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Aim: The frequent visual attention deficiency reported in children with attention-deficit/hyperactivity disorder (ADHD) could represent a relevant biomarker but robust estimates of such cognitive impairment in clinical populations remained challenging. To assess visual attention impairment in children ADHD using a new design tablet-based computerized test battery which allowed objective recording of visual search performances.Methods: Forty-nine children with ADHD and their IQ- and age-matched typically developmental (TD) children were enrolled in the study. Visual attention abilities were estimated by using the computerized modified barrage test developed by Metrisquare. We analyzed the time spent to achieve the whole battery and, the errors and omissions done by each child during each of the three sub-tasks.Results: We observed a significant association between the load of sustained attention requested to perform a sub-task and the numbers of errors and omissions made by the children whatever the group considered. During the most stringent sub-task in term of visual attention engagement, children with ADHD displayed more significant errors and omissions when compared to IQ- and age-matched controls. This effect was not mediated by the time spent to perform the task since we did not report any significant difference between groups.Conclusion: The different performance of the most stringent sub-task observed in children with ADHD could be due to their deficient neural activity in frontal areas responsible of visual endogenous attention needed for difficult visual searching tasks. This cognitive battery could be a useful instrument to estimate visual attention impairment in children with ADHD.HIGHLIGHTSWe assessed if a new design tablet-based computerized test battery would allow objective recording of visual search performances.We observed that children with ADHD made significantly more errors and omissions with respect to age-, sex- matched controls during the most stringent sub-task in terms of visual attention engagementThe tablet-based computerized test battery could be a promising tool to objectively estimate abnormal attention search impairment in ADHD.
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Trastorno por Déficit de Atención con Hiperactividad , Disfunción Cognitiva , Humanos , Niño , Trastorno por Déficit de Atención con Hiperactividad/diagnóstico , Trastorno por Déficit de Atención con Hiperactividad/psicología , Proyectos Piloto , Pruebas NeuropsicológicasRESUMEN
AIM: Eye movements have rarely been explored in preterm born children. The aim of this study was to compare horizontal eye movements in children born preterm and full term when they reached 8 years of age. METHODS: Eye movements were recorded in 24 preterm born children (18 boys) and 26 matched controls (19 boys), recruited by a French hospital, using an eye tracker. This identified different types of visually guided saccades, namely step, gap, overlap and antisaccades and pursuit eye movements. The saccades task measured the latency and the percentage of anticipatory and express saccades and errors. The pursuit task measured the gain and percentage of intrusive saccades. RESULTS: This study confirmed that children born at 24-28 weeks of gestation demonstrated a global deficit in inhibitory processes compared to children born full term. The saccades were less precise in the preterm group, anticipatory and express saccades were elevated and there was a high occurrence of intrusive saccades during pursuit movements. CONCLUSION: These findings suggest that preterm born children have immature brain structures, particularly the parietal and frontal cortexes that are responsible for both saccade and pursuit performance. These could have been the cause of the abnormal inhibitory control measured in this study.
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Movimientos Oculares , Movimientos Sacádicos , Encéfalo , Niño , Humanos , Recién Nacido , MasculinoRESUMEN
PURPOSE: Given the importance of spatial representation and navigation in the natural environment and the presence of sensory motor integration impairment in dyslexic children the aim of this study was to explore the capability in spatial orientation task in dyslexic children. MATERIALS AND METHODS: We included forty children: 26 dyslexic children (mean age: 10.1 ± 0.3 years old) and 14 typically developing (TD) children (mean age: 10.1 ± 0.4 years old). Children have to walk on an unguided isosceles rectangle triangle of 3 meters that was marked on the ground of a room, during two visual conditions: eyes open and eyes closed. Their paths were recorded using the HTC Vive system (Base + Trackers) with a refresh rate of 90 Hz with accuracy < 0.05 mm. RESULTS: Results underlined that both groups of children reported poor performance during eyes closed condition. Moreover, dyslexic children, reported poor spatial orientation capabilities in the most difficult conditions, that is during reproduction of hypotenuse and angle of 45 deg. CONCLUSIONS: We suggested that visual information is important during walking; the poor body orientation observed in dyslexic children could be due to a deficient integration of the sensorial inputs (visual, vestibular and proprioceptive). Further studies testing vestibular/cerebellar rehabilitation could be useful for these kinds of children.HighlightsChildren with dyslexia showed poor spatial orientation capabilities compared to typically developing children, particularly when visual inputs are not available and in the most difficult conditions (like rotation of the body).Poor motor abilities reported by children with dyslexia could be due to cerebrocerebellar pathways impairments.
