scholarly journals Photobiological Neuromodulation of Resting-State EEG and Steady-State Visual-Evoked Potentials by 40 Hz Violet Light Optical Stimulation in Healthy Individuals

2021 ◽  
Vol 11 (6) ◽  
pp. 557
Author(s):  
Yoshihiro Noda ◽  
Mayuko Takano ◽  
Motoshi Hayano ◽  
Xuemei Li ◽  
Masataka Wada ◽  
...  
Keyword(s):  
Visual Processing ◽  
Gamma Oscillations ◽  
Electrode Site ◽  
Eeg Activity ◽  
Violet Light ◽  
Gamma Frequency ◽  
Specific Effects ◽  
Spectrum Density ◽  
Healthy Participants ◽  
40 Hz

Photobiological neuromodulation and its clinical application has been investigated in recent years. The response of the gamma-oscillation to human visual stimuli is known to be both burst and resonant in nature, and the coupling between alpha and gamma oscillations may play a functional role in visual processing. To date, there is no study that examined the effects of gamma-frequency violet light (VL) stimulation on human electroencephalography (EEG). In this study, we investigated the neurophysiological changes induced by light stimulation using EEG. The purpose of this study was to evaluate the specific effects of 40 Hz gamma-frequency VL stimulation on EEG activity by comparing the effects of white light (WL) with the same condition. Twenty healthy participants (10 females: 37.5 ± 14.3 years; 10 males: 38.0 ± 13.3 years) participated in this study and the following results were observed. First, when compared with the power spectrum density (PSD) of baseline EEG, 40 Hz-WL induced significant increase of PSD in theta band. Second, compared the PSDs between EEG with 40 Hz-VL and EEG with 40 Hz-WL, 40 Hz-VL induced significantly lower enhancement in delta and theta bands than 40 Hz-WL. Third, when focused on the occipital area, negative peak of VEP with 40 Hz-VL was smaller than that of 40 Hz-WL. Fourth, 40 Hz-VL induced an increase of alpha-gamma coupling during the VEP at the F5 electrode site as well as post-EEG at the C4 electrode site, compared with baseline EEG. Thus, the present study suggested that 40 Hz-VL stimulation may induce unique photobiological neuromodulations on human EEG activity.

scholarly journals Neural network dynamics underlying gamma synchronization deficits in schizophrenia

2020 ◽  
Author(s):  
Daisuke Koshiyama ◽  
Makoto Miyakoshi ◽  
Yash B. Joshi ◽  
Juan L. Molina ◽  
Kumiko Tanaka-Koshiyama ◽  
...  
Keyword(s):  
Steady State ◽  
Neural Circuit ◽  
Gamma Oscillations ◽  
Brain Regions ◽  
Gamma Band ◽  
Causality Analysis ◽  
Response Dynamics ◽  
Gamma Frequency ◽  
Gamma Band Activity ◽  
40 Hz

AbstractGamma band (40-Hz) activity is associated with many sensory and cognitive functions, and is critical for cortico-cortical transmission and the integration of information across neural networks. The capacity to support gamma band activity can be indexed by the auditory steady-state response (ASSR); schizophrenia patients have selectively reduced synchrony to 40-Hz stimulation. While 40-Hz ASSR is a translatable electroencephalographic biomarker with emerging utility for therapeutic development for neuropsychiatric disorders, the spatiotemporal dynamics underlying the ASSR have not yet been characterized. In this study, a novel Granger causality analysis was applied to assess the propagation of gamma oscillations in response to 40-Hz steady-state stimulation across cortical sources in schizophrenia patients (n=426) and healthy comparison subjects (n=293). Results revealed distinct, hierarchically sequenced temporal and spatial response dynamics underlying gamma synchronization deficits in patients. During the response onset interval, patients exhibited abnormal connectivity of superior temporal and frontal gyri, followed by decreased information flow from superior temporal to middle cingulate gyrus. In the later (300–500 ms) interval of the ASSR response, patients showed significantly increased connectivity from superior temporal to middle frontal gyrus followed by broad failures to engage multiple prefrontal brain regions. In conclusion, these findings reveal the rapid disorganization of neural circuit functioning in response to simple gamma-frequency stimulation in schizophrenia patients. Deficits in the generation and maintenance of gamma-band oscillations in schizophrenia reflect a fundamental connectivity abnormality across a distributed network of temporo-frontal networks.

