The canonical deep neural network as a model for human symmetry processing.

A key property of our environment is the mirror symmetry of many objects, although symmetry is an abstract global property with no definable shape template, making symmetry identification a challenge for standard template-matching algorithms. We therefore ask whether Deep Neural Networks (DNNs) trained on typical natural environmental images develop a selectivity for symmetry similar to that of the human brain. We tested a DNN trained on such typical natural images with object-free random-dot images of 1, 2, and 4 symmetry axes.

The transformation of sensory to perceptual braille letter representations in the visually deprived brain.

Experience-based plasticity of the human cortex mediates the influence of individual experience on cognition and behavior. The complete loss of a sensory modality is among the most extreme such experiences. Investigating such a selective, yet extreme change in experience allows for the characterization of experience-based plasticity at its boundaries.

Visual Cortical Function Changes After Perceptual Learning with Dichoptic Attention Tasks in Adults with Amblyopia: A Case Study Evaluated Using fMRI.

Amblyopia is a neurodevelopmental disorder of vision, commonly caused by strabismus or anisometropia during early childhood. While studies demonstrated that perceptual learning improves visual acuity and stereopsis in adults with amblyopia, accompanying changes in visual cortical function remain unclear. We measured functional magnetic resonance imaging (fMRI) responses before and after perceptual learning in seven adults with amblyopia.

Touch to text: Spatiotemporal evolution of braille letter representations in blind readers.

Visual deprivation does not silence the visual cortex, which is responsive to auditory, tactile, and other nonvisual tasks in blind persons. However, the underlying functional dynamics of the neural networks mediating such crossmodal responses remain unclear. Here, using braille reading as a model framework to investigate these networks, we presented sighted (N=13) and blind (N=12) readers with individual visual print and tactile braille alphabetic letters, respectively, during MEG recording.

Higher visual function deficits are independent of visual acuity measures in children with cerebral visual impairment.

Cerebral visual impairment (CVI), the leading cause of bilateral visual impairment in children, is often characterized by visual acuity (VA) loss and higher visual function deficits (HVFDs). However, the relationship between VA loss and HVFDs remains unknown. A previous study using the Higher Visual Function Question Inventory (HVFQI) demonstrated that normal VA did not preclude HVFDs.

The visual experience dataset: Over 200 recorded hours of integrated eye movement, odometry, and egocentric video.

We introduce the Visual Experience Dataset (VEDB), a compilation of more than 240 hours of egocentric video combined with gaze- and head-tracking data that offer an unprecedented view of the visual world as experienced by human observers. The dataset consists of 717 sessions, recorded by 56 observers ranging from 7 to 46 years of age. This article outlines the data collection, processing, and labeling protocols undertaken to ensure a representative sample and discusses the potential sources of error or bias within the dataset.

Self-assembled thin films as alternative surface textures in assistive aids with users who are blind.

Current tactile graphics primarily render tactile information for blind users through physical features, such as raised bumps or lines. However, the variety of distinctive physical features that can be created is effectively saturated, and alternatives to these physical features are not currently available for static tactile aids. Here, we explored the use of chemical modification through self-assembled thin films to generate distinctive textures in tactile aids.

Special Commentary: My Perspective on Vision and Vision Rehabilitation.

Unlabelled: Vision is the most powerful sense guiding our interaction with the environment. Its process starts with the retinal image as input and results in visually guided behaviors as output. This paper summarizes insights I gained over >40 years dealing with clinical ophthalmology, visual science, and vision rehabilitation, disciplines that all involve vision, but from different points of view.

Accessible Point-and-Tap Interaction for Acquiring Detailed Information about Tactile Graphics and 3D Models.

We have devised a novel "Point-and-Tap" interface that enables people who are blind or visually impaired (BVI) to easily acquire multiple levels of information about tactile graphics and 3D models. The interface uses an iPhone's depth and color cameras to track the user's hands while they interact with a model. When the user points to a feature of interest on the model with their index finger, the system reads aloud basic information about that feature.

Sensory and Perceptual Decisional Processes Underlying the Perception of Reverberant Auditory Environments.

Reverberation, a ubiquitous feature of real-world acoustic environments, exhibits statistical regularities that human listeners leverage to self-orient, facilitate auditory perception, and understand their environment. Despite the extensive research on sound source representation in the auditory system, it remains unclear how the brain represents real-world reverberant environments. Here, we characterized the neural response to reverberation of varying realism by applying multivariate pattern analysis to electroencephalographic (EEG) brain signals.

The digital signature of emergent tremor in Parkinson's disease.

Emergent tremor in Parkinson's disease (PD) can occur during sustained postures or movements that are different from action tremor. Tremor can contaminate the clinical rating of bradykinesia during finger tapping. Currently, there is no reliable way of isolating emergent tremor and measuring the cardinal motor symptoms based on voluntary movements only.

Advanced computational model of rod ERG kinetics.

Purpose: The electroretinogram (ERG) is the summed response from all levels of the retinal processing of light, and exhibits several profound nonlinearities in the underlying processing pathways. Accurate computational models of the ERG are important, both for understanding the multifold processes of light transduction to ecologically useful signals by the retina, and for their diagnostic capabilities for the identification and characterization of retinal disease mechanisms. There are, however, very few computational models of the ERG waveform, and none that account for the full extent of its features over time.

Smooth pursuit deficits impact dynamic visual acuity in macular degeneration.

