Development and validation of a practical solution for detecting motion artefacts in the EOS X-ray system.

The EOS™2D/3D system is a low-dose, 3D imaging system that utilizes two perpendicular X-ray beams to create simultaneous frontal and lateral images of the body. This is a useful modality to assess spinal pathologies. However, due to the slow imaging acquisition time up to 25 s, motion artifacts (MA) frequently occur.

Self-modulation of the sense of agency via neurofeedback enhances sensory-guided behavioral control.

The sense of agency is a fundamental aspect of human self-consciousness, whose neural correlates encompass widespread brain networks. Research has explored the neuromodulatory properties of the sense of agency with noninvasive brain stimulation, which induces exogenous manipulations of brain activity; however, it is unknown whether endogenous modulation of the sense of agency is also achievable. We investigated whether the sense of agency can be self-regulated with electroencephalography-based neurofeedback.

Fixel-Based Analysis Reveals Whole-Brain White Matter Abnormalities in Cervical Dystonia.

Background: Cervical dystonia (CD) is a form of isolated focal dystonia typically associated to abnormal head, neck, and shoulder movements and postures. The complexity of the clinical presentation limits the investigation of its pathophysiological mechanisms, and the neural networks associated to specific motor manifestations are still the object of debate.

Objectives: We investigated the morphometric properties of white matter fibers in CD and explored the networks associated with motor symptoms, while regressing out nonmotor scores.

Multivariate classification provides a neural signature of Tourette disorder.

Background: Tourette disorder (TD), hallmarks of which are motor and vocal tics, has been related to functional abnormalities in large-scale brain networks. Using a fully data driven approach in a prospective, case-control study, we tested the hypothesis that functional connectivity of these networks carries a neural signature of TD. Our aim was to investigate (i) the brain networks that distinguish adult patients with TD from controls, and (ii) the effects of antipsychotic medication on these networks.

Somatotopy of cervical dystonia in motor-cerebellar networks: Evidence from resting state fMRI.

Introduction: Cervical dystonia is the most frequent form of isolated focal dystonia. It is often associated with a dysfunction in brain networks, mostly affecting the basal ganglia, the cerebellum, and the somatosensory cortex. However, it is unclear if such a dysfunction is somato-specific to the brain areas containing the representation of the affected body part, and may thereby account for the focal expression of cervical dystonia.

Neural correlates of sense of agency in motor control: A neuroimaging meta-analysis.

The sense of agency (SoA) refers to the perception that an action is the consequence of one's own intention. Studies exploring the SoA with neuroimaging techniques summarized the available data and confirmed a role of fronto-parietal areas and subcortical structures. However, these studies focused on specific regions of interest.

Transcranial magnetic stimulation over the right temporoparietal junction influences the sense of agency in healthy humans.

Background: The sense of agency is an important aspect of motor control. Impaired sense of agency has been linked to several medical conditions, including schizophrenia and functional neurological disorders. A complex brain network subserves the sense of agency, and the right temporoparietal junction is one of its main nodes.

Abnormal postural behavior in patients with functional movement disorders during exposure to stress.

Background: Patients affected by functional (psychogenic) movement disorders (FMD) have abnormal processing of stress responses. However, little is known about the influence of this abnormal stress processing on automatic motor defense behavior, such as freeze response. Our aim was thus to investigate stress-induced postural motor responses in FMD.

Development and Pilot Testing of a Novel Electromechanical Device to Measure Wrist Rigidity in Parkinson's Disease.

Quantitative assessment of the muscle tone is important when studying patients with neurological disorders such as Parkinson's disease (PD). For the assessment of therapeutic progress, quantitative and objective outcome measures are needed. This article presents a novel electromechanical device to monitor the quantitative rigidity of the wrist joint against passive movement.

Attentional reorienting triggers spatial asymmetries in a search task with cross-modal spatial cueing.

Cross-modal spatial cueing can affect performance in a visual search task. For example, search performance improves if a visual target and an auditory cue originate from the same spatial location, and it deteriorates if they originate from different locations. Moreover, it has recently been postulated that multisensory settings, i.

