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BioRxiv : the Preprint Server For... Jun 2024Our intuition suggests that when a movie is played in reverse, our perception of motion in the reversed movie will be perfectly inverted compared to the original. This...
UNLABELLED
Our intuition suggests that when a movie is played in reverse, our perception of motion in the reversed movie will be perfectly inverted compared to the original. This intuition is also reflected in many classical theoretical and practical models of motion detection. However, here we demonstrate that this symmetry of motion perception upon time reversal is often broken in real visual systems. In this work, we designed a set of visual stimuli to investigate how stimulus symmetries affect time reversal symmetry breaking in the fruit fly 's well-studied optomotor rotation behavior. We discovered a suite of new stimuli with a wide variety of different properties that can lead to broken time reversal symmetries in fly behavioral responses. We then trained neural network models to predict the velocity of scenes with both natural and artificial contrast distributions. Training with naturalistic contrast distributions yielded models that break time reversal symmetry, even when the training data was time reversal symmetric. We show analytically and numerically that the breaking of time reversal symmetry in the model responses can arise from contrast asymmetry in the training data, but can also arise from other features of the contrast distribution. Furthermore, shallower neural network models can exhibit stronger symmetry breaking than deeper ones, suggesting that less flexible neural networks promote some forms of time reversal symmetry breaking. Overall, these results reveal a surprising feature of biological motion detectors and suggest that it could arise from constrained optimization in natural environments.
SIGNIFICANCE
In neuroscience, symmetries can tell us about the computations being performed by a circuit. In vision, for instance, one might expect that when a movie is played backward, one's motion percepts should all be reversed. Exact perceptual reversal would indicate a time reversal symmetry, but surprisingly, real visual systems break this symmetry. In this research, we designed visual stimuli to probe different symmetries in motion detection and identify features that lead to symmetry breaking in motion percepts. We discovered that symmetry breaking in motion detection depends strongly on both the detector's architecture and how it is optimized. Interestingly, we find analytically and in simulations that time reversal symmetries are broken in systems optimized to perform with natural inputs.
PubMed: 38915608
DOI: 10.1101/2024.06.08.598068 -
PeerJ 2024To evaluate the efficacy and safety of Brolucizumab for neovascular age-related macular degeneration (n-AMD) through a systematic review and meta-analysis. (Meta-Analysis)
Meta-Analysis
BACKGROUND
To evaluate the efficacy and safety of Brolucizumab for neovascular age-related macular degeneration (n-AMD) through a systematic review and meta-analysis.
MATERIALS AND METHODS
Cochrane, PubMed, Embase, and Web of Science databases were comprehensively searched for relevant studies. Stata and RevMan5.4 were applied for meta-analysis and risk of bias assessment. Data on the best-corrected visual acuity (BCVA), central subfield thickness (CSFT), presence of intraretinal fluid (IRF) and/or subretinal fluid (SRF), participants with ≥1 serious adverse events, and participants with ≥1 adverse events were analyzed.
RESULTS
Six studies were finally included. Meta-analysis showed statistical differences in BCVA [SMD = -0.65, 95% CI [-0.17 to -0.23], < 0.05], the presence of IRF and/or SRF [RR = 0.67, 95% CI [0.56-0.79], < 0.05], and the safety of participants with ≥1 serious adverse events [RR = 0.57, 95% CI [0.39-0.84], < 0.05] between the experimental group and the control group. However, no statistical differences were observed in CSFT [SMD = -1.16, 95% CI [-2.79 to 0.47], > 0.05] or the safety of participants with ≥1 adverse events [RR = 1.07, 95% CI [0.97-1.17], > 0.05].
CONCLUSIONS
Compared to other anti-VEGF drugs such as Aflibercept and Ranibizumab, intravitreal injection of 6 mg Brolucizumab is more effective and safer for n-AMD, especially in the presence of IRF and/or SRF, and for participants with ≥1 serious adverse events.
