Biblioteca Digital

Independent component analysis (ICA) is a widely applied technique to derive functionally connected brain networks from fMRI data. Group ICA (GICA) and Independent Vector Analysis (IVA) are extensions of ICA that enable users to perform group fMRI analyses; however a full comparison of the performance limits of GICA and IVA has not been investigated. Recent interest in resting state fMRI data with potentially higher degree of subject variability makes the evaluation of the above techniques important. In this paper we compare component estimation accuracies of GICA and an improved version of IVA using simulated fMRI datasets. We systematically change the degree of inter-subject spatial variability of components and evaluate estimation accuracy over all spatial maps (SMs) and time courses (TCs) of the decomposition. Our results indicate the following: (1) at low levels of SM variability or when just one SM is varied, both GICA and IVA perform well, (2) at higher levels of SM variability or when more than one SMs are varied, IVA continues to perform well but GICA yields SM estimates that are composites of other SMs with errors in TCs, (3) both GICA and IVA remove spatial correlations of overlapping SMs and introduce artificial correlations in their TCs...

New paradigms are required in Brain-Computer Interface (BCI) systems for the needs and expectations of healthy people. To solve this issue, we explore the emerging field of cooperative BCIs, which involves several users in a single BCI system. Contrary to classical BCIs that are dependent on the unique subject’s will, cooperative BCIs are used for problem solving tasks where several people shall be engaged by sharing a common goal. Similarly as combining trials over time improves performance, combining trials across subjects can significantly improve performance compared with when only a single user is involved. Yet, cooperative BCIs may only be used in particular settings, and new paradigms must be proposed to efficiently use this approach. The possible benefits of using several subjects are addressed, and compared with current single-subject BCI paradigms. To show the advantages of a cooperative BCI, we evaluate the performance of combining decisions across subjects with data from an event-related potentials (ERP) based experiment where each subject observed the same sequence of visual stimuli. Furthermore, we show that it is possible to achieve a mean AUC superior to 0.95 with 10 subjects and 3 electrodes on each subject, or with 4 subjects and 6 electrodes on each subject. Several emerging challenges and possible applications are proposed to highlight how cooperative BCIs could be efficiently used with current technologies and leverage BCI applications.

A brain-computer-interface (BCI) allows the user to control a device or software with brain activity. Many BCIs rely on visual stimuli with constant stimulation cycles that elicit steady-state visual evoked potentials (SSVEP) in the electroencephalogram (EEG). This EEG response can be generated with a LED or a computer screen flashing at a constant frequency, and similar EEG activity can be elicited with pseudo-random stimulation sequences on a screen (code-based BCI). Using electrocorticography (ECoG) instead of EEG promises higher spatial and temporal resolution and leads to more dominant evoked potentials due to visual stimulation. This work is focused on BCIs based on visual evoked potentials (VEP) and its capability as a continuous control interface for augmentation of video applications. One 35 year old female subject with implanted subdural grids participated in the study. The task was to select one out of four visual targets, while each was flickering with a code sequence. After a calibration run including 200 code sequences, a linear classifier was used during an evaluation run to identify the selected visual target based on the generated code-based VEPs over 20 trials. Multiple ECoG buffer lengths were tested and the subject reached a mean online classification accuracy of 99.21% for a window length of 3.15 s. Finally...

Several fMRI studies have examined brain regions mediating inter-subject variability in cognitive efficiency, but none have examined regions mediating intra-subject variability in efficiency. Thus, the present study was designed to identify brain regions involved in intra-subject variability in cognitive efficiency via participant-level correlations between trial-level reaction time (RT) and trial-level fMRI BOLD percent signal change on a processing speed task. On each trial, participants indicated whether a digit-symbol probe-pair was present or absent in an array of nine digit-symbol probe-pairs while fMRI data were collected. Deconvolution analyses, using RT time-series models (derived from the proportional scaling of an event-related hemodynamic response function model by trial-level RT), were used to evaluate relationships between trial-level RTs and BOLD percent signal change. Although task-related patterns of activation and deactivation were observed in regions including bilateral occipital, bilateral parietal, portions of the medial wall such as the precuneus, default mode network regions including anterior cingulate, posterior cingulate, bilateral temporal, right cerebellum, and right cuneus, RT-BOLD correlations were observed in a more circumscribed set of regions. Positive RT-BOLD correlations...

