No description available.

No

In adolescence, the use of cognitive reappraisal (CR) is adaptive for general emotion regulation and for decreasing symptoms of depression. Still, with all of the literature indicating the usefulness of CR, minimal research attempts to understand the childhood processes contributing to CR in adolescence. My dissertation study examined individual factors of executive function and frontal EEG asymmetry during late childhood, and environmental factors of parenting in adolescence, as predictors of adolescent CR and depressive symptoms. Data were from 123 participants in late childhood (age 10) and adolescence (age 14.5). During the late childhood visit, executive function and frontal EEG asymmetry were assessed. The adolescent visit included questionnaires for maternal CR, maternal supportive and unsupportive responses to adolescent's negative emotions, adolescent CR and depressive symptoms. Results indicated that maternal unsupportive reactions moderated the association between maternal CR and adolescent CR, such that higher unsupportive reactions were associated with higher adolescent CR when mothers reported higher CR. Higher CR in turn was associated with lower depressive symptoms. Regarding individual factors, frontal EEG asymmetry moderated the association between inhibitory control during late childhood and adolescent CR, such that better inhibitory control during late childhood was associated with higher CR when children had right frontal asymmetry. Higher CR was associated with lower depressive symptoms in adolescence. The results suggest the potential for targeting inhibitory control and parenting as two mechanisms for improving CR among adolescents to diminish depressive symptoms. / Doctor of Philosophy / Changing the way one thinks of an emotional event is considered highly adaptive, this strategy is referred to as cognitive reappraisal (CR). 123 participants during late childhood and adolescence and their mothers participated in this study. During the late childhood visit, children completed executive function tasks and electrical brain activity was collected during rest. For the adolescent visit, mothers completed questionnaires regarding their emotion regulation strategies and parenting styles, adolescents completed questionnaires regarding their own emotion regulation strategies and depressive symptoms. Results indicated that when mothers indicated more CR and higher unsupportive reactions this was associated with higher adolescent CR. Higher CR in turn was associated with lower depressive symptoms. Late childhood electrical brain activity and a child's ability to inhibit prepotent responses (inhibitory control) were associated with higher adolescent CR. Higher CR was associated with lower depressive symptoms in adolescence. The results suggest the potential for targeting inhibitory control and parenting as two mechanisms for improving CR among adolescents to diminish depressive symptoms.

Fearful temperament represents one of the robust predictors of the development of child and adolescent anxiety. Not all children with fearful temperament unvaryingly develop anxiety, however. Diverse processes resulting from the interplay among attention, cognitive control, and motivational system drive the trajectories toward more adaptive or maladaptive directions. In this study, I examined various factors that underlie the association between fearful temperament at age 9 and adolescent anxiety symptoms including attention biases, different components of effortful control, and frontal EEG asymmetry. 78 children participated in this study. Results indicate that fearful temperament at age 9 significantly predicted adolescent anxiety symptoms. This association, however, was moderated by children's effortful control and frontal EEG asymmetry at age 9. Specifically, fear at 9 years predicted adolescent anxiety only when children had low attentional control, low inhibitory control, low activation control, and exhibited greater right activation from baseline to task. The associations between AB and fearful temperament as well as anxiety were not significant. The association between fear at 9 years and sustained AB during adolescence, however, was moderated by children's attentional control, inhibitory control, and frontal EEG asymmetry at age 9. Specifically, fear predicted attention biases away from threat when children had high attentional control, high inhibitory control, and showed greater left activation. The findings will be discussed in terms of the roles of attention biases in the development of anxiety and how different components of effortful control and frontal EEG asymmetry contribute to the resilience process. / Doctor of Philosophy / Anxiety disorders represent one of the most commonly occurring mental health problems in childhood and adolescence. Children who tend to show wariness and distress to negative stimuli are more likely to have anxiety. Not all children with fearful temperament develop anxiety, however. Certain individual characteristics can protect fearful children from having anxiety symptoms. In this study, I examined the roles of attentional biases toward threat (AB), different components of self-regulation (EC), and the asymmetrical frontal brain activation (FA) in changing the relation between fearful temperament and anxiety. 78 children participated in this study. Results indicated that adolescents were at higher risk for anxiety if they showed high fearful temperament at age 9. However, the risk could be attenuated if children were better able to control their attention and behaviors, and exhibited greater left activation from resting to a mildly stressful situation at age 9. In addition, fearful children were better able to direct attention away from threat during adolescence if they were better able to control their attention and behaviors, and exhibited greater left activation from resting to a mildly stressful situation at age 9. The findings provide suggestions for early identification and intervention of children who are more vulnerable to anxiety during adolescence.

