27 research outputs found

    Image Content Enhancement Through Salient Regions Segmentation for People With Color Vision Deficiencies

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    Color vision deficiencies affect visual perception of colors and, more generally, color images. Several sciences such as genetics, biology, medicine, and computer vision are involved in studying and analyzing vision deficiencies. As we know from visual saliency findings, human visual system tends to fix some specific points and regions of the image in the first seconds of observation summing up the most important and meaningful parts of the scene. In this article, we provide some studies about human visual system behavior differences between normal and color vision-deficient visual systems. We eye-tracked the human fixations in first 3 seconds of observation of color images to build real fixation point maps. One of our contributions is to detect the main differences between the aforementioned human visual systems related to color vision deficiencies by analyzing real fixation maps among people with and without color vision deficiencies. Another contribution is to provide a method to enhance color regions of the image by using a detailed color mapping of the segmented salient regions of the given image. The segmentation is performed by using the difference between the original input image and the corresponding color blind altered image. A second eye-tracking of color blind people with the images enhanced by using recoloring of segmented salient regions reveals that the real fixation points are then more coherent (up to 10%) with the normal visual system. The eye-tracking data collected during our experiments are in a publicly available dataset called Eye-Tracking of Color Vision Deficiencies

    Image Content Enhancement Through Salient Regions Segmentation for People With Color Vision Deficiencies.

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    Color vision deficiencies affect visual perception of colors and, more generally, color images. Several sciences such as genetics, biology, medicine, and computer vision are involved in studying and analyzing vision deficiencies. As we know from visual saliency findings, human visual system tends to fix some specific points and regions of the image in the first seconds of observation summing up the most important and meaningful parts of the scene. In this article, we provide some studies about human visual system behavior differences between normal and color vision-deficient visual systems. We eye-tracked the human fixations in first 3 seconds of observation of color images to build real fixation point maps. One of our contributions is to detect the main differences between the aforementioned human visual systems related to color vision deficiencies by analyzing real fixation maps among people with and without color vision deficiencies. Another contribution is to provide a method to enhance color regions of the image by using a detailed color mapping of the segmented salient regions of the given image. The segmentation is performed by using the difference between the original input image and the corresponding color blind altered image. A second eye-tracking of color blind people with the images enhanced by using recoloring of segmented salient regions reveals that the real fixation points are then more coherent (up to 10%) with the normal visual system. The eye-tracking data collected during our experiments are in a publicly available dataset called Eye-Tracking of Color Vision Deficiencies

    AI recognition of patient race in medical imaging: a modelling study

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    Background Previous studies in medical imaging have shown disparate abilities of artificial intelligence (AI) to detect a person's race, yet there is no known correlation for race on medical imaging that would be obvious to human experts when interpreting the images. We aimed to conduct a comprehensive evaluation of the ability of AI to recognise a patient's racial identity from medical images. Methods Using private (Emory CXR, Emory Chest CT, Emory Cervical Spine, and Emory Mammogram) and public (MIMIC-CXR, CheXpert, National Lung Cancer Screening Trial, RSNA Pulmonary Embolism CT, and Digital Hand Atlas) datasets, we evaluated, first, performance quantification of deep learning models in detecting race from medical images, including the ability of these models to generalise to external environments and across multiple imaging modalities. Second, we assessed possible confounding of anatomic and phenotypic population features by assessing the ability of these hypothesised confounders to detect race in isolation using regression models, and by re-evaluating the deep learning models by testing them on datasets stratified by these hypothesised confounding variables. Last, by exploring the effect of image corruptions on model performance, we investigated the underlying mechanism by which AI models can recognise race. Findings In our study, we show that standard AI deep learning models can be trained to predict race from medical images with high performance across multiple imaging modalities, which was sustained under external validation conditions (x-ray imaging [area under the receiver operating characteristics curve (AUC) range 0·91-0·99], CT chest imaging [0·87-0·96], and mammography [0·81]). We also showed that this detection is not due to proxies or imaging-related surrogate covariates for race (eg, performance of possible confounders: body-mass index [AUC 0·55], disease distribution [0·61], and breast density [0·61]). Finally, we provide evidence to show that the ability of AI deep learning models persisted over all anatomical regions and frequency spectrums of the images, suggesting the efforts to control this behaviour when it is undesirable will be challenging and demand further study. Interpretation The results from our study emphasise that the ability of AI deep learning models to predict self-reported race is itself not the issue of importance. However, our finding that AI can accurately predict self-reported race, even from corrupted, cropped, and noised medical images, often when clinical experts cannot, creates an enormous risk for all model deployments in medical imaging. Funding National Institute of Biomedical Imaging and Bioengineering, MIDRC grant of National Institutes of Health, US National Science Foundation, National Library of Medicine of the National Institutes of Health, and Taiwan Ministry of Science and Technology

