Shape partitioning interacts with global shape integration.
This study exploits the proposition that the visual system decomposes objects at matched deep concavities on their boundaries. Rapid decreases in thresholds for detection of sinusoidal deformation of a circle's radius with number of cycles of modulation shows that shape information is integrated around radial frequency (RF) patterns. Here we merge RF patterns to form composite patterns with concavities and show that integration around the RF patterns is disrupted if the concavities are shallow but preserved if they are deep, consistent with their decomposition at matched deep concavities. Geon theory identifies complex pat...
Source: Vision Research - December 5, 2019 Category: Opthalmology Authors: Wong VSY, Dickinson JE, Badcock DR Tags: Vision Res Source Type: research

Effect of duration, and temporal modulation, of monochromatic light on emmetropization in chicks.
Abstract Previous experiments disagree on the effect of monochromatic light on emmetropization. Some species respond to wavelength defocus created by longitudinal chromatic aberration and become more myopic in monochromatic red light and more hyperopic in monochromatic blue light, while other species do not. Using the chicken model, we studied the effect of the duration of light exposure, modes of lighting, and circadian interruption on emmetropization in monochromatic light. To achieve this goal, we exposed one-week-old chicks to flickering or steady monochromatic red or blue light for a short (10 days) or long...
Source: Vision Research - November 28, 2019 Category: Opthalmology Authors: Lin G, Taylor C, Rucker F Tags: Vision Res Source Type: research

Same-object costs and benefits in the object-based attentional blink.
Abstract Object-based attention (OBA) studies using the double-rectangle paradigm have revealed same-object costs with vertical rectangles but same-object benefits with horizontal rectangles, showing asymmetry in the OBA effect. Attentional blink (AB) studies using rapid serial visual presentation (RSVP) paradigms have shown that when two targets (T1 and T2) are successively presented within 400 msec, T2 performance is significantly impaired (i.e., an AB effect). Some object-based AB studies have indicated that the stable representation of single objects before T1 reduced the same-object AB effect, and some have c...
Source: Vision Research - November 27, 2019 Category: Opthalmology Authors: Cheng Q, Mo L Tags: Vision Res Source Type: research

Perceptual impact of astigmatism induction in presbyopes.
Abstract We investigated the effect of induced astigmatism on subjective best focus and on visual acuity in 28 subjects of different ages (pre-presbyopic and presbyopic) and with different refractive profiles (emmetropes and astigmats). Measurements were performed using a custom-developed Adaptive Optics system, which allowed correction of high order aberrations and induction of astigmatism (0.5, 1, 1.5 and 2.0 D; axis: 180°, 45° and 22.5°). Upon induction of astigmatism, best focus shifted towards negative values in pre-presbyopic emmetropic eyes (by -0.14 D for 0.5 D and by -0.33 D for 2.0 D), while ...
Source: Vision Research - November 18, 2019 Category: Opthalmology Authors: Benedi-Garcia C, Velasco-Ocana M, Dorronsoro C, Pascual D, Hernandez M, Marin G, Marcos S Tags: Vision Res Source Type: research

Visual attention modulates reading acquisition.
Abstract The processing of letters within strings is challenging for beginning readers. Letter identification is affected by visual similarity, loss of information with eccentricity and interference from nearby letters. In contrast, visual attention enhances letter identification. We here explored whether visual attention resources for multi-element processing, as measured through tasks of visual attention span prior to literacy instruction, predicted reading fluency performance one year later. One hundred and twenty-four mainstream children were assessed in kindergarten on their visual attention span abilities, p...
Source: Vision Research - November 18, 2019 Category: Opthalmology Authors: Valdois S, Roulin JL, Line Bosse M Tags: Vision Res Source Type: research

The hippocampus as a visual area organized by space and time: A spatiotemporal similarity hypothesis.
Abstract The hippocampus is the canonical memory system in the brain and is not typically considered part of the visual system. Yet, it sits atop the ventral visual stream and has been implicated in certain aspects of vision. Here I review the place of the hippocampal memory system in vision science. After a brief primer on the local circuity, external connectivity, and computational functions of the hippocampus, I explore what can be learned from each field about the other. I first present four areas of vision science (scene perception, imagery, eye movements, attention) that challenge our current understanding o...
Source: Vision Research - November 14, 2019 Category: Opthalmology Authors: Turk-Browne NB Tags: Vision Res Source Type: research

