12 research outputs found

    No gender differences in egocentric and allocentric environmental transformation after compensating for male advantage by manipulating familiarity

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    The present study has two-fold aims: to investigate whether gender differences persist even when more time is given to acquire spatial information; to assess the gender effect when the retrieval phase requires recalling the pathway from the same or a different reference perspective (egocentric or allocentric). Specifically, we analyse the performance of men and women while learning a path from a map or by observing an experimenter in a real environment. We then asked them to reproduce the learned path using the same reference system (map learning vs. map retrieval or real environment learning vs. real environment retrieval) or using a different reference system (map learning vs. real environment retrieval or vice versa). The results showed that gender differences were not present in the retrieval phase when women have the necessary time to acquire spatial information. Moreover, using the egocentric coordinates (both in the learning and retrieval phase) proved easier than the other conditions, whereas learning through allocentric coordinates and then retrieving the environmental information using egocentric coordinates proved to be the most difficult. Results showed that by manipulating familiarity, gender differences disappear, or are attenuated in all conditions

    Navigational style influences eye movement pattern during exploration and learning of an environmental map

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    During navigation people may adopt three different spatial styles (i.e., Landmark, Route, and Survey). Landmark style (LS) people are able to recall familiar landmarks but cannot combine them with directional information; Route style (RS) people connect landmarks to each other using egocentric information about direction; Survey style (SS) people use a map-like representation of the environment. SS individuals generally navigate better than LS and RS people. Fifty-one college students (20 LS; 17 RS, and 14 SS) took part in the experiment. The spatial cognitive style (SCS) was assessed by means of the SCS test; participants then had to learn a schematic map of a city, and after 5 min had to recall the path depicted on it. During the learning and delayed recall phases, eye-movements were recorded. Our intent was to investigate whether there is a peculiar way to explore an environmental map related to the individual's spatial style. Results support the presence of differences in the strategy used by the three spatial styles for learning the path and its delayed recall. Specifically, LS individuals produced a greater number of fixations of short duration, while the opposite eye movement pattern characterized SS individuals. Moreover, SS individuals showed a more spread and comprehensive explorative pattern of the map, while LS individuals focused their exploration on the path and related targets. RS individuals showed a pattern of exploration at a level of proficiency between LS and SS individuals. We discuss the clinical and anatomical implications of our data

    Episodix: a serious game to detect cognitive impairment in senior adults. A psychometric study

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    Introduction Assessment of episodic memory is traditionally used to evaluate potential cognitive impairments in senior adults. The present article discusses the capabilities of Episodix, a game to assess the aforementioned cognitive area, as a valid tool to discriminate among mild cognitive impairment (MCI), Alzheimer’s disease (AD) and healthy individuals (HC); that is, it studies the game’s psychometric validity study to assess cognitive impairment. Materials and Methods After a preliminary study, a new pilot study, statistically significant for the Galician population, was carried out from a cross-sectional sample of senior adults as target users. A total of 64 individuals (28 HC, 16 MCI, 20 AD) completed the experiment from an initial sample of 74. Participants were administered a collection of classical pen-and-paper tests and interacted with the games developed. A total of six machine learning classification techniques were applied and four relevant performance metrics were computed to assess the classification power of the tool according to participants’ cognitive status. Results According to the classification performance metrics computed, the best classification result is obtained using the Extra Trees Classifier (F1 = 0.97 and Cohen’s kappa coefficient = 0.97). Precision and recall values are also high, above 0.9 for all cognitive groups. Moreover, according to the standard interpretation of Cohen’s kappa index, classification is almost perfect (i.e., 0.81–1.00) for the complete dataset for all algorithms. Limitations Weaknesses (e.g., accessibility, sample size or speed of stimuli) detected during the preliminary study were addressed and solved. Nevertheless, additional research is needed to improve the resolution of the game for the identification of specific cognitive impairments, as well as to achieve a complete validation of the psychometric properties of the digital game. Conclusion Promising results obtained about psychometric validity of Episodix, represent a relevant step ahead towards the introduction of serious games and machine learning in regular clinical practice for detecting MCI or AD. However, more research is needed to explore the introduction of item response theory in this game and to obtain the required normative data for clinical validityThis research was supported by the University of VigoS

