occipitoparietal electrode pairs. In contrast, no effect of imagery was observed in the connectivity between occipitotemporal electrode pairs. Gamma range synchronisation between occipitoparietal electrode pairs predicted subjective ratings of the contour definition of imagined faces. Furthermore, we found that visual imagery of faces is associated with an increase of short-range frontal synchronisation in the theta frequency range, which temporally preceded the long-range increase in the gamma synchronisation. We speculate that the local frontal synchrony in the theta frequency range might be associated with an effortful top-down mnemonic reactivation of faces. In contrast, the long-range connectivity in the gamma frequency range along the fronto-parieto-occipital axis might be related to the endogenous binding and subjective clarity of facial visual features.

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Phase synchronization of oscillatory brain activity and the matching of top-down and bottom up visual information

International Journal of Psychophysiology ◽

10.1016/j.ijpsycho.2008.05.414 ◽

2008 ◽

Vol 69 (3) ◽

pp. 162

Author(s):

P. Sauseng

Keyword(s):

Visual Information ◽

Phase Synchronization ◽

Brain Activity ◽

Top Down ◽

Bottom Up ◽

Oscillatory Brain Activity

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Association Between Phase Coupling of Respiratory Sinus Arrhythmia and Slow Wave Brain Activity During Sleep

Frontiers in Physiology ◽

10.3389/fphys.2018.01338 ◽

2018 ◽

Vol 9 ◽

Cited By ~ 3

Author(s):

Kyuichi Niizeki ◽

Tadashi Saitoh

Keyword(s):

Slow Wave ◽

Respiratory Sinus Arrhythmia ◽

Brain Activity ◽

Phase Coupling ◽

Sinus Arrhythmia

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Neural correlates of motion processing through echolocation, source hearing, and vision in blind echolocation experts and sighted echolocation novices

Journal of Neurophysiology ◽

10.1152/jn.00501.2013 ◽

2014 ◽

Vol 111 (1) ◽

pp. 112-127 ◽

Cited By ~ 28

Author(s):

L. Thaler ◽

J. L. Milne ◽

S. R. Arnott ◽

D. Kish ◽

M. A. Goodale

Keyword(s):

Visual Motion ◽

Brain Activity ◽

Region Of Interest ◽

Occipital Cortex ◽

Neural Substrates ◽

Motion Processing ◽

Planum Temporale ◽

Show Evidence ◽

Visual Cortical ◽

Source Motion

We have shown in previous research (Thaler L, Arnott SR, Goodale MA. PLoS One 6: e20162, 2011) that motion processing through echolocation activates temporal-occipital cortex in blind echolocation experts. Here we investigated how neural substrates of echo-motion are related to neural substrates of auditory source-motion and visual-motion. Three blind echolocation experts and twelve sighted echolocation novices underwent functional MRI scanning while they listened to binaural recordings of moving or stationary echolocation or auditory source sounds located either in left or right space. Sighted participants' brain activity was also measured while they viewed moving or stationary visual stimuli. For each of the three modalities separately (echo, source, vision), we then identified motion-sensitive areas in temporal-occipital cortex and in the planum temporale. We then used a region of interest (ROI) analysis to investigate cross-modal responses, as well as laterality effects. In both sighted novices and blind experts, we found that temporal-occipital source-motion ROIs did not respond to echo-motion, and echo-motion ROIs did not respond to source-motion. This double-dissociation was absent in planum temporale ROIs. Furthermore, temporal-occipital echo-motion ROIs in blind, but not sighted, participants showed evidence for contralateral motion preference. Temporal-occipital source-motion ROIs did not show evidence for contralateral preference in either blind or sighted participants. Our data suggest a functional segregation of processing of auditory source-motion and echo-motion in human temporal-occipital cortex. Furthermore, the data suggest that the echo-motion response in blind experts may represent a reorganization rather than exaggeration of response observed in sighted novices. There is the possibility that this reorganization involves the recruitment of “visual” cortical areas.

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Altered effective connectivity in migraine patients during emotional stimuli: a multi-frequency magnetoencephalography study

The Journal of Headache and Pain ◽

10.1186/s10194-021-01379-4 ◽

2022 ◽

Vol 23 (1) ◽

Author(s):

Jing Ren ◽

Qun Yao ◽

Minjie Tian ◽

Feng Li ◽

Yueqiu Chen ◽

...

Keyword(s):

Brain Activity ◽

Effective Connectivity ◽

Temporal Cortex ◽

Primary Headache ◽

Clustering Coefficient ◽

Frequency Range ◽

Emotional Stimuli ◽

Emotional Modulation ◽

Gamma Frequency ◽

Wide Range

Abstract Background Migraine is a common and disabling primary headache, which is associated with a wide range of psychiatric comorbidities. However, the mechanisms of emotion processing in migraine are not fully understood yet. The present study aimed to investigate the neural network during neutral, positive, and negative emotional stimuli in the migraine patients. Methods A total of 24 migraine patients and 24 age- and sex-matching healthy controls were enrolled in this study. Neuromagnetic brain activity was recorded using a whole-head magnetoencephalography (MEG) system upon exposure to human facial expression stimuli. MEG data were analyzed in multi-frequency ranges from 1 to 100 Hz. Results The migraine patients exhibited a significant enhancement in the effective connectivity from the prefrontal lobe to the temporal cortex during the negative emotional stimuli in the gamma frequency (30–90 Hz). Graph theory analysis revealed that the migraine patients had an increased degree and clustering coefficient of connectivity in the delta frequency range (1–4 Hz) upon exposure to positive emotional stimuli and an increased degree of connectivity in the delta frequency range (1–4 Hz) upon exposure to negative emotional stimuli. Clinical correlation analysis showed that the history, attack frequency, duration, and neuropsychological scales of the migraine patients had a negative correlation with the network parameters in certain frequency ranges. Conclusions The results suggested that the individuals with migraine showed deviant effective connectivity in viewing the human facial expressions in multi-frequencies. The prefrontal-temporal pathway might be related to the altered negative emotional modulation in migraine. These findings suggested that migraine might be characterized by more universal altered cerebral processing of negative stimuli. Since the significant result in this study was frequency-specific, more independent replicative studies are needed to confirm these results, and to elucidate the neurocircuitry underlying the association between migraine and emotional conditions.

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