Attention deficit and hyperactivity disorder disrupts selective mechanisms of action.

Objective: People with attention deficit and hyperactivity disorder (ADHD) present attentional and emotional deficits and show paradoxical qualities such as hyperfocus. Previous studies have reported errors, slowness, and reaction time (RT) variability using eye movements. This study aimed to explore the underlying mechanisms of ADHD further.

First-wave COVID-19 daily cases obey gamma law.

Modelling how a pandemic is spreading over time is a challenging issue. The new coronavirus disease called COVID-19 does not escape this rule as it has embraced over two hundred countries. As for previous pandemics, several studies have attempted to model the occurrence of cases caused by COVID-19.

Standardization of the psychometric hepatic encephalopathy score in a French population.

The Psychometric Hepatic Encephalopathy Score (PHES) has previously been standardized in thirteen countries on three continents, confirming its status of gold standard test to detect minimal hepatic encephalopathy (MHE). In the meantime, performance has also been shown to vary with variables such as age, education, and barely sex. The present study aimed at standardizing the PHES in a French population.

Measuring vergence and fixation disparity in 3D space.

As the eyes continuously move in 3D space, they rarely converge at the exact depth of the plane even when fixating a 2D image or computer screen. Rather, the lines of gaze measured by eye movement recordings show some misalignment so-called fixation disparity. Fixation disparity occurs in front of or behind the plane, and the eyes may also be lagged vertically.

Temporal representation impairment in developmental dyslexia for unisensory and multisensory stimuli.

Dyslexia has been associated with a problem in visual-audio integration mechanisms. Here, we investigate for the first time the contribution of unisensory cues on multisensory audio and visual integration in 32 dyslexic children by modelling results using the Bayesian approach. Non-linguistic stimuli were used.

Transcranial magnetic stimulation in basic and clinical neuroscience: A comprehensive review of fundamental principles and novel insights.

Non-invasive brain stimulation methods, such as Transcranial Magnetic Stimulation (TMS), are widely used worldwide to make causality-based inferences about brain-behavior interactions. TMS-based clinical applications have been shown promising to treat neurological or psychiatric diseases. TMS works by inducing non-invasively electric currents in localized cortical regions thus modulating their excitability levels and ongoing activity patterns depending on stimulation settings: frequency, number of pulses, train duration and intertrain intervals.

An Integrative Model for the Neural Mechanism of Eye Movement Desensitization and Reprocessing (EMDR).

Since the seminal report by Shapiro that bilateral stimulation induces cognitive and emotional changes, 26 years of basic and clinical research have examined the effects of Eye Movement Desensitization and Reprocessing (EMDR) in anxiety disorders, particularly in post-traumatic stress disorder (PTSD). The present article aims at better understanding EMDR neural mechanism. I first review procedural aspects of EMDR protocol and theoretical hypothesis about EMDR effects, and develop the reasons why the scientific community is still divided about EMDR.

Educating the blind brain: a panorama of neural bases of vision and of training programs in organic neurovisual deficits.

Vision is a complex function, which is achieved by movements of the eyes to properly foveate targets at any location in 3D space and to continuously refresh neural information in the different visual pathways. The visual system involves five main routes originating in the retinas but varying in their destination within the brain: the occipital cortex, but also the superior colliculus (SC), the pretectum, the supra-chiasmatic nucleus, the nucleus of the optic tract and terminal dorsal, medial and lateral nuclei. Visual pathway architecture obeys systematization in sagittal and transversal planes so that visual information from left/right and upper/lower hemi-retinas, corresponding respectively to right/left and lower/upper visual fields, is processed ipsilaterally and ipsialtitudinally to hemi-retinas in left/right hemispheres and upper/lower fibers.

Visualizing the blind brain: brain imaging of visual field defects from early recovery to rehabilitation techniques.

Visual field defects (VFDs) are one of the most common consequences observed after brain injury, especially after a stroke in the posterior cerebral artery territory. Less frequently, tumors, traumatic brain injury, brain surgery or demyelination can also determine various visual disabilities, from a decrease in visual acuity to cerebral blindness. Visual field defects is a factor of bad functional prognosis as it compromises many daily life activities (e.

One month of contemporary dance modulates fractal posture in aging.

Understanding the human aging of postural control and how physical or motor activity improves balance and gait is challenging for both clinicians and researchers. Previous studies have evidenced that physical and sporting activity focusing on cardiovascular and strength conditioning help older adults develop their balance and gait and/or decrease their frequency of falls. Motor activity based on motor-skill learning has also been put forward as an alternative to develop balance and/or prevent falls in aging.

Saccade and vergence eye movements: a review of motor and premotor commands.

Neuropsychology examines the relationship between cognitive activity and corresponding cerebral conditions. At one end, psychophysics meticulously describes the details of behavior. At the other, physiology records brain cell activity during cognitive tasks.

Optic neuritis: from magnocellular to cognitive residual dysfunction.

Optic Neuritis (ON) has been associated to both parvocellular dysfunction and to an alteration of the magnocellular pathway. After objective visual field and acuity recovery, ON patients may complain about their vision suggesting a residual subclinical deficit. To better characterize visual abnormalities, 8 patients recovering from a first ON episode as well as 16 healthy controls performed a simple detection task and a more complex categorization task of images presented in low spatial frequencies (to target the magnocellular system) or in high spatial frequencies (to target the parvocellular system) or of non-filtered images.

A method for processing multivariate data in medical studies.

Traditional displays of principal component analyses lack readability to discriminate between putative clusters of variables or cases. Here, the author proposes a method that clusterizes and visualizes variables or cases through principal component analyses thus facilitating their analysis. The method displays pre-determined clusters of variables or cases as urchins that each has a soma (the average point) and spines (the individual variables or cases).

Maxwellian eye fixation during natural scene perception.

When we explore a visual scene, our eyes make saccades to jump rapidly from one area to another and fixate regions of interest to extract useful information. While the role of fixation eye movements in vision has been widely studied, their random nature has been a hitherto neglected issue. Here we conducted two experiments to examine the Maxwellian nature of eye movements during fixation.

An FMRI investigation of the cortical network underlying detection and categorization abilities in hemianopic patients.

The current study aims to investigate visual scene perception and its neuro-anatomical correlates for stimuli presented in the central visual field of patients with homonymous hemianopia, and thereby to assess the effect of a right or a left occipital lesion on brain reorganization. Fourteen healthy participants, three left brain damaged (LBD) patients with right homonymous hemianopia and five right brain damaged (RBD) patients with left homonymous hemianopia performed a visual detection task (i.e.

Fall prevention modulates decisional saccadic behavior in aging.

As society ages and frequency of falls increases in older adults, counteracting motor decline is a challenging issue for developed countries. Physical activity based on aerobic and strength training as well as motor activity based on skill learning both help benefit balance and reduce the risk of falls, as assessed by clinical or laboratory measures. However, how such programs influence motor control is a neglected issue.

Practice of contemporary dance promotes stochastic postural control in aging.

As society ages and the frequency of falls increases, counteracting gait and posture decline is a challenging issue for countries of the developed world. Previous studies have shown that exercise and hazard management help to improve balance and/or decrease the risks for falling in normal aging. Motor activity based on motor-skill learning, particularly dance, can also benefit balance and decreases falls with age.