Multi-scale and cross-dimensional TMS mapping: A proof of principle in patients with Parkinson's disease and deep brain stimulation.

Introduction: Transcranial magnetic stimulation (TMS) mapping has become a critical tool for exploratory studies of the human corticomotor (M1) organization. Here, we propose to gather existing cutting-edge TMS-EMG and TMS-EEG approaches into a combined multi-dimensional TMS mapping that considers local and whole-brain excitability changes as well as state and time-specific changes in cortical activity. We applied this multi-dimensional TMS mapping approach to patients with Parkinson's disease (PD) with Deep brain stimulation (DBS) of the sub-thalamic nucleus (STN) ON and OFF.

Exploring the spatial resolution of TMS-EEG coupling on the sensorimotor region.

The use of TMS-EEG coupling as a neuroimaging tool for the functional exploration of the human brain recently gained strong interest. If this tool directly inherits the fine temporal resolution from EEG, its spatial counterpart remains unknown. In this study, we explored the spatial resolution of TMS-EEG coupling by evaluating the minimal distance between two stimulated cortical sites that would significantly evoke different response dynamics.

Micro-pursuit: A class of fixational eye movements correlating with smooth, predictable, small-scale target trajectories.

Humans generate ocular pursuit movements when a moving target is tracked throughout the visual field. In this article, we show that pursuit can be generated and measured at small amplitudes, at the scale of fixational eye movements, and tag these eye movements as micro-pursuits. During micro-pursuits, gaze direction correlates with a target's smooth, predictable target trajectory.

Probing regional cortical excitability via input-output properties using transcranial magnetic stimulation and electroencephalography coupling.

The modular organization of the cortex refers to subsets of highly interconnected nodes, sharing specific cytoarchitectural and dynamical properties. These properties condition the level of excitability of local pools of neurons. In this study, we described TMS evoked potentials (TEP) input-output properties to provide new insights into regional cortical excitability.

Twice-daily neuronavigated intermittent theta burst stimulation for bipolar depression: A Randomized Sham-Controlled Pilot Study.

The safety and efficacy of neuronavigated intermittent theta burst stimulation (iTBS) in patients with bipolar depression has not yet been investigated. We hypothesized the superiority of active iTBS over sham. Twenty-six patients were randomly allocated to receive either active (n=12) or sham (n=14) iTBS.

Augmented-Feedback Training Improves Cognitive Motor Performance of Soccer Players.

Purpose: In this study, we tested the hypothesis that augmented feedback (AF) training can improve both perceptual-cognitive and/or motor skills specific to soccer.

Methods: Three groups of young elite players (U14-U15 categories) performed a test consisting in passing the ball as accurately and as quickly as possible toward a visual target moving briefly across a large screen located at 6 m from the player. The performed task required players to correctly perceive the target, anticipate its future location, and to adequately adjust the pass direction and power.

Face perception influences the programming of eye movements.

Previous studies have shown that face stimuli elicit extremely fast and involuntary saccadic responses toward them, relative to other categories of visual stimuli. In the present study, we further investigated to what extent face stimuli influence the programming and execution of saccades examining their amplitude. We performed two experiments using a saccadic choice task: two images (one with a face, one with a vehicle) were simultaneously displayed in the left and right visual fields of participants who had to initiate a saccade toward the image (Experiment 1) or toward a cross in the image (Experiment 2) containing a target stimulus (a face or a vehicle).

The importance of recurrent top-down synaptic connections for the anticipation of dynamic emotions.

Different studies have shown the efficiency of a feed-forward neural network in categorizing basic emotional facial expressions. However, recent findings in psychology and cognitive neuroscience suggest that visual recognition is not a pure bottom-up process but likely involves top-down recurrent connectivity. In the present computational study, we compared the performances of a pure bottom-up neural network (a standard multi-layer perceptron, MLP) with a neural network involving recurrent top-down connections (a simple recurrent network, SRN) in the anticipation of emotional expressions.

