39 research outputs found
A relevância da localização para a recuperação de informações visuais
The role of localization in the integration of visual characteristics into memory is controversial. Some evidence suggests that location loses importance soon after the consolidation of information; others, that the location remains associated with the representation of the object for longer. We investigated the role of location for the memory of objects defined by color and shape. Partici- pants (36) performed a change detection task with 3 and 6 stimuli, with two retention intervals (500 and 1. 500 milliseconds). Performance is better when the load is lower, stimuli are presented in the same places where they were memorized, and it depends on the interaction between these factors. The retention interval does not interfere with the location effect but modulates that of the load. These results suggest that localization is incidentally encoded with visual stimuli and that this association remains unchanged within the time limits investigated.El papel de la localización en la integración de las características visuales en la memoria es controvertido. Algunas evidencias sugieren que la localización pierde importancia poco después de la consolidación de la información; otras, que la localización permanece asociada a la representación del objeto durante más tiempo. Investigamos el papel de la localización para la memoria de los objetos definidos por el color y la forma. Los 36 participantes realizaron una tarea de detección de cambios con 3 y 6 estímulos, con dos intervalos de retención (500 y 1500 milisegundos). El rendimiento es mejor cuando la carga es menor, cuando los estímulos se presentan en los mismos lugares donde fueron memorizados, y depende de la interacción entre estos factores. El intervalo de retención no interfiere con el efecto de ubicación, pero modula el efecto de carga. Estos resultados sugieren que la ubicación se codifica incidentalmente con estímulos visuales y que esta asociación permanece sin cambios dentro de los límites de tiempo investigados.O papel da localização na integração das características visuais na memória é controverso. Algumas evidências sugerem que a localização perde importância logo depois da consolidação da informação, outras, que a localização permanece associada à representação do objeto por mais tempo. Nós investigamos o papel da localização para a memória de objetos definidos por cor e forma. Os participantes (36) realizaram uma tarefa de detecção de mudança com 3 e 6 estímulos, com dois intervalos de retenção (500 e 1.500 milissegundos). O desempenho é melhor quando a carga é menor, quando os estímulos são apresentados nos mesmos lugares em que foram memorizados, e depende da interação entre estes fatores. O intervalo de retenção não interfere no efeito da localização, mas modula o efeito da carga. Estes resultados sugerem que a localização é codificada de forma incidental com os estímulos visuais e que esta associação permanece inalterada dentro dos limites de tempo investigados
Distribuição da atenção visual dentro de áreas indicadas: evidência baseada em julgamentos de ordem temporal
Three experiments were performed to investigate the distribution of attention across the visual field and the possibility of attentional resources to be more concentrated inside an abrupt onset frame (cue). The participants performed a temporal order judgment task of two letters presented in sequence; one letter presented inside and the other outside the frame. The results showed that the information presented inside the frame had its perceptual latency shortened in relation to the information presented outside the frame in experimental conditions where the frame orientation, the distance between the two letters and the cue onset time were manipulated. The advantage of the information presented inside the frame was attributed to the displacement of attention to the area delimited by the frame. The results contribute to the understanding of visual perception, showing that attentional resources may be redistributed inside the borders of a geometric figure.Três experimentos foram realizados para investigar a distribuição da atenção pelo campo visual e a possibilidade dos recursos de atenção serem mais concentrados no interior de uma moldura (dica) de