Behavioral and physiological correlates of hostility, such as cardiovascular lability and increased risk of cardiovascular disease, are vital when considering the possible health risks associated with high levels of hostility (Henry & Meehan, 1981; Matthew & Haynes, 1986; Johnson, 1990; Heller, 1993; Heilman, Bowers, & Valenstein, 1993; Demaree & Harrison, 1997; Demaree Harrison, & Rhodes, 2000; and Shenal & Harrison, 2001). By examining this issue through a functional cerebral systems approach, one is better able to conceptualize changes that occur when men with extreme hostility levels (e.g. high and low) carry out emotional regulation tasks. High and low hostile groups have been shown to differ in their auditory, visual, somatosensory, and motor processes. Moreover, they differ in lateralized cerebral functions within these modalities where high hostiles have shown a right cerebral/ negative affective bias while low hostiles have shown a left cerebral/ positive affective bias in perception and in motor functions to stress. Right cerebral activation in high hostiles has occurred with heightened reactivity and persistence in sympathetic tone and with cardiovascular changes in heart rate, blood pressure, and Galvanic skin response. In the present experiment, this systematic line of research (Harrison & Gorelczenko, 1990; Herridge & Harrison. 1996; Demaree & Harrison, 1997; Herridge, Harrison, & Demaree, 1997; Demaree, Higgins, Williamson, and Harrison, 2002; Williamson & Harrison, in press) was extended to the investigation of the premotor frontal eye fields using rapid directional eye movements toward the contralateral hemisphere. It was predicted that high hostiles would evidence right frontal deficits in lateral eye movements (LEM) resulting in decreased LEM toward and within the left hemispace. Moreover, concurrent processing of lateralized eye movements and regulation over cardiovascular responding was predicted to yield sympathetic dysregulation on leftward LEM (lLEM) and potentially parasympathetic dysregulation on rightward LEM (rLEM). Leftward LEM appeared to result in more fatigue effects than rightward LEM. However, the primary behavioral hypothesis was not supported. Moreover, the directional relationship predicted between left side LEM and sympathetic tone was not found. Instead, LEM in either direction occurred with corresponding reduction in sympathetic blood pressure. Diametrically opposite results were found for the non- directional cold pressor stressor. High hostiles were found to be more reactive in their cardiovascular response to stress than the low hostiles. / Master of Science / [The Beck Depression Inventory, p. 62-66, was removed March 22, 2010 GMc]

El Distrito Minero Castaño Nuevo, localizado en el flanco oriental de la región morfoestructural de Cordillera Frontal de San Juan, constituye un sistema complejo donde dos tipos de depósitos epitermales de diferente naturaleza evolucionaron independientemente. La geología del sector comprende una sucesión de rocas volcánicas y piroclásticas que evolucionó desde composiciones andesíticas a riodacíticas, entre los 272,6 ± 2,3 Ma y los 267,6 ± 2,6 Ma (edades U/Pb en circones). Las edades de estas rocas, en conjunto con las características petrográficas y geoquímicas permiten asignarlas a la Formación Vega de Los Machos, la cual representa rocas emplazadas en un arco magmático sobre corteza continental, activo en el Pérmico inferior a medio, y que forman parte de la sección inferior del Grupo Choiyoi. En forma conjunta con la evolución de este vulcanismo, se desarrollaron dos sistemas hidrotermales cuyas características particulares permiten difrenciarlos. En primer lugar, se desarrolló un sistema vinculado a la circulación de fluidos ácidos, representado por texturas tipo vuggy silica, brechas freáticas con fragmentos de vuggy, y depósitos de sílice pulverulenta de tipo steam heated. Las asociaciones de alteración hidrotermal evidencian también el carácter ácido de los mismos, predominando dickita, NH4 illita, jarosita, alunita y sílice. Este sistema presenta una disposición coincidente con un corredor estructural NO-SE, y contiene anomalías de Au, Bi, As, Hg. Estas manifestaciones son cortadas por venillas de cuarzo-turmalina y presentan una alteración sobreimpuesta de turmalina-muscovita, en conjunto con anomalías de Cu-Mo. La edad estaría acotada por una serie de cuerpos intrusivos básicos irregulares, con edad U/Pb en circones de 270,6 ± 3,0 Ma. El segundo sistema hidrotermal presente en el distrito minero es el que reviste mayor importancia. Constituye el resultado de la circulación de fluidos neutralizados, y se manifiesta