    Avaliação das relações entre a memória de trabalho verbal e visuoespacial de adultos saudáveis

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    Orientador: Prof. Dr. Amer Cavalheiro HamdanDissertação (mestrado) - Universidade Federal do Paraná, Setor de Ciências Humanas, Programa de Pós-Graduação em Psicologia. Defesa: Curitiba, 16/12/2016Inclui referências : f. 43-59Linha de pesquisa: Avaliação e reabilitação neuropsicológicaResumo: A Memória de Trabalho é a ação combinada entre atenção e memória que regula o fluxo de informações sustentadas para a realização de uma atividade, possibilitando reter e manipular informações por um curto período de tempo. O Teste Dígitos, da Escala Wechesler de Inteligência para Adultos, é indicado para avaliar a capacidade de memória de trabalho verbal, enquanto que o Teste dos Cubos de Corsi (TCC) é tido como avaliador da memória de trabalho visuoespacial. Esta pesquisa teve como objetivo avaliar a relação entre estas duas estruturas cognitivas em 107 adultos jovens saudáveis divididos em 2 grupos etários. Além dos testes supracitados, foram utilizados um questionário estruturado e a Escala Wechsler de Inteligência Abreviada. Os resultados indicam que os testes de memória de trabalho verbal e visuoespacial apresentam níveis de dificuldades diferentes na ordem inversa, sendo o TCC mais fácil do que o Dígitos. Estes achados corroboram pesquisa anteriores que questionam a analogia não verbal do TCC ao Dígitos. Palavras-chave: Avaliação Neuropsicológica; Memória de Trabalho; Cubos de Corsi; Saúde Mental.Abstract: Working Memory is the combined action of attention and memory that regulates the flow of sustained information to perform an activity, allowing to retain and manipulate information for a short period of time. The Digit Span, from the Wechesler Adult Intelligence Scale, is a test indicated to evaluate verbal work memory capacity, while the Corsi Block Test (CBT) is considered as a visual space memory assessor. This study aimed to evaluate the relationship between these two cognitive structures in 107 healthy young adults divided into 2 age groups. In addition to the aforementioned tests, a structured questionnaire and the Wechsler Scale of Abbreviated Intelligence were used. The results indicate that verbal and visuospatial work memory tests have different difficulty levels in the reverse order, with CBT being easier than Digits. These findings corroborate previous research that questions the nonverbal analogy of CBT to Digit Span. Keywords: Neuropsychological Assessment; Working Memory; Corsi Blocks Tapping Task; Mental Health