Contributions of shape and reflectance information to social judgments from faces.
Abstract Face perception is based on both shape and reflectance information. However, we know little about the relative contribution of these kinds of information to social judgments of faces. In Experiment 1, we generated faces using validated computational models of attractiveness, competence, dominance, extroversion, and trustworthiness. Faces were manipulated orthogonally on five levels of shape and reflectance for each model. Both kinds of information had linear and additive effects on participants' social judgments. Shape information was more predictive of dominance, extroversion, and trustworthiness judgmen...
Source: Vision Research - November 14, 2019 Category: Opthalmology Authors: Oh D, Dotsch R, Todorov A Tags: Vision Res Source Type: research

Use of a new composite index to demonstrate improved stereoacuity after training on stimuli with dichoptically asymmetric contrast.
Abstract Many people with stereo-deficiency cannot perform stereoacuity tasks at any binocular disparity, so their threshold cannot be measured. We developed a generally useful new composite stereodepth or CSD score, with range 0 to 20, that combines stereoacuity (from 0 to 13.3) and percent correct (13.3 to 20) into a single index. CSD allows differences in stereodepth performance to be measured across groups when thresholds cannot be reliably measured, and across time when individuals gain stereodepth perception during training. We used CSD scores to assess the benefit of unequal (mixed) left- and right-eye cont...
Source: Vision Research - November 14, 2019 Category: Opthalmology Authors: Law CL, Backus BT Tags: Vision Res Source Type: research

Influence of reading skill and word length on fixation-related brain activity in school-aged children during natural reading.
We examined standard eye-movement variables and deconvoluted FRP estimates: intercept of the response, categorical effect of first fixation versus additional fixation and continuous effect of word length. We replicated the pattern of stronger word length effect in eye movements for slow readers. We found a difference between typical readers and slow readers in the FRP intercept, which contains activity that is common to all fixations, within a fixation time-window of 50-300 ms. For both groups, the word length effect was present in brain activity during additional fixations; however, this effect was not different between...
Source: Vision Research - November 8, 2019 Category: Opthalmology Authors: Loberg O, Hautala J, Hämäläinen JA, Leppänen PHT Tags: Vision Res Source Type: research

One-shot categorization of novel object classes in humans.
Abstract One aspect of human vision unmatched by machines is the capacity to generalize from few samples. Observers tend to know when novel objects are in the same class despite large differences in shape, material or viewpoint. A major challenge in studying such generalization is that participants can see each novel sample only once. To overcome this, we used crowdsourcing to obtain responses from 500 human observers on 20 novel object classes, with each stimulus compared to 1 or 16 related objects. The results reveal that humans generalize from sparse data in highly systematic ways with the number and variance o...
Source: Vision Research - November 7, 2019 Category: Opthalmology Authors: Morgenstern Y, Schmidt F, Fleming RW Tags: Vision Res Source Type: research

LWS visual pigment in owls: Spectral tuning inferred by genetics.
Abstract Owls constitute a diverse group of raptors, active at different times of the day with distinct light conditions that might be associated with multiple visual adaptations. We investigated whether shifts in the spectral sensitivity of the L cone visual pigment, as inferred by analysis of gene structure, could be one such adaptive mechanism. Using Sanger sequencing approach, we characterized the long wavelength-sensitive (LWS) opsin gene expressed in the retina of five owl species, specifically chosen to represent distinct patterns of activity. Nocturnality was epitomized by the American barn owl (Tyto furca...
Source: Vision Research - November 6, 2019 Category: Opthalmology Authors: Vasconcelos FTGR, Naman MJV, Hauzman E, Baron J, Fix Ventura D, Bonci DMO Tags: Vision Res Source Type: research

Dominance wave propagation during binocular rivalry in mild glaucoma.
This study evaluated dominance wave propagation during binocular rivalry to probe the efficacy of the inter-hemispheric transfer in 20 patients with mild open angle glaucoma and 25 age-matched controls. The two groups were matched for functional measures such as stereo-acuity, binocular visual acuity, and visual field mean deviation. Monocular functional and structural measures were equivalent for the left and right eye of each participant. Using Wilson et al.'s travelling wave paradigm [Nature, 412 (2001) 907-910], intra- and inter-hemispheric failure rates of traveling wave transmission and the travelling wave propagatio...
Source: Vision Research - October 31, 2019 Category: Opthalmology Authors: Tarita-Nistor L, Samet S, Trope GE, González EG Tags: Vision Res Source Type: research

