EEG amplitude modulation analysis for semi-automated diagnosis of Alzheimer's disease

Recent experimental evidence has suggested a neuromodulatory deficit in Alzheimer's disease (AD). In this paper, we present a new electroencephalogram (EEG) based metric to quantitatively characterize neuromodulatory activity. More specifically, the short-term EEG amplitude modulation rate-of-change (i.e., modulation frequency) is computed for five EEG subband signals. To test the performance of the proposed metric, a classification task was performed on a database of 32 participants partitioned into three groups of approximately equal size: healthy controls, patients diagnosed with mild AD, and those with moderate-to-severe AD. To gauge the benefits of the proposed metric, performance results were compared with those obtained using EEG spectral peak parameters which were recently shown to outperform other conventional EEG measures. Using a simple feature selection algorithm based on area-under-the-curve maximization and a support vector machine classifier, the proposed parameters resulted in accuracy gains, relative to spectral peak parameters, of 21.3% when discriminating between the three groups and by 50% when mild and moderate-to-severe groups were merged into one. The preliminary findings reported herein provide promising insights that automated tools may be developed to assist physicians in very early diagnosis of AD as well as provide researchers with a tool to automatically characterize cross-frequency interactions and their changes with disease

A percepção de estudantes sobre a convivência na escola: um estudo sobre contribuições dos Sistemas de Apoio entre Iguais (SAIS) em instituições escolares brasileiras e espanholas

The world literature has indicated more effective ways of prevention and intervention to bullying and its consequences in school. They are strategies that rely on the quality improvement of the school climate and the implementation of Support Systems between Equals (SAI). The present research seeks to verify students' perceptions regarding the quality of coexistence in schools with and without the implementation of a type of SAI called "Help Teams"(HT), a Spanish model adapted to the Brazilian schools. For that, a field research was carried out, with an exploratory and descriptive character, using a questionnaire between students from Brazil and Spain. Participated in this investigation 756 students of Brazilian Schools, 454 with the HT and 302 without HT and 438 Spain, 243 with HT and 195 without HT. The results show better quality in interpersonal relationships in schools with Help Teams. However, comparing the perception of the interpersonal relations of students from Brazilian and Spanish, even in Brazilian schools with SAI implemented, there are more problems than in Spanish schools that do not have such a model of work with the students. Although the coexistence theme is present in the Brazilian Law, the model is still recent and there are no public policies for the educational programs implementation to prevent these problems as in Spain.La literatura mundial ha señalado formas más eficaces de prevención e intervención al bullying y sus consecuencias en la escuela. Se tratan de estrategias que se apoyan en la mejora de calidad del clima escolar y en la implantación de Sistemas de Apoyo entre Iguales (SAI). La investigación busca verificar la percepción de los estudiantes respecto a la calidad de la convivencia en escuelas con y sin la implantación de un tipo de SAI llamado “Equipos de Ayuda”, un modelo español adaptado a las escuelas brasileñas. Para ello se realizó una investigación de campo, de carácter exploratorio y descriptivo utilizando un cuestionario entre estudiantes de Brasil y España. Participaron de esta investigación 756 estudiantes de Escuelas brasileñas, 454 con los EAs y 302 sin EAs y 438 de España, 243 con EAs y 195 sin EAs. Los resultados evidencian mejor calidad en las relaciones interpersonales en escuelas con Equipos de Ayuda. Sin embargo, comparando la percepción de las relaciones interpersonales de estudiantes de escuelas brasileñas y españolas, en escuelas brasileñas, aunque con SAI implantado hay más problemas que en escuelas españolas que no poseen tal modelo de trabajo con los alumnos. Se comprende que el modelo brasileño es aún reciente y que, aunque al tema de la convivencia esté presente en la Ley, no se dispone de políticas públicas para la implementación de programas educativos para prevenir estos problemas como en España.A literatura mundial tem indicado formas mais eficazes de prevenção e intervenção ao bullying e suas consequências na escola. São estratégias que se apoiam na melhoria da qualidade do clima escolar e na implantação de Sistemas de Apoio entre Iguais (SAI). A presente investigação busca verificar a percepção dos estudantes em relação à qualidade da convivência em escolas com e sem a implantação de um tipo de SAI chamado “Equipes de Ajuda”, um modelo espanhol adaptado às escolas brasileiras. Para isso foi realizada uma pesquisa de campo, de caráter exploratório e descritivo utilizando-se de um questionário entre estudantes do Brasil da Espanha. Participaram dessa investigação 756 estudantes de Escolas brasileiras, 454 de escolas com as EAs e 302 de escolas sem EAs; e 438 estudantes da Espanha, 243 de escolas com EAs e 195 de escolas sem EAs. Os resultados evidenciam melhor qualidade nas relações interpessoais em escolas com Equipes de Ajuda. Contudo, comparando a percepção das relações interpessoais de estudantes de escolas brasileiras e espanholas, em escolas brasileiras, mesmo com SAI implantado tem-se mais problemas do que em escolas espanholas que não possuem tal modelo de trabalho com os alunos. Entende-se que o modelo brasileiro é ainda recente e que, embora a temática da convivência esteja presente em leis brasileiras, não se dispõe de políticas públicas para a implementação de programas educacionais de prevenção aos problemas de convivência como na Espanha

