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Doctorat internacional This thesis takes inspiration from biology to replicate in robots the oculomotor strategies humans and other species use to acquire visual information. Firstly, it establishes the foundations of the work by reviewing current knowledge on the primate oculomotor system, the state of the art on adaptive learning in artificial neural networks, and the main types of robotic heads that would enable imitation of eye movements. Afterwards, the thesis goes in detail on selecting a specific head configuration, developing algorithms for the generation of accurate saccades, and developing internal models that are generalizable across different robotic instantiations. The acquired knowledge is then applied to the specific task of using saccadic gaze shifts to extract depth information from the scene. Programa de Doctorat en Informàtica

Este trabajo de revision sistematica tiene como objetivo principal el sintetizar los articulos de investigacion de alto impacto que contengan informacion relacionada a los movimientos sacadicos y sus componentes como indicadores del engano, para ello se utiliza un diseno de revision documental en donde se implementa el metodo Prisma para contar con criterios de inclusion y exclusion de las investigaciones a utilizar; despues de realizar la busqueda por las diferentes revistas cientificas se obtienen al final 38 articulos los cuales cumple con los criterios de seleccion. Al realizar el analisis de los trabajos de investigacion para la variable de carga cognitiva se obtiene 9 articulos que confirman, 7 que niegan y 4 mencionan que los datos no son concluyentes, en cuanto a la siguiente variable que es la dilatacion pupilar la situacion cambia ya que 12 articulos confirman que es posible detectar la mentira mediante la medida de la pupila y solo 1 menciona que los resultados no son concluyentes, en cuanto a la ultima variable los resultados cambian de nuevo ya que al terminar de revisar las investigaciones se pudo obtener 7 articulos que confirman el postulado y 4 que lo niegan dejando 3 articulos que mencionan que los resultados no son concluyentes. Al contar con la informacion necesaria se concluye que las variables movimientos sacadicos y carga cognitiva no muestran evidencia suficiente para considerar que pudieran funcionar como indicadores en la veracidad del testimonio, sin embargo, la variable dilatacion pupilar muestra mejores evidencias para cumplir con el trabajo de indicador de la verdad. The main objective of this systematic review is to synthesize high impact research articles containing information related to saccadic movements and their components as indicators of deception, for this purpose a documentary review design is used where the Prisma method is implemented to have inclusion and exclusion criteria of the research to be used; after performing the search through the different scientific journals, 38 articles are obtained which meet the selection criteria. When analyzing the research works for the cognitive load variable, 9 articles confirm, 7 deny and 4 mention that the data are not conclusive. As for the next variable, which is pupil dilation, the situation changes since 12 articles confirm that it is possible to detect lying by measuring the pupil and only 1 mentions that the results are not conclusive, As for the last variable, the results change again, since after reviewing the research, 7 articles confirm the postulate and 4 deny it, leaving 3 articles that mention that the results are not conclusive. Having the necessary information, it is concluded that the variables saccadic movements and cognitive load do not show sufficient evidence to consider that they could function as indicators of the truthfulness of the testimony; however, the variable pupillary dilation shows better evidence to fulfill the job of truth indicator.

The article reviews the author’s research on two selected eyetracking parameters, i.e., spatial saccades and pupil dilation, and their relationship with the mental activity of the translator during sight translation performance. An overview and discussion of the results of studies conducted in recent years show how we can detect particular mental processes involved in translation thanks to the analysis of specific saccadic movements. It also points out the advantages and limitations of pupil dilation in the assessment of the cognitive load. Both eyetracking parameters have been analysed in relation to their neurobiological determinants.

Purpose: To investigate saccadic movements in subjects with eccentric fixation due to a deep central scotoma in Stargardt disease (STGD). Methods: We studied 10 patients with STGD and 10 healthy subjects (control group). Saccadic movements of all the 20 subjects were assessed by using the eye tracker technique Tobii Glasses Pro 2. Standard measurements of reading ability (MNREAD charts), visual acuity (ETDRS charts), contrast sensitivity (Pelli-Robson charts), reading contrast threshold and speed (REX charts), retinal sensitivity and stability and localization of the fixation (MP1 fundus perimetry) were obtained in all subjects. Results: The saccadic movements time was significantly slower in STGD than in healthy subjects (699 ± 193 ms vs 299 ± 40 ms, p Conclusion: Ocular saccades guided by eccentric fixation in STGD patients are significantly slower than in the control group, especially when the target corresponds to retinal areas with a deep scotoma. These results can explain the worse reading performance in STGD subjects, in particular when a non-viewing area on the right part of the text is present.