    Spectacularly Binocular: Exploiting Binocular Luster Effects for HCI Applications

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    Ph.DDOCTOR OF PHILOSOPH

    Reading Race: AI Recognises Patient's Racial Identity In Medical Images

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    Background: In medical imaging, prior studies have demonstrated disparate AI performance by race, yet there is no known correlation for race on medical imaging that would be obvious to the human expert interpreting the images. Methods: Using private and public datasets we evaluate: A) performance quantification of deep learning models to detect race from medical images, including the ability of these models to generalize to external environments and across multiple imaging modalities, B) assessment of possible confounding anatomic and phenotype population features, such as disease distribution and body habitus as predictors of race, and C) investigation into the underlying mechanism by which AI models can recognize race. Findings: Standard deep learning models can be trained to predict race from medical images with high performance across multiple imaging modalities. Our findings hold under external validation conditions, as well as when models are optimized to perform clinically motivated tasks. We demonstrate this detection is not due to trivial proxies or imaging-related surrogate covariates for race, such as underlying disease distribution. Finally, we show that performance persists over all anatomical regions and frequency spectrum of the images suggesting that mitigation efforts will be challenging and demand further study. Interpretation: We emphasize that model ability to predict self-reported race is itself not the issue of importance. However, our findings that AI can trivially predict self-reported race -- even from corrupted, cropped, and noised medical images -- in a setting where clinical experts cannot, creates an enormous risk for all model deployments in medical imaging: if an AI model secretly used its knowledge of self-reported race to misclassify all Black patients, radiologists would not be able to tell using the same data the model has access to

    Task Encoding across the Multiple Demand Cortex Is Consistent with a Frontoparietal and Cingulo-Opercular Dual Networks Distinction.

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    UNLABELLED: Multiple-demand (MD) regions of the human brain show coactivation during many different kinds of task performance. Previous work based on resting-state functional magnetic resonance imaging (fMRI) has shown that MD regions may be divided into two closely coupled subnetworks centered around the lateral frontoparietal (FP) and cingulo-opercular cortex. Here, we used on-task fMRI to test whether this division is apparent during the performance of an executive task. Furthermore, we investigated whether there is a difference in the encoding of task between the two subnetworks. Using connectivity methods, we found that activity across the entire MD cortex is correlated during task performance. Meanwhile, however, there was significantly stronger connectivity within each of the subnetworks than between them. Using multivoxel pattern analysis, we also found that, although we were able to decode task-relevant information from all regions of the MD cortex, classification accuracy scores were significantly higher in the FP subnetwork. These results suggest a nested picture with MD regions as a whole showing coactivation and broad rule representation, but with significant functional distinctions between component subnetworks. SIGNIFICANCE STATEMENT: Multiple-demand (MD) regions of frontal and parietal cortex appear essential for the orchestration of goal-directed behavior and problem solving. Understanding the relative specialization of regions within the MD cortex is crucial to understanding how we can coordinate and execute complex action plans. By examining functional connectivity during task performance, we extend previous findings suggesting that the MD cortex can be divided into two subnetworks centered around the frontoparietal (FP) and cingulo-opercular (CO) cortex. Furthermore, using multivoxel pattern analysis, we show that, compared with the CO subnetwork, the FP subnetwork manifests more differentiated coding of specific task events

    Un modelo de atención visual para la detección de regiones de interés en imágenes radiológicas