Topics: Humans; Angiogenesis Inhibitors; Antibodies, Monoclonal, Humanized; Intravitreal Injections; Macular Degeneration; Treatment Outcome; Visual Acuity; Wet Macular Degeneration
PubMed: 38915383
DOI: 10.7717/peerj.17561 -
International Ophthalmology Jun 2024Evaluation of anterior segment parameters using the Scheimpflug corneal topography 1 year after surgery in patients who underwent sutureless scleral fixation...
PURPOSE
Evaluation of anterior segment parameters using the Scheimpflug corneal topography 1 year after surgery in patients who underwent sutureless scleral fixation intraocular lens (SFIOL) implantation using the modified Yamane technique and retropupillary iris-claw intraocular lens (RPIOL) implantation.
METHODS
A total of 60 eyes from 57 patients who underwent sutureless SFIOL implantation and 57 eyes from 52 patients who underwent RPIOL implantation were included. Anterior chamber depth (ACD), anterior chamber angle (ACA), anterior chamber volume (ACV), anterior-posterior corneal astigmatism, and keratometric values were assessed using the Scheimpflug corneal topography (Pentacam HR, Germany).
RESULTS
There was no statistically significant difference in postoperative UCVA and BCVA between the sutureless SFIOL and the RPIOL group (p = 0.236, p = 0.293, respectively). While there was no statistically significant difference in postoperative IOP between the two groups (p = 0.223), a statistically significant decrease in IOP was observed in both groups (p < 0.001). While there was no statistical difference between the sutureless SFIOL group and the RPIOL group in terms of spherical value (p = 0.441) and spherical equivalence (p = 0.237), there was a statistically significant difference in cylindrical value (p < 0.001). While there was a statistical difference in anterior astigmatism (p < 0.001), there was no statistical difference in posterior astigmatism (p = 0.405). There was no statistical difference in terms of ACV, ACD, and ACA between the sutureless SFIOL and the RPIOL group (p = 0.812, p = 0.770, p = 0.401, respectively).
CONCLUSION
In this study, although there was a statistical difference in cylindrical value and anterior corneal astigmatism between the sutureless SFIOL and RPIOL groups, vision was not affected. According to this study, sutureless SFIOL and RPIOL are two successful methods in terms of visual acuity, anterior segment, and keratometry outcomes in aphakic patients after phacoemulsification.
Topics: Humans; Male; Female; Visual Acuity; Sclera; Lens Implantation, Intraocular; Middle Aged; Corneal Topography; Aged; Iris; Sutureless Surgical Procedures; Lenses, Intraocular; Retrospective Studies; Anterior Eye Segment; Adult; Treatment Outcome; Prosthesis Design; Aphakia, Postcataract; Follow-Up Studies; Aphakia
PubMed: 38914871
DOI: 10.1007/s10792-024-03187-6 -
Scientific Reports Jun 2024People often interact with groups (i.e., ensembles) during social interactions. Given that group-level information is important in navigating social environments, we...
People often interact with groups (i.e., ensembles) during social interactions. Given that group-level information is important in navigating social environments, we expect perceptual sensitivity to aspects of groups that are relevant for personal threat as well as social belonging. Most ensemble perception research has focused on visual ensembles, with little research looking at auditory or vocal ensembles. Across four studies, we present evidence that (i) perceivers accurately extract the sex composition of a group from voices alone, (ii) judgments of threat increase concomitantly with the number of men, and (iii) listeners' sense of belonging depends on the number of same-sex others in the group. This work advances our understanding of social cognition, interpersonal communication, and ensemble coding to include auditory information, and reveals people's ability to extract relevant social information from brief exposures to vocalizing groups.