Tools are wielded by their handles, but a lot of information about their function comes from their heads (the action-ends). Here we investigated whether eye saccadic movements are primed by tool handles, or whether they are primed by tool heads. We measured human saccadic reaction times while subjects were performing an attentional task. We found that saccades were executed quicker when performed to the side congruent with the tool head, even though “toolness” was irrelevant for the task. Our results show that heads are automatically processed by the visual system to orient eye movements, indicating that eyes are attracted by functional parts of manipulable objects and by the characteristic information these parts convey.

The objective of this study was to characterize saccades in children with neurodevelopmental disorders (NDDG, 17 children, age: 7–12 years) and compare them with a control group (CG, 15 children, age: 7–12 years), comparing the outcomes obtained with a subjective score system (Northeastern State University College of Optometry’s Oculomotor test, NSUCO) with the objective analysis obtained through a commercially available Eye Tracker (Tobii Eye X, Tobii, Stockholm, Sweden) and a specialized software analysis (Thomson Software Solutions, Welham Green, UK). Children from the NDDG obtained significantly lower NSUCO scores (p &lt, 0.001) compared with CG. Concerning eye tracking analyses, we found a significantly higher number of hypometric saccades in NDGG (p ≤ 0.044). Likewise, we found a significantly higher percentage of regressions in the NDDG for a time interval of presentation of stimuli of 1 s (p = 0.012). Significant correlations were found between different NSUCO scores and percentage of regressions, number of saccades completed and number of hypometric saccades. The presence of hypometric saccades and regressions seems to be a differential characteristic sign of children with neurodevelopmental disorders that can be detected using an objective eye tracking analysis, but also using the subjective test NSUCO that can be easily implemented in all clinical settings.

Attention deficit with/without hyperactivity is one of the most controversial and currently studied disorders. From a neuropsychological point of view, its characterization is gaining ground with a view to obtaining a more effective diagnosis and treatment. However, there are not many studies that have compared the different profiles of ADHD from this approach. Thus, the aim of the present study was to compare groups of school-aged children with characteristics of attention deficit, hyperactivity-impulsivity and controls, with respect to the neuropsychological variables: saccadic movements, auditory discrimination, executive functions and working memory. A sample of 36 students aged 8-10 years was evaluated, distributed equally among the 3 groups. After analyzing the results obtained from the application of different tests: King-Devick,(KD), Phoneme Articulation Test (PAF), Stroop Color and Word Test and the index of working memory of the Weschler Intelligence Scale for children; it was confirmed that subjects with behavioral characteristics of attention deficit and hyperactivity showed a worse performance than the control group in all variables, and no statistically significant differences were found between inattentive and hyperactive ADHD profiles. Results were discussed and it is concluded that based on the present comparative study, a differential neuropsychological profile cannot be established between children with a characteristic pattern of inattention versus one of hyperactivity-impulsivity, and generally the children with clinical features of ADHD presented a decrease in the neuropsychological variables evaluated.

One of the main ocular diseases is age-related macular degeneration, actually treated with antibodies injections into the eye. This problem has been faced by computational approaches, taking into account either the influence of the tissues surrounding the vitreous, or the saccades. The aim of this work is to propose a combined fluid dynamic model of the vitreous chamber that analyses the impact of the saccades on the fluid dynamic mechanisms. The ocular vitreous humor was modeled considering liquefaction occurring in presence of age-related macular degeneration. We identified two kinds of boundary conditions, one related to the physiological environment outside the chamber, and one related to the saccades. The scleral hydraulic conductivity was evaluated by means of experimental permeability tests. An exponential decay was used to describe the trend of the scleral hydraulic conductivity with the acting pressure drop. The streamline analysis shows two main stagnant regions on the equatorial plane and peculiar fluid dynamics in absence of saccades. This study demonstrates the major role played by the saccades in determining the fluid dynamic mechanisms inside the vitreous chamber of the eye and represents a powerful tool to investigate vitreous dynamics and its relation to clinical issues.

Experimental goal of retinal tracker device was to show ability to detect retinal motions caused by eye drifts, saccades and microsaccades with an ultrafast optoelectronic device that provides up to 1240 retinal images per second. Moreover, high speed of the device, related to optical scanning and detection guarantees safe, non-invasive and objective measurements of the living eye.

