Validation of a screening test based on symbols visual search to detect visuo-attentionnal reading difficulties.

Objective: Visuo-attentional dyslexia has been associated with impaired simultaneous visual processing of multiple items made of separable features (i.e. symbols).

Impact of macular scotoma and tubular vision on oculomotor behavior and performance in visuospatial comparison tasks.

Our aim in this study was to understand how we perform visuospatial comparison tasks by analyzing ocular behavior and to examine how restrictions in macular or peripheral vision disturb ocular behavior and task performance. Two groups of 18 healthy participants with normal or corrected visual acuity performed visuospatial comparison tasks (computerized version of the elementary visuospatial perception [EVSP] test) (Pisella et al., 2013) with a gaze-contingent mask simulating either tubular vision (first group) or macular scotoma (second group).

Striking the Balance: Embracing Technology While Upholding Humanistic Principles in Neurorehabilitation.

Background: The rapid advancement of technology-focused strategies in neurorehabilitation has brought optimism to individuals with neurological disorders, caregivers, and physicians while reshaping medical practice and training.

Objectives: We critically examine the implications of technology in neurorehabilitation, drawing on discussions from the 2021 and 2024 World Congress for NeuroRehabilitation. While acknowledging the value of technology, it highlights inherent limitations and ethical concerns, particularly regarding the potential overshadowing of humanistic approaches.

Effect of juggling expertise on pointing performance in peripheral vision.

Juggling is a very complex activity requiring motor, visual and coordination skills. Expert jugglers experience a "third eye" monitoring leftward and rightward ball zenith positions alternately, in the upper visual fields, while maintaining their gaze straight-ahead. This "third eye" reduces their motor noise (improved body stability and decrease in hand movement variability) as it avoids the numerous head and eye movements that add noise into the system and make trajectories more uncertain.

Visuospatial Perception in Prematurely Born Children Without Cerebral Palsy or Retinopathy but With Scholar Complaints.

In the absence of any complaints in early childhood, preterm children remain more at risk of encountering academic difficulties, but their clinical picture remains not well characterized. We screened visuospatial perception in 70 children born preterm consulting for scholar complaints. Developmental Coordination Disorder (with or without comorbidities) was associated with high prevalence (27%) of impaired perception of spatial relationship.

Reduced spatial attentional distribution in older adults.

Older adults show decline in visual search performance, but the underlying cause remains unclear. It has been suggested that older adults' altered performance may be related to reduced spatial attention to peripheral visual information compared with younger adults. In this study, 18 younger (M = 21.

Toward the characterization of a visual form of developmental dyslexia: Reduced visuo-attentional capacity for processing multiple stimuli made of separable features.

Some dyslexics cannot process multiple letters simultaneously. It has been argued that this reduced visuo-attentional (VA) letter span could result from poor reading ability and experience. Here, moving away from reading context, we showed that dyslexic group exhibited slower visual search than normal readers group for "symbols", defined as graphic stimuli made up of separable visual features, but not for filled objects.

Spatial bias in anti-saccade endpoints following bilateral dorsal posterior parietal lesions.

Anti-saccades are eye movements in which the saccade is executed in the opposite direction of a visual target and are often hypometric. Because the visual target and saccade goal are decoupled, it has been suggested that competition between the two locations occurs and needs to be resolved. It has been hypothesized that the hypometria of anti-saccades reflects this spatial competition by revealing a bias towards the visual target.

Pre-saccadic attention relies more on suppression than does covert attention.

During covert and pre-saccadic attentional shifts, it is unclear how facilitation and suppression processes interact for target selection. A recent countermanding task pointed to greater suppression at unattended locations during trials with saccades compared to trials without saccades (i.e.

Role of the Dorsal Posterior Parietal Cortex in the Accurate Perception of Object Magnitude in Peripheral Vision.

Following superior parietal lobule and intraparietal sulcus (SPL-IPS) damage, optic ataxia patients underestimate the distance of objects in the ataxic visual field such that they produce hypometric pointing errors. The metrics of these pointing errors relative to visual target eccentricity fit the cortical magnification of central vision. The SPL-IPS would therefore implement an active "peripheral magnification" to match the real metrics of the environment for accurate action.

Impaired Spatial Inhibition Processes for Interhemispheric Anti-saccades following Dorsal Posterior Parietal Lesions.