início abrupto. Os participantes realizaram uma tarefa de julgamento de ordem temporal de duas letras apresentadas em seqüência; uma letra apresentada dentro e a outra fora da moldura. Os resultados mostraram que a informação apresentada dentro da moldura teve a sua latência perceptual encurtada em relação à informação apresentada fora da moldura em condições experimentais onde a orientação da moldura, a distância entre as duas letras e o tempo de exposição da moldura foram manipulados. Esta vantagem para a informação apresentada dentro da moldura foi atribuída ao deslocamento da atenção para a área delimitada pela moldura. Os resultados contribuem para o entendimento da percepção visual, mostrando que recursos de atenção podem ser redistribuídos dentro das bordas de uma figura geométrica.Co-ordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES
Componentes funcionais da memória visuoespacial
O estudo da memória de trabalho está centrado no fracionamento desse sistema em subsistemas especializados na armazenagem de informação verbal, visuoespacial e multimodal. Neste artigo abordamos o fracionamento da memória visuoespacial em seus componentes visuais e espaciais. A presença de códigos visuais na memória de trabalho é sugerida pelos efeitos de similaridade visual e de informação visual irrelevante. A memória espacial parece depender fortemente de recursos da atenção e sua relação com a memória visual ainda é controversa.Research on working memory has been focused on fractionating specialized subsystems responsible for storage of verbal, visuospatial and multimodal information. In the present paper, we review the fractionation of visuospatial working memory into separate visual and spatial components. The availability of visual codes in working memory is supported by the effects of visual similarity and irrelevant information. Spatial memory seems to depend on attention resources and its relationship with visual memory is still controversia
The nature of the representation of short-term memorized scenes: the effect of intervening tasks on the memory for the distances between objects
Three intervening tasks (verbal, visual and arithmetical) performed by participants during the study of a scene were used to explicit the nature of the memorized representations of the distances between scene objects. The effect of the intervening task on the distances representation was determined through the exponent of the power function estimated from the judgments of distances based on estimation and the distances between objects in scene. The results showed that the exponents obtained by magnitude estimation do not differ from unit. On the contrary, the exponents obtained on the basis of the x and y coordinates of the drawing have lower values. The exponents obtained with judgments of magnitude and from the y axe of the drawing were affected by the arithmetical task performed during the study time, but not by visual one. These results suggest that visual and spatial components contribute with differentiated weights for the representation quality.Três tarefas intervenientes (verbal, visual e aritmética), realizadas durante estudo de uma cena, foram utilizadas com o objetivo de explicitar a natureza da representação memorizada das distâncias entre os objetos da cena. O efeito delas sobre a representação das distâncias foi estimado por expoentes da função potência baseados em julgamentos da distância relembrada entre pares de objetos e reprodução em desenho da disposição espacial dos objetos da cena. Os resultados mostram que expoentes obtidos não diferem da unidade. Por outro lado, os estimados pelas coordenadas x e y com base nos desenhos são menores. Tanto os expoentes obtidos nos julgamentos de magnitude de distância aos pares como aqueles a partir do eixo y do desenho foram afetados pela realização da tarefa aritmética durante o tempo de estudo, mas não pela realização da tarefa visual. Estes resultados sugerem que componentes visuais e espaciais contribuem com pesos diferenciados para a qualidade da representação
Predictive Value of Cardiac Magnetic Resonance Feature Tracking after Acute Myocardial Infarction: A Comparison with Dobutamine Stress Echocardiography