como vetas epitermales de cuarzo/adularia con mineralización de Au (± Ag), de edades entre 267,0 ± 2,2 y 265,9 ± 2,1 (Ar/Ar en adularia). Las vetas principales se emplazan en fallas de tipo normal y de rumbo, con desarrollo de zonas de apertura donde se reconocieron seis eventos de relleno y brechamiento, que evidencian fluctuaciones en las velocidades de ascenso de los fluidos. Dichos eventos fueron agrupados en episodios de acuerdo a su relación con la mineralización. Asimismo, se registran variaciones en las temperaturas de formación del cuarzo que compone a cada uno de los eventos y se identifican procesos de enfriamiento normal, ebullición sutil y ebullición violenta. El proceso de ebullición constituye el mecanismo principal de precipitación de la mena en las vetas del distrito, caracterizando a los episodios sin- y post-mineralización. La alteración hidrotermal vinculada a estas estructuras es reducida espacialmente, y las asociaciones de minerales reflejan condiciones de pH neutro. La relación Ag/Au para estos sistemas vetiformes es inferior a 10, lo que permite catalogarlos como depósitos epitermales auríferos. Las manifestaciones hidrotermales identificadas en el Distrito Minero Castaño Nuevo forman parte del Cinturón Metalogenético Gondwánico asociado al magmatismo del Grupo Choiyoi. Constituyen dos sistemas epitermales desarrollados en distintos niveles corticales, con anomalías moderadas de oro, cuyo estudio y correcto entendimiento son de gran importancia a escala local y regional. / The Castaño Nuevo Mining District, located on the eastern side of Cordillera Frontal, San Juan province, consists on a complex system where two different epithermal deposits with distinct characteristics evolved independently. The studied area comprises volcanic and volcaniclastic rocks that were extruded between 272.6 ± 2.3 Ma and 267.6 ± 2.6 Ma (Zircon U/Pb dating). The ages of these rocks in addition to the petrological and geochemical characteristics, allow to assign this sequence to the Vega de los Machos Formation, which was interpreted as the result of a magmatic arc evolution developed during Lower to Medium Permian, and make up the lower part of the Choiyoi Group. Together with the volcanism, two hydrothermal systems of different nature have evolved. The first one was developed from acidic fluids, and produced vuggy silica textures, phreatic breccias with vuggy fragments and steam heated-type alteration. Hydrothermal mineral assemblages also reflect fluid acidity, the main minerals associated are dickite, NH4 illite, jarosite, alunite and quartz. The distribution of these features is controlled by a NO-SE structural corridor, where anomalous values of Au, Bi, As and Hg are registered. The previous manifestations are cut by quartz-tourmaline veinlets, overprinting the acidic clays and involving Cu-Mo anomalies. The age of the whole system has not been determinated directly, but could be restricted by the age of the intrusion of irregular andesitic bodies (270.6 ± 3.0 Ma, zircon U/Pb). The second hydrothermal system is the most important deposit of the Castaño Nuevo Mining District, and has been developed from neutral fluids, and is represented by quartz/adularia epithermal veins with Au (± Ag) mineralization also from Permian age (267.0 ± 2.2 and 265.9 ± 2.1, adularia Ar/Ar dating). The main veins are related to normal and strike-slip faults, where, depending on the cinematics of each fault, open spaces are generated (jogs) where six events of infill and brecciation were identified. These events are related to fluid ascent velocity which fluctuated along time and was controlled by fracture opening speed. The events could be differentiated in terms of mineralization in three episodes pre-, sin- and post-mineralization. The main mechanism for gold precipitation on these veins is boiling, and each infill event could be classified as non-boiling, gentle boiling or flashing boiling event. Alteration assemblages related to these veins reflect the neutral conditions of the fluids and developed narrow halos surrounding the main structures. All veins show silver/gold ratios below 10, so quartz/adularia veins from Castaño Nuevo Mining District could be classified as gold-rich low sulfidation epithermal system. Hydrothermal manifestations identified at Castaño Nuevo Mining District belongs to the Choiyoi Magmatic Belt related to arc and back-arc extensional tectonism. The epithermal systems identified were developed at different depths from the surface and could be derived from different magmatic sources. The study and correct understanding of this district has a relevant regional and local significance.

