Functional Headings’ Effects on Selective Attention and Reading Processes / [La influencia de los encabezados funcionales en los procesos de atención selectiva y lectura]

Textual devices such as headings convey both content information and functional information. One type of headings is referred to as functional headings, since they provide functional information but not content information. Headings such as “Introduction” denote the function of a text section but not the content information of that section. The current study included three experiments that investigated the processing of functional information during reading. Experiment 1 investigated the effects of functional information in a timed reading situation. Experiments 2 and 3 looked at the effects of functional information when there was a contradiction in the text. Our results indicated that functional information promoted selective attention during timed reading (Experiment 1). Findings from our contradiction manipulation (Experiments 2 and 3) revealed that readers used functional headings to guide their structural reading process. Implications for cognitive processes during reading and pedagogical practices are described in the general discussion section.(AU)

Las ayudas de texto, como los encabezados, transmiten tanto información de contenido como información funcional. Uno de los tipos de encabezados se conoce como encabezados funcionales, pues proporcionan información funcional pero no información de contenido. Los encabezados como “Introducción” denotan la función de una sección de texto, pero no la información de contenido de esa sección. El estudio actual incluyó tres experimentos que investigaron el procesamiento de información funcional durante la lectura. El experimento 1 investigó los efectos de la información funcional en una situación de lectura cronometrada. Los experimentos 2 y 3 analizaron los efectos de la información funcional cuando había una contradicción en el texto. Nuestros resultados indicaron que la información funcional propició la atención selectiva durante la lectura cronometrada (experimento 1). Los resultados de nuestra manipulación de contradicciones (experimentos 2 y 3) revelaron que los lectores usaban encabezados funcionales para guiar su proceso de lectura estructural. Las implicaciones para los procesos cognitivos durante la lectura y las prácticas pedagógicas se describen en la sección de discusión general.(AU)

Oversimplifying Teaching of the Control of Variables Strategy / La excesiva simplificación de la enseñanza de control de estrategia de variables

Two experiments compared closely related interventions to teach the control of variables strategy (CVS) to fourth-grade students. Over the two experiments, an intervention first developed by Chen and Klahr (1999) was most effective at helping students learn how to design and evaluate single-factor experiments. In Experiment 1, attempts to reduce the cognitive load imposed by Chen and Klahr’s basic teaching intervention actually produced poorer learning and transfer of CVS. In Experiment 2, attempts to simplify Chen and Klahr’s algorithm for teaching students how to set up a valid experimental design also produced poorer learning and transfer of CVS. Both experiments illustrate that oversimplifying a domain or the logic behind controlling variables can undermine the effectiveness of an intervention designed to teach CVS

Mediante dos experimentos se compararon intervenciones estrechamente relacionadas con el objetivo de enseñar el control de estrategia de variables (CVS) a estudiantes de cuarto grado. Durante los dos experimentos, una intervención desarrollada primero por Chen y Klahr (1999) fue más eficaz para ayudar a los estudiantes a aprender a diseñar y evaluar experimentos de un solo factor. En el experimento 1, los intentos de reducir la carga cognitiva impuesta por la intervención básica de enseñanza de Chen y Klahr produjeron un aprendizaje y transferencia de CVS peores. En el experimento 2, los intentos de simplificar el algoritmo de Chen y Klahr para enseñar a los estudiantes cómo establecer un diseño experimental válido también produjeron un aprendizaje y transferencia de CVS peores. Ambos experimentos ilustran que simplificar excesivamente un dominio o la lógica que subyace en el control de variables puede socavar la eficacia de una intervención diseñada para enseñar CVS

Effects of audio headings on learning.

Text-to-speech (TTS) programs often do a poor job of translating writing devices such as headings from visual into audio mode. Previous research studies have attempted to address this problem but these studies have mainly used heading detection tasks. The current study seeks to investigate (a) whether the presence of audio headings improves performance in natural learning tasks and (b) the type of heading rendering that is the most useful in natural learning tasks. Two experiments compared the effects of two types of rendering strategies on note-taking and cued recall. Results from this study revealed that a prosodic rendering strategy was most useful to the listeners in natural learning tasks. (PsycINFO Database Record

Communicating printed headings to the ear.

