Alzheimer's Disease (AD) is the most common form of dementia. Mild Cognitive Impairment (MCI) is the term given to the stage describing prodromal AD and represents a 'risk factor' in early-stage AD diagnosis from normal cognitive decline due to ageing. The electroencephalogram (EEG) has been studied extensively for AD characterization, but reliable early-stage diagnosis continues to present a challenge.
View Article and Find Full Text PDFAim: The present study investigated the differences between the Panic Disorder (PD) patients groups' and healthy controls for the EEG alpha dynamics under the frontal cortex and reaction time during the oddball task.
Material And Methods: The reaction time during the oddball paradigm concomitant to EEG alpha power was tested in nine PD patients and ten healthy controls before and after a computer simulation presentation.
Results: The findings revealed a decrease in EEG alpha power in PD patients concerning the control group ( ≤ 0.
This study aimed to produce a novel deep learning (DL) model for the classification of subjects with Alzheimer's disease (AD), mild cognitive impairment (MCI) subjects and healthy ageing (HA) subjects using resting-state scalp electroencephalogram (EEG) signals.The raw EEG data were pre-processed to remove unwanted artefacts and sources of noise. The data were then processed with the continuous wavelet transform, using the Morse mother wavelet, to create time-frequency graphs with a wavelet coefficient scale range of 0-600.
View Article and Find Full Text PDFThe voluntary movement demands integration between cognitive and motor functions. During the initial stages of motor learning until mastery of a new motor task, and during a demanding task that is not automatic, cognitive and motor functions can be perceived as independent from each other. Areas used for actually performing motor tasks are essentially the same used by Motor Imagery (MI).
View Article and Find Full Text PDFThis study investigated the effects of dopaminergic drugs on the EEG mu power during motor imagery, action observation, and execution. This is a double-blind, crossover study with a sample of 15 healthy adults under placebo vs. methylphenidate vs.
View Article and Find Full Text PDFAverage slow potentials (SPs) can be computed from any voluntary task, minimally involving attention to anticipated stimuli. Their topography when recorded by large electrode arrays even during simple tasks is complex, multifocal, and its generators appear to be equally multifocal and highly variable across subjects. Various sources of noise of course contaminate such averages and must contribute to the topographic complexity.
View Article and Find Full Text PDFBackground: The current study is a reanalysis in the time domain of EEG data collection in healthy adults during an oddball paradigm using levetiracetam (LEV) vs. placebo acute administration. Specifically, the event-related potential (ERP) technique provides a tool for exploring the EEG responses to a specific event/stimulus.
View Article and Find Full Text PDFChronic deep brain stimulation (CDBS) is a surgical treatment that reduces the cardinal signs of Parkinson's disease (PD). Although CDBS has been in use for a long time, very little has been reported on its supposed effects on cognition, particularly in relation to implants in the subthalamic nucleus. The results of the rare studies that do exist are controversial, and in many cases the studies have several design flaws.
View Article and Find Full Text PDFDement Neuropsychol
January 2017
Unlabelled: Alzheimer's disease (AD) is a dementia that affects a large contingent of the elderly population characterized by the presence of neurofibrillary tangles and senile plaques. Traumatic brain injury (TBI) is a non-degenerative injury caused by an external mechanical force. One of the main causes of TBI is diffuse axonal injury (DAI), promoted by acceleration-deceleration mechanisms.
View Article and Find Full Text PDFWe have recently provided evidence for highly idiosyncratic topographic distributions of beta oscillations (as well as slow potentials) across individuals. More recently, by emphasizing the analysis of similarity instead of differences across tasks, we concluded that differences between an attention task and quiet resting may be negligible or at least unsystematic across subjects. Due to the possibility that individual differences could be due to noise in a wide sense or some inherent instability of beta activity, we designed a replication study to explicitly test whether pairs of individuals matched for head size and shape would still present less similar beta topography than each individual between sessions or tasks.
View Article and Find Full Text PDFPanic disorder (PD) is characterized by repeated and unexpected attacks of intense anxiety, which are not restricted to a determined situation or circumstance. The coherence function has been used to investigate the communication among brain structures through the quantitative EEG (qEEG). The objective of this study is to analyze if there is a difference in frontoparietal gamma coherence (GC) between panic disorder patients (PDP) and healthy controls (HC) during the Visual oddball paradigm; and verify if high levels of anxiety (produced by a computer simulation) affect PDP's working memory.
View Article and Find Full Text PDFSeveral studies have demonstrated that Repetitive Transcranial Magnetic Stimulation (rTMS) promotes alterations in the Central Nervous System circuits and networks. The focus of the present study is to examine the absolute beta power patterns in the Parieto-frontal network. We hypothesize that rTMS alters the mechanisms of the sensorimotor integration process during a visuomotor task.