Shyness is highly related to internalizing problems. However, not all shy children develop serious internalizing problems (IP). The aim of the current study was to identify the endogenous factors that might contribute to the resilience process from a self-regulation perspective. Participants included 73 children (33 boys; 40girls) who visited the lab at 6 and 9 years of age. Shyness, attentional control (AC), inhibitory control (IC), frontal electroencephalogram (EEG) asymmetry were measured at both 6 and 9 years using age appropriate questionnaires and tasks. Results indicated that age 6 shyness did not directly predict age 9 IP; instead it indirectly predicted IP through age 9 shyness. Neither AC, IC, frontal EEG asymmetry, nor the stability of frontal EEG asymmetry moderated the association between age 6 shyness and age 9 IP. However, there was a positive concurrent association between shyness and IP at 9 years. In addition, AC and IC moderated the shyness-IP association at age 9. Shyness was significantly associated with IP only when children had low AC or IC, but not when children had high AC or IC. / Master of Science / Shyness is highly related to internalizing problems. However, not all shy children develop serious internalizing problems (IP). The aim of the current study was to identify the within-individual factors that might protect children away from having IP from a self-regulation perspective. Participants included 73 children (33 boys; 40girls) who visited the lab at 6 and 9 years of age. Shyness, attentional control (AC), inhibitory control (IC), frontal electroencephalogram (EEG) asymmetry were measured at both 6 and 9 years using age appropriate questionnaires and tasks. Results indicated that children who are shy at 6 years old may not have IP at 9 years old. Instead children who are shy at 6 years old tend to be shy at 9 years old. And those who are shy at 9 years old are more likely to have IP at the same period of time. Neither AC, IC, frontal EEG asymmetry, nor the stability of frontal EEG asymmetry affect the direction or degree of the association between age 6 shyness and age 9 IP. In addition, AC and IC affect the concurrent shyness-IP association at age 9. Shyness was significantly associated with IP only when children had low AC or IC, but not when children had high AC or IC.