Desenvolvimento moral de uma criança considerada "difícil": foco na relação escola-família

A partir do relato de um caso vivenciado na escola, objetivou-se compreender e analisar as intervenções realizadas pela escola, no desenvolvimento moral de uma criança considerada “difícil”, especificamente na relação entre a escola e a família. A partir da análise realizada desse caso, concluiu-se que a criança convive em um ambiente escolar autocrático, onde não há reflexão sobre as regras, não se permite a expressão dos sentimentos dos alunos e utiliza sanções expiatórias como formas de educação. Conclui-se também que existe uma dificuldade de se estabelecer uma parceria entre as instituições formadoras, visto que há terceirização das resoluções dos conflitos da escola para a família

Neurofeedback and the Aging Brain: A Systematic Review of Training Protocols for Dementia and Mild Cognitive Impairment

Dementia describes a set of symptoms that occur in neurodegenerative disorders and that is characterized by gradual loss of cognitive and behavioral functions. Recently, non-invasive neurofeedback training has been explored as a potential complementary treatment for patients suffering from dementia or mild cognitive impairment. Here we systematically reviewed studies that explored neurofeedback training protocols based on electroencephalography or functional magnetic resonance imaging for these groups of patients. From a total of 1,912 screened studies, 10 were included in our final sample (N = 208 independent participants in experimental and N = 81 in the control groups completing the primary endpoint). We compared the clinical efficacy across studies, and evaluated their experimental designs and reporting quality. In most studies, patients showed improved scores in different cognitive tests. However, data from randomized controlled trials remains scarce, and clinical evidence based on standardized metrics is still inconclusive. In light of recent meta-research developments in the neurofeedback field and beyond, quality and reporting practices of individual studies are reviewed. We conclude with recommendations on best practices for future studies that investigate the effects of neurofeedback training in dementia and cognitive impairment

Bullying e cyberbullying: quando os valores morais nos faltam e a convivência se estremece