La percepción visual tiene influencias sobre la competencia de lectoescritura (Condemarín, Chadwick, y Milicic de López, 2003). No en vano, de la sincronía entre las diferentes destrezas visuales y motoras dependen los resultados de aprendizaje de la lectura, pues posibilitan que el niño responda satisfactoriamente a las diferentes demandas que implica este ejercicio académico. Sin embargo, existen resultados poco concluyentes en las investigaciones que abordan su correlación. Por otra parte, dado que las habilidades viso-perceptuales son fruto de nuestra experiencia con el entorno, estas pueden ser reorientadas para lograr mejores resultados en la experiencia de la lectura (Saona Santos y Costa Vila, 2012). Con el fin de contribuir al conocimiento en esta área de investigación, así como a la puesta en práctica del aprendizaje de las habilidades viso-perceptuales, planteamos un estudio para determinar la incidencia de un programa de estimulación perceptivo-visual en el desarrollo de la capacidad de la lectura en niños de educación infantil, primaria y ESO. En consecuencia, se realizó la evaluación periódica de 39 pacientes con dificultades de lectoescritura, problemas del lenguaje y con problemas perceptivos, discriminativos visuales y con alteraciones en los movimientos oculares sacádicos. Los primeros resultados señalan que aquellos pacientes que mejoran los movimientos sacádicos mejoran también sus capacidades lectoras. Por otro lado, se evidencian diferencias significativas en la puntuación media de las capacidades lectoras entre los niños evaluados, en virtud de si tienen definida o no la lateralidad, alcanzando valores superiores en aquellos que han desarrollado esta destreza viso-perceptual. En términos generales, los aportes de este estudio no solo ratifican la importancia de evaluar adecuadamente el desempeño de la percepción visual para el aprendizaje de la lectura, sino que demuestran que la atención a su interdependencia puede contribuir a orientar las prácticas educativas y optimizar el esfuerzo de estudiantes para mejorar su rendimiento académico. Visual perception influences literacy skills (Condemarín, Chadwick, & Milicic de López, 2003). Not surprisingly, the learning outcomes of reading depend on the synchrony between the different visual and motor skills, since they enable the child to respond satisfactorily to the different demands that this academic exercise implies. However, there are inconclusive results in the investigations that address its correlation. On the other hand, since visual-perceptual skills are the result of our experience with the environment, they can be reoriented to achieve better results in the reading experience (Saona Santos and Costa Vila, 2012). In order to contribute to knowledge in this area of research, as well as to the implementation of learning viso-perceptual skills, we propose a study to determine the incidence of a perceptual-visual stimulation program in the development of capacity of reading in preschool, primary and ESO children. Consequently, the periodic evaluation of 39 patients with reading and writing difficulties, language problems and perceptual, discriminatory visual problems and alterations in saccadic eye movements was carried out. The first results indicate that those patients who improve saccadic movements also improve their reading abilities. On the other hand, there are significant differences in the mean score of reading skills among the children evaluated, by virtue of whether they have defined laterality or not, reaching higher values in those who have developed this visually-perceptual skill. In general terms, the contributions of this study not only confirm the importance of properly evaluating the performance of visual perception for learning to read, but also demonstrate that attention to their interdependence can help guide educational practices and optimize effort of students to improve their academic performance.

El reconocimiento de rostros es una habilidad innata, la cual muestra una ventana de integridad y desarrollo del cerebro que se puede explorar en etapas muy tempranas de la vida. Esta construcción del cerebro se da a partir de experiencias sensoriales multimodales, dentro de las cuales a nivel visual los movimientos oculares juegan un papel importante en cuanto a la maduración y organización de los patrones fisiológicos que participan en la construcción del desarrollo visual, cognitivo y social temprano. Partiendo de esta concepción el objetivo de este trabajo es describir los patrones de motilidad ocular involucrados en el reconocimiento de rostros y de rostro materno en lactantes prematuros por medio del Eye Tracker; en el estudio participaron lactantes prematuros tardíos que asisten al programa Madre Canguro del Hospital San Ignacio de Bogotá, a quienes se les presentaron estímulos visuales en tres tareas de preferencia visual y reconocimiento de rostros y de objeto, encontrando aportes significativos, dentro de los cuales se observó que a los 2 meses de edad los bebés sí presentan una preferencia por la imagen del rostro de su madre respecto a otros estímulos no faciales. Se observaron diferencias madurativas en las características fisiológicas de los movimientos sacadicos y microsacadicos a los dos y a los tres meses de edad corregida. Abstract: The recognition of faces in babies is an innate ability, which is a window of integrity and brain development that can be explored in the early stages of life, this is the construction of the brain is given bilaterally from multimodal sensory experiences, within which ocular movements play an important role in the maturation and organization of the physiological patterns that participate in the construction of visual, cognitive and social early development. From this conception the objective of this work is to describe the patterns of ocular motility involved in the recognition of faces and maternal face in premature infants through Eye Tracker; In the study, late preterm infants attended the Madre Canguro program of the Hospital San Ignacio de Bogotá, to whom visual stimuli were presented in three tasks of visual preference and face recognition and of object. Significant contributions were found, within which it was observed that at 2 months of age babies do have a preference for the image of their mother's face with respect to other non-facial stimuli, Maturational differences were observed in the physiological characteristics of the sacchadic and microsaccadic movements at two and three months of corrected age. Maestría