Anti-saccades are eye movements that require inhibition to stop the automatic saccade to the visual target and to perform instead a saccade in the opposite direction. The inhibitory processes underlying anti-saccades have been primarily associated with frontal cortex areas for their role in executive control. Impaired performance in anti-saccades has also been associated with the parietal cortex, but its role in inhibitory processes remains unclear.

Attentional limits in visual search with and without dorsal parietal dysfunction: space-based window or object-based span?

Attentional resource and distribution are specifically impaired in simultanagnosia, and also in the visuo-attentional form of developmental dyslexia. Both clinical conditions are conceived as a limitation of simultaneous visual processing after superior parietal lobule (SPL) dysfunction (review in Valdois et al., 2019).

Post-saccadic changes disrupt attended pre-saccadic object memory.

Trans-saccadic memory consists of keeping track of objects' locations and features across saccades; pre-saccadic information is remembered and compared with post-saccadic information. It has been shown to have limited resources and involve attention with respect to the selection of objects and features. In support, a previous study showed that recognition of distinct post-saccadic objects in the visual scene is impaired when pre-saccadic objects are relevant and thus already encoded in memory (Poth, Herwig, Schneider, 2015).

The posterior parietal cortex processes visuo-spatial and extra-retinal information for saccadic remapping: A case study.

Optimally collecting information and controlling behaviour require that we constantly scan our visual environment through eye movements. How the dynamic interaction between short-lived retinal images and extra-retinal signals of eye motion results in our subjective experience of visual stability remains a major issue in Cognitive Neuroscience. The present study aimed to assess and determine the nature of the contribution of the posterior parietal cortex (PPC) to the saccadic remapping mechanisms which contribute to such perceptual visual constancy.

Bálint syndrome.

This chapter starts by reviewing the various interpretations of Bálint syndrome over time. We then develop a novel integrative view in which we propose that the various symptoms, historically reported and labeled by various authors, result from a core mislocalization deficit. This idea is in accordance with our previous proposal that the core deficit of Bálint syndrome is attentional (Pisella et al.

Movement drift in optic ataxia reveals deficits in hand state estimation in oculocentric coordinates.

When vision is removed, limb position has been shown to progressively drift during repetitive arm movements. The posterior parietal cortex (PPC) is known to be involved in the processing of multisensory information, the formation of internal hand estimate, and online motor control. Here, we compared hand position drift between healthy controls and 2 patients with PPC damage to gain insight into the mechanisms underlying movement drift and investigate the possible role of the PPC in this process.

Elementary visuospatial perception deficit in children with neurodevelopmental disorders.

Aim: To assess the prevalence of elementary visuospatial perception (EVSP) deficit in children with neurodevelopmental disorders.

Method: Using a screening test designed and validated to measure dorsal EVSP ability, 168 children (122 males, 46 females; mean age 10y [SD 1y 10mo], range 4y 8mo-16y 4mo) diagnosed with developmental coordination disorder (DCD), specific learning disorder (SLD), attention-deficit/hyperactivity disorder (ADHD), and/or oral language disorder were compared with a group of 184 typically developing children. We also tested 14 children with binocular vision dysfunction and no neurodevelopmental disorder.

Validation of a simple screening test for elementary visuo-spatial perception deficit.

Objective: The reliability and validity of a screening test for a deficit in elementary visuo-spatial perception (EVSP) were evaluated.

Method: This prospective study collected performance from 210 typically developing individuals and evaluated the internal consistency of the EVSP screening test. Test-retest reliability was examined with 25 individuals.

Spatial and temporal dynamics of presaccadic attentional facilitation before pro- and antisaccades.

The premotor theory of attention and the visual attention model make different predictions about the temporal and spatial allocation of presaccadic attentional facilitation. The current experiment investigated the spatial and temporal dynamics of presaccadic attentional facilitation during pro- and antisaccade planning; we investigated whether attention shifts only to the saccade goal location or to the target location or elsewhere, and when. Participants performed a dual-task paradigm with blocks of either anti- or prosaccades and also discriminated symbols appearing at different locations before saccade onset (measure of attentional allocation).

Paradoxical adaptation of successful movements: The crucial role of internal error signals.

Visuo-motor adaptation has been classically studied using movements aimed at visual targets with visual feedback. In this type of experimental design, the respective roles of the different error signals cannot be fully disentangled. Here, we show that visuo-motor adaptation occurs despite the terminal success of the action and the compensation of the external error by a jump of the visual target.