Appearance of Maxwell's spot in images rendered using a cyan primary.
Abstract The discovery of melanopsin as a third type of retinal photoreceptor, contributing to both perceptual vision and reflex light responses, represents a new opportunity to optimise the design of artificial light sources for practical applications and to generate experimental stimuli. In the case of emissive displays, multiprimary designs incorporating a cyan primary could be used to allow melanopic radiance to be controlled independent of colour and luminance. Here we explore the performance a five-primary (violet, cyan, green, yellow, red) display device and find an anomaly in colour appearance when the cya...
Source: Vision Research - October 31, 2019 Category: Opthalmology Authors: Gardasevic M, Lucas RJ, Allen AE Tags: Vision Res Source Type: research

A new visual illusion of aspect-ratio context.
Abstract Perception of local properties of the visual field is influenced by aftereffects of adaptation. The tilt aftereffect describes repulsion of the perceived orientation of a line from the orientation of an adapting line. Analogous effects of spatial context are often called illusions. Repulsion of the perceived orientation of a grating from the orientation of a surrounding grating is referred to as the tilt illusion. In the same manner, the size aftereffect and Ebbinghaus illusion form a complementary pair of temporal and spatial context effects of size. Here we report psychophysical evidence for a previousl...
Source: Vision Research - October 31, 2019 Category: Opthalmology Authors: Dickinson JE, Green RJ, Harkin GM, Tang MF, Badcock DR Tags: Vision Res Source Type: research

Contrast discrimination under task-induced mental load.
This study investigated the effects of auditory task-induced mental load on contrast discrimination threshold across several spatial frequencies. Binocular contrast discrimination thresholds were measured in 14 participants at spatial frequencies of 0.25, 1, 4, 8, 14 cpd across pedestal contrast levels of 10, 16, 24, 38 and 60%. The task was repeated with an auditory 0-back task and 2-back task to impose a mental load, the magnitude of which was measured through subjective ratings and heart rate recording. A concurrent 2-back task significantly increased contrast discrimination thresholds across all spatial frequencies w...
Source: Vision Research - October 31, 2019 Category: Opthalmology Authors: Mahjoob M, Anderson AJ Tags: Vision Res Source Type: research

Changes (but not differences) in motion direction fail to capture attention.
In this study we investigated under what conditions motion direction changes pop out in continuously moving target/distractor environments. Participants were presented with vertically oriented Gabor patches whose carrier components drifted at a constant speed from left to right and then reversed direction. On any given trial, one of these elements was nominated as the target and the remaining elements were distractors. Distractor elements all changed direction simultaneously. The distractors either moved in a homogeneous manner (i.e. all moved in the same direction), or in a heterogeneous manner (i.e. direction was randomi...
Source: Vision Research - October 23, 2019 Category: Opthalmology Authors: Van der Burg E, Cass J, Theeuwes J Tags: Vision Res Source Type: research

Monocular accommodation response to random defocus changes induced by a tuneable lens.
Abstract Accommodation of the human eye relies on multiple factors and visual cues that include object size, monochromatic and chromatic aberrations, and vergence. Yet, even in monocular conditions, accommodation corrects for defocus. Studies of eye growth in chicks have addressed whether the retina can decode the sign of defocus as this may play a role for emmetropization and possibly also accommodation. However, findings have not been unambiguous and questions remain. Here, we report on monocular accommodation studies of emmetropic and myopic human subjects to clarify whether foveal vision drives accommodation i...
Source: Vision Research - October 18, 2019 Category: Opthalmology Authors: Sharmin N, Vohnsen B Tags: Vision Res Source Type: research

Neighboring chromaticity influences how white a surface looks.
Abstract To identify surface properties independently of the illumination the visual system must make assumptions about the statistics of scenes and their illumination. Are assumptions about the intensity of the illumination independent of assumptions about its chromaticity? To find out, we asked participants to judge whether test patches within three different sets of surrounding surfaces were white or grey. Two sets were matched in terms of their maximal luminance, their mean luminance and chromaticity, and the variability in their luminance and chromaticity, but differed in how luminance and chromaticity were a...
Source: Vision Research - October 14, 2019 Category: Opthalmology Authors: Nascimento SMC, Pastilha RC, Brenner E Tags: Vision Res Source Type: research