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Dislexia , Orientación Espacial , Cerebelo , Niño , HumanosRESUMEN
Mixed and inconsistent findings have been reported across languages concerning grammatical morphology in speakers with Autism Spectrum Disorders (ASD). Some researchers argue for a selective sparing of grammar whereas others claim to have identified grammatical deficits. The present study aimed to investigate this issue in 26 participants with ASD speaking European French who were matched on age, gender and SES to 26 participants with typical development (TD). The groups were compared regarding their productivity and accuracy of syntactic and agreement categories using the French MOR part-of-speech tagger available from the CHILDES. The groups significantly differed in productivity with respect to nouns, adjectives, determiners, prepositions and gender markers. Error analysis revealed that ASD speakers exhibited a disrupted behaviour in grammatical morphology. They made gender, tense and preposition errors and they omitted determiners and pronouns in nominal and verbal contexts. ASD speakers may have a reduced sensitivity to perceiving and processing the distributional structure of syntactic categories when producing grammatical morphemes and agreement categories. The theoretical and cross-linguistic implications of these findings are discussed.
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Trastorno del Espectro Autista/psicología , Lingüística , Semántica , Habla , Femenino , Francia , Humanos , Masculino , Medición de la Producción del HablaRESUMEN
Importance: Children with profound hearing loss (HL) and vestibular impairment have worse cochlear implant outcomes compared with those without vestibular impairment. However, the decision for cochlear implantation is rarely based on vestibular function assessment as a complement to audiologic testing. Objectives: To identify the prevalence of vestibular impairment according to HL origin and to assess the association between vestibular impairment and delayed posturomotor development in children with profound HL. Design, Setting, and Participants: This cohort study was conducted in a pediatric referral center for cochlear implantation in Paris, France, using medical records data on HL origin, vestibular assessment, and ages of developmental milestone achievement. The cohort included children with profound HL (loss >90 dB HL) who completed vestibular assessment prior to cochlear implantation between January 1, 2009, and December 31, 2019. Data analyses were conducted between January and June 2023. Main Outcomes and Measures: The primary outcome was prevalence of vestibular impairment according to HL origin. Children were classified into 3 groups according to their responses to vestibular testing: normal vestibular function (NVF), partially impaired vestibular function (PVF), and complete bilateral vestibular loss (CBVL). Generalized logit models were performed to evaluate the association between vestibular impairment and causes of HL as well as posturomotor development delay. Results: A total of 592 children were included (308 males [52.0%]; mean [SD] age, 38 [34] months). In children with documented HL origin (n = 266), 45.1% (120) had HL with genetic origin, 50.0% of which were syndromic (mainly Usher and Waardenburg syndromes) and 50.0% were nonsyndromic (mainly associated with connexin 26). Among patients with infectious HL origin (n = 74), 70.3% (52) had cytomegalovirus (CMV) infection. Vestibular impairment was found in 44.4% (263 of 592) of the children; it was mostly symmetrical in 88.9% (526) and was CBVL in 5.7% (34) of the cases. Vestibular impairment was present in 78.3% (47) of children with genetic syndromic HL (56.7% [34] with PVF; 21.7% [13] with CBVL) and in 69.2% (36) of children with CMV infection (57.7% [30] with PVF; 11.5% [6] with CBVL). Genetic syndromic HL origin was found to be more often associated with both PVF and CBVL than other HL causes. The odds of having delays in 4 developmental milestones (head holding, sitting, standing with support, and independent walking) were higher in both PVF and CBVL (eg, head-holding odds ratios: 2.55 and 4.79) compared with NVF, and the age of achieving these milestones was higher in CBVL than PVF (eg, head holding: 7.33 vs 4.03 years; P < .001). All 4 developmental milestones were associated with the degree of vestibular impairment. Conclusions and Relevance: This cohort study found that among children with profound HL, vestibular impairment was prevalent, varied according to HL origin, and associated with posturomotor development; while all developmental milestones were associated with vestibular impairment severity, not all HL causes were associated with vestibular impairment severity. Children with profound HL may benefit from complete vestibular assessment before cochlear implantation, which would support early and adapted management, such as physical therapy for CBVL and cochlear implantation strategy.