Early Emotional Attention is Impacted in Alzheimer's Disease: An Eye-Tracking Study.

Emotional deficits have been repetitively reported in Alzheimer's disease (AD) without clearly identifying how emotional processing is impaired in this pathology. This paper describes an investigation of early emotional processing, as measured by the effects of emotional visual stimuli on a saccadic task involving both pro (PS) and anti (AS) saccades. Sixteen patients with AD and 25 age-matched healthy controls were eye-tracked while they had to quickly move their gaze toward a positive, negative, or neutral image presented on a computer screen (in the PS condition) or away from the image (in the AS condition).

Effects of age on the soccer-specific cognitive-motor performance of elite young soccer players: Comparison between objective measurements and coaches' evaluation.

The cognitive-motor performance (CMP), defined here as the capacity to rapidly use sensory information and transfer it into efficient motor output, represents a major contributor to performance in almost all sports, including soccer. Here, we used a high-technology system (COGNIFOOT) which combines a visual environment simulator fully synchronized with a motion capture system. This system allowed us to measure objective real-time CMP parameters (passing accuracy/speed and response times) in a large turf-artificial grass playfield.

Do low spatial frequencies explain the extremely fast saccades towards human faces?

The visual perception of human faces by man is fast and efficient compared to that of other categories of objects. Using a saccadic choice task, recent studies showed that participants were able to initiate fast reliable saccades in just 100-110ms toward an image of a human face, when this was presented alongside another image without a face. This extremely fast saccadic reaction time is barely predicted using classical models of visual perception.

Of guns and snakes: testing a modern threat superiority effect.

Previous studies suggest that ancient (i.e. evolutionary-based) threats capture attention because human beings possess an inborn module shaped by evolution and dedicated to their detection.

Mapping dynamical properties of cortical microcircuits using robotized TMS and EEG: Towards functional cytoarchitectonics.

Brain dynamics at rest depend on the large-scale interactions between oscillating cortical microcircuits arranged into macrocolumns. Cytoarchitectonic studies have shown that the structure of those microcircuits differs between cortical regions, but very little is known about interregional differences of their intrinsic dynamics at a macro-scale in human. We developed here a new method aiming at mapping the dynamical properties of cortical microcircuits non-invasively using the coupling between robotized transcranial magnetic stimulation and electroencephalography.

Effective connectivity in the neural network underlying coarse-to-fine categorization of visual scenes. A dynamic causal modeling study.

According to current models of visual perception scenes are processed in terms of spatial frequencies following a predominantly coarse-to-fine processing sequence. Low spatial frequencies (LSF) reach high-order areas rapidly in order to activate plausible interpretations of the visual input. This triggers top-down facilitation that guides subsequent processing of high spatial frequencies (HSF) in lower-level areas such as the inferotemporal and occipital cortices.

Spatial frequency processing in scene-selective cortical regions.

Visual analysis begins with the parallel extraction of different attributes at different spatial frequencies. Low spatial frequencies (LSF) convey coarse information and are characterized by high luminance contrast, while high spatial frequencies (HSF) convey fine details and are characterized by low luminance contrast. In the present fMRI study, we examined how scene-selective regions-the parahippocampal place area (PPA), the retrosplenial cortex (RSC) and the occipital place area (OPA)-responded to spatial frequencies when contrast was either equalized or not equalized across spatial frequencies.

Rapid scene categorization: role of spatial frequency order, accumulation mode and luminance contrast.

Visual analysis follows a default, predominantly coarse-to-fine processing sequence. Low spatial frequencies (LSF) are processed more rapidly than high spatial frequencies (HSF), allowing an initial coarse parsing of visual input, prior to analysis of finer information. Our study investigated the influence of spatial frequency processing order, accumulation mode (i.

What saccadic eye movements tell us about TMS-induced neuromodulation of the DLPFC and mood changes: a pilot study in bipolar disorders.

