scholarly journals Denser Retinal Microvascular Network Is Inversely Associated With Behavioral Outcomes and Sustained Attention in Children

2021 ◽  
Vol 12 ◽  
Author(s):  
Eline B. Provost ◽  
Tim S. Nawrot ◽  
Luc Int Panis ◽  
Arnout Standaert ◽  
Nelly D. Saenen ◽  
...  
Keyword(s):  
Fractal Dimension ◽  
Sustained Attention ◽  
Evaluation System ◽  
Behavioral Outcomes ◽  
Performance Testing ◽  
Retinal Vessel ◽  
Sensitivity Analyses ◽  
Continuous Performance ◽  
Microvascular Network ◽  
Retinal Microvasculature

Changes in geometry of the retinal microvascular network, including vessel width, vessel density, and tortuosity, have been associated with neurological disorders in adults. We investigated metrics of the retinal microvasculature in association with behavior and cognition in 8- to 12-year-old children. Digital fundus images of 190 children (48.2% girls, mean age 9.9 years) were used to calculate retinal vessel diameters, fractal dimension, lacunarity, and tortuosity. Parents filled out a Strengths and Difficulties Questionnaire (SDQ) for behavioral screening. Cognitive performance testing included a computerized version of the Stroop test (selective attention), the Continuous Performance (sustained attention), the Digit-Symbol (visual scanning and information-processing speed) and the Pattern Comparison (visuospatial analytic ability) tests from the Neurobehavioral Evaluation System (NES3) battery. Retinal vessel geometry was significantly associated with the SDQ problem score, which increased with 1.1 points (95% CI: 0.3 to 1.9 points) per interquartile (IQR) increment in retinal fractal dimension, and decreased 1.4 points (95% CI: −2.4 to −0.4 points) or decreased 1.0 points (95% CI: −2.1 to 0.1 points) per IQR increment in retinal vascular lacunarity or tortuosity, respectively. Sensitivity analyses showed that results were driven by the hyperactivity/inattention and conduct problem scales of the SDQ. Correspondingly, mean reaction time on the Continuous Performance test increased by 11 ms (95% CI: 4.4 to 17.6 ms) with an IQR increase in fractal dimension. The results indicate that a denser retinal microvascular network, exemplified by a higher fractal dimension and lower lacunarity, are inversely associated with behavioral outcomes and sustained attention in children.

scholarly journals Scale Characteristics and Optimization of Park Green Space in Megacities Based on the Fractal Measurement Model: A Case Study of Beijing, Shanghai, Guangzhou, and Shenzhen

2021 ◽  
Vol 13 (15) ◽  
pp. 8554
Author(s):  
Zhen Li ◽  
Wanmin Zhao ◽  
Miaoyao Nie
Keyword(s):  
Fractal Dimension ◽  
Evaluation System ◽  
Goodness Of Fit ◽  
Green Space ◽  
Fractal Theory ◽  
Measurement Model ◽  
Scale Structure ◽  
Qualitative Description ◽  
Urban Spatial Structure ◽  
Factors Affecting

This paper applies fractal theory to research of green space in megacity parks due to the lack of a sufficient qualitative description of the scale structure of park green space, a quantifiable evaluation system, and operable planning methods in traditional studies. Taking Beijing, Shanghai, Guangzhou, and Shenzhen as examples, GIS spatial analysis technology and the Zipf model are used to calculate the fractal dimension (q), the goodness of fit (R2), and the degree of difference (C) to deeply interpret the connotation of indicators and conduct a comparative analysis between cities to reveal fractal characteristics and laws. The research results show that (1) the fractal dimension is related to the complexity of the park green space system; (2) the fractal dimension characterizes the hierarchical iteration of the park green space to a certain extent and reflects the internal order of the scale distribution; (3) the scale distribution of green space in megacity parks deviates from the ideal pyramid configuration; and (4) there are various factors affecting the scale structure of park green space, such as natural base conditions, urban spatial structure, and the continuation of historical genes working together. On this basis, a series of targeted optimization strategies are proposed.

