Revealing the influence of bias in a letter acuity identification task: A noisy template model

Georgeson, Mark A.; Barhoom, Hatem; Joshi, Mahesh Raj; Artes, Paul H.; Schmidtmann, Gunnar

doi:10.1016/j.visres.2023.108233

Cited by 3 publications

(2 citation statements)

References 18 publications

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“…Comparing confusion matrices and noise thresholds between computer models and humans allows us to generate hypotheses about the strategy used by humans. Past work modelling letter identification has primarily used templatebased models (Beckmann and Legge, 2002;Chung et al, 2002;Gold et al, 1999;Parish and Sperling, 1991;Watson and Ahumada, 2008Georgeson et al, 2023). In our bandpass noise (BN) condition, since we used noiseless templates (which should be optimal for this task), the template matching (TM) model was able to greatly outperform, as expected.…”

Section: Discussionsupporting

confidence: 55%

Human visual performance for identifying letters affected by physiologically-inspired scrambling

Zhu,

Hess,

Baldwin

2024

Preprint

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In human vision, the retinal input is transformed into internal representations through a series of stages. In earlier stages, the signals from a particular visual field locus are passed in parallel from one visual processing area to the next. The connections at each stage may therefore introduce "error", where incorrect or convergent projections result in a loss of spatial precision. Psychophysical and physiological studies have implicated spatial scrambling of this sort as a cause of the visual deficits in amblyopia. Several methods to measure scrambling (both in amblyopia and in healthy vision) have been developed in recent decades. In this work, we introduce a new approach. We consider two stages of visual processing where scrambling may occur: either at the input to or the output from the simple cell stage in V1. We refer to these as "subcortical" and "cortical" scrambling respectively. We investigated the impact of these two types of scrambling on a letter identification task. A physiologically-inspired decomposition and resynthesis algorithm was used to generate letter stimuli that simulate scrambling at each of these two stages. To establish a performance benchmark, we trained separate Convolutional Neural Networks (CNNs) to perform the task with each scrambling type. Comparing CNN performance against that of eight humans with normal healthy vision, we found humans exhibited greater resilience to subcortical scrambling compared to cortical scrambling. We further investigated performance by comparing confusion matrices. Compared to a simple template matching model, we found the human strategy to be more consistent with our CNNs. We conclude: i) the human resilience for subcortical scrambling suggests this may be the stage at which a greater degree of scrambling is introduced in the visual hierarchy, and ii) humans employ flexible strategies for identifying scrambled stimuli, more sophisticated than a simple template match to the expected target.

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Section: Discussionsupporting

confidence: 55%

Human visual performance for identifying letters affected by physiologically-inspired scrambling

Zhu,

Hess,

Baldwin

2024

Preprint

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“…SpotChecks overcomes the limitations associated with letter recognition such as language barriers, education background and the potential influence of letter bias. 50 The inclusion of the game-like element in locating 'spots' could enhance attention span, potentially making SpotChecks useful for children or individuals facing cognitive challenges. 14,21 In a recent study that demonstrated the feasibility of home testing with SpotChecks for children, when compared to two electronic CS tests, SpotChecks provided 100% completion rate, better test-retest repeatability and was preferred by older children.…”

Section: Age (Years)mentioning

confidence: 99%

Evaluation of the SpotChecks contrast sensitivity test in healthy adults

Vu,

Tran,

Niu

et al. 2024

Ophthalmic Physiologic Optic

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PurposeSpotChecks is a new contrast sensitivity (CS) test designed for self‐monitoring of vision. This study assessed the test–retest repeatability of take‐home SpotChecks, in‐office SpotChecks and near Pelli–Robson charts in healthy adults.MethodsOne eye of 61 healthy adults with near visual acuity (VA) of 6/9 or better (age range 22–84, mean 49 [18] years) was tested during two office visits (mean 10 [8] days apart). Each visit included high‐contrast VA, then 12 randomly ordered CS tests (6 different SpotChecks and 6 different Pelli–Robson) under the same lighting (luminance 110 cd/m2), all at near in the same eye with habitual correction. The same eye was self‐tested with take‐home SpotChecks once a day on 6 days between the office visits. SpotChecks was scored by the logCS at the highest line with ≥2 errors. Pelli–Robson was scored by [0.05 × number of letters read correctly − 0.15]. Repeatability of logCS was defined as 1.96 Sw, Sw representing within‐subject standard deviation. Comparison for repeatability was performed with Bootstrap hypothesis test.ResultsSpotChecks and Pelli–Robson showed similar intra‐session or inter‐visit repeatability (p = 0.14–0.81). Inter‐day repeatability for take‐home SpotChecks was 0.18 logCS, the same as that from the first measurements of two office visits with SpotChecks or Pelli–Robson. Inter‐visit repeatability improved to 0.15 by using the average of two repeated measurements for SpotChecks (p = 0.02) or three repeated measurements for Pelli–Robson (p = 0.04). Age showed a small effect on logCS (−0.015/decade, p = 0.02) for both SpotChecks and Pelli–Robson. Mean logCS was 0.05 lower in those ≥50 years (SpotChecks 1.84 [0.10] and Pelli–Robson 1.77 [0.10]) compared with those <50 years of age (SpotChecks 1.89 [0.07] and Pelli–Robson 1.83 [0.07]).ConclusionsSpotChecks showed good repeatability with take‐home and in‐office testing in healthy adults, making it a promising tool for monitoring disease progression at home.

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Clinical validation of a cross-platform digital visual acuity measurement system

Costa,

de Amorim,

Lins

2024

Revista Brasileira De Oftalmologia

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Revealing the influence of bias in a letter acuity identification task: A noisy template model

Cited by 3 publications

References 18 publications

Human visual performance for identifying letters affected by physiologically-inspired scrambling

Human visual performance for identifying letters affected by physiologically-inspired scrambling

Evaluation of the SpotChecks contrast sensitivity test in healthy adults

Clinical validation of a cross-platform digital visual acuity measurement system

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