This study examined the cumulative, more insidious, impact of repeated drinking on sober-state aggression based on research that has pointed to the negative neural effects of chronic alcohol consumption, especially on frontal lobe functioning. In particular, it examined the relationship between repeated alcohol use and sober-state reactive aggression as it is mediated or moderated by sober-state executive cognitive functioning (ECF), thus expanding upon research that has examined the relationship between acute alcohol intoxication and consequent aggression while under the influence (Giancola, 2000b). It was hypothesized that ECF would mediate the relationship between repeated alcohol use and sober-state reactive aggression in college students in that a history of alcohol use would lower sober-state ECF which in turn would increase sober-state impulsive aggression in individuals. It was further hypothesized with a moderational model that high levels of ECF would offset the more insidious effects of repeated alcohol use on subsequent sober-state aggressive acts. Moreover, those effects would remain after controlling for potential confounds of violence exposure, gender, and intelligence. Eighty college students, aged 18-23 years, from Virginia Tech were recruited to participate in this study. A self-report measure for aggression, neuropsychological tests for ECF, and a lifetime drinking interview schedule were used to assess the relationship between cumulative alcohol use, sober ECF, and sober aggression. A combination of bivariate and hierarchical regression analyses was used to analyze the data. The hypotheses of this study were not supported. Instead, the results supported a positive relationship between prior exposure to violence and later escalation of alcohol use and perpetrated violence. Additionally, these results support the presence of a "binge drinking" pattern within the sample. / Master of Science

<p dir="ltr">Abstract: Atypical frontal alpha asymmetry is the difference in EEG-measured alpha-band power between right and left hemispheres, and patterns of lateralization are thought to reflect motivational direction (approach/withdrawal) and affective processing. Increased rightward frontal alpha asymmetry is associated with tendency toward approach-related behavior often displayed in attention-deficit/hyperactivity disorder (ADHD), though findings have been inconsistent. While differences in results may be partially accounted for by within-diagnosis heterogeneity, growing evidence suggests individual response tendency and emotional salience of a situation may influence one another. Investigating the potential interactions between trait and state measured variables may therefore clarify lateralization patterns in ADHD. The current study measured frontal alpha asymmetry in a well-characterized sample of school-aged children with and without ADHD. EEG during standard resting-state and emotional passive-viewing tasks were recorded from 220 children (nADHD = 97). A semi-structured clinical interview and standardized rating scales were collected to assign DSM-5 diagnoses and temperament group belonging. Parent measures included the behaviorally-rated Temperament in Middle Childhood Questionnaire (TMCQ). Latent profile analysis within the ADHD group revealed two temperament subgroups: emotionally regulated and emotionally dysregulated (high anger and sadness). EEG assessment suggests children broadly produced a more rightward asymmetry while in resting state compared to a task-based condition, though show no notable differences between neutral and negative emotional task conditions. ADHD diagnostic status, temperament group, and sex assigned at birth did not impact patterns of asymmetry. Results emphasize measurement differences in frontal alpha asymmetry between lab-based tasks and further highlight the importance of state influences on alpha lateralization.</p>

[EN] Considering the importance of games and new technologies for learning, in this thesis, two different systems that use Natural User Interfaces (NUI) for learning about a period of history were designed and developed. One of these systems uses autostereoscopic visualization, which lets the children see themselves as a background in the game, and that renders the elements with 3D sensation without the need for wearing special glasses or other devices. The other system uses frontal projection over a large-size tabletop display for visualization. The two systems have been developed from scratch. A total of five studies were carried out to determine the efficacy of games with NUI interaction with regard to acquiring knowledge, ease of use, satisfaction, fun and engagement, and their influence on children. In the first study, a comparison of the autostereoscopic system with the frontal projected system was carried out. 162 children from 8 to 11 years old participated in the study. We observed that the different characteristics of the systems did not influence the children's acquired knowledge, engagement, or satisfaction; we also observed that the systems are specially suitable for boys and older children (9-11 years old). The children had the depth perception with the autostereoscopic system. The children considered the two systems easy to use. However, they