The review relates to modern point of view on the role of cerebellar structures in eye movement control. The review dedicates todisorders of all types of eye movements involving participating cerebellum in oculomotor and vestibular systems which are supported by experimental results. Revealing the mechanisms of eye movement disorders, especially when gaze-holding and saccadic movements, opens possibilities for its therapy.

Most neurological diseases are usually accompanied by a broad spectrum of oculomotor alterations. Being able to record and analyze these different types of eye movements would be a valuable tool to understand the functional integrity of brain structures. Nowadays, video-oculography is the most widely used eye-movements assessing method. This paper presents a study of the existing eye tracking video-oculography techniques and also analyzes the importance of measuring slight head movements for diseases diagnosis. In particular, two types of methods are reviewed and compared, including appearance-based and feature-based methods which are further subdivided into 2D-mapping and 3D model-based approaches. In order to demonstrate the advantages and disadvantages of these different eye tracking methods for disease diagnosis, a series of comparisons are conducted between them, addressing the complexity of the system, the accuracy achieved, the ability to measure head movements and the external conditions for which they have been designed. Lastly, it also highlights the open challenges in this research field and discusses possible future directions., The authors wish to thank the support of (UNL (CAID-PIC-50420150100098LI), ANPCyT (PICT 2016-0651) and RoboCity2030-DIH-CM Madrid Robotics Digital Innovation Hub (S2018/NMT-4331), funded by “Programas de Actividades I+D en la Comunidad de Madrid” and cofunded by Structural Funds of the EU.

Purpose of present study is to evaluate whether the Pre-Macular Bursa (PMB) modifies Wall Shear Stress (WSS) at the retinal surface during saccadic movements. We created a mathematical model consisting of 25,000 grid cells and simulated a horizontal saccade spanning 50° in 0.17s, both in absence and in presence of the PMB. Wall Shear Stress SS was computed throughout the retinal surface and the posterior pole was divided into 3 Zones comprising 400 nodes each: Zone 1 (radius 3.5 mm; 0°-17°) corresponding to the PMB area; Zone 2 (concentric annular area 5 mm in radius; 22°) and Zone 3 (concentric annular area 5.5 mm; 28°). The PMB reduced WSS significantly at the macula and increased it in the immediate surroundings. Average WSS in Zone 1 was 1.53 ± 1.01 (max 4.23 Pa) with PMB Vs 6.94 ± 9.23 (max 35.83 Pa) without. Zone 2 WSS was 9.39 ± 10.33 (max 48.36 Pa) with PMB Vs 6.95 ± 9.40 (max 38.60 Pa) without Zone 3 WSS was 8.41 ± 10.03 (max 43.16 Pa) with PMB Vs 6.88 ± 9.42 (max 39.43 Pa) without (p 0.001 in all cases). The PMB significantly reduces WSS over the retinal surface underlying the bursa region; conversely, WSS slightly increases it in the immediate neighboring areas.