The study assumed that the antisaccade (AS) task is a relevant psychophysical tool to assess (i) short-term neuromodulation of the dorsolateral prefrontal cortex (DLPFC) induced by intermittent theta burst stimulation (iTBS); and (ii) mood change occurring during the course of the treatment. Saccadic inhibition is known to strongly involve the DLPFC, whose neuromodulation with iTBS requires less stimulation time and lower stimulation intensity, as well as results in longer aftereffects than the conventional repetitive transcranial magnetic stimulation (rTMS). Active or sham iTBS was applied every day for 3 weeks over the left DLPFC of 12 drug-resistant bipolar depressed patients.

Age-related changes in intracortical inhibition are mental-cognitive state-dependent.

Introduction: This study aimed to assess the impact of aging and 'state-dependency' on cortical excitability. Two studies investigated these factors using a motor task and found that the age-related differences observed at rest disappeared in the task condition. However, as both their tasks and excitability measurements involved the motor cortex, their results could be specific only to the motor system.

Brain processing of emotional scenes in aging: effect of arousal and affective context.

Research on emotion showed an increase, with age, in prevalence of positive information relative to negative ones. This effect is called positivity effect. From the cerebral analysis of the Late Positive Potential (LPP), sensitive to attention, our study investigated to which extent the arousal level of negative scenes is differently processed between young and older adults and, to which extent the arousal level of negative scenes, depending on its value, may contextually modulate the cerebral processing of positive (and neutral) scenes and favor the observation of a positivity effect with age.

Coarse-to-fine categorization of visual scenes in scene-selective cortex.

Neurophysiological, behavioral, and computational data indicate that visual analysis may start with the parallel extraction of different elementary attributes at different spatial frequencies and follows a predominantly coarse-to-fine (CtF) processing sequence (low spatial frequencies [LSF] are extracted first, followed by high spatial frequencies [HSF]). Evidence for CtF processing within scene-selective cortical regions is, however, still lacking. In the present fMRI study, we tested whether such processing occurs in three scene-selective cortical regions: the parahippocampal place area (PPA), the retrosplenial cortex, and the occipital place area.

Microsaccades are modulated by both attentional demands of a visual discrimination task and background noise.

Microsaccades are miniature saccades occurring once or twice per second during visual fixation. While microsaccades and saccades share similarities at the oculomotor level, the functional roles of microsaccades are still debated. In this study, we examined the hypothesis that the microsaccadic activity is affected by the type of noisy background during the execution of a particular discrimination task.

Saccadic performance and cortical excitability as trait-markers and state-markers in rapid cycling bipolar disorder: a two-case follow-up study.

Background: The understanding of physiopathology and cognitive impairments in mood disorders requires finding objective markers. Mood disorders have often been linked to hypometabolism in the prefrontal dorsolateral cortex, and to GABAergic and glutamatergic neurotransmission dysfunction. The present study aimed to discover whether saccadic tasks (involving DPLFC activity), and cortical excitability (involving GABA/Glutamate neurotransmission) could provide neuropsychophysical markers for mood disorders, and/or of its phases, in patients with rapid cycling bipolar disorders (rcBD).

Is coarse-to-fine strategy sensitive to normal aging?

Theories on visual perception agree that visual recognition begins with global analysis and ends with detailed analysis. Different results from neurophysiological, computational, and behavioral studies all indicate that the totality of visual information is not immediately conveyed, but that information analysis follows a predominantly coarse-to-fine processing sequence (low spatial frequencies are extracted first, followed by high spatial frequencies). We tested whether such processing continues to occur in normally aging subjects.

Having to identify a target reduces antisaccade latencies in mixed saccadic paradigms: A top-down effect released by tonic prefrontal activation?

Instructing participants to "identify a target" dramatically reduces saccadic reaction times in prosaccade tasks (PS). However, it has been recently shown that this effect disappears in antisaccade tasks (AS). The instruction effect observed in PS may result from top-down processes, mediated by pathways connecting the prefrontal cortex (PFC) to the superior colliculus.