Our research is focused on the development of an at-home health care biomonitoring mobile robot for the people in demand. Main task of the robot is to detect and track a designated subject while recognizing his/her activity for analysis and to provide warning in an emergency. In order to push forward the system towards its real application, in this study, we tested the robustness of the robot system with several major environment changes, control parameter changes, and subject variation. First, an improved color tracker was analyzed to find out the limitations and constraints of the robot visual tracking considering the suitable illumination values and tracking distance intervals. Then, regarding subject safety and continuous robot based subject tracking, various control parameters were tested on different layouts in a room. Finally, the main objective of the system is to find out walking activities for different patterns for further analysis. Therefore, we proposed a fast, simple, and person specific new activity recognition model by making full use of localization information, which is robust to partial occlusion. The proposed activity recognition algorithm was tested on different walking patterns with different subjects, and the results showed high recognition accuracy.

A number of statistical textbooks recommend using an analysis of covariance (ANCOVA) to control for the effects of extraneous factors that might influence the dependent measure of interest. However, it is not generally recognized that serious problems of interpretation can arise when the design contains comparisons of participants sampled from different populations (classification designs). Designs that include a comparison of younger and older adults, or a comparison of musicians and non-musicians are examples of classification designs. In such cases, estimates of differences among groups can be contaminated by differences in the covariate population means across groups. A second problem of interpretation will arise if the experimenter fails to center the covariate measures (subtracting the mean covariate score from each covariate score) whenever the design contains within-subject factors. Unless the covariate measures on the participants are centered, estimates of within-subject factors are distorted, and significant increases in Type I error rates, and/or losses in power can occur when evaluating the effects of within-subject factors. This paper: (1) alerts potential users of ANCOVA of the need to center the covariate measures when the design contains within-subject factors...

Automatic tissue segmentation of the neonate brain using Magnetic Resonance Images (MRI) is extremely important to study brain development and perform early diagnostics but is challenging due to high variability and inhomogeneity in contrast throughout the image due to incomplete myelination of the white matter tracts. For these reasons, current methods often totally fail or give unsatisfying results. Furthermore, most of the subcortical midbrain structures are misclassified due to a lack of contrast in these regions. We have developed a novel method that creates a probabilistic subject-specific atlas based on a population atlas currently containing a number of manually segmented cases. The generated subject-specific atlas is sharp and adapted to the subject that is being processed. We then segment brain tissue classes using the newly created atlas with a single-atlas expectation maximization based method. Our proposed method leads to a much lower failure rate in our experiments. The overall segmentation results are considerably improved when compared to using a non-subject-specific, population average atlas. Additionally, we have incorporated diffusion information obtained from Diffusion Tensor Images (DTI) to improve the detection of white matter that is not visible at this early age in structural MRI (sMRI) due to a lack of myelination. Although this necessitates the acquisition of an additional sequence...

Autonomic cardiorespiratory activity changes across sleep stages. However, it is unknown to what extent it is affected by between- and within-subject variability during sleep. As it is hypothesized that the variability is caused by differences in subject demographics (age, gender, and body mass index), time, and physiology, we quantified these effects and investigated how they limit reliable cardiorespiratory-based sleep staging. Six representative parameters obtained from 165 overnight heartbeat and respiration recordings were analyzed. Multilevel models were used to evaluate the effects evoked by differences in sleep stages, demographics, time, and physiology between and within subjects. Results show that the between- and within-subject effects were found to be significant for each parameter. When adjusted by sleep stages, the effects in physiology between and within subjects explained more than 80% of total variance but the time and demographic effects explained less. If these effects are corrected, profound improvements in sleep staging can be observed. These results indicate that the differences in subject demographics, time, and physiology present significant effects on cardiorespiratory activity during sleep. The primary effects come from the physiological variability between and within subjects...

