Amblyopic binocular imbalance quantified by the dichoptic contrast ordering test and dichoptic letters test.

In amblyopia, abnormal binocular interactions lead to an overwhelming dominance of one eye. One mechanism implied in this imbalance is the suppression between the inputs from the two eyes. This interocular suppression involves two components: an overlay suppression and a surround suppression.

Discovery of MDI-114215: A Potent and Selective LIMK Inhibitor To Treat Fragile X Syndrome.

LIMKs are serine/threonine and tyrosine kinases responsible for controlling cytoskeletal dynamics as key regulators of actin stability, ensuring synaptic health through normal synaptic bouton structure and function. However, LIMK1 overactivation results in abnormal dendritic synaptic development that characterizes the pathogenesis of Fragile X Syndrome (FXS). As a result, the development of LIMK inhibitors represents an emerging disease-modifying therapeutic approach for FXS.

Patch-free streaming contrast-rebalanced dichoptic cartoons versus patching for treatment of amblyopia in children aged 3 to 5 years: a pilot, randomized clinical trial.

Background: We developed and tested a dichoptic treatment designed for younger children that can be viewed freely and involves a dichoptic manipulation of a popular animation series that enables contrast-rebalancing without disrupting fusion. Our aim was to assess whether this novel amblyopia treatment is superior to patching in children aged 3-5 years.

Methods: A total of 34 children with amblyopia were randomly assigned to contrast-rebalanced dichoptic cartoons (4 hours/week) or patching (14 hours/week) for 2 weeks.

Stereo-anomaly is found more frequently in tasks that require discrimination between depths.

Within the population of humans with otherwise normal vision, there exists some proportion whose ability to perceive depth from binocular disparity is poor or absent. The prevalence of this "stereo-anomaly" has been reported to be as small as 2%, or as great as 30%. We set out to investigate this discrepancy.

Binocular function in the aging visual system: fusion, suppression, and stereoacuity.

Introduction: Changes in vision that occur in normal healthy aging can be seen in fundamental measures of monocular vision. However, the nature of the changes in binocular vision with age remain unclear.

Methods: A total of 28 older (53-66 years) and 28 younger adults (20-31 years) were enrolled in this study.

Amblyopic stereo vision is efficient but noisy.

People with amblyopia demonstrate a reduced ability to judge depth using stereopsis. Our understanding of this deficit is limited, as standard clinical stereo tests may not be suited to give a quantitative account of the residual stereo ability in amblyopia. In this study we used a stereo test designed specifically for that purpose.

Comparative Analysis of Small-Molecule LIMK1/2 Inhibitors: Chemical Synthesis, Biochemistry, and Cellular Activity.

LIM domain kinases 1 and 2 (LIMK1 and LIMK2) regulate actin dynamics and subsequently key cellular functions such as proliferation and migration. LIMK1 and LIMK2 phosphorylate and inactivate cofilin leading to increased actin polymerization. As a result, LIMK inhibitors are emerging as a promising treatment strategy for certain cancers and neurological disorders.

Exercise does not enhance short-term deprivation-induced ocular dominance plasticity: evidence from dichoptic surround suppression.

The input from the two eyes is combined in the brain. In this combination, the relative strength of the input from each eye is determined by the ocular dominance. Recent work has shown that this dominance can be temporarily shifted.

A psychophysical performance-based approach to the quality assessment of image processing algorithms.

Image processing algorithms are used to improve digital image representations in either their appearance or storage efficiency. The merit of these algorithms depends, in part, on visual perception by human observers. However, in practice, most are assessed numerically, and the perceptual metrics that do exist are criterion sensitive with several shortcomings.

The effects of optically and digitally simulated aniseikonia on stereopsis.

Purpose: To simulate both lens-induced and screen-induced aniseikonia, and to assess its influence on stereopsis. Additionally, to determine if screen-based size differences could neutralise the effects of lens-induced aniseikonia.

Method: A four-circle (4-C) paradigm was developed, where one circle appears in front or behind the others because of crossed or uncrossed disparity.

A portable multi-sensor module for monitoring external ventricular drains.

External ventricular drains (EVDs) are used clinically to relieve excess fluid pressure in the brain. However, EVD outflow rate is highly variable and typical clinical flow tracking methods are manual and low resolution. To address this problem, we present an integrated multi-sensor module (IMSM) containing flow, temperature, and electrode/substrate integrity sensors to monitor the flow dynamics of cerebrospinal fluid (CSF) drainage through an EVD.

Balanced Binocular Inputs Support Superior Stereopsis.

Purpose: Our visual system compares the inputs received from the two eyes to estimate the relative depths of features in the retinal image. We investigated how an imbalance in the strength of the input received from the two eyes affects stereopsis. We also explored the level of agreement between different measurements of sensory eye imbalance.