Resumen: La lectura es un proceso complejo en el que intervienen factores perceptivos, lingüísticos, cognitivos y neuropsicológicos. Algunos factores neuropsicológicos participan en el proceso lector desde su inicio, tales como los movimientos oculares que se realizan en la lectura, la motricidad y la lateralidad. El objetivo de este estudio fue evaluar la relación entre estos factores neuropsicológicos y la comprensión lectora en alumnos de Educación Primaria. Para ello se seleccionó una muestra de 52 niños de ocho años de edad en los que se evaluaron los movimientos oculares sacádicos para leer, los patrones motores básicos, la lateralidad y la comprensión lectora. Con los datos obtenidos se ha realizado un estudio descriptivo y correlacional cuyos resultados mostraron que existe una relación positiva y significativa entre las variables y que los alumnos con mejor habilidad de movimientos oculares sacádicos, mejor ejecución en patrones motores básicos y lateralidad homogénea obtuvieron mayores puntuaciones en comprensión lectora. Este estudio abre nuevas perspectivas teóricas y científicas para el aprendizaje de la lectura y la calidad educativa. Abstract: Reading is a complex process which involves perceptual, linguistic, cognitive, and neuropsychological factors. Some neuropsychological factors are involved in the acquisition of the reading process such as eye movements that are carried out during the reading process, motor functions, and laterality. The aim of this study is the evaluation of the relationship between such neuropsychological factors and the reading comprehension process in Elementary Education students. A sample of 52 eight year old children was observed. Their saccadic movements while reading, basic motor patterns, laterality, and reading comprehension were evaluated. With the data obtained a descriptive and correlational study was carried out whose results showed that there is a positive and significant relationship between the abovesaid variables. It was also evidenced that those students with better execution of ocular saccadic movements, better execution of basic motor patterns and homogenous laterality showed a higher reading comprehension level. This study opens up new theoretical and scientific prospects for literacy learning and quality of education.

Objetivo: Determinar si los movimientos sacádicos influyen en el rendimiento académico de estudiantes de básica primaria. Metodología: Se tomó una muestra no probabilística por conveniencia de 121 estudiantes de básica primaria con situación de vulnerabilidad en una Institución Educativa de la ciudad de Cúcuta, Colombia. La muestra se dividió en dos grupos: el primero, de alto rendimiento académico, conformado por 56 estudiantes, 60 % niñas y 40 % niños, con una media de 11,70 años; el segundo, de bajo rendimiento, constituido por 65 estudiantes, 40 % niñas y 60 % niños, con una media de 12,29 años. A ambos grupos se aplicó el test de King y Devick (1976) o test K-D de movimientos sacádicos. Resultados: Los resultados mostraron diferencias estadísticamente significativas entre las medias de los tiempos de lectura de cada una de las tarjetas como en la media del tiempo total de lectura de las tres tarjetas del test K-D. También se encontraron diferencias significativas en el porcentaje de estudiantes que presentan problemas en relación con los movimientos sacádicos: en el grupo con alto rendimiento el porcentaje de estudiantes con problemas relacionados con movimientos oculares en función del tiempo es mucho menor que en el grupo con bajo rendimiento académico. Conclusión: Los resultados ponen de manifiesto la importancia de trabajar los movimientos oculares sacádicos, pues parecen influir en el rendimiento académico de los estudiantes. Objective: This paper aims to determine whether saccades influence academic performance of elementary school students. Methodology: 121 vulnerable elementary school students from an educational institution from Cucuta, Colombia were used as non-probabilistic or convenience samples. These students were divided into two groups, as follows: 56 high academic achievers students: 60 % girls and 40 % boys, with an average age of 11.70 years and 65 underperforming average students: 40 % girls and 60 % boys, with an average age of 12.29 years. King & Devick (1976), or K-D test saccades test was applied. Results: The results showed statistically significant differences between the means of reading times of each of the cards and the average total reading time of the three test cards K-D. Also significant differences in the percentage of students who had problems with saccades, showing in the group with high yield a much higher percentage of students without problems in eye movement function at the time that the group with low academic performance was found. Conclusion: The results highlight the importance of working eye movements as saccadic issue which seem to influence on their students academic performance.

Primates frequently reach toward visual targets. Neurons in early visual areas respond to stimuli in the contralateral visual hemifield and without regard to which limb will be used to reach toward that target. In contrast, neurons in motor areas typically respond when reaches are performed using the contralateral limb and with minimal regard to the visuospatial location of the target. The parietal reach region (PRR) is located early in the visuomotor processing hierarchy. PRR neurons are significantly modulated when targets for either limb or eye movement appear, similar to early sensory areas; however, they respond to targets in either visual field, similar to motor areas. The activity could reflect the subject's attentional locus, movement of a specific effector, or a related function, such as coordinating eye-arm movements. To examine the role of PRR in the visuomotor pathway, we reversibly inactivated PRR. Inactivation effects were specific to contralateral limb movements, leaving ipsilateral limb and saccadic movements intact. Neither visual hemifield bias nor visual attention deficits were observed. Thus our results are consistent with a motoric rather than visual organization in PRR, despite its early location in the visuomotor pathway. We found no effects on the temporal coupling of coordinated saccades and reaches, suggesting that this mechanism lies downstream of PRR. In sum, this study clarifies the role of PRR in the visuomotor hierarchy: despite its early position, it is a limb-specific area influencing reach planning and is positioned upstream from an active eye-hand coordination-coupling mechanism.