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Enfermedades Vestibulares , Humanos , Femenino , Masculino , Preescolar , Enfermedades Vestibulares/epidemiología , Enfermedades Vestibulares/complicaciones , Niño , Pérdida Auditiva Bilateral/epidemiología , Implantación Coclear , Estudios de Cohortes , Equilibrio Postural/fisiología , Pruebas de Función Vestibular , Prevalencia , Paris/epidemiología , LactanteRESUMEN
AIM: The aim was to evaluate the effect of body actions on learning process, particularly semantic memory capabilities in drug-naïve children with attention deficit hyperactivity disorder (ADHD). METHOD: Thirty children had to listen to a story which was repeated three times in a row and then a fourth time five minutes later. After each listen, the child was asked what she/he remembered from the story. The whole sample was split randomly into three subgroups of equal IQ (mean 102.2 ± 12.7), age (mean age 8 ± 0.6 years), sex (ratio female to male 1:5) and severity of ADHD symptoms (34.2 ± 7.4); a G1 "Freeze" subgroup, which implied listening to the story while sitting on a chair without moving; a G2 "Minimal" subgroup, which implied listening to the story while sitting on a chair but free movement was allowed; a G3 "Prescribed movement" subgroup, which implied listening to the story standing up, while copying the experimenter movements that mimicked the actions told in the story. RESULTS: Although our sample was limited in size, interestingly, children in the G3 subgroup showed the highest short-term semantic memory retention compared to G1. In all subgroups, repetition allowed an increase in performance. CONCLUSIONS: Our exploratory findings stress the positive role of movement in children with ADHD to increase semantic memorization. Hyperactivity may counteract the deficit of memorization related to attention impairment in children with ADHD. Our results may encourage parents or teachers to allow children with ADHD to move around during short-term memory-retention tasks.
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BACKGROUND: Dysmetria in children with autism spectrum disorders is considered depend on executive dysfunctions. To explore the impact of inhibitory control and working memory on oculomotor performance in children with autism spectrum disorder (ASD), we used the memory guided saccade (MGS) paradigm. METHOD: We enrolled in our study a group of 26 children with ASD and in a group of 26 children age-, sex-, and IQ-matched of with typically development, using only one single delay period and one single stimulus amplitude. We recorded with a video eye-tracker system- the latency and the accuracy of the MGS as well as the number of anticipatory saccades during the MGS paradigm. RESULTS: Children with ASD displayed significant increased latency (p < .01), decreased amplitude of memory guided saccades (p < .01) and an elevated number of anticipatory saccades (p < .003), when compared to age-, sex-, IQ- matched children with typical development. CONCLUSION: These abnormalities may underline the executive dysfunctions frequently reported in ASD: the increased latency and the decreased amplitude of memory guides saccades may be related to planning and working memory impairments; the increased number of anticipatory saccades may be linked to a deficit in inhibitory control.
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Trastorno del Espectro Autista , Humanos , Niño , Movimientos Sacádicos , Memoria a Corto Plazo , Inhibición PsicológicaRESUMEN
Cognitive remediation therapy interventions could improve cognitive functioning in subjects with autism. To investigate the benefit of a short cognitive training rehabilitation in children with autism spectrum disorder (ASD) on pursuit and fixation performances. We recruited two groups (G1 and G2) of 30 children with ASD, sex-, IQ- and age-matched (mean 11.6 ± 0.5 years), and pursuit and fixation eye movements were recorded twice at T1 and T2. Between T1 and T2, a 10-min cognitive training was performed by the G1 group only, whereas the G2 group had a 10-min of rest. For all children with ASD enrolled in the study, there was a positive correlation between restricted and repetitive behaviour scores of both Autism Diagnostic Interview-Revised (ADI-R) and the Autism Diagnostic Observation Schedule (ADOS) and the number of saccades recorded during the fixation task at T1. At T1, oculomotor performances were similar for both groups of ASD children (G1 and G2). At T2, we observed a significant reduction in the number of saccades made during both pursuit and fixation tasks. Our findings underlined the importance to promote cognitive training rehabilitation for children with ASD, leading to a better performance in inhibitory and attention functioning responsible for pursuit and fixation eye movement's performance.