Towards free 3D end-point control for robotic-assisted human reaching using binocular eye tracking.

Eye-movements are the only directly observable behavioural signals that are highly correlated with actions at the task level, and proactive of body movements and thus reflect action intentions. Moreover, eye movements are preserved in many movement disorders leading to paralysis (or amputees) from stroke, spinal cord injury, Parkinson's disease, multiple sclerosis, and muscular dystrophy among others. Despite this benefit, eye tracking is not widely used as control interface for robotic interfaces in movement impaired patients due to poor human-robot interfaces.

"Wink to grasp" - comparing eye, voice & EMG gesture control of grasp with soft-robotic gloves.

The ability of robotic rehabilitation devices to support paralysed end-users is ultimately limited by the degree to which human-machine-interaction is designed to be effective and efficient in translating user intention into robotic action. Specifically, we evaluate the novel possibility of binocular eye-tracking technology to detect voluntary winks from involuntary blink commands, to establish winks as a novel low-latency control signal to trigger robotic action. By wearing binocular eye-tracking glasses we enable users to directly observe their environment or the actuator and trigger movement actions, without having to interact with a visual display unit or user interface.

Effects of Alzheimer's Disease on Visual Target Detection: A "Peripheral Bias".

Visual exploration is an omnipresent activity in everyday life, and might represent an important determinant of visual attention deficits in patients with Alzheimer's Disease (AD). The present study aimed at investigating visual search performance in AD patients, in particular target detection in the far periphery, in daily living scenes. Eighteen AD patients and 20 healthy controls participated in the study.

Behavioral Differences in the Upper and Lower Visual Hemifields in Shape and Motion Perception.

Perceptual accuracy is known to be influenced by stimuli location within the visual field. In particular, it seems to be enhanced in the lower visual hemifield (VH) for motion and space processing, and in the upper VH for object and face processing. The origins of such asymmetries are attributed to attentional biases across the visual field, and in the functional organization of the visual system.

Higher visual functions in the upper and lower visual fields: A pilot study in healthy subjects.

Visual perception is not identical in the upper and lower visual hemifields. The mechanisms behind this difference can be found at the retinal, cortical, or higher attentional level. In this study, a new visual test battery, that involves real-time comparisons of complex visual stimuli, such as shape of objects, and speed of moving dot patterns, in the upper and lower visual hemifields, is presented.

Theta burst stimulation improves overt visual search in spatial neglect independently of attentional load.

Visual neglect is considerably exacerbated by increases in visual attentional load. These detrimental effects of attentional load are hypothesised to be dependent on an interplay between dysfunctional inter-hemispheric inhibitory dynamics and load-related modulation of activity in cortical areas such as the posterior parietal cortex (PPC). Continuous Theta Burst Stimulation (cTBS) over the contralesional PPC reduces neglect severity.

Cathodal HD-tDCS on the right V5 improves motion perception in humans.

Brain lesions in the visual associative cortex are known to impair visual perception, i.e., the capacity to correctly perceive different aspects of the visual world, such as motion, color, or shapes.

A new method to measure higher visual functions in an immersive environment.

Background: Higher visual functions can be defined as cognitive processes responsible for object recognition, color and shape perception, and motion detection. People with impaired higher visual functions after unilateral brain lesion are often tested with paper pencil tests, but such tests do not assess the degree of interaction between the healthy brain hemisphere and the impaired one. Hence, visual functions are not tested separately in the contralesional and ipsilesional visual hemifields.

Effects of age and eccentricity on visual target detection.

The aim of this study was to examine the effects of aging and target eccentricity on a visual search task comprising 30 images of everyday life projected into a hemisphere, realizing a ±90° visual field. The task performed binocularly allowed participants to freely move their eyes to scan images for an appearing target or distractor stimulus (presented at 10°; 30°, and 50° eccentricity). The distractor stimulus required no response, while the target stimulus required acknowledgment by pressing the response button.