This theoretical study aims to highlight the absence of moral content in situations of bullying and cyberbullying, emphasizing, on the other hand, the need to understand this phenomenon of violence as a moral problem. In a context of violent interpersonal relations experienced in educational institutions, whether face-to-face or virtual form, it is urgent to highlight the evidences of the current investigations on this subject that aim to overcome the problem through processes that prioritize the composition of an environment that favors moral formation and ethical coexistence. Since the school is very important in building the morality of its students, there must be, in every educational institution, the consolidation of a project of ethical living, in order to make explicit the pact of all its characters with the prevention of violence. The current literature indicates the need for programs and projects of ethical coexistence that are intentional, systematized and continuous, providing spaces of protagonism of the students, in order to exercise and experience moral values so that they will be priority in their personality precisely by highlighting how much these values are absent in those who attack as well as often in those who receive or witness the aggression.Este estudio teórico visa clarear la ausencia de contenidos morales en situaciones de bullying y ciberbullying resaltando, por otro lado, la necesidad de entender este fenómeno de violencia como un problema moral. En medio a un contexto de relaciones violentas entre personas que viven en instituciones educativas, aunque de forma presencial o virtual, insta-se clarear las evidencias de investigaciones actuales sobre este tema, que apuntan para una superación del problema a partir de procesos que valoran la composición de un ambiente que favorezca la formación moral y la convivencia ética. Una vez que la escuela se compromete a un papel significativo en la construcción de la moralidad de la persona, es necesario que haya, en cada institución educativa, la fijación de un proyecto de convivencia ética, de modo a explicitar lo papel de todos los personajes visando la prevención de la violencia. La literatura actual apunta la necesidad de estos programas y proyectos de convivencia ética que sellan intencionales, sistemáticos y continuos, de modo a ofrecer espacios de protagonismo a los alumnos, con el objetivo de que ejerciten y vivencien valores morales para que estos tomen lugar central en suyas personalidades, justamente para destacar la importancia de valores ausentes aquellos que agreden, bien como, muchas veces, en los que reciben o testigüen la agresión. Este estudo teórico objetiva evidenciar a ausência de conteúdos morais em situações de bullying e cyberbullying, destacando, em contrapartida, a necessidade de compreender esse fenômeno da violência como um problema moral. Em meio a um contexto de relações interpessoais violentas vivenciado nas instituições de ensino, seja de forma presencial ou virtual, urge destacar as evidências das investigações atuais sobre esse tema que apontam para a superação do problema por meio de processos que priorizem a composição de um ambiente que favoreça a formação moral e a convivência ética. Uma vez que a escola desempenha um papel significativo na construção da moralidade do sujeito, é necessário que haja, em cada instituição de ensino, a sedimentação de um projeto de convivência ética, de modo a explicitar o pacto de todos os seus personagens com a prevenção à violência. A literatura atual aponta a necessidade de tais programas e projetos de convivência ética que sejam intencionais, sistematizados e contínuos, proporcionando espaços de protagonismo para os alunos a fim de que exercitem e vivenciem valores morais para que estes tomem lugar central em sua personalidade, justamente por destacar o quanto tais valores estão ausentes naqueles que agridem, bem como muitas vezes naqueles que recebem ou testemunham a agressão

Interpreting EEG alpha activity

Exploring EEG alpha oscillations has generated considerable interest, in particular with regards to the role they play in cognitive, psychomotor, psycho-emotional and physiological aspects of human life. However, there is no clearly agreed upon definition of what constitutes ‘alpha activity’ or which of the many indices should be used to characterize it. To address these issues this review attempts to delineate EEG alpha-activity, its physical, molecular and morphological nature, and examine the following indices: (1) the individual alpha peak frequency; (2) activation magnitude, as measured by alpha amplitude suppression across the individual alpha bandwidth in response to eyes opening, and (3) alpha “auto-rhythmicity” indices: which include intra-spindle amplitude variability, spindle length and steepness. Throughout, the article offers a number of suggestions regarding the mechanism(s) of alpha activity related to inter and intra-individual variability. In addition, it provides some insights into the various psychophysiological indices of alpha activity and highlights their role in optimal functioning and behavior

Global Generation

condizioni affinche' il fascio d'ideali di una curva di P3 sia generato dalle sezioni global

ACC-striatal Projections are Uniquely Positioned to Interact With an Unusually Functionally Diverse Set of Cortical Areas

