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1.
Neuroimage ; 149: 244-255, 2017 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-28163139

RESUMEN

Reading involves activation of phonological and semantic knowledge. Yet, the automaticity of the activation of these representations remains subject to debate. The present study addressed this issue by examining how different brain areas involved in language processing responded to a manipulation of bottom-up (level of visibility) and top-down information (task demands) applied to written words. The analyses showed that the same brain areas were activated in response to written words whether the task was symbol detection, rime detection, or semantic judgment. This network included posterior, temporal and prefrontal regions, which clearly suggests the involvement of orthographic, semantic and phonological/articulatory processing in all tasks. However, we also found interactions between task and stimulus visibility, which reflected the fact that the strength of the neural responses to written words in several high-level language areas varied across tasks. Together, our findings suggest that the involvement of phonological and semantic processing in reading is supported by two complementary mechanisms. First, an automatic mechanism that results from a task-independent spread of activation throughout a network in which orthography is linked to phonology and semantics. Second, a mechanism that further fine-tunes the sensitivity of high-level language areas to the sensory input in a task-dependent manner.


Asunto(s)
Encéfalo/fisiología , Reconocimiento Visual de Modelos/fisiología , Adolescente , Adulto , Mapeo Encefálico/métodos , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Imagen por Resonancia Magnética , Masculino , Fonética , Lectura , Semántica , Adulto Joven
2.
J Sleep Res ; 24(6): 666-72, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26173051

RESUMEN

Sleep deprivation is known to exert detrimental effects on various cognitive domains, including attention, vigilance and working memory. Seemingly at odds with these findings, prior studies repeatedly failed to evidence an impact of prior sleep deprivation on cognitive interference in the Stroop test, a hallmark paradigm in the study of cognitive control abilities. The present study investigated further the effect of sleep deprivation on cognitive control using an adapted version of the Stroop test that allows to segregate top-down (attentional reconfiguration on incongruent items) and bottom-up (facilitated processing after repetitions in responses and/or features of stimuli) components of performance. Participants underwent a regular night of sleep or a night of total sleep deprivation before cognitive testing. Results disclosed that sleep deprivation selectively impairs top-down adaptation mechanisms: cognitive control no longer increased upon detection of response conflict at the preceding trial. In parallel, bottom-up abilities were found unaffected by sleep deprivation: beneficial effects of stimulus and response repetitions persisted. Changes in vigilance states due to sleep deprivation selectively impact on cognitive control in the Stroop test by affecting top-down, but not bottom-up, mechanisms that guide adaptive behaviours.


Asunto(s)
Adaptación Psicológica , Cognición , Privación de Sueño/psicología , Test de Stroop , Atención , Femenino , Humanos , Masculino , Memoria a Corto Plazo , Sueño/fisiología , Privación de Sueño/fisiopatología , Adulto Joven
3.
Int J Pediatr Otorhinolaryngol ; 186: 112128, 2024 Oct 06.
Artículo en Inglés | MEDLINE | ID: mdl-39378540

RESUMEN

INTRODUCTION: Auditory perception process is a transient phenomenon, which enables the person to make the relationship between events and auditory factor by working memory and obtain the sequence of auditory features and be able differentiate the auditory sources by using these component. In auditory processing, the basis formed by bottom - up process (data - driven). This pathway is dependent on the central auditory integration and also on acoustic signal input and interpreting auditory information is involved top-down process (concept - driven), which this pathway is dependent on central higher resource such as perception, attention, working memory and its span. The purpose of this study was to address information about top-down processing and auditory processing disorder. MATERIALS AND METHODS: A review of the latest literature on (central) auditory processing disorders and top-down processing was performed using PUBMED, EBSCO, SCIENCE DIRECT, ASHA, GOOGLE SCHOLAR, THIEME, PROQUEST data sources. CONCLUSION: Deficit in cognitive processing of auditory information in children cause difficulty in processing auditory information and outbreak auditory processing disorder symptoms. Cognitive evaluation (especially working memory) in this subject is important as bottom-up processing evaluation.

4.
Cogn Sci ; 46(5): e13131, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35579883

RESUMEN

Viewers' attentional selection while looking at scenes is affected by both top-down and bottom-up factors. However, when watching film, viewers typically attend to the movie similarly irrespective of top-down factors-a phenomenon we call the tyranny of film. A key difference between still pictures and film is that film contains motion, which is a strong attractor of attention and highly predictive of gaze during film viewing. The goal of the present study was to test if the tyranny of film is driven by motion. To do this, we created a slideshow presentation of the opening scene of Touch of Evil. Context condition participants watched the full slideshow. No-context condition participants did not see the opening portion of the scene, which showed someone placing a time bomb into the trunk of a car. In prior research, we showed that despite producing very different understandings of the clip, this manipulation did not affect viewers' attention (i.e., the tyranny of film), as both context and no-context participants were equally likely to fixate on the car with the bomb when the scene was presented as a film. The current study found that when the scene was shown as a slideshow, the context manipulation produced differences in attentional selection (i.e., it attenuated attentional synchrony). We discuss these results in the context of the Scene Perception and Event Comprehension Theory, which specifies the relationship between event comprehension and attentional selection in the context of visual narratives.