Ergative case, the special case of transitive subjects, raises questions not only for the theory of case but also for theories of subjecthood and transitivity. This paper analyzes the case system of Nez Perce, a ”three-way ergative” language, with an eye towards a formalization of the category of transitive subject. I show that it is object agreement that is determinative of transitivity, and hence of ergative case, in Nez Perce. I further show that the transitivity condition on ergative case must be coupled with a criterion of subjecthood that makes reference to participation in subject agreement, not just to origin in a high argument-structural position. These two results suggest a formalization of the transitive subject as that argument uniquely accessing both high and low agreement information, the former through its (agreement-derived) connection with T and the latter through its origin in the specifier of a head associated with object agreement (v). In view of these findings, I argue that ergative case morphology should be analyzed not as the expression of a syntactic primitive but as the morphological spell-out of subject agreement and object agreement on a nominal.; Linguistics

The aim of this research is to investigate the knowledge and the practices constituting the training of the Geography teacher. The relationship between knowledge and teaching practice is sought to be understood from the participation of this subject in the universe city, as school content. The subject city marks then, in this proposal, a point of reflection about the study of the space, in its dialectical understanding. It is having in mind the theoretical proposal of school Geography that I take a look at the teaching practice, as a bias which enables and promotes the training of students who are citizens and critical individuals who see the city as a place of rights, access, and social insertion. This research is considered a case study due to its nature, which aims to analyze the knowledge that a group of Geography teachers, who work at the Public Education Network, has upon the city. It is an inquiry that covers a qualitative approach for the analysis and observation of lessons and interviews. Having three chapters, this thesis is structured in parts which are interrelated and complete each other. Thus, the first part presents a discussion about the training of the Geography teacher emphasizing, specifically, the construction of professional knowledge that guides the teaching practice. In the second part of the text...

Este estudo procurou analisar os discursos dos profissionais e dos usuários sobre o “fazer artístico” tomando-se em consideração a realidade atual do trabalho de Oficinas Terapêuticas em Centros de Atenção Psicossocial nos Serviços de Saúde Mental no Estado de Minas Gerais, estratégias oriundas da Reforma Psiquiátrica no Brasil. Para tanto, utilizou-se do conceito de repetição conforme as proposições de Freud, Lacan, Kierkegaard e Deleuze, enfatizando dois diferentes níveis, espacial e temporal, uma vez que a repetição traz a marca da diferença e do tempo. Buscou-se neste estudo: analisar o fenômeno descrito em psicanálise por automatismo de repetição a partir da fala dos atores envolvidos nas oficinas; investigar como os profissionais entendem a função da arte na terapêutica com os pacientes psicóticos; produzir uma articulação entre a clínica do sujeito advinda da prática psicanalítica e a clínica psicossocial, e os possíveis reflexos disso na produção da subjetividade e na criação de laços sociais dos sujeitos. Para a realização das entrevistas e a análise dos resultados encontrados empregou-se o método psicanalítico. Foram empreendidas entrevistas semi-estruturadas com 11 profissionais e 19 usuários em quatro municípios do Estado...

Nesse estudo nos propusemos a analisar a constituição discursiva e identitária de Austregésilo Carrano Bueno, por meio de práticas de subjetivação e da tomada de uma pluralidade de posições-sujeito – dentre elas, a de sujeito de razão e a posição-sujeito de desrazão – das quais nos ocupamos para desenvolver a pesquisa em questão. Para tal, nos apoiamos na Análise do Discurso de linha Francesa, pautados numa perspectiva foucaultiana, observando os processos de subjetivação e objetivação que levam um adolescente comum a ser enquadrado na posição-sujeito “louco” e a constituir-se por ela. Desse modo, tratamos da constituição histórico-discursiva do objeto loucura e de sua emergência no corpus de análise a partir de superfícies de emergência e de grades de especificação. Abordamos, também, os procedimentos de controle do discurso que levam um sujeito a inserir-se na posição de louco. Para tanto, tratamos o manicômio como um espaço heterotópico no qual discursividades são instauradas. Abordamos em nossas análises, também, os procedimentos de controle do discurso (disciplinarização, rejeição, separação etc.) que determinam se um sujeito está ou não autorizado a falar de determinado lugar. Precisamos destacar...