Background: Cortico-striatal projections play a central role in providing the basal ganglia with integrated information relevant to action selection and execution, making them a key candidate for the treatment of goal-directed and habitual disorders such as addiction and OCD. Probabilistic models have successfully summarized the spatial topography of this circuitry (Averbeck et al., 2014). For example, projections originating caudally from motor control areas terminate in the dorsolateral striatum, whereas rostral projections from ventromedial prefrontal cortex (PFC) terminate in ventromedial striatum. However, unlike the dorsolateral and ventromedial striatal sectors, the rostral and central striatum receives converging projections from multiple areas. This region is particularly complex and serves as an interface between functionally diverse cortical regions, the orbitofrontal cortex (OFC), ventrolateral PFC (vlPFC), and anterior cingulate cortex (ACC). Although there is an underlying topography to these connections, this alone may not be sufficient to understand the complexity of their interactions. The ACC is a particularly good example with its functional diversity and distributed striatal projections. The goal of this study was to develop a data-driven methodology that works in tandem with the more traditional topographic approach, to uncover additional key organizational principles of cortico-striatal circuitry. We focus specifically on the relationship between ACC-striatal projections to those originating in other areas of PFC. Methods: We analyzed 30 anterograde injections sites evenly distributed throughout macaque PFC (Averbeck et al., 2014). For each injection, we tabulated the loci of its terminal projections according to a striatal grid composed of 600 μm isotropic voxels. We then computed the similarity of the projections among every pair of cortical injections using a metric that corrects for chance agreement (adjusted rand index), and clustered cortical regions using spectral methods on the resulting similarity matrix. This identified two dominant gradients of cortical organization. We then visually examined the pattern of projections of every cortical cluster. Finally, based on previous qualitative observations that PFC projections to the striatum are mirrored along a dorso-ventral axis in ACC (Tang et al., 2019), we asked whether PFC regions could be similarly organized based on their connectivity to this region. We replicated the clustering analysis using 10 cortico-cortical retrograde injections distributed along the ACC. For each injection site, we computed the proportion of cells that projected to it from each area in PFC, and clustered cortical areas by the similarity of their projection pattern across injection sites. Results: The primary gradient organized cortical areas based on the location of their terminal projections along a ventromedial to dorsolateral axis in striatum. The secondary gradient captured the size of these projections. In line with classic topographic findings, the combined gradients positioned areas in ventromedial PFC as focally projecting to ventromedial striatum, whereas motor and dorsal PFC areas projected focally to dorsolateral striatum. In contrast, regions in ACC and portions of OFC had broad projections in central striatum, displaying partial overlap with the two more focal clusters. We found no significant relationship among injection volume, size of terminal projections, or the mean similarity of a given area (all pairwise correlations p > 0.1). Clustering performed on retrograde ACC injections resulted in a comparable primary gradient in PFC; motor and limbic areas primarily projected to dorsal and subgenual ACC, respectively, with remaining areas mostly projecting to rostral ACC. Conclusions: In this project, we used a data-driven approach to further characterize the underlying organizational principles of cortico-striatal circuitry. We used this approach and identify that ACC stands out in its connectivity within this network. We show that projections to striatum are organized by the size of their terminal fields in addition to their rostro-caudal location. The combination of these axes of organization distinguished ACC as an area with particularly widespread connections to the striatum. These results were not explained by methodological issues, such as injection volume. Further, we note commonalities between the organization of connections between prefrontal areas and both the ACC and the striatum. Based on these findings, we conclude that the ACC integrates information from diverse functional areas and relays this information to other functional groups via its relatively large projections to striatum. The mirrored cortico-cortical organization observed here raises the possibility that an individual’s topography of cortico-striatal projections, which can be difficult to precisely map using neuroimaging methods, could be approximated using cortico-cortical connectivity with ACC. This possibility could facilitate the identification of cortical targets for transcranial stimulation. Future work will test these findings using networks derived from diffusion and functional MRI in human and non-human primates