Asunto(s)
Comprensión , Movimientos Oculares , Atención , Humanos , Películas Cinematográficas , Motivación , Percepción Visual
5.
Front Psychol ; 13: 1027742, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36726514

RESUMEN

People often form different aesthetic preferences for natural and built environments, which affects their behavioral intention; however, it remains unknown whether this difference in aesthetic preference is due to differences in thinking styles. However, whether tourists' aesthetic preferences differ when using different visual attention processes has not been studied further. This study used eye-tracking and self-reporting to investigate these questions. The results show that natural environment images are more favored visually because they can evoke in tourists larger pupil diameters and longer scan paths, but we found no significant difference in fixation duration and fixation counts. We also found that the scanning path of tourists who predominantly rely on intuitive thinking is modulated by the bottom-up attention process, while the scanning path of tourists who prefer rational thinking is modulated by the top-down attention process. In the bottom-up process, tourists who prefer rational thinking exhibit more positive aesthetic preferences and emotional arousal. In summary, the present study verified that aesthetic preference is more likely to be influenced by both thinking style and visual attention processing. The results of the present work provide preliminary evidence that the aesthetic preference of the environment is not only related to visual attention but also affected by the individual visual attention process and thinking style.

6.
S Afr J Physiother ; 77(2): 1583, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34722944

RESUMEN

BACKGROUND: Studies have shown that perceptual and cognitive asymmetries are present in the auditory system in patients with adolescent idiopathic scoliosis (AIS). The Dichotic Listening (DL) paradigm was formerly performed in non-forced (NF) conditions only, and no study has examined the conditions of attention to one ear. OBJECTIVE: To investigate the perceptual and cognitive asymmetry in the auditory system in patients with AIS as well as the asymmetry changes according to the curvature characteristics of patients with AIS. METHOD: The DL paradigm was performed on 38 patients with AIS and 10 healthy individuals in all conditions (NF, Forced Right [FR], Forced Left [FL]). RESULTS: In the NF and FL conditions, the mean number of correct responses for the left ear was significantly lower in patients with AIS than in healthy individuals (p < 0.05). The correct responses for the right ear in the NF condition, right and left ear in the FR condition, and right ear in the FL condition did not show a significant difference between the groups (p > 0.05). Also, there was no difference between patients with AIS with both functional 3-curve and 4-curve (p > 0.05). CONCLUSION: Our study indicates perceptual and cognitive asymmetry or lateralisation in the auditory system in patients with AIS. The asymmetry might be caused by the inability to direct their attention to the left ear, which is not affected by their curvature type. Further studies are needed to investigate perceptual and cognitive asymmetry behaviour models in the auditory system in patients with AIS. CLINICAL IMPLICATIONS: Determination of perceptual and cognitive asymmetry in the auditory system may offer a new perspective on conservative treatment protocols for AIS patients. Besides, the DL paradigm can be easily used in patients with AIS as a non-invasive evaluation method in clinics.

7.
Front Syst Neurosci ; 15: 734660, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34776884

RESUMEN

Our brains do not mechanically process incoming stimuli; in contrast, the physiological state of the brain preceding stimuli has substantial consequences for subsequent behavior and neural processing. Although previous studies have acknowledged the importance of this top-down process, it was only recently that a growing interest was gained in exploring the underlying neural mechanism quantitatively. By utilizing the attentional blink (AB) effect, this study is aimed to identify the neural mechanism of brain states preceding T2 and predict its behavioral performance. Interarea phase synchronization and its role in prediction were explored using the phase-locking value and support vector machine classifiers. Our results showed that the phase coupling in alpha and beta frequency bands pre-T1 and during the T1-T2 interval could predict the detection of T2 in lag 3 with high accuracy. These findings indicated the important role of brain state before stimuli appear in predicting the behavioral performance in AB, thus, supporting the attention control theories.

8.
Iperception ; 12(1): 2041669520987254, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33613956

RESUMEN

Although most people are not aware of it, bias can occur when interpreting graphs. Within-the-bar bias describes a misinterpretation of the distribution of data underlying bar graphs that indicate an average or where the average estimation point moves inside the bar when the average of several graphs is estimated. This study proposes and tests two methods based on information processing to reduce within-the-bar bias. The first method facilitates bottom-up processing by changing various graph features, such as presenting confidence intervals, placing boundaries around the graph, and showing cumulative bars with different tones. The second method facilitates top-down processing by instructing participants to estimate the mean based on a dot at the end of each bar. Testing of the first method showed that cumulative bars reduced bias, but the other methods did not. The second method was found to reduce bias. Overall, our results demonstrate that the accurate interpretation of bar graphs can be facilitated through the manipulation of specific graph features and instruction.