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Trastorno del Espectro Autista , Entrenamiento Cognitivo , Movimientos Oculares , Fijación Ocular , Femenino , Humanos , Masculino , Atención/fisiología , Trastorno del Espectro Autista/fisiopatología , Trastorno del Espectro Autista/rehabilitación , Análisis de Datos , Movimientos Oculares/fisiología , Tecnología de Seguimiento Ocular , Fijación Ocular/fisiología , Desempeño Psicomotor , Seguimiento Ocular Uniforme/fisiología , Movimientos Sacádicos/fisiología , Test de Stroop , Factores de Tiempo , NiñoRESUMEN
Children with ADHD show poor motor control. The aim of the present study was to test whether children with ADHD improved their motor performances (oculomotor as well as posture) after a short visuopostural training period. Two groups (G1 trained and G2 non-trained), each comprising 15 children with ADHD matched in IQ (intelligence quotient), sex, and age, participated in the study. Eye movements and postural sway were measured before (T1) and after (T2) 10 min of visuopostural training for the trained group and after 10 min of resting for the non-trained group. Training consisted of a visual search task performed while the child was standing on an unstable platform. At T1, oculomotor and postural abilities were statistically similar for both groups of children with ADHD (trained and non-trained). At T2, significant improvements in both oculomotor and postural capabilities were observed for the trained group but not for the non-trained group. These findings suggest that a short visuopostural training period could help children with ADHD to learn how to focus their visual attention in order to improve motor performance. Visuopostural training could allow a better integration of sensory inputs via central mechanisms, leading to improvement in both oculomotor and postural control. Further studies on a larger number of children with ADHD will be needed to confirm these findings and explore the eventual possible persistence of the training effect.
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Reading disabilities have a profound impact on the academic performance and achievement of children. Although oculomotor pattern abnormalities during reading in children with dyslexia are well known, those in individuals with attention deficit and hyperactive disorders (ADHD) - who also frequently exhibit a reading impairment - remain largely undetermined. The objective of the present study was to evaluate the peculiarities of oculomotor pattern abnormalities during a reading task. An eye-tracker was used to record eye movements in four distinct groups of children with neurodevelopmental disorders: children with dyslexia, children with ADHD with and without comorbid dyslexia, and in a group of typically developing children (TD). Ninety-six children participated in the study (24 children per group, IQ- and age-matched groups). The duration of fixation, the total reading time, and the number of forward and backward saccades were similar in children with dyslexia and ADHD + dyslexia, but were significantly different from those observed in children with ADHD and with TD. Our findings suggest a link between dyslexia and oculomotor reading impairments in both children with dyslexia and children with ADHD + dyslexia, indicating that the oculomotor pattern in children with ADHD without comorbid dyslexia is similar to that observed in TD children. We suggest that an objective eye movement recording during a reading task could help clinicians to better evaluate the possible presence of comorbid dyslexia in children with ADHD. Furthermore, children with ADHD with and without comorbid dyslexia could also have working memory deficiencies. Further studies are needed to confirm this finding.
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Trastorno por Déficit de Atención con Hiperactividad , Dislexia , Trastorno por Déficit de Atención con Hiperactividad/complicaciones , Niño , Dislexia/complicaciones , Movimientos Oculares , Tecnología de Seguimiento Ocular , Humanos , LecturaRESUMEN
To our knowledge, there are no studies recording the reading eye movements of children born prematurely. We examined the oculomotor patterns during reading of 23 children born prematurely (M age = 7.8, SD = 0.2 years) to compare them with those from two groups of children born at full-term who were matched for chronological age or reading age, respectively. We found the oculomotor reading pattern in children who were preterm to be similar to that of children who were full-term and matched for reading age; this shared pattern was characterized by longer duration of fixations, frequent prosaccades of smaller amplitude and several backward saccades. In contrast, when these two groups were compared to full-term children matched for chronological age, the latter group showed significantly shorter duration of fixations, less frequent saccades and larger amplitude prosaccades. Thus, the oculomotor pattern we observed in 7-year-old children who were either preterm or reading-delayed, relative to their age-matched peers, reflected delayed development of brain areas involved in reading-related eye movements.