Topics: Humans; Male; Female; Adult; Voice; Sex Ratio; Social Perception; Young Adult; Auditory Perception; Interpersonal Relations; Social Interaction
PubMed: 38914752
DOI: 10.1038/s41598-024-65535-x -
Scientific Reports Jun 2024This study compares postoperative visual outcomes and optical aberrations after Small Incision Lenticule Extraction (SMILE) in patients with both small (S-Kappa: Kappa... (Comparative Study)
Comparative Study
This study compares postoperative visual outcomes and optical aberrations after Small Incision Lenticule Extraction (SMILE) in patients with both small (S-Kappa: Kappa angle < 0.2 mm) and large Kappa (L-Kappa: Kappa angle ≥ 0.2 mm) angles. The evaluated aberrations include total higher-order aberrations (HOAs), horizontal coma (HC), vertical coma (VC), and spherical aberrations (SA), with procedures incorporating intraoperative Kappa angle adjustments. We retrospectively analyzed patient records undergoing SMILE utilizing linear mixed models (LMM). We assessed adjusted mean uncorrected distance visual acuity (UDVA), Strehl ratio (SR), total HOAs, VC, and SA at pupils of 3 mm and 6 mm for both S-Kappa and L-Kappa. The disparities between S-Kappa and L-Kappa were evaluated by LMM's adjusted mean differences. The differences in optical metrics were also assessed in eyes grouped by myopia levels: low, moderate, and high. A sensitivity analysis was conducted on a threshold of Kappa angle at 0.3 mm. Eight-five patients (169 eyes) were analyzed, and no significant pre-operative difference was found in UDVA (p = .222) or spherical equivalent (p = .433). Post-operative differences were found in SR at 3 mm pupil size (-0.06, p = .022), total HOA 3 mm (0.15, p = .022), HC 3 mm (0.04, p = .042), VC 3 mm and 6 mm (-0.08, p = .041; 0.04, p = .041). The stratified analysis for high myopia revealed significant differences in UDVA (-0.04, p = .037), HC 3 mm (0.07, p = .03), VC 6 mm (-0.21, p = .001), and SA 3 mm and 6 mm (0.07, p = .037; -0.09, p = .037). Sensitivity analysis showed no significant difference using a 0.3 mm Kappa threshold. While some optical aberrations exhibited statistical differences between S-Kappa and L-Kappa, their clinical significance is limited. Thus, a large Kappa angle might not substantially influence post-operative optical aberrations when intraoperative Kappa angle adjustments are implemented.
Topics: Humans; Female; Visual Acuity; Male; Adult; Retrospective Studies; Myopia; Young Adult; Corneal Surgery, Laser; Corneal Wavefront Aberration; Treatment Outcome; Refraction, Ocular
PubMed: 38914606
DOI: 10.1038/s41598-024-65366-w -
PloS One 2024Uncorrected refractive errors pose a significant challenge globally, particularly in remote regions of low-middle income countries where access to optometric care is...
INTRODUCTION
Uncorrected refractive errors pose a significant challenge globally, particularly in remote regions of low-middle income countries where access to optometric care is often limited. Telerefraction, which involves refraction by a trained technician followed by real-time consultation with remote optometrist, is a promising approach for such remote settings. This study aimed to evaluate the accuracy of this model.
METHODS
This prospective study, conducted in New Delhi, compared tele-refraction to in-person examinations. Trained technicians used a simple device, Click-check, to perform objective refraction and a tele-refraction platform to enter the findings of objective refraction. Final prescription was made after consulting a remote optometrist on that platform. Masked face-to-face optometrists served as the gold standard. The study involved refraction in 222 patients and 428 eyes.
RESULTS
Tele-refraction demonstrated a strong agreement with in-person optometry, achieving 84.6% in spherical correction and 81% conformity in spherical equivalent. The mean difference of spherical equivalent between the two arms was only 0.11 D. The consultation with a remote optometrist improved conformity of spherical equivalent by 14.8% over objective refraction. 82 percent eyes matched in best corrected visual acuity and 92 percent were within 0.1 logMAR difference. For cylindrical axis, 74% eye were within acceptable 10 degrees of difference. The mismatch amongst the individual trained technicians, in terms of difference between the tele-refraction arm and the face-to face optometrist arm was found to be significant for cylindrical axis and not for spherical power and spherical equivalent.