A millipede compound eye mediating low-resolution vision.
Abstract Millipedes are a species-rich and ancient arthropod clade which typically bear a pair of lateral compound eyes with a small number of large facets. To understand the visual tasks that underlie the evolution of millipede eyes, their spatial resolving performance is of key importance. We here investigate the spatial resolution of the millipede Cylindroiulus punctatus using behavioural assays. Individual animals were placed in the centre of a cylindrical arena under bright downwelling light, with dark stimuli of varying angular dimensions placed on the arena wall. We used continuous isoluminant stimuli based...
Source: Vision Research - October 14, 2019 Category: Opthalmology Authors: Kirwan JD, Nilsson DE Tags: Vision Res Source Type: research

Peripheral threat detection in facial expressions by younger and older adults.
Abstract Everyday threat detection includes recognizing threat cues in facial expressions found in our peripheral visual field. The current study examined age differences in the detection of emotion in low and high intensity angry and fearful facial expressions presented in younger and older adults' parafoveal (±5°) and peripheral visual field (±10°, ±15°). For both age groups, detection performance was better for higher than for lower intensity stimuli, and detection performance declined with greater peripheral distance. Although younger and older adults displayed a similar patter...
Source: Vision Research - October 12, 2019 Category: Opthalmology Authors: Mienaltowski A, Groh BN, Hahn LW, Norman JF Tags: Vision Res Source Type: research

Quantifying the effect of viewpoint changes on sensitivity to face identity.
Abstract Although faces can be recognized from different viewpoints, variations in viewpoint impair face identification ability. The present study quantified the effect of changes in viewpoint on sensitivity to face identity. We measured discrimination thresholds for synthetic faces presented from several viewpoints (same viewpoint condition) and the same faces shown with a change in viewpoint (5°, 10° or 20°) between viewing and test. We investigated three types of viewpoint change: (i) front-to-side (front-view matched to 20°° side-view), (ii) side-to-front (20° side-view matched to front...
Source: Vision Research - October 11, 2019 Category: Opthalmology Authors: Swystun AG, Logan AJ Tags: Vision Res Source Type: research

Spatial frequency selectivity of the human visual cortex estimated with pseudo-random visual evoked cortical potential (VECP).
Abstract Single-cell recordings in the primary visual cortex (V1) show neurons with spatial frequency (SF) tuning, which had different responses to chromatic and luminance stimuli. Visually evoked cortical potential (VECP) investigations have reported different spatial profiles. The current study aimed to investigate the spatial selectivity of V1 to simultaneous stimulus of chromatic and luminance contrasts. Compound stimuli temporally driven by m-sequences at 8 SFs were utilized to generate VECP records from thirty subjects (14 trichromats and 16 colorblind subjects). We extracted the second-order kernel, first a...
Source: Vision Research - October 11, 2019 Category: Opthalmology Authors: Martins ICVS, Brasil A, Miquilini L, Goulart PRK, Herculano AM, Silveira LCL, Souza GS Tags: Vision Res Source Type: research

Objective and quantitative assessment of interocular suppression in strabismic amblyopia based on steady-state motion visual evoked potentials.
In this study, we aimed to explore an objective, sensitive and quantitative measurement of interocular suppression in strabismic amblyopia. We compared 11 strabismic subjects with 12 normal vision subjects to explore the different response characterizations in normal eyes, nondominant and dominant eyes of strabismic subjects by using steady-state motion visual evoked potentials (SSMVEPs). Stimulation at different temporal frequencies was presented to two eyes by using an interocular dichoptic technique. Furthermore, canonical correlation analysis (CCA), signal-to-noise ratio (SNR) and some statistical methods, such as the ...
Source: Vision Research - October 1, 2019 Category: Opthalmology Authors: Zheng X, Xu G, Zhi Y, Wang Y, Han C, Wang B, Zhang S, Zhang K, Liang R Tags: Vision Res Source Type: research

Part and whole face representations in immediate and long-term memory.
Abstract Although there is empricial support for the old adage that "we never forget a face" (Journal of Experimental Psychology: General 104 (1975) 54-75), the cognitive processes responsible for our long-term face memories are not well understood. By manipulating the upright and inverted orientation of faces during encoding and retrieval, we investigated the influence of holistic processing on our ability to recognize faces stored in long-term memory. In Experiment 1, participants were trained to identify 12 novel upright faces (six male, six female) by name (e.g., "Joe," "Sue") to ...
Source: Vision Research - October 1, 2019 Category: Opthalmology Authors: Tanaka JW, Heptonstall B, Campbell A Tags: Vision Res Source Type: research