    VR systems for memory assessment and depth perception

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    La evolución de la tecnología de Realidad Virtual (RV) ha contribuido en todos los campos, incluyendo la psicología. Esta evolución implica mejoras tanto en hardware como en software, que permiten experiencias más inmersivas. En un entorno de RV los usuarios pueden percibir la sensación de "presencia" y sentirse "inmersos". Estas sensaciones son posibles utilizando HMDs. Hoy en día, el desarrollo de los HMDs se ha centrado en mejorar sus características técnicas para ofrecer inmersión total. En psicología, los entornos de RV son una herramienta de investigación. Hay algunas aplicaciones para evaluar la memoria espacial que utilizan métodos básicos de interacción. Sin embargo, sistemas de RV que incorporen estereoscopía y movimiento físico todavía no se han explotado en psicología. En esta tesis, se ha desarrollado un nuevo sistema de RV que combina características inmersivas, interactivas y de movimiento. El sistema de RV (tarea en un laberinto virtual) se ha utilizado para evaluar la memoria espacial y la percepción de profundidad. Se han integrado dos tipos diferentes de interacción: una basada en locomoción que consistió en pedalear en una bicicleta fija (condición1) y otra estacionaria usando un gamepad (condición2). El sistema integró dos tipos de visualización: 1) Oculus Rift (OR); 2) Una gran pantalla estéreo. Se diseñaron dos estudios. El primer estudio (N=89) evaluó la memoria espacial a corto plazo usando el OR y los dos tipos de interacción. Los resultados indican que existían diferencias significativas entre ambas condiciones. Los participantes que utilizaron la condición2 obtuvieron mejor rendimiento que los que utilizaron la tarea en la condición1. Sin embargo, no se encontraron diferencias significativas en las puntuaciones de satisfacción e interacción entre ambas condiciones. El desempeño en la tarea correlacionó con el desempeño en las pruebas neuropsicológicas clásicas, revelando la verosimilitud entre ellas. El segundo estudio (N=59) incluyó participantes con y sin estereopsis. Este estudio evaluó la percepción de profundidad comparando los dos sistemas de visualización. Los participantes realizaron la tarea usando la condición2. Los resultados mostraron que las diferentes características del sistema de visualización no influyeron en el rendimiento en la tarea entre los participantes con y sin estereopsis. Se encontraron diferencias significativas a favor del HMD entre las dos condiciones y entre los dos grupos de participantes respecto a la percepción de profundidad. Los participantes que no tenían estereopsis y no podían percibir la profundidad cuando utilizaban otros sistemas de visualización, tuvieron la ilusión de percepción de profundidad cuando utilizaron el OR. El estudio sugiere que para las personas que no tienen estereopsis, el seguimiento de la cabeza influye en gran medida en la experiencia 3D. Los resultados estadísticos de ambos estudios han demostrado que el sistema de RV desarrollado es una herramienta apropiada para evaluar la memoria espacial a corto plazo y la percepción de profundidad. Por lo tanto, los sistemas de RV que combinan inmersión total, interacción y movimiento pueden ser una herramienta útil para la evaluación de procesos cognitivos humanos como la memoria. De estos estudios se han extraído las siguientes conclusiones generales: 1) La tecnología de RV y la inmersión proporcionada por los actuales HMDs son herramientas adecuadas para aplicaciones psicológicas, en particular, la evaluación de la memoria espacial a corto plazo; 2) Un sistema de RV como el presentado podría ser utilizado como herramienta para evaluar o entrenar adultos en habilidades relacionadas con la memoria espacial a corto plazo; 3) Los dos tipos de interacción utilizados para la navegación en el laberinto virtual podrían ser útiles para su uso con diferentes colectivos; 4) El OR permite que los usuarios sin estereopsis puedan percibir lThe evolution of Virtual Reality (VR) technology has contributed in all fields, including psychology. This evolution involves improvements in hardware and software allowing more immersive experiences. In a VR environment users can perceive the sensation of "presence" and feel "immersed". These sensations are possible using VR devices as HMDs. Nowadays, the development of the HMDs has focused on improving their technical features to offer full immersion. In psychology, VR environments are research tools because they allow the use of new paradigms that are not possible to employ in a real environment. There are some applications for assessing spatial memory that use basic methods of HCI. However, VR systems that incorporate stereoscopy and physical movement have not yet been exploited in psychology. In this thesis, a novel VR system combining immersive, interactive and motion features was developed. This system was used for the assessment of the spatial memory and the evaluation of depth perception. For this system, a virtual maze task was designed and implemented. In this system, two different types of interaction were integrated: a locomotion-based interaction pedaling a fixed bicycle (condition1), and a stationary interaction using a gamepad (condition2). This system integrated two types of display systems: 1) The Oculus Rift; 2) A large stereo screen. Two studies were designed to determine the efficacy of the VR system using physical movement and immersion. The first study (N=89) assessed the spatial short term memory using the Oculus Rift and the two types of interaction The results showed that there were statistically significant differences between both conditions. The participants who performed the condition2 got better performance than participants who performed the condition1. However, there were no statistically significant differences in satisfaction and interaction scores between both conditions. The performance on the task correlated with the performance on other