Acetylcholine (ACh) is a neuromodulatory transmitter implicated in perception and learning under uncertainty. This study combined computational simulations pharmaco-electroencephalography humans, to test formulation of perceptual inference based upon the free energy principle. suggests that ACh enhances precision bottom-up synaptic transmission cortical hierarchies by optimizing gain supragranular pyramidal cells. Simulations mismatch negativity paradigm predicted rapid trial-by-trial...

Background One common criterion for classifying electrophysiological brain responses is based on the distinction between transient (i.e. event-related potentials, ERPs) and steady-state (SSRs). The generation of SSRs usually attributed to entrainment a neural rhythm driven by stimulus train. However, more parsimonious account suggests that might result from linear addition elicited each stimulus. This study aimed investigate this possibility. Methodology/Principal Findings We recorded...

Cognitive processes require a functional interaction between specialized multiple, local and remote brain regions. Although these interactions can be strongly altered by an acquired injury, plasticity allows network reorganization to principally responsible for recovery. The present work evaluates the impact of injury on connectivity patterns. Networks were calculated from resting-state magnetoencephalographic recordings 15 injured patients 14 healthy controls means wavelet coherence in...

<h3>Context</h3> Neuropsychological models of depression highlight temporoparietal hypofunction associated with low emotional arousal in major depressive disorder (MDD). These were derived from indirect measures such as neuropsychological tests and electroencephalography alpha band power. <h3>Objective</h3> To determine if high-arousing stimuli directly modulated activity attention arousal–related sensory brain regions patients MDD. <h3>Design</h3> Between-group comparison (patients MDD vs...

Abstract Selective attention mechanisms allow us to focus on information that is relevant the current behavior and, equally important, ignore irrelevant information. An influential model proposes oscillatory neural activity in alpha band serves as an active functional inhibitory mechanism. Recent studies have shown that, same way can be selectively oriented bias sensory processing favor of stimuli perceptual tasks, it also possible retrospectively orient internal representations held working...

Brain oscillations are considered to play a pivotal role in neural communication. However, detailed information regarding the typical oscillatory patterns of individual brain regions is surprisingly scarce. In this study we applied multivariate data-driven approach create an atlas natural frequencies resting human on voxel-by-voxel basis. We analysed resting-state magnetoencephalography (MEG) data from 128 healthy adult volunteers obtained Open MEG Archive (OMEGA). Spectral power was...

Mild cognitive impairment (MCI) has been considered an intermediate state between healthy aging and dementia. The early damage in anatomical connectivity progressive loss of synapses that characterize Alzheimer's disease suggest MCI co

Summary Objective Small temporal pole encephalocele ( STPE ) can be the pathologic substrate of epilepsy in a subgroup patients with noninformative magnetic resonance imaging MRI ). Herein, we analyzed clinical, neurophysiologic, and radiologic features found 22 , frequency refractory focal RFE Methods We performed an observational study all identified at our unit from January 2007 to December 2014. Cases were detected through systematic search database evaluated for surgery, prospective...

Abstract Ongoing brain activity preceding visual stimulation has been suggested to shape conscious perception. According the pulsed inhibition framework, bouts of functional arise in each alpha cycle (every ~100 ms), allowing information be processed a pulsatile manner. Consequently, it hypothesized that perceptual outcome can influenced by specific phase oscillations prior stimulus onset, although empirical findings are controversial. In this study, we aimed shed light on role prestimulus...

Theta oscillations in the local field potential of neural ensembles are considered key mediators human working memory. Theoretical accounts arising from animal hippocampal recordings propose that phase theta serves to instantiate sequential neuronal firing form discrete representations items held online. Human evidence relationships visual memory has enhanced this theory, implicating long cycles supporting greater capacity. Here we use magnetoencephalographic examine a novel, alternative...

Accumulating evidence suggests a role for the medial temporal lobe (MTL) in working memory (WM). However, little is known concerning its functional interactions with other cortical regions distributed neural network subserving WM. To reveal these, we availed of subjects MTL damage and characterized changes effective connectivity while engaged WM task. Specifically, compared dynamic causal models, extracted from magnetoencephalographic recordings during verbal encoding, epilepsy patients...

Pattern separation is considered a crucial process that allows us to distinguish among the highly similar and overlapping experiences constitute our episodic memory. Not only do different episodes share common features, but it often case they context in which occurred. While there have been great number of studies investigating pattern its behavioral counterpart, known as mnemonic discrimination, surprisingly, research exploring influence on or discrimination has less common. The available...

Several studies have shown that pharmacological and cognitive treatments for Alzheimers’s disease improve function short periods, but fewer evaluated the efficacy of those longer (2-year) periods. An initial sample 68 subjects with mild Alzheimer’s underwent clinical evaluation. After evaluation, were assigned to four different groups participated in a 2-year follow-up study. Group 1 (n = 14) received combined drug stimulation, group 2 20) only treatment, 3 4 30) no treatment at all. Results...

Mesial temporal lobe epilepsy (mTLE) is the most prevalent form of focal epilepsy, and hippocampal sclerosis (HS) considered frequent associated pathological finding. Recent connectivity studies have shown that abnormalities, either structural or functional, are not confined to affected hippocampus, but can be found in other connected structures within same hemisphere, even contralesional hemisphere. Despite role hippocampus memory functions, these explored network properties at resting...

A study was performed on patients with Alzheimer’s disease (AD) in order to evaluate the efficacy of a combined treatment (donepezil plus cognitive training) both processes and affective states. Eighty-six subjects, 25 men 61 women, an average age 75.58 years, were studied. Almost all subjects had basic educational level. Donezepil administered at dose 10 mg daily along involving images everyday life reminiscent music; sessions took place Monday Friday lasted three quarters hour. The 12...

Subjects with mild cognitive impairment (MCI) are at a higher risk of experiencing Alzheimer disease (AD). Magnetoencephalographic temporoparietal dipole densities low-frequency activity good predictors individuals' status, and might be useful tool to investigate the conversion from MCI AD.To role as developing AD.Whole-head magnetoencephalographic recordings were obtained 19 probable AD patients, 17 healthy control subjects. The generators focal magnetic slow waves located using single...

An increasing amount of evidence supports a crucial role for the anterior temporal lobe (ATL) in semantic processing. Critically, selective disruption functional connectivity between left and right ATLs patients with chronic aphasic stroke has been illustrated. The aim current study was to evaluate consequences that lesions on ATL have neurocognitive network supporting cognition. Unlike previous work, this magnetoencephalography we selected group small centered anteroventral before surgery....

Working memory (WM) is the ability to transiently maintain and manipulate internal representations beyond its external availability senses. This process thought support high level cognitive abilities been shown be strongly predictive of individual intelligence reasoning abilities. While early models WM have relied on a modular perspective brain functioning, more recent evidence suggests that functions emerge from interactions multiple regions generate large-scale networks. Here we will...