Vertical size disparity induces enhanced neural responses in good stereo observers.
Abstract Stereoscopic three-dimensional vision requires cortical processing for horizontal binocular disparity between the two eyes' retinal images. Behavioral and theoretical studies suggest that vertical size disparity is used to recover the viewing geometry and to generate the slant of a large surface. However, unlike horizontal disparity, the relation between stereopsis and neural responses to vertical disparity remains controversial. To determine the role of cortical processing for vertical size disparity in stereopsis, we measured neuromagnetic responses to disparities in people with good and poor stereopsis...
Source: Vision Research - September 23, 2019 Category: Opthalmology Authors: Mitsudo H, Hironaga N, Ogata K, Tobimatsu S Tags: Vision Res Source Type: research

Analysis of the visual spatiotemporal properties of American Sign Language.
Abstract Careful measurements of the temporal dynamics of speech have provided important insights into phonetic properties of spoken languages, which are important for understanding auditory perception. By contrast, analytic quantification of the visual properties of signed languages is still largely uncharted. Exposure to sign language is a unique experience that could shape and modify low-level visual processing for those who use it regularly (i.e., what we refer to as the Enhanced Exposure Hypothesis). The purpose of the current study was to characterize the visual spatiotemporal properties of American Sign Lan...
Source: Vision Research - September 23, 2019 Category: Opthalmology Authors: Bosworth RG, Wright CE, Dobkins KR Tags: Vision Res Source Type: research

Effects of the gravity direction in the environment and the visual polarity and body direction on the perception of object motion.
This study investigates the effects of up-down direction, as obtained from these cues on motion perception, with a focus on acceleration perception. We presented the participants with moving objects that had various acceleration speeds and measured the physical acceleration to be perceived as constant velocity. We examined the effect of the up-down direction from the visual polarity by changing the relationship between the up-down direction indicated by the gravity direction cue and the up-down direction indicated by visual polarity by manipulating the posture of the observer. The results showed that the up-down direction ...
Source: Vision Research - September 19, 2019 Category: Opthalmology Authors: Miwa T, Hisakata R, Kaneko H Tags: Vision Res Source Type: research

The melanopsin-directed white noise electroretinogram (wnERG).
Abstract The white noise electroretinogram (wnERG) provides a measure of the impulse response function under conditions of retinal equilibrium; it is yet to be determined how the electrical response generated by melanopsin ganglion cell photoreception is expressed in the impulse response. To this end, we recorded the human wnERG to continuous temporal white noise (TWN) stimuli that were melanopsin-directed (rod and cone silent) or cone-directed (rod and melanopsin silent). The impulse response of the electroretinogram was derived by cross-correlating the TWN stimulus with the wnERG response. We observed that the L...
Source: Vision Research - September 18, 2019 Category: Opthalmology Authors: Adhikari P, Zele AJ, Cao D, Kremers J, Feigl B Tags: Vision Res Source Type: research

Gender and hometown population density interact to predict face recognition ability.
Abstract Several studies have found that individuals from small hometowns show diminished face recognition ability as compared with individuals from larger hometowns. We further this line of research by relating six measures of face recognition ability to hometown density. We predicted that the three face recognition ability measures which included a learning component would relate to hometown density whereas the three measures which did not include such a learning component would not. Instead, we found that none of the six measures related to hometown density. Interestingly, we found interactions between gender a...
Source: Vision Research - August 28, 2019 Category: Opthalmology Authors: Sunday MA, Patel PA, Dodd MD, Gauthier I Tags: Vision Res Source Type: research

The temporal and spatial constraints of saccade planning to double-step target displacements.
Abstract The double-step paradigm investigates the characteristics of planning and execution when the motor system must rapidly adjust for a new goal location. Studies have provided detailed temporal information based on the duration available for the motor system to prepare a new movement trajectory (here referred to as re-preparation time). However, previous work has largely examined single displacement sizes, limiting the spatiotemporal understanding of movement planning and execution. The lack of a description of this behavioral timecourse across increasing displacement sizes is true for saccades, rapid eye mo...
Source: Vision Research - August 9, 2019 Category: Opthalmology Authors: Kelly S, Zhou W, Bansal S, Petersen M, Joiner WM Tags: Vision Res Source Type: research