The association of age and aerobic activity history with 40-Hz EEG activity during cognitive challenge

1996 ◽  
Author(s):  
B. Hatfield ◽  
D. Santa Maria ◽  
T. Spalding ◽  
C. Blanchard ◽  
A. Haufler ◽  
...  
Keyword(s):  
Eeg Activity ◽  
Aerobic Activity ◽  
Cognitive Challenge ◽  
40 Hz

scholarly journals Properties of precise firing synchrony between synaptically coupled cortical interneurons depend on their mode of coupling

2015 ◽  
Vol 114 (1) ◽  
pp. 624-637 ◽  
Author(s):  
Hang Hu ◽  
Ariel Agmon
Keyword(s):  
Firing Rate ◽  
Electrical Coupling ◽  
Gamma Oscillations ◽  
Inhibitory Synapses ◽  
Data Set ◽  
Temporal Precision ◽  
Gamma Frequency ◽  
Rate Dependent ◽  
Cortical Interneurons

Precise spike synchrony has been widely reported in the central nervous system, but its functional role in encoding, processing, and transmitting information is yet unresolved. Of particular interest is firing synchrony between inhibitory cortical interneurons, thought to drive various cortical rhythms such as gamma oscillations, the hallmark of cognitive states. Precise synchrony can arise between two interneurons connected electrically, through gap junctions, chemically, through fast inhibitory synapses, or dually, through both types of connections, but the properties of synchrony generated by these different modes of connectivity have never been compared in the same data set. In the present study we recorded in vitro from 152 homotypic pairs of two major subtypes of mouse neocortical interneurons: parvalbumin-containing, fast-spiking (FS) interneurons and somatostatin-containing (SOM) interneurons. We tested firing synchrony when the two neurons were driven to fire by long, depolarizing current steps and used a novel synchrony index to quantify the strength of synchrony, its temporal precision, and its dependence on firing rate. We found that SOM-SOM synchrony, driven solely by electrical coupling, was less precise than FS-FS synchrony, driven by inhibitory or dual coupling. Unlike SOM-SOM synchrony, FS-FS synchrony was strongly firing rate dependent and was not evident at the prototypical 40-Hz gamma frequency. Computer simulations reproduced these differences in synchrony without assuming any differences in intrinsic properties, suggesting that the mode of coupling is more important than the interneuron subtype. Our results provide novel insights into the mechanisms and properties of interneuron synchrony and point out important caveats in current models of cortical oscillations.

scholarly journals Optogenetic gamma stimulation rescues memory impairments in an Alzheimer’s disease mouse model

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Guillaume Etter ◽  
Suzanne van der Veldt ◽  
Frédéric Manseau ◽  
Iman Zarrinkoub ◽  
Emilie Trillaud-Doppia ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Mouse Model ◽  
Spatial Memory ◽  
Gamma Oscillations ◽  
Optogenetic Stimulation ◽  
Phase Amplitude ◽  
Ad Mouse Model ◽  
Parvalbumin Neurons ◽  
Stimulation Of ◽  
40 Hz

AbstractSlow gamma oscillations (30–60 Hz) correlate with retrieval of spatial memory. Altered slow gamma oscillations have been observed in Alzheimer’s disease. Here, we use the J20-APP AD mouse model that displays spatial memory loss as well as reduced slow gamma amplitude and phase-amplitude coupling to theta oscillations phase. To restore gamma oscillations in the hippocampus, we used optogenetics to activate medial septal parvalbumin neurons at different frequencies. We show that optogenetic stimulation of parvalbumin neurons at 40 Hz (but not 80 Hz) restores hippocampal slow gamma oscillations amplitude, and phase-amplitude coupling of the J20 AD mouse model. Restoration of slow gamma oscillations during retrieval rescued spatial memory in mice despite significant plaque deposition. These results support the role of slow gamma oscillations in memory and suggest that optogenetic stimulation of medial septal parvalbumin neurons at 40 Hz could provide a novel strategy for treating memory deficits in AD.