View Article and Find Full Text PDFBipolar disorder (BD) is characterized by an alternated occurrence between acute mania episodes and depression or remission moments. The objective of this study is to analyze the information processing changes in BP (Bipolar Patients) (euthymia, depression and mania) during the oddball paradigm, focusing on the P300 component, an electric potential of the cerebral cortex generated in response to external sensorial stimuli, which involves more complex neurophysiological processes related to stimulus interpretation. Twenty-eight bipolar disorder patients (BP) (17 women and 11 men with average age of 32.
View Article and Find Full Text PDFObjective: Our aim was to investigate and compare the neuromodulatory effects of bromazepam (6 mg) and modafinil (200 mg) during a sensorimotor task analyzing the changes produced in the absolute alpha power.
Method: The sample was composed of 15 healthy individuals exposed to three experimental conditions: placebo, modafinil and bromazepam. EEG data were recorded before, during and after the execution of the task.
Objective: The present study aimed at comparing frontal beta power between long-term (LTM) and first-time meditators (FTM), before, during and after a meditation session. We hypothesized that LTM would present lower beta power than FTM due to lower effort of attention and awareness.
Methods: Twenty one participants were recruited, eleven of whom were long-term meditators.
The present study analyzed absolute theta power (ATP) in brain areas involved with attention in the three phase of BD while the patients performing a saccadic attention task. We hypothesized that patients in depression and mania states show a higher ATP compared to euthymic patients, since a higher ATP is indicative of attention deficit. We analyzed the frontal (F7, F3, Fz, F4 and F8) and central (C3, Cz and C4) areas.
View Article and Find Full Text PDFThe observation of highly variable sets of association neocortical areas across individuals, containing the estimated generators of Slow Potentials (SPs) and beta oscillations, lead to the persistence in individual analyses. This brought to notice an unexpected within individual topographic similarity between task conditions, despite our original interest in task-related differences. A recent related work explored the quantification of the similarity in beta topography between largely differing tasks.
View Article and Find Full Text PDFThe present study investigates the influence of bromazepam while executing a motor task. Specifically, we intend to analyze the changes in alpha absolute power under two experimental conditions, bromazepam and placebo. We also included analyses of theta and beta frequencies.
View Article and Find Full Text PDFObjective: The present study sought to analyze the influence of Levetiracetam (LEV) in cognitive performance by identifying the changes produced by LEV in reaction time, in neuropsychological assessment of attention and memory and in absolute theta power in frontal activity.
Methods: Twelve healthy subjects (5 men and 7 women; mean age, 30.08 years, standard deviation, 4.
This study aimed to verify the electrophysiological correlates of the changes in long-term regular meditators. We use modern techniques of high-resolution electroencephalography applied to slow potentials, power spectra, and potencies related to the events. To obtain encephalographic records, we use an assembly of 128 channels in 31 subjects (17 Soto Zen Buddhist meditators).
View Article and Find Full Text PDFCNS Neurol Disord Drug Targets
May 2015
This article considered already existing studies about Deep Brain Stimulation in Mood and Anxiety Disorders. In particular, articles regarding Obsessive-Compulsive Disorder and Major Depression were mostly analyzed, due to the lack of researches about other types of Mood and Anxiety Disorders. We have concentrated on the target areas where Deep Brain Stimulation was most commonly applied, and on the effects this measure had on treatment-refractory patients.
View Article and Find Full Text PDFFor many decades the parietal cortex (PC) has been considered the key area in tasks which involve the integration of different stimuli. PC is fundamental to determine spatial sense, information navigation and integration, and is involved in several aspects of the complex motor repertoire and in neurological and psychiatric disorders. In this review, we focus on seven different aspects of PC: (i) neuroanatomy of the parietal cortex; (ii) sensory motor integration processes; iii) hand movement control: reaching, grasping, and pointing; (iv) saccadic eye movements; (v) movement observation; (vi) neurological aspects: ataxia, autism and Parkinson's disease; and (vii) psychiatric aspects: schizophrenia, bipolar disorder and depression.
View Article and Find Full Text PDFTraumatic brain injury (TBI) is a major cause of lifelong disability and death worldwide. Sport-related traumatic brain injury is an important public health concern. The purpose of this review was to highlight the importance of sport-related concussions.
View Article and Find Full Text PDFClin Pract Epidemiol Ment Health
November 2013
This study aims to compare the topographic distribution of cortical activation between real and imagined movement through event-related potential (ERP). We are specifically interested in identifying, the topographic distribution of activated areas, the intensity of activated areas, and the temporal occurrence of these activations on preparation and motor response phases. Twelve healthy and right handed subjects were instructed to perform a task under real and imagery conditions.
View Article and Find Full Text PDFAlzheimer's disease (AD) is considered the main cause of dementia in Western countries. Consequently, there is a need for an accurate, universal, specific and cost-effective biomarker for early AD diagnosis, to follow disease progression and therapy response. This article describes a new diagnostic approach to quantitative electroencephalogram (QEEG) diagnosis of mild and moderate AD.
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