Effects of Temporal Frequency on Binocular Deficits in Amblyopia.
We examined the effects of temporal modulation on contrast sensitivity and binocular interactions in a preliminary study of 8 adults with amblyopia and 14 normally-sighted control subjects. For each observer, we measured interocular balance and stereopsis thresholds with binocular flicker across a range of four temporal (0, 4, 7.5, and 12 Hz) and spatial (1, 2, 4, and 8 cpd) frequencies. Interocular balance was estimated by varying the relative contrast of dichoptic letter pairs to produce perceptual reports of each letter with equal frequency, and stereopsis thresholds were measured by determining the minimum disparity at...
Source: Vision Research - August 9, 2019 Category: Opthalmology Authors: Kosovicheva A, Ferreira A, Vera-Diaz FA, Bex PJ Tags: Vision Res Source Type: research

Attentional guidance varies with display density.
Abstract The aim of the present study was to investigate how display density affects attentional guidance in heterogeneous search displays. In Experiment 1 we presented observers with heterogeneous sparse and dense search displays which were adaptively changed over the course of the experiment using genetic algorithms. We generated random displays, and based upon fastest search times, the displays that allowed most efficient search were selected to generate new displays for the next generations, thus revealing which properties facilitated or inhibited target search across display densities. The results showed that...
Source: Vision Research - August 8, 2019 Category: Opthalmology Authors: van de Weijgert M, Van der Burg E, Donk M Tags: Vision Res Source Type: research

Emmetropes and myopes differ little in their accommodation dynamics but strongly in their ciliary muscle morphology.
Abstract Previous work suggested an association between near vision and myopia. We therefore investigated the accommodation process in emmetropes and myopes regarding morphologic changes of the ciliary muscle (CM) and power changes of the lens for different accommodation demands. The temporal CM of 18 emmetropic and 20 myopic students was imaged via anterior segment optical coherence tomography during far and near accommodation (2.5D, 3D, 4D). Additionally, accommodation dynamics to the stimuli pattern far-near-far (15s each; 2.5D, 3D, 4D) were recorded with eccentric infrared photorefraction. OCT images were proc...
Source: Vision Research - August 8, 2019 Category: Opthalmology Authors: Wagner S, Zrenner E, Strasser T Tags: Vision Res Source Type: research

Assessment of stereovision with digital testing in adults and children with normal and impaired binocularity.
Abstract 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. We used digital testing in subjects of a large age range (4-59 years), with groups having both normal (n=34) and impaired binocular vision due to unilateral amblyopia, with or without strabismus (n=27). Ra...
Source: Vision Research - August 1, 2019 Category: Opthalmology Authors: Tittes J, Baldwin AS, Hess RF, Cirina L, Wenner Y, Kuhli-Hattenbach C, Ackermann H, Kohnen T, Fronius M Tags: Vision Res Source Type: research

Associations between accommodative dynamics, heart rate variability and behavioural performance during sustained attention: A test-retest study.
This study evaluated the time-on-task effect of a sustained attention task on the accommodative response, explored the link between ocular accommodation, cardiac autonomic regulation and behavioral performance, and tested the inter-session repeatability of these results by performing the same experimental procedure on different days. The accommodative response was measured in 25 university students using a WAM-5500 autorefractor, while participants performed a 10-minute psychomotor vigilance task at 50 cm. There were no time-on-task effects for the lag of accommodation, whereas the microfluctuations of accommodation and re...
Source: Vision Research - July 30, 2019 Category: Opthalmology Authors: Redondo B, Vera J, Luque-Casado A, García-Ramos A, Jiménez R Tags: Vision Res Source Type: research

Individual variation in inter-ocular suppression and sensory eye dominance.
Abstract The competitive and inhibitory interactions between the two eyes' images are a pervasive aspect of binocular vision. Over the last decade, our understanding of the neural processes underpinning binocular rivalry (BR) and continuous flash suppression (CFS) has increased substantially, but we still have little understanding of the relationship between these two effects and their variation in the general population. Studies that pool data across individuals and eyes risk masking substantial variations in binocular vision that exist in the general population. To investigate this issue we compared the depth of...
Source: Vision Research - July 30, 2019 Category: Opthalmology Authors: Wang M, McGraw P, Ledgeway T Tags: Vision Res Source Type: research

Effect of spatial filtering on accommodation.
Abstract The purpose of this study was to develop and test a new method that uses natural images to investigate the influence of their spatial frequency content on the accommodation response (AR). Furthermore, the minimum spatial frequency content was determined that was necessary to induce an AR. Blur of the images was manipulated digitally in the Fourier domain by filtering with a Sinc function. Fourteen young subjects participated in the experiment. A 2-step procedure was used: (1) verifying that a high amount of Sinc-blur does not evoke accommodation, (2) increasing the width of the Sinc-blur filter in logarit...
Source: Vision Research - July 26, 2019 Category: Opthalmology Authors: Diez PS, Ohlendorf A, Schaeffel F, Wahl S Tags: Vision Res Source Type: research