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Movimientos Oculares , Lectura , Encéfalo , Niño , Fijación Ocular , Humanos , Recién Nacido , Movimientos SacádicosRESUMEN
A decrease in visual perception with age was observed due to a decline in neurocognitive and visual functions. Previous studies showed that aging affects visual processes and contextual perceptual phenomena. The aim of our study was to explore the effect of age as well as the effect of Age-Related Macular Degeneration (AMD) on the visual searching task. Three groups of twenty-one subjects were recruited: AMD subjects (mean age 72.29 ± 4.83 years); healthy elderly (72.55 ± 4.95); and young healthy volunteers (28.38 ± 2.77). Visual perception functions were evaluated with a modified barrage test developed by Metrisquare. Our results showed that AMD patients and elderly do not differ in terms of time, omissions and errors. However both were slower to perform the visual perception tests when compared with young adults. Regarding the number of errors and omissions, we only found significant differences between the young and the AMD subjects, the later making more omissions and errors respect to young healthy volunteers. Despite AMD patients made more errors likely because to their poor fixation capability, we could conclude that AMD patients, as well as healthy elderly subjects, could compensate their altered visual strategies by taking more time to perform the visual searching tasks, probably due to cortical plasticity.HighlightsAMD patients and healthy elderly subjects do not differ in terms of time, omissions and errors.AMD patients, as well as healthy elderly subjects could compensate their visual difficulties by taking more time to perform the visual searching tasks when compared to young healthy volunteers. It is probably due to cortical plasticity.Note, however that AMD patients could make more errors when compared to young healthy volunteers, probably due to their poor fixation capability.The number of omissions and errors not different in healthy young and in elderly subjects.
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Degeneración Macular , Anciano , Envejecimiento , Humanos , Degeneración Macular/complicaciones , Pruebas Neuropsicológicas , Percepción Visual , Adulto JovenRESUMEN
(1) Background: This study explored the effect of short vestibular and cognitive training on the reading speed in dyslexic children. (2) Methods: The reading speed was evaluated by using a reading test (Évaluation de la Lecture en FluencE, ELFE) in a crossover design before (baseline) and after vestibular training (post VT) and no vestibular training (post no VT). Nineteen dyslexic children (9.48 ± 0.15 years) participated in the study. The vestibular and cognitive training (software developed by BeonSolution S.r.l.) consisted in four exercises presented on a Wacom tablet 10â³ done for 16 min per session two times per week for four weeks; each exercise was composed of eight levels with increased difficulty. (3) Results: Following vestibular and cognitive training, dyslexic children increased their reading speed; interestingly, such an increase persisted at least one month after training. (4) Conclusions: Vestibular and cognitive training could improve the vestibular network, which is well known for being involved in several cognition functions leading to reading improvement in dyslexic children. Adaptive mechanisms could be responsible for maintaining such improvement for at least one month.
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Background: Dyslexia is a disorder found in 5-10% of school-aged children. Several studies reported visual deficits and oculomotor abnormalities in dyslexic children. The objective of our study was to examine horizontal pursuit performance in dyslexic children, despite its poor involvement in reading. Methods: Eye movements were recorded by video-oculography in 92 children (46 dyslexic children, mean age: 9.77 ± 0.26 and 46 non dyslexic, IQ- and age-matched children). Both the number of catch-up saccades occurring during pursuit task and the gain of pursuit were measured. Results: Catch-up saccades were significantly more frequent in the dyslexic group than in the non-dyslexic group of children. Pursuit performance (in terms of the number of catch-up saccades and gain) significantly improved with increasing age in the non-dyslexic children group only. Conclusions: The atypical pursuit patterns observed in dyslexic children suggest a deficiency in the visual attentional processing and an immaturity of brain structures responsible for pursuit triggering. This finding needs to be validated by neuroimaging studies on dyslexia population.