Two experiments compared three methods of translating printed headings into an auditory format. In both experiments, college students listened to a text with instructions to stop the recording whenever they heard a heading and type the hierarchical level and exact wording of the heading. Listeners were poor at identifying headings and their levels if the headings were not distinguished from the rest of the text. However, listeners were very good at identifying headings if any method of signalling was used to distinguish headings and communicate their hierarchical level. The methods included: (1) tones preceding headings, (2) changes of speaker to indicate headings or (3) verbal labels preceding headings. Although all three signalling methods improved identification of a heading's hierarchical level, the labelling method was the most effective means of communicating hierarchical level. Thus, the study identifies a simple method of effectively communicating headings in spoken text. Practitioner Summary: The study attempted to identify effective ways of communicating heading information in spoken text. College students listened to texts in order to detect headings and record their wording and hierarchical level. Performance was excellent when headings were preceded by verbal phrases that signalled the upcoming headings and their levels.

Conducting silver networks based on electrospun poly(methyl methacrylate) and silver trifluoroacetate.

Silver networks with high transmittance and low resistance were prepared on transparent substrates via a polymer-assisted electrospinning technique and post treatments. Nonaqueous media containing poly(methyl methacrylate) (PMMA) and silver trifluoroacetate (STA) were formulated and electrospun as polymer/metal-precursor nanofibers with as-spun fiber diameters ranging from 640 to 3000 nm. Nanofibers randomly deposited on transparent substrates formed a plane scaffold, which served as the raw material for the conducting silver network. Post-thermal treatment at a moderate temperature of 100 °C reduced the STA precursors to silver nanoparticles (Ag NPs). Further heat treatment at elevated temperatures thermally decomposed the organic polymer and triggered sintering of the Ag NPs into a connected one-dimensional (1D) domain. Silver fibers with diameters ranging between 800 and 4500 nm formed continuous conducting networks on the substrate surface. The sheet resistances of these conducting silver networks revealed strong correlations with the original STA/PMMA ratios and with the silver network morphologies after the polymers were removed. The material fabrication was carefully investigated, and the surface plasmon resonances (SPRs), fiber morphologies, and electrical and optical properties of the products were examined. The optimized conducting silver networks exhibited sheet resistances as low as 15 Ω/sq and diffusive optical transparencies of approximately 54%.

Communicating headings and preview sentences in text and speech.

Two experiments tested the effects of preview sentences and headings on the quality of college students' outlines of informational texts. Experiment 1 found that performance was much better in the preview sentences condition than in a no-signals condition for both printed text and text-to-speech (TTS) audio rendering of the printed text. In contrast, performance in the headings condition was good for the printed text but poor for the auditory presentation because the TTS software failed to communicate nonverbal information carried by the visual headings. Experiment 2 compared outlining performance for five headings conditions during TTS presentation. Using a theoretical framework, "signaling available, relevant, accessible" (SARA) information, to provide an analysis of the information content of headings in the printed text, the manipulation of the headings systematically restored information that was omitted by the TTS application in Experiment 1. The result was that outlining performance improved to levels similar to the visual headings condition of Experiment 1. It is argued that SARA is a useful framework for guiding future development of TTS software for a wide variety of text signaling devices, not just headings.

Protective effects from carnosine and histidine on acetaminophen-induced liver injury.

Protective effects of carnosine or histidine against acetaminophen-induced hepatotoxicity in Balb/cA mice were examined. Each compound, at 0.5, 1, or 2 g/L, was added into the drinking water for 4 wk. Acute liver injury was induced by acetaminophen treatment intraperitoneally (i.p. 350 mg/kg body weight). Acetaminophen treatment significantly depleted hepatic GSH and ascorbic acid levels, increased hepatic level of malonyldialdehyde (MDA), reactive oxygen species (ROS), and oxidized glutathione (GSSG), as well as decreased hepatic activity of glutathione peroxidase (GPX), catalase, and superoxide dismutase (SOD) (P < 0.05). However, the pre-intake of carnosine or histidine significantly alleviated acetaminophen-induced oxidative stress by increasing GSH content, decreasing MDA, ROS, and GSSG formations, and retaining activity of GPX, catalase, and SOD in liver (P < 0.05). The pre-intake of these compounds also significantly retarded subsequent acetaminophen-induced increase of cytochrome P450 2E1 activity (P < 0.05). Acetaminophen treatment increased the hepatic levels of interleukin (IL)-6, IL-10, tumor necrosis factor (TNF)-alpha, and monocyte chemoattractant protein (MCP)-1 (P < 0.05). The pre-intake of carnosine or histidine significantly diminished acetaminophen-induced elevation of these cytokines (P < 0.05). The impact of these compounds on mRNA expression of GPX, TNF-alpha, and MCP-1 indicated that these compounds could act at a transcription level. These results support that carnosine and histidine are potent hepatoprotective agents.