Ecocardiografía de seguimiento de manchas; Deformación del miocardio; Seguimiento de características de resonancia magnética cardíacaSpeckle-tracking echocardiography; Myocardial deformation; Cardiac magnetic resonance feature-trackingEcocardiografia de seguiment de taques; Deformació del miocardi; Seguiment de característiques de ressonància magnètica cardíacaIn acute ST-segment elevation myocardial infarction (STEMI) late gadolinium enhancement (LGE) may underestimate segmental functional recovery. We evaluated the predictive value of cardiac magnetic resonance (CMR) feature-tracking (FT) for functional recovery and whether it incremented the value of LGE compared to low-dose dobutamine stress echocardiography (LDDSE) and speckle-tracking echocardiography (STE). Eighty patients underwent LDDSE and CMR within 5–7 days after STEMI and segmental functional recovery was defined as improvement in wall-motion at 6-months CMR. Optimal conventional and FT parameters were analyzed and then also applied to an external validation cohort of 222 STEMI patients. Circumferential strain (CS) was the strongest CMR-FT predictor and addition to LGE increased the overall accuracy to 74% and was especially relevant in segments with 50–74% LGE (AUC 0.60 vs. 0.75, p = 0.001). LDDSE increased the overall accuracy to 71%, and in the 50–74% LGE subgroup improved the AUC from 0.60 to 0.69 (p = 0.039). LGE + CS showed similar value as LGE + LDDSE. In the validation cohort, CS was also the strongest CMR-FT predictor of recovery and addition of CS to LGE improved overall accuracy to 73% although this difference was not significant (AUC 0.69, p = 0.44). Conclusion: CS is the strongest CMR-FT predictor of segmental functional recovery after STEMI. Its incremental value to LGE is comparable to that of LDDSE whilst avoiding an inotropic stress agent. CS is especially relevant in segments with 50–74% LGE where accuracy is lower and further testing is frequently required to clarify the potential for recovery.This research was supported by the Instituto de Salud Carlos III and co-funded by Fondo Europeo de Desarrollo Regional (FEDER) (grant numbers PI17/01836 and CIBERCV16/11/00486). JG and DM acknowledge financial support from the “Agencia Valenciana de la Innovación, Generalitat Valenciana” (grant) and from the “Conselleria d’Educació, Investigació, Cultura i Esport, Generalitat Valenciana” (grant number AEST/2019/037)
Are Aortic Root and Ascending Aorta Diameters Measured by the Pediatric versus the Adult American Society of Echocardiography Guidelines Interchangeable?
Aortic dimensions; Echocardiography; Guideline’s recommendationsDimensions aòrtiques; Ecocardiografia; Recomanacions de les directriusDimensiones aórticas; Ecocardiografía; Recomendaciones de las directricesAscending aorta diameters have important clinical value in the diagnosis, follow-up, and surgical indication of many aortic diseases. However, there is no uniformity among experts regarding ascending aorta diameter quantification by echocardiography. The aim of this study was to compare maximum aortic root and ascending aorta diameters determined by the diastolic leading edge (DLE) and the systolic inner edge (SIE) conventions in adult and pediatric patients with inherited cardiovascular diseases. Transthoracic echocardiograms were performed in 328 consecutive patients (260 adults and 68 children). Aorta diameters were measured twice at the root and ascending aorta by the DLE convention following the 2015 American Society of Echocardiography (ASE) adult guidelines and the SIE convention following the 2010 ASE pediatric guidelines. Comparison of the diameters measured by the two conventions in the overall population showed a non-significant underestimation of the diameter measured by the SIE convention at root level of 0.28 mm (CI −1.36; 1.93) and at tubular ascending aorta level of 0.17 mm (CI −1.69; 2.03). Intraobserver and interobserver variability were excellent. Maximum aorta diameter measured by the leading edge convention in end-diastole and the inner edge convention in mid-systole had similar values to a mild non-significant underestimation of the inner-to-inner method that permits them to be interchangeable when used in clinical practice
Predictive Value of Cardiac Magnetic Resonance Feature Tracking after Acute Myocardial Infarction: A Comparison with Dobutamine Stress Echocardiography