scholarly journals Posterior Alpha and Gamma Oscillations Index Divergent and Superadditive Effects of Cognitive Interference

2019 ◽  
Vol 30 (3) ◽  
pp. 1931-1945 ◽  
Author(s):  
Alex I Wiesman ◽  
Tony W Wilson
Keyword(s):  
Spatial Dynamics ◽  
Irrelevant Stimulus ◽  
Spatial Location ◽  
Cognitive Conflict ◽  
Gamma Oscillations ◽  
Relevant Stimulus ◽  
Cognitive Interference ◽  
Motor Mapping ◽  
Stimulus Response ◽  
Gamma Frequency

Abstract Conflicts at various stages of cognition can cause interference effects on behavior. Two well-studied forms of cognitive interference are stimulus–stimulus (e.g., Flanker), where the conflict arises from incongruence between the task-relevant stimulus and simultaneously presented irrelevant stimulus information, and stimulus-response (e.g., Simon), where interference is the result of an incompatibility between the spatial location of the task-relevant stimulus and a prepotent motor mapping of the expected response. Despite substantial interest in the neural and behavioral underpinnings of cognitive interference, it remains uncertain how differing sources of cognitive conflict might interact, and the spectrally specific neural dynamics that index this phenomenon are poorly understood. Herein, we used an adapted version of the multisource interference task and magnetoencephalography to investigate the spectral, temporal, and spatial dynamics of conflict processing in healthy adults (N = 23). We found a double-dissociation such that, in isolation, stimulus–stimulus interference was indexed by alpha (8–14 Hz), but not gamma-frequency (64–76 Hz) oscillations in the lateral occipital regions, while stimulus–response interference was indexed by gamma oscillations in nearby cortices, but not by alpha oscillations. Surprisingly, we also observed a superadditive effect of simultaneously presented interference types (multisource) on task performance and gamma oscillations in superior parietal cortex.

scholarly journals Genetically predicted complement component 4A expression: effects on memory function and middle temporal lobe activation

2018 ◽  
Vol 48 (10) ◽  
pp. 1608-1615 ◽  
Author(s):  
G. Donohoe ◽  
J. Holland ◽  
D. Mothersill ◽  
S. McCarthy-Jones ◽  
D. Cosgrove ◽  
...  
Keyword(s):  
Visual Processing ◽  
Structural Variation ◽  
Memory Performance ◽  
Memory Function ◽  
Temporal Cortex ◽  
Complement Component ◽  
Cortical Activation ◽  
Rna Expression ◽  
Middle Temporal ◽  
Healthy Participants

AbstractBackgroundThe longstanding association between the major histocompatibility complex (MHC) locus and schizophrenia (SZ) risk has recently been accounted for, partially, by structural variation at the complement component 4 (C4) gene. This structural variation generates varying levels ofC4RNA expression, and genetic information from the MHC region can now be used to predictC4RNA expression in the brain. Increased predictedC4ARNA expression is associated with the risk of SZ, andC4is reported to influence synaptic pruning in animal models.MethodsBased on our previous studies associating MHC SZ risk variants with poorer memory performance, we tested whether increased predictedC4ARNA expression was associated with reduced memory function in a large (n= 1238) dataset of psychosis cases and healthy participants, and with altered task-dependent cortical activation in a subset of these samples.ResultsWe observed that increased predictedC4ARNA expression predicted poorer performance on measures of memory recall (p= 0.016, corrected). Furthermore, in healthy participants, we found that increased predictedC4ARNA expression was associated with a pattern of reduced cortical activity in middle temporal cortex during a measure of visual processing (p< 0.05, corrected).ConclusionsThese data suggest that the effects ofC4on cognition were observable at both a cortical and behavioural level, and may represent one mechanism by which illness risk is mediated. As such, deficits in learning and memory may represent a therapeutic target for new molecular developments aimed at alteringC4’s developmental role.