CONCLUSION
Our study found tele-refraction by a trained technician comparable to refraction done by face-to-face optometrist. Tele-refraction, coupled with remote optometrist guidance can address the optometry resource gap in underserved areas. Thus, this model offers a transformative approach to enhancing the accessibility and quality of eye care services, which can significantly contribute to our efforts in achieving the global targets set by the World Health Organization for effective refractive error coverage. More standardized training for these technicians on ClickCheckTM for detecting the cylindrical axis with better accuracy, can improve this model further.
Topics: Humans; Refractive Errors; Adult; Female; Male; Prospective Studies; Remote Consultation; Optometrists; Middle Aged; Reproducibility of Results; Optometry; Telemedicine; Young Adult; Adolescent; Refraction, Ocular; Visual Acuity; Aged
PubMed: 38913708
DOI: 10.1371/journal.pone.0299491 -
International Ophthalmology Jun 2024To evaluate the effect of pregnancy on the anterior chamber, corneal parameter, and intraocular pressure measurements; and compare the results between trimesters,...
PURPOSE
To evaluate the effect of pregnancy on the anterior chamber, corneal parameter, and intraocular pressure measurements; and compare the results between trimesters, postpartum and non-pregnant healthy age-matched women.
METHODS
This prospective study included 41 pregnant women and 53 non-pregnant women. Four measurements were taken from the pregnant women, in each trimester and postpartum third month, and once from the control group. Of the individuals included in the study, anterior chamber depth (ACD), anterior chamber volume (ACV), K1 (flat keratometry), K2 (steep keratometry), Kmean (mean value of K1 and K2), anterior chamber angle (ACA), central corneal thickness (CCT), thinnest corneal thickness (TCT), astigmatism value (AST), corneal volume (CV), biometry, axial length (AL), spherical equivalent (SFEQ), intraocular lens power (ILP), VA (visual acuity) datas were recorded.
RESULTS
We observed a statistically significant decrease in K2, CCT, ACD, AL and CV in the postpartum period (p = 0.025, p < 0.001, p = 0.029, p = 0.005, p = 0.004 respectively) and a statistically significant increase in ACV, CCT, and TCT as the gestational week progressed in the pregnant group (p = 0.007, p < 0.001, p = 0.025, respectively). A statistically significant decrease in IOP towards to the third trimester, and an increase in the postpartum period was observed (p < 0.001). We did not observe statistically significant changes in K1, Kmean, AST, ACA, VA, ILP, and SFEQ values.
CONCLUSION
It is important to investigate the physiological changes that may occur during pregnancy, distinguish them from pathological changes, and avoid unnecessary treatment. We consider that it's also important to guide the timing of anterior segment surgeries such as cataract and refractive surgery and to prescribe glasses/contact lenses.
Topics: Humans; Female; Prospective Studies; Pregnancy; Adult; Postpartum Period; Pregnancy Trimesters; Intraocular Pressure; Anterior Eye Segment; Young Adult; Visual Acuity; Biometry; Cornea; Anterior Chamber
PubMed: 38913127
DOI: 10.1007/s10792-024-03173-y -
International Ophthalmology Jun 2024The purpose of this study was to investigate the visual and refractive outcomes in patients with pseudoexfoliation (PXF) undergoing routine cataract surgery and to...
BACKGROUND
The purpose of this study was to investigate the visual and refractive outcomes in patients with pseudoexfoliation (PXF) undergoing routine cataract surgery and to compare the accuracy of intraocular lens (IOL) power calculation formulae.
METHODS
Retrospective case-series study from Shamir medical center, a public hospital, Israel. Medical records of patients who underwent routine cataract surgery between January 2019 and August 2021 were investigated. Postoperative visual acuity and manifest refraction were examined. The error in predicted refraction and IOL power calculation accuracy within a range of ± 0.50 to ± 1.00 diopters were compared between different IOL calculating formulae.