Brief Facial Emotion Aftereffect Occurs Earlier for Angry than Happy Adaptation.
Abstract Prolonged exposure to an emotional face biases our judgement of subsequent face stimulus toward the opposite emotion. This emotion aftereffect has been suggested to occur as early as 35ms exposure duration in cartoon faces. In the current study, we are interested in investigating the time-course of brief emotional face adaptation, and the relationship between brief emotional face adaptation and prolonged emotional face adaptation. We adapted the subjects from 17ms to 1000ms with a happy or angry adapting face. We found that a facial emotion adaptation aftereffect started from 17ms adapting duration for an...
Source: Vision Research - July 17, 2019 Category: Opthalmology Authors: Sou KL, Xu H Tags: Vision Res Source Type: research

Constant Lens Fiber Cell Thickness in Fish Suggests Crystallin Transport to Denucleated Cells.
RHH Abstract The crystalline lens of the vertebrate eye grows throughout life. This growth may be enormous in fish, while the lens must be functional from larva to adult. During growth, the fiber cells of the lens must increase the concentration of specific proteins (crystallins) in the cytoplasm to increase refractive index. However, the bulk of the fiber cells in a vertebrate lens are denucleated and have no organelles to synthesize proteins. To study how this problem is solved, we first measured lens fiber cell thickness in the Nile tilapia, a teleost fish. In the lenses from 25 fish, in two size groups, fibers...
Source: Vision Research - July 3, 2019 Category: Opthalmology Authors: Kozłowski TM, Kröger RHH Tags: Vision Res Source Type: research

The association between L:M cone ratio, cone opsin genes and myopia susceptibility.
Abstract In syndromic forms of myopia caused by long (L) to middle (M) wavelength (L/M) interchange mutations, erroneous contrast signals from ON-bipolar cells activated by cones with different levels of opsin expression, are suggested to make the eye susceptible to increased growth. This susceptibility is modulated by the L:M cone ratio. Here, we examined L and M opsin genes, L:M cone ratios and their association with common refractive errors in a population with low myopia prevalence. Cycloplegic autorefraction and ocular biometry were obtained for Norwegian genetically-confirmed normal trichromats. L:M cone rat...
Source: Vision Research - June 26, 2019 Category: Opthalmology Authors: Hagen LA, Arnegard S, Kuchenbecker JA, Gilson SJ, Neitz M, Neitz J, Baraas RC Tags: Vision Res Source Type: research

Eye movements in man and other animals.
Abstract Good vision requires a near stationary image if motion blur is to be avoided. All animals with good eyesight (principally the vertebrates, arthropods and cephalopod molluscs) have adopted a very similar strategy for achieving this: fixations in which gaze is kept still, with saccades to change gaze direction as fast as possible. In all these groups the stability of fixations is maintained by reflexes that oppose the effects of head or body movement (the vestibulo-ocular reflex in vertebrates), and that oppose drift of the image on the retina (optokinetic and optomotor reflexes). A small number of species ...
Source: Vision Research - June 26, 2019 Category: Opthalmology Authors: Land M Tags: Vision Res Source Type: research

Visual search for complex objects: Set-size effects for faces, words and cars.
JJ Abstract To comparing visual processing for different object types, we developed visual search tests that generated accuracy and response time parameters, including an object set-size effect that indexes perceptual processing load. Our goal was to compare visual search for two expert object types, faces and visual words, as well as a less expert type, cars. We first asked if faces and words showed greater inversion effects in search. Second, we determined whether search with upright stimuli correlated with other perceptual indices. Last we assessed for correlations between tests within a single orientation, an...
Source: Vision Research - June 21, 2019 Category: Opthalmology Authors: Hemström J, Albonico A, Djouab S, Barton JJ Tags: Vision Res Source Type: research

Effect of high-order aberrations on pattern-reversal visual evoked potentials.
Abstract To investigate the effect of high-order aberrations (HOAs) on pattern-reversal visual evoked potentials (PR-VEPs), we measured PR-VEPs with HOAs either retained or corrected with an adaptive optics (AO) system for 12 subjects. The PR-VEPs at different spatial frequencies were recorded for the dominant eye of each subject. The results indicated that the amplitude of the first positive P1 wave at 1 to 16 cpd (except 2 cpd) and the second negative N2 wave at 12 and 16 cpd were raised statistically significantly with HOA correction. This confirmed the contributions of the HOAs to the alterations in PR-VEPs, a...
Source: Vision Research - June 14, 2019 Category: Opthalmology Authors: Yang YR, Zhao JL, Xiao F, Zhao HX, Dai Y Tags: Vision Res Source Type: research