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Dyslexia is a specific disorder in reading abilities. The aim of this study was to explore whether a short visual attentional training could improve reading capabilities in children with reading disorders by changing their oculomotor characteristics. Two groups (G1 and G2) of 25 children with reading disabilities and who are matched in IQ (intelligence quotient), sex, and age participated in the study. The allocation of a subject to a specific group (G1 = experimental group; G2 = control group) was generated in an unpredictable random sequence. The reading task was recorded twice for G1, i.e., before (T1) and after (T2) 10 min of visual attentional training. Training consisted of oculomotor tasks (saccades and pursuits movements) and searching tasks (three different exercises). For G2, the two reading tasks at T1 and T2 were done at an interval of 10 min instead. We found that at T1, oculomotor performances during reading were statistically similar for both groups of children with reading disabilities (G1 and G2). At T2, the group G1 only improved oculomotor capabilities significantly during reading; in particular, children read faster, and their fixation time was shortest. We conclude that short visual attentional training could improve the cortical mechanisms responsible for attention and reading capabilities. Further studies on a larger number of dyslexic children will be necessary in order to explore the effects of different training types on the visual attentional span given its important role on the orienting and focusing visuospatial attention and on the oculomotor performance in children with dyslexia.
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Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder without validated and objective diagnostic procedures. Several neurological dysfunctions in the frontal circuit, in the thalamus, and in the cerebellum have been observed in subjects with ADHD. These cortical and subcortical areas are responsible for eye movement control. Therefore, studying eye movements could be a useful tool to better understand neuronal alterations in subjects with ADHD. The aim of the present study was firstly to compare the quality of pursuit eye movements in a group of 40 children with ADHD (age 8.2 ± 1.2) and in a group of 40 sex-, IQ-, age-matched typically developing (TD) children; secondly, we aimed to examine if a short visuo-attentional training could affect pursuit performances in children with ADHD. Findings showed that children with ADHD presented a greater number of catch-up saccade and lower pursuit gain compared to TD children. Differently to TD children, in children with ADHD, the number of catch-up saccades and the pursuit gain were not significantly correlated with children's age. Furthermore, a short visuo-attentional training period can only slightly improve pursuit performance in children with ADHD, leading to a decrease of the occurrence of catch-up saccades only, albeit the effect size was small. The absence of any improvement in pursuit performance with age could be explained by the fact that the prefrontal and fronto-cerebellar circuits responsible for pursuit triggering are still immature. Pursuit eye movements can be used as a useful tool for ADHD diagnosis. However, attentional mechanisms controlled by these cortical structures could be improved by a short visuo-attentional training period. Further studies will be necessary to explore the effects of a longer visuo-attentional training period on oculomotor tasks in order to clarify how adaptive mechanisms are able to increase the attentional capabilities in children with ADHD.
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Autism Spectrum Disorders subjects (ASD) is characterized by postural control deficits. This study aimed to explore the effect of a short postural rehabilitation training program on postural capabilities in children with ASD. Two groups (G1 and G2) of twenty children with ASD of IQ-, sex- and age- matched (mean age 11.7 ± 2.4 years) were included in this study. Posture was recorded by using the Balance Quest from Framiral on unstable platform in three different viewing conditions. The rehabilitation program consisted in two distinct postural control training exercises. Postural recordings were performed twice at T1 and T2 for both groups of children. Between T1 and T2 a 6-minute postural training was performed by the G1 group only, while the G2 group had a 6-minute of rest. Children were allocated randomly to the G1 or G2 groups. At T1, postural instability was similar for both groups of ASD children (G1 and G2) desp+\ite viewing conditions. At T2, we observed an improvement of postural control related to a mixed effect of training rehabilitation but also of test-retest. Knowing the potential of new rehabilitation strategies, the impact of postural control deficit in ASD children needs to be reconsidered. Well design case-control studies are requested to ensure scientific validity of postural rehabilitation training program.