9.
Int J Pharm ; 553(1-2): 363-374, 2018 Dec 20.
Artículo en Inglés | MEDLINE | ID: mdl-30385372

RESUMEN

Gold nanoclusters (AuNCs) have been considered to be a promising candidate for hyperthermia-based anticancer therapy. Herein, we introduce albumin-assisted AuNCs composed of small gold nanoparticles (AuNPs, <6 nm) assembled with strands of polyallylamine (PAH), which exhibited strong surface plasmon resonance upon near-infrared (NIR, ∼808 nm) laser irradiation and good in vivo stability. Our albumin-assisted PAH-AuNCs (BSA/PAH-AuNCs) were facilely fabricated as a top-down process by a simple ultrasonication after the preparation of large nano-aggregates of PAH-AuNPs. Albumin played a critical role as a stabilizer and surfactant in making loosely associated large aggregates and thereby producing small gold nanoclusters (∼60 nm) of slightly negative charge upon ultrasonication. The prepared BSA/PAH-AuNCs displayed excellent hyperthermal effects (∼60 °C) in response to ∼808-nm NIR laser irradiation in a 4T1 cell system in vitro and in 4T1 cell tumor xenograft mice in vivo, indicating their remarkable potential to suppress breast cancer growth, without almost no significant toxicity in histology. Consequently, our gold nanoclusters should be considered as a promising photothermal agent that are easy to manufacture and exhibit marked anticancer effects in terms of tumor ablation.


Asunto(s)
Hipertermia Inducida/métodos , Terapia por Láser/métodos , Neoplasias Mamarias Experimentales/terapia , Nanopartículas del Metal , Albúminas/química , Animales , Femenino , Oro , Masculino , Neoplasias Mamarias Experimentales/patología , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Poliaminas/química , Resonancia por Plasmón de Superficie , Ensayos Antitumor por Modelo de Xenoinjerto
10.
PeerJ ; 5: e3988, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-29152415

RESUMEN

In its most basic form, empathy refers to the ability to understand another person's feelings and emotions, representing an essential component of human social interaction. Owing to an increase in the use of mass media, which is used to distribute high levels of empathy-inducing content, media plays a key role in individual and social empathy induction. We investigated empathy induction in cartoons using eye movement, EEG and behavioral measures to explore whether empathy factors correlate with character drawing styles. Two different types of empathy-inducing cartoons that consisted of three stages and had the same story plot were used. One had an iconic style, while the other was realistic style. Fifty participants were divided into two groups corresponding to the individual cartoon drawing styles and were presented with only one type of drawing style. We found that there were no significant differences of empathy factors between iconic and realistic style. However, the Induced Empathy Score (IES) had a close relationship with subsequent attentional processing (total fixation length for gaze duration). Furthermore, iconic style suppressed the fronto-central area more than realistic style in the gamma power band. These results suggest that iconic cartoons have the advantage of abstraction during empathy induction, because the iconic cartoons induced the same level of empathy as realistic cartoons while using the same story plot (top-down process), even though lesser time and effort were required by the cartoon artist to draw them. This also means that the top-down process (story plot) is more important than the bottom-up process (drawing style) in empathy induction when viewing cartoons.

11.
Expert Opin Drug Deliv ; 12(11): 1741-54, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26098043

RESUMEN

INTRODUCTION: The top-down approach is frequently used for drug nanocrystal production. A large number of review papers have referred to the top-down approach in terms of process parameters such as stabilizer selection. However, a very important factor, that is, the influence of drug properties, has been not addressed so far. AREAS COVERED: This review will first discuss different nanocrystal technologies in brief. The focus will be on reviewing the different drug properties such as solid state and particle morphology on the efficiency of particle size reduction during top-down processes. Furthermore, the drug properties in the final nanosuspensions are critical for drug dissolution velocity. Therefore, another focus is the characterization of drugs in obtained nanosuspension. EXPERT OPINION: Drug physical properties play an important role in the production efficiency. The combinative technologies using modified drugs could significantly improve the performances of top-down processes. However, further understanding of the drug millability and homogenization will still be needed. In addition, a carefully established characterization system for nansuspension is essential.