Saccadic movements of the eyes were analyzed in children with the attention deficit and hyperactivity syndrome. Saccadic movements of the eyes were recorded by a special method for their isolated registration without involvement of the head and in coordination tests (eye-head, eye-hand, and eye-head-hand). Comparative analysis of saccadic movements in children with attention deficit and hyperactivity and in normal subjects was carried out. Saccades recorded in each participant in complex tests with one or two additional motor acts, such as movements of the head and hand, were compared and the changes were analyzed for the group. Children with attention deficit and hyperactivity syndrome had problem with gaze fixation on the peripheral target after the end of the saccade and these changes augmented in more complex tasks with one or two additional acts. This could be due to discrepancy between the difficulty of the task and the potentialities of the frontal cortex, more immature in these patients than in healthy children. The changes could form the objective base for disorders in the formation of reading and writing habits, often observed in children with attention deficit and hyperactivity syndrome.

Moving animals can estimate the distance of visual objects from image shift on their retina (optic flow) created during translational, but not rotational movements. To facilitate this distance estimation, many terrestrial and flying animals perform saccadic movements, thereby temporally separating translational and rotational movements keeping rotation times short. In this study, we analysed if a semiaquatic mammal, the harbour seal, also adopts a saccadic movement strategy. We recorded the seals‘ normal swimming pattern with video cameras and analysed head and body movements. The swimming seals indeed minimized rotation times by saccadic head and body turns with top rotation speeds exceeding 350 deg s−1 which leads to an increase of translational movements. Saccades occurred during both types of locomotion of the seals‘ intermittent swimming mode, active propulsion and gliding. In conclusion, harbour seals share the saccadic movement strategy of terrestrial animals. If this movement strategy is adopted to facilitate distance estimation from optic flow or serves a different function will be a topic of future research.

Supervised machine learning techniques have proven very effective to solve the problems arising from model learning in robotics. A significant limitation of such approaches is that internal models learned for a specific robot are likely to fail when transferred to a robot with a different morphology. One of the challenges to relate the morphology and the internal model is the difference in the number of parameters that define them. We propose three neural network architectures for solving this problem, along with a case study to evaluate their performance, namely saccadic movements in a robotic head. We generate a huge dataset to test the performance of the proposed architectures. Our results suggest that the best solution is provided by the parallel neural network, due to the fact that the trained weights are independent of one another.

This paper proposes a method for detecting eye saccadic signatures from Electrooculograms (EOG). Saccadic movements bear a particular pattern in the raw EOG time-series data. In this work, we interpret this signature of saccades as time-series motifs. The major issue in finding a saccade using standard motif identification methods is that saccadic signatures may be shrunk or stretched in the EOG time-series based on the saccadic duration. This shrinkage or stretching issue has been overcome in this work by using Dynamic Time Warping (DTW). This approach has been tested on our created EOG database and compared with existing methods of saccade detection in EOG. The proposed method shows higher accuracy as compared to existing ones. However, the execution time poses to be a limitation of the proposed method, which may be overcome by using high-speed processors and parallel computing platforms.

Eye movements of hyperactive and normal boys were compared on a visual pursuit task in three experiments. In the first series of tests, irregular pursuit occurred more often in hyperactive than in normal boys. Hyperactive boys made more saccadic movements, their average saccades were larger, and they looked away from the pursuit path more frequently than the normal boys. In a second series of tests three years later, the differences between normal and hyperactive boys still existed. In a third set of experiments the effects of an attention task, different stimulus velocities and stimulant medication were studied in another group of control and hyperactive boys. With or without the attention task, hyperactive boys not receiving stimulant medication made more saccades than normal boys. Differences were greatest at lower target velocities and decreased at higher stimulus velocities. Differences between hyperactive and normal boys disappeared when the former received both stimulant medication and the attention task. The findings were the same in the two groups of hyperactive boys: they had more saccades superimposed on ocular pursuit than did normal boys. Differences between the groups may be related to their relative ability to attend to the target. The differences are of a magnitude that might make them useful as an adjunct for diagnosis of hyperactivity or for evaluating the effects of treatment.