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Trastorno del Espectro Autista/fisiopatología , Trastorno del Espectro Autista/rehabilitación , Equilibrio Postural , Análisis de Varianza , Trastorno del Espectro Autista/diagnóstico , Niño , Cognición , Humanos , Postura , Índice de Severidad de la EnfermedadRESUMEN
Attention is a major cognitive function that allows the individuals to focus selectively on a discrete stimulus while ignoring others. Visual information could be driven endogenously, when the goals or desires are voluntary, or exogenously, in response to salient visual events in the environment. Since subjects with attention deficit hyperactivity disorder (ADHD) show heightened distractibility during activities that require significant attentional engagement, we hypothesized that they may be more severely impaired in their ability to perform endogenous tasks than controls. To elicit endogenous and exogenous shifts of attention, we thus used a modified version of Posner's cueing task. We compared oculomotor performance measured by an eye tracker in a group of 31 children with ADHD (mean age = 9.1 ± 1.3 years) and age-, sex-, and IQ-matched typically developing children. Endogenous and exogenous conditions were explored in three distinct visual sub-conditions (valid, invalid, and neutral). We found that children with ADHD showed longer latency during endogenous conditions compared to TD children in invalid sub-conditions. They also performed more errors than controls, during the endogenous task in neutral sub-conditions and during exogenous task in neutral and invalid sub-conditions. Our study suggests that children with ADHD may allocate their attention resource toward the detection of exogenous targets with a deficit in their ability to perform endogenous task. We suggest also that they have a difficulty in the engagement of the inhibitory control system particularly during voluntary saccade performance. This could result from impaired interactions between the ventral and dorsal attention networks as well as in the frontal eye field, although neuroimaging studies are necessary to validate this hypothesis in the ADHD population.
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To identify quantitative indicators of social communication dysfunctions, we explored the oculomotor performances in subjects with autism spectrum disorders. Discordant findings in the literature have been reported for oculomotor behavior in subjects with autism spectrum disorders. This study aimed to explore reflexive and voluntary saccadic performance in a group of 32 children with autism spectrum disorders (mean age: 12.1 ± 0.5 years) compared to 32 age-, sex-, and IQ-matched typically developing children (control group). We used different types of reflexive and voluntary saccades: gap, step, overlap, and anti-saccades. Eye movements were recorded using an eye tracker (Mobile EBT®) and we measured latency, percentage of anticipatory and express saccades, errors of anti-saccades and gain. Children with autism spectrum disorders reported similar latency values with respect to typically developing children for reflexive and voluntary saccades; in contrast, they made more express and anticipatory saccades overall, as shown in paradigm testing (gap, step, overlap, and anti-saccades). Our findings support previous evidence of the atypicality of the cortical network, which is involved in saccade triggering and attentional processes in children with autism spectrum disorders.
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Trastorno del Espectro Autista/fisiopatología , Movimientos Oculares , Atención , Trastorno del Espectro Autista/complicaciones , Estudios de Casos y Controles , Niño , Femenino , Fijación Ocular , Humanos , Masculino , Tiempo de Reacción , Movimientos SacádicosRESUMEN
BACKGROUND: Verticality, or more precisely the ability to perceive spatial orientation with regard to gravity, is based on the integration of visual, vestibular and somesthetic information. OBJECTIVE: The purpose of the present study was to compare the subjective visual vertical (SVV) in patients with Usher (type I and type II) with visual or vestibular impairment, and in healthy participants, in order to explore the importance of the visual and vestibular functions on the vertical's perception. METHODS: We evaluated the SVV using a wall housing which projects on the opposite wall a red-light line of about 2 meters, obtained by laser cannon. The evaluation was carried out under two tilt conditions: clockwise and counter-clockwise randomly performed five times in each direction. The response to the SVV task was quantified by the mean of the absolute values of the SVV. RESULTS: Responses to the SVV were significantly less accurate in patients with Usher with respect to healthy participants while it was similar for the two groups of patients with Usher. CONCLUSIONS: We hypothesize that visual inputs play a very important role in the perception of verticality and that the symmetrical bilateral vestibular deficit in Usher type I does not have a strong impact in perception of verticality.