Role of the occipito-temporal theta rhythm in hand visual identification

2020 ◽  
Vol 123 (1) ◽  
pp. 167-177 ◽  
Author(s):  
Quentin Moreau ◽  
Eleonora Parrotta ◽  
Vanessa Era ◽  
Maria Luisa Martelli ◽  
Matteo Candidi
Keyword(s):  
Visual Processing ◽  
Functional Role ◽  
Pattern Analysis ◽  
Multivariate Pattern Analysis ◽  
Theta Band ◽  
Time Frequency ◽  
Visual Identification ◽  
Multivariate Pattern ◽  
Healthy Participants

Neuroimaging and EEG studies have shown that passive observation of the full body and of specific body parts is associated with 1) activity of an occipito-temporal region named the extrastriate body area (EBA), 2) amplitude modulations of a specific posterior event-related potential (ERP) component (N1/N190), and 3) a theta-band (4–7 Hz) synchronization recorded from occipito-temporal electrodes compatible with the location of EBA. To characterize the functional role of the occipito-temporal theta-band increase during the processing of body-part stimuli, we recorded EEG from healthy participants while they were engaged in an identification task (match-to-sample) of images of hands and nonbody control images (leaves). In addition to confirming that occipito-temporal electrodes show a larger N1 for hand images compared with control stimuli, cluster-based analysis revealed an occipito-temporal cluster showing an increased theta power when hands are presented (compared with leaves) and show that this theta increase is higher for identified hands compared with nonidentified ones while not being significantly different between not identified nonhand stimuli. Finally, single trial multivariate pattern analysis revealed that time-frequency modulation in the theta band is a better marker for classifying the identification of hand images than the ERP modulation. The present results support the notion that theta activity over the occipito-temporal cortex is an informative marker of hand visual processing and may reflect the activity of a network coding for stimulus identity. NEW & NOTEWORTHY Hands provide crucial information regarding the identity of others, which is a key information for social processes. We recorded EEG activity of healthy participants during the visual identification of hand images. The combination of univariate and multivariate pattern analysis in time- and time-frequency domain highlights the functional role of theta (4–7 Hz) activity over visual areas during hand identification and emphasizes the robustness of this neuromarker in occipito-temporal visual processing dynamics.

Human cortical responses to slow and fast binaural beats reveal multiple mechanisms of binaural hearing

2014 ◽  
Vol 112 (8) ◽  
pp. 1871-1884 ◽  
Author(s):  
Bernhard Ross ◽  
Takahiro Miyazaki ◽  
Jessica Thompson ◽  
Shahab Jamali ◽  
Takako Fujioka
Keyword(s):  
Binaural Hearing ◽  
Gamma Oscillations ◽  
Neural Population ◽  
Neural Firing ◽  
Sound Location ◽  
Binaural Beats ◽  
Cortical Responses ◽  
Left And Right ◽  
Auditory Cortices ◽  
40 Hz

When two tones with slightly different frequencies are presented to both ears, they interact in the central auditory system and induce the sensation of a beating sound. At low difference frequencies, we perceive a single sound, which is moving across the head between the left and right ears. The percept changes to loudness fluctuation, roughness, and pitch with increasing beat rate. To examine the neural representations underlying these different perceptions, we recorded neuromagnetic cortical responses while participants listened to binaural beats at a continuously varying rate between 3 Hz and 60 Hz. Binaural beat responses were analyzed as neuromagnetic oscillations following the trajectory of the stimulus rate. Responses were largest in the 40-Hz gamma range and at low frequencies. Binaural beat responses at 3 Hz showed opposite polarity in the left and right auditory cortices. We suggest that this difference in polarity reflects the opponent neural population code for representing sound location. Binaural beats at any rate induced gamma oscillations. However, the responses were largest at 40-Hz stimulation. We propose that the neuromagnetic gamma oscillations reflect postsynaptic modulation that allows for precise timing of cortical neural firing. Systematic phase differences between bilateral responses suggest that separate sound representations of a sound object exist in the left and right auditory cortices. We conclude that binaural processing at the cortical level occurs with the same temporal acuity as monaural processing whereas the identification of sound location requires further interpretation and is limited by the rate of object representations.

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