Significance: Prior studies with large, highly visible targets report low smooth pursuit gains in individuals with macular degeneration (MD). We show that lower gains persist even when observers are pursuing a target that requires discrimination at the acuity limit. This low gain causes retinal slip, potentially leading to motion blur and target disappearance in the scotoma, which further compromise the visibility of moving object.

Spatial summation for motion detection.

We used the psychophysical summation paradigm to reveal some spatial characteristics of the mechanism responsible for detecting a motion-defined visual target in central vision. There has been much previous work on spatial summation for motion detection and direction discrimination, but none has assessed it in terms of the velocity threshold or used velocity noise to provide a measure of the efficiency of the velocity processing mechanism. Motion-defined targets were centered within square fields of randomly selected gray levels.

Co-Designing Auditory Navigation Solutions for Traveling as a Blind Individual During the COVID-19 Pandemic.

A group co-design was held in March 2021 with six blind and low-vision individuals (BLIs) from the United States. Participants were asked to discuss problems related to travel during the COVID-19 pandemic and make recommendations for possible solutions. Two probes (prototypes) of a non-visual neighborhood travel map and a non-visual COVID-19 choropleth map (a map using colors or sounds over each state to represent different values) of COVID-19 state data were shown to participants for inspiration.

Object recognition via echoes: quantifying the crossmodal transfer of three-dimensional shape information between echolocation, vision, and haptics.

Active echolocation allows blind individuals to explore their surroundings via self-generated sounds, similarly to dolphins and other echolocating animals. Echolocators emit sounds, such as finger snaps or mouth clicks, and parse the returning echoes for information about their surroundings, including the location, size, and material composition of objects. Because a crucial function of perceiving objects is to enable effective interaction with them, it is important to understand the degree to which three-dimensional shape information extracted from object echoes is useful in the context of other modalities such as haptics or vision.

Visual Field Dependence Persists in Age-Related Central Visual Field Loss.

Purpose: To examine whether the age-related increase in visual field dependence persists in older adults with central field loss (CFL).

Methods: Twenty individuals with CFL were grouped into participants with age-related binocular CFL (CFL, n = 9), age-related monocular CFL/relative scotomata (mCFL, n = 8), and CFL occurring at a young age (yCFL, n = 3). Seventeen controls were age-matched to the older CFL groups (OA) and three to the yCFL group (yOA).

Evaluating the effect of action-like video game play and of casual video game play on anxiety in adolescents with elevated anxiety: protocol for a multi-center, parallel group, assessor-blind, randomized controlled trial.

Background: Adolescence is a critical period for the onset and maintenance of anxiety disorders, which raises the importance of intervening early; one possibility of doing so is via digital interventions. Within that research field, at least two important research paths have been explored in the past years. On the one hand, the anxiolytic effect of casual video games has been tested as such gaming activity may distract away from anxious thoughts through the induction of flow and redirection of attention toward the game and thus away of anxious thoughts.

Genetic Variants of the Beta-Adrenergic Receptor Pathways as Both Risk and Protective Factors for Retinopathy of Prematurity.

Purpose: There is strong evidence that genetic factors influence retinopathy of prematurity (ROP), a neovascular eye disease. It has been previously suggested that polymorphisms in the genes involved in β-adrenergic receptor (ADRβ) pathways could protect against ROP. Antagonists for the ADRβ are actively tested in clinical trials for ROP treatment, but not without controversy and safety concerns.

A new approach to measure interocular suppression in amblyopia and strabismus.

Interocular suppression is commonly estimated by the contrast "balance point" between the eyes in individuals with amblyopia, in which the depth of suppression is defined as the increased contrast in the amblyopic eye that is perceptually matched to the fellow eye. However, this method may not be suitable for individuals with strabismus who have normal or even better contrast sensitivity in the non-fixating eye. In this study, I introduced a new approach that can be used for measuring interocular suppression for both amblyopia and strabismus without balancing contrasts between the eyes.

The utility of peripheral stereopsis.

This perspective article makes the case for evaluating and training peripheral stereopsis, particularly when the central visual field is compromised in one or both eyes. Examples of clinical conditions that preferentially affect the central visual field include macular degeneration, which affects the central macular region in one or both eyes, and amblyopia where the central field is often affected in one eye, but the peripheral field is largely intact. While binocular acuity may be preserved when the monocular central field of one eye is affected, fine stereopsis is compromised because it requires intact vision in corresponding locations in the two eyes.

A Comparison of Walking Behavior during the Instrumented TUG and Habitual Gait.

The timed up and go test (TUG) is a common clinical functional balance test often used to complement findings on sensorimotor changes due to aging or sensory/motor dysfunction. The instrumented TUG can be used to obtain objective postural and gait measures that are more sensitive to mobility changes. We investigated whether gait and body coordination during TUG is representative of walking.

Cannabidiol as an Adjunct to Botulinum Toxin in Blepharospasm - A Randomized Pilot Study.

Purpose: The purpose of this study was to evaluate the safety and efficacy of low dose cannabidiol (CBD; Epidiolex) as adjunctive therapy for idiopathic adult-onset blepharospasm (BPS), as well as develop a novel objective assessment methodology to gauge response.

Methods: Prospective, randomized, double-masked, placebo-controlled crossover design of 6 months duration of 12 patients with BPS undergoing routine maximal botulinum toxin (BTX) therapy and experiencing breakthrough symptoms. Participants received their standard BTX every 3 months and were randomized to group A = CBD daily in cycle 1, followed by placebo in cycle 2 or group B = placebo followed by CBD.