Sustained Attention in Brain Damaged Children

1970 ◽  
Vol 36 (5) ◽  
pp. 317-323 ◽  
Author(s):  
Peter A. Campanelli
Keyword(s):  
Sustained Attention ◽  
Performance Test ◽  
Continuous Performance Test ◽  
Specific Site ◽  
Control Group ◽  
Continuous Performance ◽  
Convulsive Disorders

This study explored sustained attention in children with convulsive disorders diagnosed as having cortical and subcortical lesions by means of the Continuous Performance Test (CPT). Significant differences were found between and within these 2 groups and a control group. Results support other findings concerning specific site of lesion on sustained attention in brain damaged children when measured by the CPT. Implications for learning are discussed.

scholarly journals Sustained Attention in Intellectually Gifted Children Assessed Using a Continuous Performance Test

PLoS ONE ◽  
2013 ◽  
Vol 8 (2) ◽  
pp. e57417 ◽  
Author(s):  
Jiannong Shi ◽  
Ting Tao ◽  
Wei Chen ◽  
Li Cheng ◽  
Long Wang ◽  
...  
Keyword(s):  
Sustained Attention ◽  
Performance Test ◽  
Continuous Performance Test ◽  
Gifted Children ◽  
Continuous Performance ◽  
Intellectually Gifted

Sustained Attention and Grade Retention

1994 ◽  
Vol 78 (2) ◽  
pp. 555-560 ◽  
Author(s):  
Michael Gordon ◽  
Barbara B. Mettelman ◽  
Martin Irwin
Keyword(s):  
Attention Deficit Hyperactivity Disorder ◽  
Sustained Attention ◽  
Grade Retention ◽  
Academic Failure ◽  
Academic Careers ◽  
Continuous Performance ◽  
Continuous Performance Task ◽  
Performance Task ◽  
Hyperactivity Disorder ◽  
History Of

Two studies are reported which explore the possible relationship between academic failure, as measured by grade retention, and the capacity to sustain attention on a computerized continuous performance task. In a nonreferred sample, 89 children who had been retained at some point in their academic careers showed a higher frequency of abnormal scores on an index of sustained attention than did 93 children who had never repeated a grade. In a sample of children who had been referred for an evaluation of Attention-Deficit Hyperactivity Disorder, children with a history of grade retention had significantly lower scores on the same measure of sustained attention. Results are discussed in terms of the possible contribution of attention deficits to over-all academic achievement, even for children who have not necessarily been referred for a clinical evaluation.

scholarly journals Short-Term Effects of Meditation on Sustained Attention as Measured by fNIRS

2020 ◽  
Vol 10 (9) ◽  
pp. 608
Author(s):  
Meltem Izzetoglu ◽  
Patricia A. Shewokis ◽  
Kathryn Tsai ◽  
Phillip Dantoin ◽  
Kathryn Sparango ◽  
...  
Keyword(s):  
Sustained Attention ◽  
Psychological Health ◽  
Structural Changes ◽  
Near Infrared ◽  
Behavioral Outcomes ◽  
Cognitive Activity ◽  
Short Term ◽  
Functional Near Infrared Spectroscopy ◽  
First Time ◽  
Short Term Effects