Some psychophysical tasks measure ocular dominance plasticity more reliably than others.

In the recent decade, studies have shown that short-term monocular deprivation strengthens the deprived eye's contribution to binocular vision. However, the magnitude of the change in eye dominance after monocular deprivation (i.e.

Shifting eye balance using monocularly directed attention in normal vision.

In binocular vision, even without conscious awareness of eye of origin, attention can be selectively biased toward one eye by presenting a visual stimulus uniquely to that eye. Monocularly directed visual cues can bias perceptual dominance, as shown by studies using discrete measures of percept changes in continuous-flash suppression. Here, we use binocular rivalry to determine whether eye-based visual cues can modulate eye balance using continuous percept reporting.

Comparison of blur and magnification effects on stereopsis: overall and meridional, monocularly- and binocularly-induced.

Purpose: To determine whether monocularly- and binocularly-induced spherical and meridional blur and aniseikonia had similar effects on stereopsis thresholds.

Methods: Twelve participants with normal binocular vision viewed McGill modified random dot stereograms to determine stereoacuities in a four-alternative forced-choice procedure. Astigmatism was induced by placing trial lenses in front of the eyes.

Integration of contours defined by second-order contrast-modulation of texture.

Boundaries in the visual world can be defined by changes in luminance and texture in the input image. A "contour integration" process joins together local changes into percepts of lines or edges. A previous study tested the integration of contours defined by second-order contrast-modulation.

Suppression Rather Than Visual Acuity Loss Limits Stereoacuity in Amblyopia.

Purpose: To investigate the influence of interocular suppression and visual acuity loss on stereoacuity in observers with and without abnormal vision development from strabismus or amblyopia. To determine whether stereoacuity improves in amblyopic observers when suppression is neutralized.

Methods: Experiment 1: Visual acuity (VA), depth of suppression (contrast ratio [CR]), and stereoacuity (digital random-dot) were tested in adult amblyopic observers (n = 21; age 27 ± 11 years).

Factors limiting sensitivity to binocular disparity in human vision: Evidence from a noise-masking approach.

Our visual system uses the disparity between the images received by the two eyes to judge three-dimensional distance to surfaces. We can measure this ability by having subjects discriminate the disparity of rendered surfaces. We wanted to know the basis of the individual differences in this ability.

Effects of simulated anisometropia and aniseikonia on stereopsis.

Purpose: Stereopsis depends on horizontally disparate retinal images but otherwise concordance between eyes. Here we investigate the effect of spherical and meridional simulated anisometropia and aniseikonia on stereopsis thresholds. The aims were to determine effects of meridian, magnitude and the relative effects of the two conditions.

Increased Noise in Cortico-Cortical Integration After Mild TBI Measured With the Equivalent Noise Technique.

The bulk of deficits accompanying mild traumatic brain injury (mTBI) is understood in terms of cortical integration-mnemonic, attentional, and cognitive disturbances are believed to involve integrative action across brain regions. Independent of integrative disturbances, mTBI may increase cortical noise, and this has not been previously considered. High-level integrative deficits are exceedingly difficult to measure and model, motivating us to utilize a tightly-controlled task within an established quantitative model to separately estimate internal noise and integration efficiency.

Assessment of stereovision with digital testing in adults and children with normal and impaired binocularity.

New digital approaches allow stereovision to be assessed with greater precision than current clinical stereo tests. Those current tests present a relatively narrow range of stimulus disparities in coarsely quantized steps. With dichoptic treatments for amblyopia emerging, more accurate assessment of especially coarse stereopsis becomes increasingly important for verifying their aim to improve 3D vision.

Visual plasticity and exercise revisited: No evidence for a "cycling lane".

Experiments using enriched environments have shown that physical exercise modulates visual plasticity in rodents. A recent study (Lunghi & Sale, 2015) investigated whether exercise also affects visual plasticity in adult humans. The plastic effect they measured was the shift in ocular dominance caused by 2 hr of monocular deprivation (e.

Ocular dominance plasticity: A binocular combination task finds no cumulative effect with repeated patching.

Short-term monocular deprivation strengthens the contribution of the deprived eye to binocular vision. This change has been observed in adults with normal vision or amblyopia. The change in ocular dominance is transient and recovers over approximately one hour.

Cholinergic Potentiation Alters Perceptual Eye Dominance Plasticity Induced by a Few Hours of Monocular Patching in Adults.

A few hours of monocular deprivation with a diffuser eye patch temporarily strengthens the contribution of the deprived eye to binocular vision. This shift in favor of the deprived eye is characterized as a form of adult visual plasticity. Studies in animal and human models suggest that neuromodulators can enhance adult brain plasticity in general.