This research aims to understand my construction process as an actress-womanteacher based on Paulo Freire s thoughts and having the idea of elaborating reflections about the of the historical subject in its aesthetic dimension and theatrical praxis as a pedagogical possibility in constructing this subject. The study has the qualitative bibliographical character with the focus on the theoretical production of Paulo Freire and in the autobiographical perspective of the research. The central theory is that Freire s thought of the construction of the historical subject in its aesthetic dimension, contributes to the re-signification of the pedagogical possibilities in the theatrical praxis on the process of constitution of this subject. In the attempt of establishing a dialogue between Freire s thought and scholars in the fields of philosophy, education and drama, I searched in Marx, Adorno, Fiori, Boron, Boal, Brecht, Duarte Jr, Gadotti, N??voa, Passeggi, Josso, Casali, among others, the basis to develop my theory. In this work, it was possible to verify that the theatrical pedagogical-praxis with the focus in the view of the world by the subjects involved can be an open space for the construction of historical subjects, that is, committed with the reflections concerning the relations between people and their humanization processes aiming social transformation; Esta pesquisa visa a compreender o meu processo de constru????o como atrizmulher-professora...

peer-reviewed; Technology education in Irish post-primary schools is undergoing significant change. In recent years the syllabi of all technology-related subjects have been revised. A new subject, Design and Communication Graphics, has replaced the traditional Technical Drawing subject. This new subject aims to develop students’ spatial awareness and graphical communication skills in the context of design. Parametric CAD forms a significant element of the subject. This research paper reports on a study into the use of parametric CAD by teachers in Irish post-primary schools. The research found that teachers were enthusiastic and welcomed the inclusion of the software as part of their teaching. However, the novel teaching environment was challenging which had a significant affect on their pedagogical approaches. The findings highlight the need for affective teacher professional development that explores the declarative as well as the procedural knowledge required for mastery of the CAD software.

From the analytical viewpoint a norm can formally be regarded as a right-duty (or claim-obligation) relation (1) that regulates behaviour (action/inaction) (2) among subjects (3) in definite space (4) and time (5). In normative terms, general principles (the ‘basis’) of (international) law can be conceived of as general obligations, i.e. obligations erga omnes (towards everyone). Obligations erga omnes, indivisible or divisible because of their content, link a subject to every other subject of international law, endowed with a correlative claim, so that the whole obligations erga omnes are matched by the whole claims erga omnes of all the subjects of international law. Indivisible obligations erga omnes are unavailable from the viewpoint of the power, so cogentes, breaches violate necessarily all the correlative claims, possibly enabling every subject to invoke the responsibility and impose sanctions. Correspondingly, sanctions should be regarded as indivisible obligations erga omnes, the violation of which allows universal enforcement. Nevertheless, specifically by reason of the gravity of the breach, it is possible to split primary and secondary norms, conceiving of the sanction as a bilateral relation allowing solely reciprocal enforcement in the case of an infringement. Divisible obligations erga omnes are available from the viewpoint of the power...

From the analytical viewpoint a norm can formally be regarded as a right-duty (or claim-obligation) relation (1) that regulates behaviour (action/inaction) (2) among subjects (3) in definite space (4) and time (5). Consequently, a legal order can be defined as a system of right-duty (or claim-obligation) relations that regulate behaviour (action/inaction) among subjects in definite space and are procedurally organised in the vertical and horizontal sense according to time. An iconic representation of these minimum necessary concepts allows switching from natural language to a purely formal representation of the legal system(s) (deontic network). Within this ‘geometrical’ frame, general principles (the ‘basis’) of (international) law can be conceived of as general obligations, i.e. obligations erga omnes (towards everyone). Obligations erga omnes (ties), indivisible or divisible because of their content, link a subject (node) to every other subject of international law, endowed with a correlative claim (s – s), so that the whole obligations erga omnes are matched by the whole claims erga omnes of all the subjects of international law. Indivisible obligations erga omnes are unavailable from the viewpoint of the power, so cogentes...

