1,721,200 research outputs found
Individual differences in alpha frequency drive crossmodal illusory perception
No full textPerception routinely integrates inputs from different senses. Stimulus temporal proximity critically determines whether or not these inputs are bound together. Despite the temporal window of integration being a widely accepted notion, its neurophysiological substrate remains unclear. Many types of common audio-visual interactions occur within a time window of ∼100 ms [1-5]. For example, in the sound-induced double-flash illusion, when two beeps are presented within ∼100 ms together with one flash, a second illusory flash is often perceived [2]. Due to their intrinsic rhythmic nature, brain oscillations are one candidate mechanism for gating the temporal window of integration. Interestingly, occipital alpha band oscillations cycle on average every ∼100 ms, with peak frequencies ranging between 8 and 14 Hz (i.e., 120-60 ms cycle). Moreover, presenting a brief tone can phase-reset such oscillations in visual cortex [6, 7]. Based on these observations, we hypothesized that the duration of each alpha cycle might provide the temporal unit to bind audio-visual events. Here, we first recorded EEG while participants performed the sound-induced double-flash illusion task [4] and found positive correlation between individual alpha frequency (IAF) peak and the size of the temporal window of the illusion. Participants then performed the same task while receiving occipital transcranial alternating current stimulation (tACS), to modulate oscillatory activity [8] either at their IAF or at off-peak alpha frequencies (IAF±2 Hz). Compared to IAF tACS, IAF-2 Hz and IAF+2 Hz tACS, respectively, enlarged and shrunk the temporal window of illusion, suggesting that alpha oscillations might represent the temporal unit of visual processing that cyclically gates perception and the neurophysiological substrate promoting audio-visual interactions
Adults with autism overestimate the volatility of the sensory environment
Full text linkInsistence on sameness and intolerance of change are among the diagnostic criteria for autism spectrum disorder (ASD), but little research has addressed how people with ASD represent and respond to environmental change. Here, behavioral and pupillometric measurements indicated that adults with ASD are less surprised than neurotypical adults when their expectations are violated, and decreased surprise is predictive of greater symptom severity. A hierarchical Bayesian model of learning suggested that in ASD, a tendency to overlearn about volatility in the face of environmental change drives a corresponding reduction in learning about probabilistically aberrant events, thus putatively rendering these events less surprising. Participant-specific modeled estimates of surprise about environmental conditions were linked to pupil size in the ASD group, thus suggesting heightened noradrenergic responsivity in line with compromised neural gain. This study offers insights into the behavioral, algorithmic and physiological mechanisms underlying responses to environmental volatility in ASD
Attentional Modulation of Apparent Stimulus Contrast
No full textVoluntary attention modulates sensory processing in the visual system of primates by multiplying the response of neurons to attended/unattended stimuli. This effect resembles the modulation of neuronal responses caused by varying stimulus contrast. Additionally, attentional and contrast modulation of neuronal responses in monkey cortical area MT share a nonlinearity. Neuronal responses are more strongly modulated by attention and contrast changes for intermediate contrast stimuli than for low and high contrast stimuli. These similarities between attention and contrast suggests that they use similar or closely related mechanisms to modulate visual processing in the cortex
Data-Driven Learning : feasibility for Young Learners in the Context of ESO
Full text linkData-Driven Learning (DDL) refers to a language approach where the learner is exposed to authentic material from corpus linguistics. DDL has been successfully applied in university levels. This research questions whether this methodology would be feasible in ESO context. This study highlights DDL success and raises awareness about its limitations. A detailed guide about how to adapt DDL to ESO context is offered. One of the main obstacles is that methodologies introducing DDL into ESO classrooms are inappropriate. A solution to this would be blending DDL with another methodology, in this case TBLT. The results of this study conclude that further empirical research has to be done to know if DDL would be feasible in ESO context.Data-Driven Learning (DDL) fa referència a un enfocament lingüístic on l'estudiant està exposat a material autèntic extret d'un corpus lingüístic. DDL ha estat introduït amb èxit a nivell universitari. Aquest treball qüestiona si aquesta metodologia seria factible amb alumnat d'ESO i analitza els seus punts forts però també els seus problemes. Un dels majors obstacles és que les metodologies emprades per aplicar DDL no són apropiades per alumnes de secundària. Una possible solució seria combinar-ho amb una altra metodologia, en aquest cas, TBLT. Els resultats d'aquest estudi demostren que, per poder comprovar si la metodologia DDL seria factible en un context d'ESO, hauria de dur-se a terme més recerca empírica.Data-Driven Learning (DDL) hace referencia a un enfoque lingüístico donde el estudiante está expuesto a material auténtico extraído de un corpus lingüístico. DDL ha sido introducido con éxito a nivel universitario. Este trabajo cuestiona si esta metodología seria factible a nivel de ESO y analiza los puntos fuertes de dicha metodología y además menciona sus limitaciones. Uno de los mayores obstáculos es que las metodologías utilizadas para aplicar DDL no son apropiadas para alumnos de secundaria. Una solución sería combinarla con otra metodología ya usada, en este caso, TBLT. El resultado de este estudio demuestra que, para demostrar si DDL sería factible en un contexto de ESO, tiene que llevarse a cabo más investigación empírica
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Promoting learner generated error repair on preposition and preposition combinations through indirect written feedback and self-directed learning
Full text linkEste estudio es el resultado de una investigación llevada a cabo en 18 semanas de clase con estudiantes de inglés de nivel pre-intermedio en un contexto universitario en la ciudad de Bogotá, Colombia. A través de la instrucción intencionada de preposiciones, estrategias de aprendizaje y la promoción de la independencia y auto-dirección de los estudiantes, el estudio tuvo como intención la medición del aprendizaje de las preposiciones en inglés por parte de los estudiantes a través de los datos recolectados de sus tareas de composición de texto, así como el lograr establecer sus logros en auto-dirección por medio de escalas de medición de conductas precisas y entrevistas semi-estructuradas. El estudio muestra que solamente unos cuantos logros pueden lograrse en auto-dirección y auto-monitoreo a través de la implementación de estrategias, como estrategia aislada en la enseñanza de un segundo idioma, aunque con un consenso amplio en el cuerpo docente, se pueden producir resultados más amplios y expeditos.
Nota: Para consultar la carta de autorización de publicación de este documento por favor copie y pegue el siguiente enlace en su navegador de Internet: http://hdl.handle.net/10818/890
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