Theta band activity in response to emotional expressions and its relationship with gamma band activity as revealed by MEG and advanced beamformer source imaging

Between attacks, migraineurs lack habituation in standard visual evoked potentials (VEPs). Visual stimuli also evoke high-frequency oscillations in the gamma band range (GBOs, 20–35 Hz) assumed to be generated both at subcortical (early GBOs) and cortical levels (late GBOs). The consecutive peaks of GBOs were analysed regarding amplitude and habituation in six successive blocks of 100 averaged pattern reversal (PR)-VEPs in healthy volunteers and interictally in migraine with (MA) or without aura patients. Amplitude of the two early GBO components in the first PR-VEP block was significantly increased in MA patients. There was a significant habituation deficit of the late GBO peaks in migraineurs. The increased amplitude of early GBOs could be related to the increased interictal visual discomfort reported by patients. We hypothesize that the hypo-functioning serotonergic pathways may cause, in line with the thalamocortical dysrhythmia theory, a functional disconnection of the thalamus leading to decreased intracortical lateral inhibition, which can induce dishabituation.

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High-threshold Ca2+channels behind gamma band activity in the pedunculopontine nucleus (PPN)

Physiological Reports ◽

10.14814/phy2.12431 ◽

2015 ◽

Vol 3 (6) ◽

pp. e12431 ◽

Cited By ~ 25

Author(s):

Brennon Luster ◽

Stasia D'Onofrio ◽

Francisco Urbano ◽

Edgar Garcia-Rill

Keyword(s):

Pedunculopontine Nucleus ◽

Gamma Band ◽

High Threshold ◽

Gamma Band Activity ◽

Ca2 Channels ◽

Band Activity

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Neurophenomenology of Out-of-Body experiences induced by hypnotic suggestions

10.31234/osf.io/6a4hc ◽

2018 ◽

Author(s):

Enrico Facco ◽

Edoardo Casiglia ◽

Benedikt Emanuel Al Khafaji ◽

Francesco Finatti ◽

Gian Marco Duma ◽

...

Keyword(s):

Positive Affect ◽

Multisensory Integration ◽

Spectral Power ◽

Gamma Band ◽

Altered State ◽

Brain Areas ◽

Body Experiences ◽

Gamma Band Activity ◽

Band Activity ◽

Hypnotic Suggestions

Inducing out-of-body experiences in hypnosis (H-OBEs) offers an almost unique opportunity to investigate them in a controlled condition.OBEs were induced as imaginative task in resting conditions (I-OBE) or in hypnosis (H-OBE) in 15 high hypnotizable subjects. A 32-channel EEG was recorded and the spectral power and imaginary coherence were calculated. At the end of each session, the Phenomenology of Consciousness Inventory (PCI) was administered to check the phenomenological aspects of their experience.Significantly higher scores in the Altered State, Positive Affect, Altered Experience and Attention subdimensions of the PCI were reported in H-OBE than in I-OBE, which were associated to a significant decrease of power in beta and gamma band activity in right parieto-temporal derivations. Our result suggest that H-OBE may be an appealing model of “true” OBEs, including an alteration of multisensory integration in right parieto-temporal brain areas.

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