classical neuropsychological tests, revealing a verisimilitude between them. The second study (N=59) involved participants who had and who had not stereopsis. This study assessed the depth perception by comparing the two display systems. The participants performed the task using the condition2. The results showed that the different features of the display system did not influence the performance on the task between the participants with and without stereopsis. Statistically significant differences were found in favor of the HMD between the two conditions and between the two groups of participants regard to depth perception. The participants who did not have stereopsis and could not perceive the depth when they used other display systems (e.g. CAVE); however, they had the illusion of depth perception when they used the Oculus Rift. The study suggests that for the people who did not have stereopsis, the head tracking largely influences the 3D experience. The statistical results of both studies have proven that the VR system developed for this research is an appropriate tool to assess the spatial short-term memory and the depth perception. Therefore, the VR systems that combine full immersion, interaction and movement can be a helpful tool for the assessment of human cognitive processes as the memory. General conclusions from these studies are: 1) The VR technology and immersion provided by current HMDs are appropriate tools for psychological applications, in particular, the assessment of spatial short-term memory; 2) A VR system like the one presented in this thesis could be used as a tool to assess or train adults in skills related to spatial short-term memory; 3) The two types of interaction (condition1 and condition2) used for navigation within the virtual maze could be helpful to use with different collectives; 4) The Oculus Rift allows that the users without stereopsis can perceive the depth perception of 3D objects and have rich 3D experiences.L'evolució de la tecnologia de Realitat Virtual (RV) ha contribuït en tots els camps, incloent la psicologia. Aquesta evolució implica millores en el maquinari i el programari que permeten experiències més immersives. En un entorn de RV, els usuaris poden percebre la sensació de "presència" i sentir-se "immersos". Aquestes sensacions són possibles utilitzant HMDs. Avui dia, el desenvolupament dels HMDs s'ha centrat a millorar les seves característiques tècniques per oferir immersió plena. En la psicologia, els entorns de RV són eines de recerca. Hi ha algunes aplicacions per avaluar la memòria espacial que utilitzen mètodes bàsics d'interacció. Tanmateix, sistemes de RV que incorporen estereoscòpia i moviment físic no s'han explotat en psicologia. En aquesta tesi, s'ha desenvolupat un sistema de RV novell que combina immersió, interacció i moviment. El sistema (tasca en un laberint virtual) s'ha utilitzat per a l'avaluació de la memòria espacial i la percepció de profunditat. S'han integrat dos tipus d'interacció: una interacció basada en locomoció pedalejant una bicicleta fixa (condició1), i l'altra una interacció estacionària usant un gamepad (condició2). S'han integrat dos tipus de sistemes de pantalla: 1) L'Oculus Rift; 2) Una gran pantalla estereoscòpica. Dos estudis van ser dissenyats. El primer estudi (N=89) va avaluar la memòria a curt termini i espacial utilitzant l'Oculus Rift i els dos tipus d'interacció. Els resultats indiquen que hi havia diferències significatives entre les dues condicions. Els participants que van utilitzar la condició2 van obtenir millor rendiment que els participants que van utilitzar la condició1. Tanmateix, no hi havia diferències significatives dins satisfacció i puntuacions d'interacció entre les dues condicions. El rendiment de la tasca va correlacionar amb el rendiment en les proves neuropsicològiques clàssiques, revelant versemblança entre elles. El segon estudi (N=59) va implicar participants que van tenir i que van haver-hi no estereopsis. Aquest estudi va avaluar la percepció de profunditat comparant els dos sistemes de pantalla. Els participants realitzen la tasca utilitzant la condició2. Els resultats van mostrar que les diferents característiques del sistema de pantalla no va influir en el rendiment en la tasca entre els participants qui tenien i els qui no tenien estereopsis. Diferències significatives van ser trobades a favor del HMD entre les dues condicions i entre els dos grups de participants. Els participants que no van tenir estereopsis i no podien percebre la profunditat quan van utilitzar altres sistemes de pantalla (per exemple, CAVE), van tenir la il.lusió de percepció de profunditat quan van utilitzar l'Oculus Rift. L'estudi suggereix que per les persones que no van tenir estereopsis, el seguiment del cap influeix en gran mesura en l'experiència 3D. Els resultats estadístics dels dos estudis han provat que el sistema de RV desenvolupat per aquesta recerca és una eina apropiada per avaluar la memòria espacial a curt termini i la percepció de profunditat. Per això, els sistemes de RV que combinen immersió plena, interacció i moviment poden ser una eina útil per la avaluació de processos cognitius humans com la memòria Les conclusions generals que s'han extret d'aquests estudis, són les següents: 1) La tecnologia de RV i la immersió proporcionada pels HMDs són eines apropiades per aplicacions psicològiques, en particular, la avaluació de memòria espacial a curt termini; 2) Un sistema de RV com el presentat podria ser utilitzat com a eina per avaluar o entrenar adults en habilitats relacionades amb la memòria espacial a curt termini; 3) Els dos tipus d'interacció utilitzats per navegació dins del laberint virtual podrien ser útils per al seu ús amb diferent col.lectius; 3) L'Oculus Rift permet que els usuaris que no tenen estereopsis puguen percebre la percepció de profunditat dels objectes 3D i tenirCárdenas Delgado, SE. (2017). VR systems for memory assessment and depth perception [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/94629TESI