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    La detección, segmentación y cuantificación de lesiones de esclerosis múltiple (MS) en imágenes de resonancia magnética (MRI) ha sido un área de estudio muy activa en las ´últimas dos décadas. Esto es debido la necesidad de correlacionar estas medidas con la efectividad de los tratamientos farmacológicos. Muchos métodos han sido desarrollados y la mayoría no son específicos para los diferentes tipos de lesiones, es decir que no pueden distinguir entre lesiones agudas y crónicas. Los médicos radiólogos por su parte son capaces de distinguir entre diferentes niveles de la enfermedad haciendo uso de las imágenes de resonancia magnética de diferentes tipos. La principal motivación de este trabajo es la de emular mediante un modelo computacional la percepción visual del radiólogo, haciendo uso de los principios fisiológicos del sistema visual. De esta manera logramos detectar satisfactoriamente las lesiones de esclerosis múltiple en imágenes de resonancia magnética del cerebro. Este tipo de análisis nos permite estudiar y mejorar el estudio de las redes neuronales al poder introducir información a priori.Abstract. The detection, segmentation and quantification of multiple sclerosis (MS) lesions on magnetic resonance images (MRI) has been a very active field for the last two decades because of the urge to correlate these measures with the e↵ectiveness of pharmacological treatment. A myriad of methods has been developed and most of these are non specific for the type of lesions, e.g. they do not di↵erentiate between acute and chronic lesions. On the other hand, radiologists are able to distinguish between several stages of the disease on di↵erent types of MRI images. The main motivation of the work presented here is to computationally emulate the visual perception of the radiologist by using modeling principles of the neuronal centers along the visual system. By using this approach we were able to successfully detect multiple sclerosis lesions in brain MRI. This type of approach allows us to study and improve the analysis of brain networks by introducing a priori informationMaestrí

    A Science Education Study Using Visual Cognition and Eye Tracking to Explore Medication Selection in the Novice Versus Expert Nurse Anesthetist

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    The purpose of this science education study is to explore visual cognition and eye tracking during medication selection in the student nurse anesthetist (first year and second year students) and the expert nurse anesthetist. The first phase of this study consisted of the selection of a specific medication (target) from an array of medications via computer simulation. Various dependent variables were recorded to examine performance (reaction time and accuracy), and the allocation of visual attention was measured with eye tracking (dwell proportion, verification, and guidance). The second phase of this study included the administration of a demographic and post experiment questionnaire to capture additional quantitative and qualitative data. Results demonstrate that similar distractors attract attention during search as evidenced by longer reaction times when similar distractors are present, most significantly in expert participants. Additionally, all participants spent a greater amount of time looking at the similar distractor as compared to randomly chosen non-similar distractors when a similar distractor was present. However, the presence of similar distractors in target present trials increased performance in experts, decreased performance in second year students, and had no effect on first year students’ performance. Expertise effects were further demonstrated, as expert participants were significantly slower than both first and second years during target verification. The post experiment questionnaire included both open-ended and close-ended questions, to allow for themes to emerge related the participants’ beliefs related to visual search and medication selection. The results reinforced the eye tracking results reported above, with most participants identifying “color” and “medication label” as the most difficult medication features to distinguish during visual search. Additionally, the majority of participants who responded they had committed a medication error, identified “similarity” as the most common factor that led to the medication error

    NeuroGame: neural mechanisms underlying cognitive improvement in video gamers

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    The video game market represents an influential and profitable industry. But concerns have been raised how video games impact on the human mind. There are reservations that video gaming may be addictive and foster aggressive behaviour. In contrast, a convincing body of research indicates that playing video games may improve cognitive processing. The exact mechanism thereof is not entirely understood. Most research suggests that video games train individuals in learning how to employ attentional control to focus on processing relevant information, while being able to suppress irrelevant information. Thus, video game players acquire the ability of being able to develop strategies to process information more efficiently. However, no algorithmic solution therefore has been provided yet. Thus, it is not clear which and how attentional control functions contribute to these effects. Moreover, neural mechanisms thereof are not well understood. We hypothesized that alterations in alpha power, i.e., modulations in brain oscillatory activity around 10 Hz, represent a promising neural substrate of video gaming effects. This was because, alpha activity represents an established neural correlate of attention processing given that its amplitude modulation corresponds to alterations in information processing. We investigated this by relating differential cognitive processing in video game players to changes in alpha power modulation. Moreover, we tried to imitate this effect using non-invasive brain stimulation. We were successful in achieving the former but not the latter. We provide a reasonable explanation for this. Thus, our results mostly support our hypothesis according to which altered alpha power may account for gaming effects
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