found the frontal projection to be easier to use. A second study was performed to determine the mode in which the children learn more about the topic of the game. The two modes were the collaborative mode, where the children played with the game in pairs; and the individual mode, where the children played with the game solo. 46 children from 7 to 10 years old participated in this study. We observed that there were statistically significant differences between playing with the game in the two modes. The children who played with the game in pairs in the collaborative mode got better knowledge scores than children who played with the game individually. A third study comparing traditional learning with a collaborative learning method (in pairs and in large groups) using the game was carried out. 100 children from 8 to 10 years old participated in this study. The results are in line with the second study. The children obtained higher score when collaborated in large groups or in pairs than attending to a traditional class. There were no statistically significant differences between playing in large groups and playing in pairs. For personalized learning, a Free Learning Itinerary has been included, where the children can decide how to direct the flow of their own learning process. For comparison, a Linear Learning Itinerary has also been included, where the children follow a determined learning flow. A fourth study to compare the two different learning itineraries was carried out. 29 children from 8 to 9 years old participated in this fourth study. The results showed that there were no statistically significant differences between the two learning itineraries. Regarding the online formative assessment and multiple-choice questions, there is usually a question and several possible answers in questionnaires of this kind in which the student must select only one answer. It is very common for the answers to be just text. However, images could also be used. We have carried out a fifth study to determine if an added image that represents/defines an object helps the children to choose the correct answer. 94 children from 7 to 8 years old participated in the study. The children who filled out the questionnaires with imaged obtained higher score than the children who filled out the text-only questionnaire. No statistically significant differences were found between the two questionnaire types with images. The results from the studies suggest that games of this kind could be appropriate educational games, and that autostereoscopy is a technology to exploit in their development. / [ES] Teniendo en cuenta la importancia de los juegos y las nuevas tecnologías en el aprendizaje, en esta tesis se han diseñado y desarrollado dos sistemas diferentes que utilizan interfaces de usuario naturales (NUI) para aprender los periodos de la historia. Uno de estos sistemas utiliza visión autoestereoscópica, la cual permite a los niños verse a ellos mismos dentro del juego y muestra los elementos del juego en 3D sin necesidad de llevar gafas especiales u otros dispositivos. El otro sistema utiliza proyección frontal como método de visualización. Los dos sistemas han sido desarrollados desde cero. Se han llevado a cabo un total de cinco estudios para determinar la eficacia de los juegos con NUI en cuanto al aprendizaje, facilidad de uso, satisfacción, diversión y su influencia en los niños. En el primer estudio, se ha comparado el sistema autoestereoscópico con el sistema de proyección frontal. Un total de 162 niños de 8 a 11 años han participado en este estudio. Observamos que las diferentes características de los sistemas no han influido en el aprendizaje, en la usabilidad o en la satisfacción; también observamos que los sistemas son especialmente apropiados para chicos y niños mayores (de 9 a 11 años). Los niños tienen percepción de profundidad con el sistema autoestereoscópico. Los niños consideraron los dos sistemas fáciles de usar. Sin embargo, encontraron el sistema de proyección frontal más fácil de usar. En el segundo estudio, se determina el modo con el que los niños pueden aprender en mayor medida el tema del juego. Los dos modos comparados han sido el modo colaborativo, en el que los niños jugaban por parejas; y el modo individual, en el que los niños jugaban solos. 46 niños de 7 a 10 años han participado en este estudio. Observamos que existen diferencias estadísticas significativas entre jugar al juego de un modo o de otro. Los niños que jugaron al juego en parejas en el modo colaborativo obtuvieron un mejor resultado que los niños que jugaron al juego en el modo individual. El tercer estudio compara el aprendizaje tradicional con el aprendizaje colaborativo (en parejas y en grupos grandes) utilizando el juego desarrollado. 