Las universidades espa??olas, al igual que otras universidades europeas, se encuentran en la actualidad inmersas en un proceso de reforma encaminado hacia la Convergencia Europea que afecta a cuestiones tanto formales como docentes. En este nuevo escenario, la distribuci??n del trabajo del alumno en horas presenciales, te??ricas y pr??cticas, as?? como en horas no presenciales es uno de los nuevos cambios que se proponen. La presente investigaci??n pretende analizar, a trav??s de un an??lisis logar??tmico lineal tipo logit, la influencia que tiene la asistencia del alumnado a las clases presenciales te??ricas y pr??cticas de la asignatura Bases Metodol??gicas de la Investigaci??n Educativa, asignatura de la Licenciatura de Pedagog??a, en la superaci??n de dicha asignatura. Los resultados muestran de forma significativa una clara relaci??n entre dichas variables.; At present, the Spanish universities, as other European universities, are immersed in a process of reform directed towards the European Convergence that concerns formal and educational changes. In this new scene, the distribution of the workload of the students in Contact Hours, lecture and practical sessions, as well as in Self-Work Hours, is one of the new changes that it proposes. The present research analyzes...

En este trabajo se aducen, en primer lugar, un conjunto de razones por las que, en el contexto norteamericano, es relevante el conocimiento de la materia en la formaci??n del profesorado. Despu??s se hace una revisi??n cr??tica de la investigaci??n que se ha hecho en este ??rea, centr??ndose en su propio programa de investigaci??n sobre ???Desarrollo del conocimiento en una profesi??n???. Finalmente, se definen y exploran cuatro dimensiones sobresalientes del conocimiento de la materia para la ense??anza: conocimiento del contenido, conocimiento sustantivo, conocimiento sint??ctico y creencias acerca de la materia.; In this paper they are put forward, in the first place, a overview of the reasons why, in the american context, teacher education must share the responsability for the transmission of subject matter knowledge to prospective teachers. They move to a discussion of the research that has been done in this area, getting into focus in your research program about ???Growth of Knowledge in Teaching???. Finally, they explore four prominent dimensions of the knowledge for the teaching: subject matter knowledge, substantive knowledge, syntactic knowledge, and beliefs about subject matter.

Purpose: To document, validate, and corroborate effect size (ES) for single-subject design in treatment of children with functional phonological disorders; to evaluate potential child-specific contributing variables relative to ES; and to establish benchmarks for interpretation of ES for the population. Method: Data were extracted from the Developmental Phonologies Archive for 135 preschool children with phonological disorders who previously participated in single-subject experimental treatment studies. Standard Mean DifferenceAll with Correction for Continuity was computed to gauge the magnitude of generalization gain that accrued longitudinally from treatment for each child, with the data aggregated for purposes of statistical analyses. Results: ES ranged from 0.09 to 27.83 for the study population. ES was positively correlated with conventional measures of phonological learning and visual inspection of learning data based on procedures standard to single-subject design. ES was linked to children’s performance on diagnostic assessments of phonology, but not other demographic characteristics or related linguistic skills and nonlinguistic skills. Benchmarks for interpretation of ES were estimated as 1.4, 3.6, and 10.1 for small...

The aim was to study whether the education level and occupation of the student's parents were related to the approval of the introductory subject influencing the admission to the university. Parent´s education level and occupation of 497 applicant students were determined. Those who approved were recorded. Differences were found among paren´t education level related to subject approval, the latter was negatively associated to father´s complete and incomplete secondary level, and to mother´s tertiary level, and was positively associated to father´s and mother´s university level. There was negative association between the subject approval and father´s occupation as employee and independent worker, and positive association to father and mother university proffesionals. To have university educated parents who work in their own proffesions would be stimulating for the students, promoting the subject approval. Parent´s education level and occupation would be relevant factors for student´s admission to the university.; El propósito del presente estudio fue determinar si la educación y ocupación de los padres de los estudiantes se relacionaban con la aprobación de la matera introductoria, condicionando el acceso a una carrera universitaria. Se indagó el nivel educativo y la ocupación de los padres de 497 estudiantes nuevos inscriptos. Se registraron los que aprobaron la asignatura. Hubo diferencias en el nivel educativo parental respecto a la aprobación de la asignatura...