scholarly journals Human oscillatory brain activity near 40 Hz coexists with cognitive temporal binding.

1994 ◽  
Vol 91 (24) ◽  
pp. 11748-11751 ◽  
Author(s):  
M. Joliot ◽  
U. Ribary ◽  
R. Llinas
2009 ◽  
Vol 30 (6) ◽  
pp. 1922-1934 ◽  
Author(s):  
Juan L.P. Soto ◽  
Dimitrios Pantazis ◽  
Karim Jerbi ◽  
Jean-Phillipe Lachaux ◽  
Line Garnero ◽  
...  

2015 ◽  
Vol 9 ◽  
pp. 300-309 ◽  
Author(s):  
Erik S. te Woerd ◽  
Robert Oostenveld ◽  
Bastiaan R. Bloem ◽  
Floris P. de Lange ◽  
Peter Praamstra

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Dieter Häussinger ◽  
Markus Butz ◽  
Alfons Schnitzler ◽  
Boris Görg

Abstract Hepatic encephalopathy (HE) is a frequent neuropsychiatric complication in patients with acute or chronic liver failure. Symptoms of HE in particular include disturbances of sensory and motor functions and cognition. HE is triggered by heterogeneous factors such as ammonia being a main toxin, benzodiazepines, proinflammatory cytokines and hyponatremia. HE in patients with liver cirrhosis is triggered by a low-grade cerebral edema and cerebral oxidative/nitrosative stress which bring about a number of functionally relevant alterations including posttranslational protein modifications, oxidation of RNA, gene expression changes and senescence. These alterations are suggested to impair astrocyte/neuronal functions and communication. On the system level, a global slowing of oscillatory brain activity and networks can be observed paralleling behavioral perceptual and motor impairments. Moreover, these changes are related to increased cerebral ammonia, alterations in neurometabolite and neurotransmitter concentrations and cortical excitability in HE patients.


2021 ◽  
Author(s):  
Kyveli Kompatsiari ◽  
Francesco Bossi ◽  
Agnieszka Wykowska

Eye contact established by a human partner has been shown to affect various cognitive processes of the receiver. However, little is known about humans’ responses to eye contact established by a humanoid robot. Here, we aimed at examining humans’ oscillatory brain response to eye contact with a humanoid robot. Eye contact (or lack thereof) was embedded in a gaze cueing task and preceded the phase of gaze-related attentional orienting. In addition to examining the effect of eye contact on the recipient, we also tested its impact on gaze cueing effects. Results showed that participants rated eye contact as more engaging and responded with higher desynchronization of alpha-band activity in left fronto-central and central electrode clusters when the robot established eye contact with them, compared to no eye contact condition. However, eye contact did not modulate gaze cueing effects. The results are interpreted in terms of the functional roles involved in alpha central rhythms (potentially interpretable also as mu rhythm), including joint attention and engagement in social interaction.


2018 ◽  
Author(s):  
Luis F. Ciria ◽  
Pandelis Perakakis ◽  
Antonio Luque-Casado ◽  
Daniel Sanabria

AbstractExtant evidence suggests that acute exercise triggers a tonic power increase in the alpha frequency band at frontal locations, which has been linked to benefits in cognitive function. However, recent literature has questioned such a selective effect on a particular frequency band, indicating a rather overall power increase across the entire frequency spectrum. Moreover, the nature of task-evoked oscillatory brain activity associated to inhibitory control after exercising, and the duration of the exercise effect, are not yet clear. Here, we investigate for the first time steady state oscillatory brain activity during and following an acute bout of aerobic exercise at two different exercise intensities (moderate-to-high and light), by means of a data-driven cluster-based approach to describe the spatio-temporal distribution of exercise-induced effects on brain function without prior assumptions on any frequency range or site of interest. We also assess the transient oscillatory brain activity elicited by stimulus presentation, as well as behavioural performance, in two inhibitory control (flanker) tasks, one performed after a short delay following the physical exercise and another completed after a rest period of 15’ post-exercise to explore the time course of exercise-induced changes on brain function and cognitive performance. The results show that oscillatory brain activity increases during exercise compared to the resting state, and that this increase is higher during the moderate-to-high intensity exercise with respect to the light intensity exercise. In addition, our results show that the global pattern of increased oscillatory brain activity is not specific to any concrete surface localization in slow frequencies, while in faster frequencies this effect is located in parieto-occipital sites. Notably, the exercise-induced increase in oscillatory brain activity disappears immediately after the end of the exercise bout. Neither transient (event-related) oscillatory activity, nor behavioral performance during the flanker tasks following exercise showed significant between-intensity differences. The present findings help elucidate the effect of physical exercise on oscillatory brain activity and challenge previous research suggesting improved inhibitory control following moderate-to-high acute exercise.


eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Lu Zhang ◽  
John Lee ◽  
Christopher Rozell ◽  
Annabelle C Singer

Oscillatory brain activity reflects different internal brain states including neurons’ excitatory state and synchrony among neurons. However, characterizing these states is complicated by the fact that different oscillations are often coupled, such as gamma oscillations nested in theta in the hippocampus, and changes in coupling are thought to reflect distinct states. Here, we describe a new method to separate single oscillatory cycles into distinct states based on frequency and phase coupling. Using this method, we identified four theta-gamma coupling states in rat hippocampal CA1. These states differed in abundance across behaviors, phase synchrony with other hippocampal subregions, and neural coding properties suggesting that these states are functionally distinct. We captured cycle-to-cycle changes in oscillatory coupling states and found frequent switching between theta-gamma states showing that the hippocampus rapidly shifts between different functional states. This method provides a new approach to investigate oscillatory brain dynamics broadly.


2018 ◽  
Vol 110 (2) ◽  
pp. 245-255 ◽  
Author(s):  
Paul Sauseng ◽  
Charline Peylo ◽  
Anna Lena Biel ◽  
Elisabeth V. C. Friedrich ◽  
Carola Romberg‐Taylor

Author(s):  
Michael A. Nitsche ◽  
Walter Paulus ◽  
Gregor Thut

Brain stimulation with weak electrical currents (transcranial electrical stimulation, tES) is known already for about 60 years as a technique to generate modifications of cortical excitability and activity. Originally established in animal models, it was developed as a noninvasive brain stimulation tool about 20 years ago for application in humans. Stimulation with direct currents (transcranial direct current stimulation, tDCS) induces acute cortical excitability alterations, as well as neuroplastic after-effects, whereas stimulation with alternating currents (transcranial alternating current stimulation, tACS) affects primarily oscillatory brain activity but has also been shown to induce neuroplasticity effects. Beyond their respective regional effects, both stimulation techniques have also an impact on cerebral networks. Transcranial magnetic stimulation (TMS) has been pivotal to helping reveal the physiological effects and mechanisms of action of both stimulation techniques for motor cortex application, but also for stimulation of other areas. This chapter will supply the reader with an overview about the effects of tES on human brain physiology, as revealed by TMS.


2019 ◽  
Vol 56 (5) ◽  
pp. e13326 ◽  
Author(s):  
Luis F. Ciria ◽  
Antonio Luque‐Casado ◽  
Daniel Sanabria ◽  
Darías Holgado ◽  
Plamen Ch. Ivanov ◽  
...  

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