Cognitive abilities such as attention, memory, processing time, perception, and reasoning can be augmented using some type of intervention. Within the broad range of conventional and unconventional intervention methods used in cognitive enhancement, meditation is one of those that is safe, widely practiced by many since ancient times, and has been shown to reduce stress and improve psychological health and cognitive functioning. Various neuroimaging studies using functional magnetic resonance imaging (fMRI) and electroencephalography (EEG) have shown functional and structural changes due to meditation in different types of meditation practices and on various groups of meditators. Recently, a few studies on meditation have used functional near infrared spectroscopy (fNIRS) to study the effects of meditation on cerebral hemodynamics. In this study, we examined the short-term effects of loving-kindness (LK) meditation on sustained attention using behavioral performance measures, physiological outcomes, and cognitive activity as measured by fNIRS in first-time meditators during Stroop color word task (SCWT) performance. Our results indicated that behavioral outcomes, assessed mainly on response time (RT) during SCWT performance, showed a significant decrease after meditation. As expected, physiological measures, primarily pulse pressure (PP) measured after meditation dropped significantly as compared to the before meditation measurement. For the hemodynamic measures of oxygenated-hemoglobin (HbO2), deoxygenated-hemoglobin (Hb), and total-hemoglobin (HbT), our findings show significant differences in SCWT performance before and after meditation. Our results suggest that LK meditation can result in improvements in cognitive, physiological, and behavioral outcomes of first-time meditators after a short-term session.

scholarly journals Continuous Performance Tasks: Not Just About Sustaining Attention

2016 ◽  
Vol 59 (3) ◽  
pp. 501-510 ◽  
Author(s):  
Hettie Roebuck ◽  
Claudia Freigang ◽  
Johanna G. Barry
Keyword(s):  
Sustained Attention ◽  
Developmental Disorders ◽  
Reaction Times ◽  
Error Rates ◽  
Continuous Performance ◽  
Performance Tasks ◽  
Tone Condition ◽  
Adults And Children ◽  
Time Variations ◽  
Continuous Performance Tasks

Purpose Continuous performance tasks (CPTs) are used to measure individual differences in sustained attention. Many different stimuli have been used as response targets without consideration of their impact on task performance. Here, we compared CPT performance in typically developing adults and children to assess the role of stimulus processing on error rates and reaction times. Method Participants completed a CPT that was based on response to infrequent targets, while monitoring and withholding responses to regular nontargets. Performance on 3 stimulus conditions was compared: visual letters (X and O), their auditory analogs, and auditory pure tones. Results Adults showed no difference in error propensity across the 3 conditions but had slower reaction times for auditory stimuli. Children had slower overall reaction times. They responded most quickly to the visual target and most slowly to the tone target. They also made more errors in the tone condition than in either the visual or the auditory spoken CPT conditions. Conclusions The results suggest error propensity and reaction time variations on CPTs cannot solely be interpreted as evidence of inattention. They also reflect stimulus-specific influences that must be considered when testing hypotheses about modality-specific deficits in sustained attention in populations with different developmental disorders.

VEA: Vessel Extraction Algorithm by Active Contour Model and a Novel Wavelet Analyzer for Diabetic Retinopathy Detection

2018 ◽  
Vol 18 (02) ◽  
pp. 1850008 ◽  
Author(s):  
Swarup Kr Ghosh ◽  
Anupam Ghosh ◽  
Amlan Chakrabarti
Keyword(s):  
Diabetic Retinopathy ◽  
Active Contour Model ◽  
Back Propagation ◽  
Diagnostic System ◽  
Retinal Vessel ◽  
Vessel Segmentation ◽  
Circulation System ◽  
Retinal Microvasculature ◽  
Retina Images

The process of retinal vessel segmentation is important for detection of various eye conditions including the effect of diabetes on eyes, or diabetic retinopathy. As we know, the retinal microvasculature is unique since it is the only part of the human circulation system that can be directly and non-evasively visualized in vivo; readily photographed as well as subjected to digital image analysis. This paper explores a new technique for detecting the idiosyncrasies of retina images, for which we have reviewed some well-known image segmentation algorithms that help in detecting retinal abnormalities. In this work, we have also focused on the extraction of the vessel from retina images and developed an automated diagnostic system for diabetic retinopathy. This paper represents techniques, such as the snake model that was used for auto-extraction of retinal blood vessels and use of wavelet decomposition and back propagation neural network to extract the retinal vessels features and analyze the dataset. Finally, an analysis of performance of the vessel segmentation algorithm and wavelet analysis on standard image databases has been done. In this context, we have used F-score for validation of the result.

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