Search results for "oscillation"

Effects of physical activity on neural markers of attention in children

2016

Huoli passiivisen elämäntavan vaikutuksista oppimisen edellytyksiin on kasvanut, kun lasten fyysinen aktiivisuus on vähentynyt. Useat tutkimukset tukevat fyysisen aktiivisuuden suojaavaa vaikutusta erilaisiin kognitiivisiin toimintoihin. Tarkkaavaisuuden kohdistaminen relevantteihin ärsykkeisiin näyttää olevan merkittävä osa oppimista, minkä vuoksi mielenkiinto on kohdistettu nykytutkimuksessa tarkkaavaisuuden mekanismeihin. Alfa-oskillaatioiden inhibitorinen rooli tarkkaavaisuudessa on saanut vahvistusta spatiaalista tarkkaavaisuutta selvittäneistä tutkimuksista. Alfa-oskillaatioiden on havaittu lateralisoituvan siten, että alfa-aktiivisuus laskee näköärsykettä prosessoivalla aivokuorella …

Physical activity and aerobic fitness show different associations with brain processes underlying anticipatory selective visuospatial attention in ad…

2021

ABSTRACTUnderlying brain processes of exercise-related benefits on executive functions and the specific contribution of physical activity vs. aerobic fitness are poorly understood, especially during adolescence. We explored whether and how physical activity and aerobic fitness are associated with selective attention and the oscillatory dynamics induced by an anticipatory spatial cue. Further, we studied whether the link between physical exercise level and cognitive control in adolescents is mediated by the task-related oscillatory activity. Magnetoencephalographic alpha oscillations during a modified Posner’s cueing paradigm were measured in 59 adolescents (37 females and 22 males, 12 to 17…

Brain dynamics of recommendation-based social influence on preference change: A magnetoencephalography study.

2022

People change their preferences when exposed to others’ opinions. We examine the neural basis of how peer feedback influences an individual’s recommendation behavior. In addition, we investigate if the personality trait of ‘agreeableness’ modulates behavioral change and neural responses. In our experiment, participants with low and high agreeableness indicated their degree of recommendation of commercial brands, while subjected to peer group feedback. The associated neural responses were recorded with concurrent magnetoencephalography. After a delay, the participants were asked to reevaluate the brands. Recommendations changed consistently with conflicting feedback only when peer recommenda…

Lyapunov quantities and limit cycles in two-dimensional dynamical systems : analytical methods, symbolic computation and visualization

2011

Altered EEG Oscillatory Brain Networks During Music-Listening in Major Depression

2021

To examine the electrophysiological underpinnings of the functional networks involved in music listening, previous approaches based on spatial independent component analysis (ICA) have recently been used to ongoing electroencephalography (EEG) and magnetoencephalography (MEG). However, those studies focused on healthy subjects, and failed to examine the group-level comparisons during music listening. Here, we combined group-level spatial Fourier ICA with acoustic feature extraction, to enable group comparisons in frequency-specific brain networks of musical feature processing. It was then applied to healthy subjects and subjects with major depressive disorder (MDD). The music-induced oscil…

Is the El Niño-Southern Oscillation likely to increase the risk of Fasciola transmission?

2007

(2007). Is the El Nino–Southern Oscillation likely to increase the risk of Fasciola transmission? Annals of Tropical Medicine & Parasitology: Vol. 101, No. 6, pp. 555-557.

Hippocampal theta phase-contingent memory retrieval in delay and trace eyeblink conditioning

2017

Hippocampal theta oscillations (3–12 Hz) play a prominent role in learning. It has been suggested that encoding and retrieval of memories are supported by different phases of the theta cycle. Our previous study on trace eyeblink conditioning in rabbits suggests that the timing of the conditioned stimulus (CS) in relation to theta phase affects encoding but not retrieval of the memory trace. Here, we directly tested the effects of hippocampal theta phase on memory retrieval in two experiments conducted on adult female New Zealand White rabbits. In Experiment 1, animals were trained in trace eyeblink conditioning followed by extinction, and memory retrieval was tested by presenting the CS at …

Hippocampal theta activity is selectively associated with contingency detection but not discrimination in rabbit discrimination-reversal eyeblink con…

2010

The relative power of the hippocampal theta-band (∼6 Hz) activity (theta ratio) is thought to reflect a distinct neural state and has been shown to affect learning rate in classical eyeblink conditioning in rabbits. We sought to determine if the theta ratio is mostly related to the detection of the contingency between the stimuli used in conditioning or also to the learning of more complex inhibitory associations when a highly demanding delay discrimination-reversal eyeblink conditioning paradigm is used. A high hippocampal theta ratio was not only associated with a fast increase in conditioned responding in general but also correlated with slow emergence of discriminative responding due to…

Brain oscillations: discovering their role in memory using Transcranial Alternating Current Stimulation

Min-Type Control Strategy of a DC-DC Synchronous Boost Converter

2019

International audience; This paper presents the analysis and design of a min-type strategy to control a synchronous boost converter in continuous conduction mode. The strategy uses a nonlinear switching surface to establish the change of topology in the converter and is analyzed by means of a sliding-mode control approach. Subsequently, the min-type strategy is modified by a hybrid control formulation, which introduces a hysteresis width and a dwell-time to obtain a finite switching frequency in the start-up and steady-state respectively. The hybrid control formulation is implemented digitally by means of a microprocessor which processes the samples of inductor current and capacitor voltage…