The impact of retinal motion on stereoacuity for physical targets.
Abstract In a series of studies using physical targets, we examined the effect of lateral retinal motion on stereoscopic depth discrimination thresholds. We briefly presented thin vertical lines, along with a fixation marker, at speeds ranging from 0 to 16 deg·s-1. Previous investigations of the effect of retinal motion on stereoacuity consistently show that there is little impact of retinal motion up to 2 deg·s-1, however, thresholds appear to rise steeply at higher velocities (greater than 3 deg·s-1). These prior experiments used computerized displays to generate their stimuli. In contrast, ...
Source: Vision Research - June 13, 2019 Category: Opthalmology Authors: Cutone MD, Allison RS, Wilcox LM Tags: Vision Res Source Type: research

Face perception: A brief journey through recent discoveries and current directions.
Abstract Faces are a rich source of information about the people around us. Identity, state of mind, emotions, intentions, age, gender, ethnic background, attractiveness and a host of other attributes about an individual can be gleaned from a face. When face perception fails, dramatic psycho-social consequences can follow at the individual level, as in the case of prosopagnosic parents who are unable to recognize their children at school pick-up. At the species level, social interaction patterns are shaped by human face perception abilities. The computational feat of recognizing faces and facial attributes, and th...
Source: Vision Research - June 12, 2019 Category: Opthalmology Authors: Oruc I, Balas B, Landy MS Tags: Vision Res Source Type: research

Visual Factors in Reading: Editorial.
PMID: 31194983 [PubMed - as supplied by publisher] (Source: Vision Research)
Source: Vision Research - June 10, 2019 Category: Opthalmology Authors: Chung S Tags: Vision Res Source Type: research

Ocular dominance plasticity: a binocular combination task finds no cumulative effect with repeated patching.
Abstract 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. This shift has been measured with various visual tasks, including binocular rivalry and binocular combination. We investigated whether the ocular dominance shift could be accumulated across multiple periods of monocular deprivation over consecutive days. We used a binocular phase combination task to measure the shift in eye dominance. We patched th...
Source: Vision Research - June 10, 2019 Category: Opthalmology Authors: Min SH, Baldwin AS, Hess RF Tags: Vision Res Source Type: research

Introduction to the special issue on face perception: Experience, models, and neural mechanisms.
il; I PMID: 31173774 [PubMed - as supplied by publisher] (Source: Vision Research)
Source: Vision Research - June 4, 2019 Category: Opthalmology Authors: Oruç I Tags: Vision Res Source Type: research

Disrupting uniformity: Feature contrasts that reduce crowding interfere with peripheral word recognition.
Abstract Peripheral word recognition is impaired by crowding, the harmful influence of surrounding objects (flankers) on target identification. Crowding is usually weaker when the target and the flankers differ (for example in color). Here, we investigated whether reducing crowding at syllable boundaries improved peripheral word recognition. In Experiment 1, a target letter was flanked by single letters to the left and right and presented at 8° in the lower visual field. Target and flankers were either the same or different in regard to color, luminance, and/or contrast polarity. Crowding was reduced when the ...
Source: Vision Research - May 23, 2019 Category: Opthalmology Authors: Rummens K, Sayim B Tags: Vision Res Source Type: research

Nonlinearities in the flicker electroretinogram: a tool for studying retinal dysfunction applied to early-stage diabetic retinopathy.
This study describes an approach to analyze the harmonic components of the flicker ERG and its application to patients who have early-stage non-proliferative diabetic retinopathy (NPDR). Of particular interest were the sub-harmonic components occurring at 1.5x and 2.5x the stimulus frequency that produce cycle-to-cycle variation in amplitude termed "period doubling." Twenty visually-normal subjects, 20 diabetic subjects who have no clinically-apparent retinopathy (NDR), and 20 diabetic subjects who have mild NPDR participated. ERGs were recorded in response to sinusoidal flicker (27 to 63 Hz) and Fourier analysis...
Source: Vision Research - May 23, 2019 Category: Opthalmology Authors: Jason McAnany J, Chen YF, Liu K, Park JC Tags: Vision Res Source Type: research