RESULTS
151 eyes of 151 patients ages 73.9 ± 7.1 years were included in this study- 58 eyes in the PXF group and 93 eyes in the control group. The mean absolute error (MAE) for the BUII formula was 0.63D ± 0.87 for the PXF group and 0.36D ± 0.48 for the control group (p < 0.05). The MAE for the Hill-RBF 3.0 formula was 0.61D ± 0.84 for the PXF group and 0.42D ± 0.55 for the control group (p = 0.05). There were significant differences in MAE and MedAE between PXF group and control group measures (p < 0.05). In the PXF group there were no significant differences between the different formulae.
CONCLUSIONS
There were significant differences in accuracy of IOL power calculations in all formulae between PXF group and control group measures. PXF patients show hyperopic shift from predicted refraction. Barret universal II formula had the highest proportion of eyes with absolute error in prediction below or equal to 0.50 D in both PXF and control groups.
Topics: Humans; Exfoliation Syndrome; Retrospective Studies; Aged; Female; Male; Visual Acuity; Refraction, Ocular; Lenses, Intraocular; Biometry; Aged, 80 and over; Optics and Photonics; Reproducibility of Results
PubMed: 38913082
DOI: 10.1007/s10792-024-03195-6 -
ELife Jun 2024Autism spectrum disorder (ASD) presents a range of challenges, including heightened sensory sensitivities. Here, we examine the idea that sensory overload in ASD may be...
Autism spectrum disorder (ASD) presents a range of challenges, including heightened sensory sensitivities. Here, we examine the idea that sensory overload in ASD may be linked to issues with efference copy mechanisms, which predict the sensory outcomes of self-generated actions, such as eye movements. Efference copies play a vital role in maintaining visual and motor stability. Disrupted efference copies hinder precise predictions, leading to increased reliance on actual feedback and potential distortions in perceptions across eye movements. In our first experiment, we tested how well healthy individuals with varying levels of autistic traits updated their mental map after making eye movements. We found that those with more autistic traits had difficulty using information from their eye movements to update the spatial representation of their mental map, resulting in significant errors in object localization. In the second experiment, we looked at how participants perceived an object displacement after making eye movements. Using a trans-saccadic spatial updating task, we found that those with higher autism scores exhibited a greater bias, indicating under-compensation of eye movements and a failure to maintain spatial stability during saccades. Overall, our study underscores efference copy's vital role in visuo-motor stability, aligning with Bayesian theories of autism, potentially informing interventions for improved action-perception integration in autism.
Topics: Humans; Male; Female; Autism Spectrum Disorder; Adult; Young Adult; Eye Movements; Psychomotor Performance; Visual Perception; Adolescent; Saccades; Autistic Disorder
PubMed: 38913073
DOI: 10.7554/eLife.94946 -
Journal of Vision Jun 2024The watercolor effect (WCE) is a striking visual illusion elicited by a bichromatic double contour, such as a light orange and a dark purple, hugging each other on a... (Review)
Review
The watercolor effect (WCE) is a striking visual illusion elicited by a bichromatic double contour, such as a light orange and a dark purple, hugging each other on a white background. Color assimilation, emanating from the lighter contour, spreads onto the enclosed surface area, thereby tinting it with a chromatic veil, not unlike a weak but real color. Map makers in the 17th century utilized the WCE to better demarcate the shape of adjoining states, while 20th-century artist Bridget Riley created illusory watercolor as part of her op-art. Today's visual scientists study the WCE for its filling-in properties and strong figure-ground segregation. This review emphasizes the superior strength of the WCE for grouping and figure-ground organization vis-à-vis the classical Gestalt factors of Max Wertheimer (1923), thereby inspiring a notion of form from induced color. It also demonstrates that a thin chromatic line, flanking the inside of a black Mondrian-type pattern, induces the WCE across a large white surface area. Phenomenological, psychophysical, and neurophysiological approaches are reviewed.
Topics: Humans; Color Perception; History, 20th Century; Optical Illusions; Form Perception; History, 17th Century; History, 19th Century; History, 18th Century
PubMed: 38913017
DOI: 10.1167/jov.24.6.15