    Illuminazione nell’architettura antica: ipotesi ricostruttive delle modalità di comunicazione visuale in alcuni contesti di edilizia religiosa tra V e VI secolo d.C.

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    Tema di questa ricerca è lo studio delle modalità di illuminazione artificiale e naturale dello spazio sacro in alcuni contesti di architettura religiosa di V e VI secolo. I contesti architettonici prescelti per questo studio sono la Basilica dell'Acheiropoietos di Salonicco e la Basilica dei Santi Sergio e Bacco, di Costantinopoli, dei quali sono stati realizzati dei modelli tridimensionali con il supporto della grafica computerizzata. Oltre allo studio dei due edifici e delle loro fasi edilizie (nonché delle loro compagini architettoniche e degli apparati di arredo liturgico), si è inteso cercare di ricostruire gli schemi di illuminazione artificiale al loro interno. A tal fine è stato condotto un lavoro preliminare di studio ad ampio raggio su questa classe di manufatti provenienti da scavi di edifici di culto di età tardo antica e protobizantina, con una particolare attenzione a quei siti che hanno restituito informazioni puntuali sul posizionamento dei lumi. Oltre a ciò sono stati considerati anche manufatti fuori contesto, contenuti in collezioni museali o private, nonchè le rappresentazioni iconografiche di questi oggetti nelle fonti documentali (anche più tarde). Un particolare approfondimento è stato dedicato alle fonti scritte che trattano, anche in maniera incidentale, di questi manufatti, soprattutto in relazione ad uno dei due casi scelti, ossia la Basilica dei Santi Sergio e Bacco. Sono stati quindi proposti schemi di distribuzione dei lumi fissi e, in parte, anche mobili per ricostruire l'assetto luminoso delle basiliche durante le celebrazioni liturgiche diurne festive. La seconda parte dello studio, invece, è consistita nel realizzare delle simulazioni virtuali, ottenute con l'ausilio della computer grafica, dell'illuminazione naturale di questi edifici in antico. Grazie ad un particolare applicativo, infatti, è stato possibile impostare la fonte luminosa naturale (sun) nel mondo virtuale calcolandone la posizione in un dato momento/giorno/anno georiferendo i modelli tridimensionali

    Procedural Learning in Virtual Environments and Serious Games

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    The role of cognitive load in navigational walking, planning and recall

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    Walking is an important and common behavior in humans and is needed frequently in everyday life. The investigation of the influence of cognitive demands in different task difficulties on walking, more specifically on walking speed, was the aim of the first part of this thesis. Besides a decrease of walking speed with increasing cognitive demands it was also hypothesized that walking a known route will require less working memory resources than planning a route while walking. Therefore, a walking version of a Traveling Salesman task (planning while walking), as well as a walking version of a Corsi task (walking a known route) were designed. In both experiments the performance and walking speed decreased with increasing route and sequence length. There was no difference between the walking speeds in the two experiments but participants' performance was better in the Traveling Salesman task. Therefore, it is supposed that different working memory resources are required for solving the two tasks. In the second part of this thesis it was investigated whether participants' performance in a Corsi task depends on the presentation and recalling type of the Corsi sequences. Besides the walking version of the Corsi task also a computerized version as well as two additional presentation and recall combinations were designed. Consequently, performance in four modality conditions was measured (i.e., Screen-Screen, Floor-Screen, Floor-Floor and Screen-Floor). Results revealed that in all experiments participants' performance decreased with increasing sequence length: This should be caused by the limited capacity of the working memory. Further, the findings indicate that different processes of spatial working memory are involved in the different modality conditions. For Screen-Screen only recall of the length of the sequence required working memory resources. For Floor-Screen and Floor-Floor additional demands on working memory were caused by reference frame transformation from floor to screen and spatial updating, respectively. In Screen-Floor all of these additional demands were required and therefore performance was poorest. It is suggested that performance in the Corsi task not only depends on the ability to recall the sequence but also on the additionally demands caused by the presentation and recall type
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