espanolEl aprendizaje de la lectura es uno de los aspectos fundamentales del curriculum escolar y determina de manera importante el rendimiento y el futuro academico de los alumnos. Actualmente, un alto porcentaje de escolares tiene dificultades de aprendizaje y no tienen el nivel esperado en funcion del curso y edad. Concretamente, las dificultades que manifiestan en el proceso de adquisicion de la lectura inciden negativamente en su aprendizaje y en su rendimiento escolar, siendo este uno de los trastornos de aprendizaje con mayor incidencia en nuestras aulas. Diversos estudios relacionan la dificultad lectora con problemas en la funcionalidad visual. Objetivo. El presente trabajo trata de comprobar si existe o no relacion entre los movimientos sacadicos y las dificultades de lectura (velocidad y comprension lectora). Metodologia. Para ello se administraron el Test de King-Devick y el PROLEC-SE que miden los movimientos sacadicos y la habilidad lectora respectivamente, a un grupo de 30 alumnos que continuan su formacion basica en unidades de curriculo especifico en centros de educacion secundaria ordinarios. Resultados. Los resultados muestran una relacion positiva entre los movimientos sacadicos y la eficiencia lectora (velocidad y comprension lectora). Conclusiones. Una mala eficiencia en los movimientos sacadicos se traduce en una baja velocidad lectora y mala compresion de la informacion. El estudio enfatiza ademas la necesidad de proponer un programa de intervencion para trabajar la funcionalidad visual del alumnado. Palabras Clave: Dificultades de aprendizaje, dificultades de lectura, movimientos sacadicos, eficacia lectora. EnglishThe reading learning is one of the basic aspects of the school curriculum and it is considered to be very important to the performance and the academic future of the students. Nowadays, a high percentage of the students have learning disability and they do not have the expected evolution according to the school year and their age. Specifically, the disability showed during the reading acquiring process, affects negatively both during their learning and their school performance. Several studies relate problems with Reading with problems in visual function. Objective. The present work tries to verify whether or not there is a relationship between the saccadic movements and the reading disability (reading speed and comprehension). Methodology. With this purpose, the King- Devick test and the PROLEC-SE, which measure the saccadic movements and the reader efficacy respectively, were set in a thirty student group who continue the basic training in some Specific Curriculum Unit in the ordinary Secondary Schools. Results. The results show a positive relationship between the saccadic movements and the reader efficacy (speed and reading comprehension). Conclusion. A bad fulfillment in the saccadic movements test is connected to a low reading speed, and besides that, to a non-appropriate understanding of the information. The study emphasizes/stresses the need of proposing an intervention programs in order to improve the visual functionality. Key words: Learning disability, reading disability, saccadic movements, reader efficacy.

Nervous system is one of the most complex networks known to mankind. An attempt in understanding and analyzing the functionalities of the nervous system would provide solutions to various problem pertaining in fields like medicine, robotics, ergonomics, bio-mechanics, medical research etc. Basic activities like rapid eye movements (Saccades), hand movements etc. are to be explored to understand the basic functionalities of complex nervous system. This paper will be aiming at analyzing the data obtained during the basic saccadic movements and hand movements. The kinematics of the saccades and the action potentials of the EMG signals that are generated during hand movements will be analyzed and the profiles and traits of these properties would be explained.

El objetivo principal del trabajo es conocer si existen diferencias entre los movimientos sacádicos, la discriminación auditiva y la lateralidad en niños de 7 a 11 años con y sin TDA-H, así como la propuesta de un programa de intervención. Se valoró una muestra de 30 niños con edades entre los 7 y los 11 año; 15 presentaban TDA-H y los otros 15, no. Los movimientos sacádicos se evaluaron mediante el Test K-D; la discriminación auditiva mediante la evaluación del desarrollo fonológico (PAF) y la lateralidad, mediante el Test de Harris. Para el análisis estadístico se utilizó el análisis de relación cualitativo Chi-cuadrado. Los resultados confirmaron la existencia de diferencias significativas en los movimientos sacadicos y la discriminación auditiva entre los niños con y sin TDA-H, pudiéndose establecer que estas diferencias están relacionadas con el TDA-H, mientras que en lateralidad no se establecieron diferencias importantes entre ambos grupos. The main objective of the work is to know if there are differences between saccadic movements, auditory discrimination and laterality in children from 7 to 11 years old with and without ADHD, as well as the proposal of an intervention program. A sample of 30 children aged between 7 and 11 years was evaluated; 15 had ADHD and the other 15 did not. Saccadic movements were evaluated using the K-D Test; auditory discrimination through the evaluation of phonological development (PAF) and laterality, through the Harris Test. Chi-square qualitative relationship analysis was used for statistical analysis. The results confirmed the existence of significant differences in saccadic movements and auditory discrimination between children with and without ADHD, being able to establish that these differences are related to ADHD, while in laterality no important differences were established between both. groups.