Asunto(s)
Sistemas de Liberación de Medicamentos , Nanopartículas , Preparaciones Farmacéuticas/administración & dosificación , Tamaño de la Partícula , Solubilidad
12.
Front Psychol ; 6: 598, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26029138

RESUMEN

The main research goal of the present study was to investigate in how far pre-training eye movements can facilitate knowledge acquisition in multimedia (pre-training principle). We combined considerations from research on eye movement modeling and pre-training to design and test a non-verbal eye movement-based pre-training. Participants in the experimental condition watched an animated circle moving in close spatial resemblance to a static visualization of a solar plant accompanied by a narration in a subsequently presented learning environment. This training was expected to foster top-down processes as reflected in gaze behavior during the learning process and enhance knowledge acquisition. We compared two groups (N = 45): participants in the experimental condition received pre-training in a first step and processed the learning material in a second step, whereas the control group underwent the second step without any pre-training. The pre-training group outperformed the control group in their learning outcomes, particularly in knowledge about processes and functions of the solar plant. However, the superior learning outcomes in the pre-training group could not be explained by eye-movement patterns. Furthermore, the pre-training moderated the relationship between experienced stress and learning outcomes. In the control group, high stress levels hindered learning, which was not found for the pre-training group. On a delayed posttest participants were requested to draw a picture of the learning content. Despite a non-significant effect of training on the quality of drawings, the pre-training showed associations between learning outcomes at the first testing time and process-related aspects in the quality of their drawings. Overall, non-verbal pre-training is a successful instructional intervention to promote learning processes in novices although these processes did not directly reflect in learners' eye movement behavior during learning.

13.
Carbohydr Polym ; 112: 284-90, 2014 Nov 04.
Artículo en Inglés | MEDLINE | ID: mdl-25129746

RESUMEN

This study involved a detailed investigation of a novel approach to reducing naturally occurring cellulose fibers into nanofibers solely by the use of aqueous counter collision (ACC) without any chemical modification. In this process, equivalent aqueous suspensions of cellulose are ejected from dual nozzles and collide at high speed and pressure. Even a few repetitions of the collision process are sufficient to produce nano-sized fibers dispersed in water. This work compared the ACC nano-pulverization of stable Iß-rich and meta-stable Iα-rich cellulose samples. The ACC method is applicable to various kinds of polymeric materials with hierarchical structures, either natural or synthetic, as a means of preparing aqueous dispersions of nano-sized structures.


Asunto(s)
Celulosa/química , Nanofibras/química , Nanotecnología/métodos , Animales , Diseño de Equipo , Gluconacetobacter xylinus/química , Nanotecnología/instrumentación , Reología/métodos , Espectroscopía Infrarroja por Transformada de Fourier , Suspensiones/química , Urocordados/química , Viscosidad , Agua , Madera , Difracción de Rayos X
14.
Front Psychol ; 5: 1533, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25610416

RESUMEN

Situation Model of Anticipated Response consequences in tactical decisions (SMART) describes the interaction of top-down and bottom-up processes in skill acquisition and thus the dynamic interaction of sensory and motor capacities in embodied cognition. The empirically validated, extended, and revised SMART-ER can now predict when specific dynamic interactions of top-down and bottom-up processes have a beneficial or detrimental effect on performance and learning depending on situational constraints. The model is empirically supported and proposes learning strategies for when situation complexity varies or time pressure is present. Experiments from expertise research in sports illustrate that neither bottom-up nor top-down processes are bad or good per se but their effects depend on personal and situational characteristics.

15.
Int J Pharm ; 476(1-2): 277-88, 2014 Dec 10.
Artículo en Inglés | MEDLINE | ID: mdl-25278040

RESUMEN

This paper describes a systematic approach to select optimum stabilizer for the preparation of nano-crystalline suspensions of an active pharmaceutical ingredient (API). The stabilizer can be either a dispersant or a combination of dispersant and wetting agent. The proposed screening method is a quick and efficient way to investigate a large number of stabilizers based on the principles of physical-chemistry and employs a stepwise approach. The methodology has been divided in two main parts; the first part being focused on the qualitative screening with the objective of selecting the best candidate(s) for further investigation, the second part has been focused on quantitative screening with the objective to optimize the ratio and amount of wetting and dispersing agents, based on wettability, surface charges measurement, adsorption evaluation, process-ability evaluation and storage stability. The results showed clearly that SDS/PVP 40/60% (w/w) (sodium dodecyl sulfate/poly(vinyl pyrrolidone)) at a total concentration of 1.2% was the optimum stabilizer composition, at which the resulting nanosuspensions were stable for more than 50 days at room temperature.


Asunto(s)
Excipientes/química , Nanopartículas , Povidona/química , Dodecil Sulfato de Sodio/química , Química Farmacéutica/métodos , Estabilidad de Medicamentos , Almacenaje de Medicamentos , Suspensiones , Temperatura , Factores de Tiempo , Humectabilidad
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