Browsing by Subject "visual perception"

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    Graphical Perception of Continuous Quantitative Maps: the Effects of Spatial Frequency and Colormap Design
    (ACM, 2018) Reda, Khairi; Nalawade, Pratik; Ansah-Koi, Kate
    Continuous 'pseudocolor' maps visualize how a quantitative attribute varies smoothly over space. These maps are widely used by experts and lay citizens alike for communicating scientific and geographical data. A critical challenge for designers of these maps is selecting a color scheme that is both effective and aesthetically pleasing. Although there exist empirically grounded guidelines for color choice in segmented maps (e.g., choropleths), continuous maps are significantly understudied, and their color-coding guidelines are largely based on expert opinion and design heuristics--many of these guidelines have yet to be verified experimentally. We conducted a series of crowdsourced experiments to investigate how the perception of continuous maps is affected by colormap characteristics and spatial frequency (a measure of data complexity). We find that spatial frequency significantly impacts the effectiveness of color encodes, but the precise effect is task-dependent. While rainbow schemes afforded the highest accuracy in quantity estimation irrespective of spatial complexity, divergent colormaps significantly outperformed other schemes in tasks requiring the perception of high-frequency patterns. We interpret these results in relation to current practices and devise new and more granular guidelines for color mapping in continuous maps.
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    Surgeons see anatomical structures faster and more accurately compared to novices: Development of a pattern recognition skill assessment platform
    (Elsevier, 2018) Mizota, Tomoko; Anton, Nicholas E.; Stefanidis, Dimitrios; Surgery, School of Medicine
    Background This study aimed to identify differences in pattern recognition skill among individuals with varying surgical experience. Methods Participants reviewed laparoscopic cholecystectomy videos of various difficulty, and paused them when the cystic duct or artery was identified to outline each structure on the monitor. Time taken to identify each structure, accuracy and work load, which was assessed using the NASA-Task Load Index (TLX), were compared among the three groups. Results Ten students, ten residents and eight attendings participated in the study. Attendings identified the cystic duct and artery significantly faster and more accurately than students, and identified the cystic artery faster than residents. The NASA-TLX score of attendings was significantly lower than that of students and residents. Conclusions Attendings identified anatomical structures faster, more accurately, and with less effort than students or residents. This platform may be valuable for the assessment and teaching of pattern recognition skill to novice surgeons. Short summary Accurate anatomical recognition is paramount to proceeding safely in surgery. The assessment platform used in this study differentiated recognition skill among individuals with varing surgical experience.