In this paper we evaluate the use of the machine learning algorithms Support Vector Machines (SVM), K-Nearest Neighbors (KNN), Classification and Regression Trees (CART) and Naive Bayes (NB) to identify non spontaneous saccades in clinical electrooculography tests. Our approach tries to solve problems like the use of manually established thresholds present in classical methods like identification by velocity threshold (I-VT) or identification by dispersion threshold (I-DT). We propose a modification to an adaptive threshold estimation algorithm for detecting signal impulses without the need of any user input. Also, a set of features were selected to take advantage of intrinsic characteristics of clinical electrooculography tests. The models were evaluated with signals recorded to subjects affected by Spinocerebellar Ataxia type 2 (SCA2). Results obtained by the algorithm show accuracies over 97%, recalls over 97% and precisions over 91% for the four models evaluated.

OBJETIVO: verificar se alterações na oculomotricidade e no reflexo vestíbulo-ocular estão relacionados com a dificuldade de leitura e escrita. MÉTODOS : foram selecionados 18 sujeitos de ambos os gêneros, faixa etária entre nove e 14 anos de idade, com audição e acuidade visual estática dentro dos padrões de normalidade, sendo um grupo de 11 sujeitos com dificuldade de leitura e escrita e outro grupo controle composto por sete sujeitos sem a dificuldade. Os exames realizados foram avaliações da linguagem escrita, acuidade visual estática, acuidade visual dinâmica, audiológica e oculomotricidade. RESULTADOS : a acuidade visual estática, calibração, nistagmo espontâneo e semi - espontâneo apresentaram-se dentro da normalidade em toda população estudada. As provas de acuidade visual dinâmica e movimento sacádico apresentaram diferença estatisticamente significante (p

During natural viewing large saccades shift the visual gaze from one target to another every few hundreds of milliseconds. The role of microsaccades (MSs), small saccades that show up during long fixations, is still debated. A major debate is whether MSs are used to redirect the visual gaze to a new location or to encode visual information through their movement. We argue that these two functions cannot be optimized simultaneously and present several pieces of evidence suggesting that MSs redirect the visual gaze and that the visual details are sampled and encoded by ocular drifts. We show that drift movements are indeed suitable for visual encoding. Yet, it is not clear to what extent drift movements are controlled by the visual system, and to what extent they interact with saccadic movements. We analyze several possible control schemes for saccadic and drift movements and propose experiments that can discriminate between them. We present the results of preliminary analyses of existing data as a sanity check to the testability of our predictions.

Purpose: To measure the effect of mullerectomy from posterior approach on the amplitudes of spontaneous blinking and downward eyelid saccades. Methods: Spontaneous blinks and downward upper eyelid saccadic movements of 16 patients (23 eyelids) with Graves orbitopathy were measured before and after mullerectomy from posterior approach. A new video system was used to continuously register the blinking activity while subjects viewed a commercial movie for 5 minutes. Downward eyelid saccades (30° of downgaze) were also measured with the video system. Results: Mullerectomy had no effect on the amplitude of the blink. However, as the eyelid margins were significantly lowered by the surgery, the amplitude of the blink movements relative to the pupil center increased substantially. The number of movements occluding the pupil center increased from 0% to 13%. Due to the increased efficiency of blinking, the blink rate decreased. Surgery induced a mean increase of 1.1 mm of downward saccades. Conclusions: The effects of mullerectomy on the blinks are indirect and related to correction of eyelid retraction. The relative amplitude of blink movements increases and blink rate decreases. Mullerectomy does affect the downward eyelid saccades increasing the ability of the upper eyelid to relax on downgaze.