100 niños de 8 a 10 años han participado en este estudio. Los resultados son similares al segundo estudio. Los niños obtuvieron una mejor puntuación jugando en colaboración que en el método tradicional en clase. No hubo diferencias estadísticas significativas entre jugar en grupos grandes y jugar en parejas. Teniendo en cuenta el aprendizaje personalizado se ha incluido un itinerario libre de aprendizaje, en el cual los niños pueden elegir cómo quieren dirigir su propio proceso de aprendizaje. A modo de comparación, se ha incluido también un itinerario lineal de aprendizaje, donde los niños siguen un flujo predeterminado. En este cuarto estudio han participado 29 niños de 8 a 9 años. Los resultados han mostrado que no hubo diferencias estadísticas significativas entre los dos itinerarios de aprendizaje. En cuanto a la evaluación online con preguntas de test, normalmente, hay una pregunta y varias opciones de respuesta, donde se debe seleccionar solo una de ellas. Es muy común que la respuesta esté formada únicamente por texto. Sin embargo, también se pueden utilizar imágenes. En este quinto estudio se ha llevado a cabo una comparación para determinar si las imágenes que representan las respuestas son de ayuda para elegir la correcta. 94 niños de 7 a 8 años han participado en este estudio. Los niños que rellenaron los cuestionarios con imágenes obtuvieron una mejor puntuación que los niños que rellenaron los cuestionarios en los que solo había texto. No se encontraron diferencias estadísticas significativas entre los dos tipos de cuestionarios con imágenes. Los resultados de estos estudios sugieren que los juegos de este tipo podrían ser apropiados para utilizarlos como juegos educativos, y que la autoestereoscopía es una te / [CA] Tenint en compte la importància dels jocs i les noves tecnologies en l'aprenentatge, en aquesta tesi s'han dissenyat i desenvolupat dos sistemes diferents que utilitzen interfícies naturals d'usuari per aprendre els períodes de la història. Un d'aquests sistemes utilitza visió autoestereoscòpica, la qual permet als xiquets veure's a ells mateixos dins del joc i mostra els elements del joc en 3D sense necessitat de portar ulleres especials o altres dispositius. L'altre sistema utilitza projecció frontal com a mètode de visualització. Els dos sistemes han sigut desenvolupats des de zero. S'han dut a terme un total de cinc estudis per a determinar l'eficàcia dels jocs amb interfícies d'usuari naturals quant a l'aprenentatge, facilitat d'ús, satisfacció, diversió i la seua influència en els xiquets. En el primer estudi, s'ha comparat el sistema autoestereoscòpic amb el sistema de projecció frontal. 162 xiquets de 8 a 11 anys han participat en aquest estudi. Pels resultats, observem que les diferents característiques dels sistemes no han influït en l'aprenentatge, en la usabilitat o en la satisfacció; també observem que els sistemes són especialment apropiats per a xics i xiquets majors (de 9 a 11 anys). Els xiquets tenen percepció de profunditat amb el sistema autoestereoscòpic. Els xiquets van considerar els dos sistemes fàcils d'usar. No obstant açò, van trobar el sistema de projecció frontal més fàcil d'usar. En el segon estudi es determina la manera amb el qual els xiquets poden aprendre en major mesura el tema del joc. Les dues maneres comparades han sigut la manera col·laborativa, en la qual els xiquets jugaven per parelles; i la manera individual, en la qual els xiquets jugaven sols. 46 xiquets de 7 a 10 anys han participat en aquest estudi. Pels resultats, observem que existeixen diferències estadístiques significatives entre jugar al joc d'una manera o d'una altra. Els xiquets que van jugar al joc en parelles en la manera col·laborativa van obtindre un millor resultat que els xiquets que van jugar al joc en la manera individual. El tercer estudi compara l'aprenentatge tradicional amb l'aprenentatge col·laboratiu (en parelles i en grups grans). 100 xiquets de 8 a 10 anys ha participat en aquest estudi. Els resultats són similars al segon. Els xiquets van obtindre una millor puntuació jugant en col·laboració que en el mètode tradicional en classe. No va haver-hi diferències estadístiques significatives entre jugar en grups grans i jugar en parelles. Tenint en compte l'aprenentatge personalitzat s'ha inclòs un itinerari lliure d'aprenentatge, en el qual els xiquets poden triar com volen dirigir el seu propi procés d'aprenentatge. A manera de comparació, s'ha inclòs també un itinerari lineal d'aprenentatge, on els xiquets segueixen un flux predeterminat. En aquest quart estudi han participat 29 xiquets de 8 a 9 anys. Els resultats han mostrat que no va haver-hi diferències estadístiques significatives entre els dos itineraris d'aprenentatge. Quant a l'avaluació online amb preguntes de test, normalment, hi ha una pregunta i diverses opcions de resposta, on s'ha de seleccionar solament una d'elles. És molt comú que la resposta estiga formada únicament per text. No obstant açò, també es poden utilitzar imatges. En aquest cinquè estudi s'ha dut a terme una comparació per a determinar si les imatges que representen les respostes són d'ajuda per a triar la correcta. 94 xiquets de 7 a 8 anys han participat en aquest estudi. Els xiquets que van emplenar els qüestionaris amb imatges van obtindre una millor puntuació que els xiquets que van emplenar els qüestionaris en els quals solament hi havia text. No es van trobar diferències estadístiques significatives entre els dos tipus de qüestionaris amb imatges. Els resultats d'aquests estudis suggereixen que els jocs d'aquest tipus podrien ser apropiats per a utilitzar-los com a jocs educatius, i que l'autoestereoscòpia és / Martín San José, JF. (2015). USING NATURAL USER INTERFACES TO SUPPORT LEARNING ENVIRONMENTS [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/55845