[EN] In acute ST-segment elevation myocardial infarction (STEMI) late gadolinium enhancement (LGE) may underestimate segmental functional recovery. We evaluated the predictive value of cardiac magnetic resonance (CMR) feature-tracking (FT) for functional recovery and whether it incremented the value of LGE compared to low-dose dobutamine stress echocardiography (LDDSE) and speckle-tracking echocardiography (STE). Eighty patients underwent LDDSE and CMR within 5-7 days after STEMI and segmental functional recovery was defined as improvement in wall-motion at 6-months CMR. Optimal conventional and FT parameters were analyzed and then also applied to an external validation cohort of 222 STEMI patients. Circumferential strain (CS) was the strongest CMR-FT predictor and addition to LGE increased the overall accuracy to 74% and was especially relevant in segments with 50-74% LGE (AUC 0.60 vs. 0.75, p = 0.001). LDDSE increased the overall accuracy to 71%, and in the 50-74% LGE subgroup improved the AUC from 0.60 to 0.69 (p = 0.039). LGE + CS showed similar value as LGE + LDDSE. In the validation cohort, CS was also the strongest CMR-FT predictor of recovery and addition of CS to LGE improved overall accuracy to 73% although this difference was not significant (AUC 0.69, p = 0.44). Conclusion: CS is the strongest CMR-FT predictor of segmental functional recovery after STEMI. Its incremental value to LGE is comparable to that of LDDSE whilst avoiding an inotropic stress agent. CS is especially relevant in segments with 50-74% LGE where accuracy is lower and further testing is frequently required to clarify the potential for recovery.This research was supported by the Instituto de Salud Carlos III and co-funded by Fondo Europeo de Desarrollo Regional (FEDER) (grant numbers PI17/01836 and CIBERCV16/11/00486). JG and DM acknowledge financial support from the "Agencia Valenciana de la Innovacion, Generalitat Valenciana" (grant) and from the "Conselleria d'Educacio, Investigacio, Cultura i Esport, Generalitat Valenciana" (grant number AEST/2019/037).Valente, FX.; Gavara-Doñate, J.; Gutiérrez, L.; Rios-Navarro, C.; Rello, P.; Maymi, M.; Fernandez-Galera, R.... (2021). Predictive Value of Cardiac Magnetic Resonance Feature Tracking after Acute Myocardial Infarction: A Comparison with Dobutamine Stress Echocardiography. Journal of Clinical Medicine. 10(22):1-12. https://doi.org/10.3390/jcm10225261S112102
Prognosis of Paradoxical Low-Flow Low-Gradient Aortic Stenosis: A Severe, Non-critical Form, With Surgical Treatment Benefits
Aortic stenosis; Echocardiography; Heart valve diseaseEstenosis aórtica; Ecocardiografía; Enfermedad de las válvulas del corazónEstenosi aòrtica; Ecocardiografia; Malaltia de les vàlvules cardíaquesObjectives: To determine the risk of mortality and need for aortic valve replacement (AVR) in patients with low-flow low-gradient (LFLG) aortic stenosis (AS).
Methods: A longitudinal multicentre study including consecutive patients with severe AS (aortic valve area [AVA] 35 ml/m2) and LFLG (mean gradient < 40 mmHg, SVi ≤ 35 ml/m2).
Results: Of 1,391 patients, 147 (10.5%) had LFLG, 752 (54.1%) HG, and 492 (35.4%) NFLG. Echocardiographic parameters of the LFLG group showed similar AVA to the HG group but with less severity in the dimensionless index, calcification, and hypertrophy. The HG group required AVR earlier than NFLG (p < 0.001) and LFLG (p < 0.001), with no differences between LFLG and NFLG groups (p = 0.358). Overall mortality was 27.7% (CI 95% 25.3–30.1) with no differences among groups (p = 0.319). The impact of AVR in terms of overall mortality reduction was observed the most in patients with HG (hazard ratio [HR]: 0.17; 95% CI: 0.12–0.23; p < 0.001), followed by patients with LFLG (HR: 0.25; 95% CI: 0.13–0.49; p < 0.001), and finally patients with NFLG (HR: 0.29; 95% CI: 0.20–0.44; p < 0.001), with a risk reduction of 84, 75, and 71%, respectively.
Conclusions: Paradoxical LFLG AS affects 10.5% of severe AS, and has a lower need for AVR than the HG group and similar to the NFLG group, with no differences in mortality. AVR had a lower impact on LFLG AS compared with HG AS. Therefore, the findings of the present study showed LFLG AS to have an intermediate clinical risk profile between the HG and NFHG groups.AGu has received funding from the Spanish Ministry of Science, Innovation and Universities (IJC2018- 037349-I)