In binocular combination, light images on the two retinas are combined to form a single “cyclopean” perceptual image, in contrast rivalry which occurs when eyes have incompatible (“rivalrous”) inputs and only one eye`s stimulus is perceived. We propose computational theory for combination with basic principles of interaction: every spatial neighborhood, each eye ( i ) exerts gain control other eye's signal proportion energy its own input ii additionally control. For stimuli ordinary...

Modulation of the steady-state visual evoked potential (SSVEP) by attention was studied in detail using 15 'tag' frequencies range 2.5-20 Hz. The stimuli were two series random disc search arrays superimposed on concentric color-marked annuli respectively. Two updated independently; one at fixed frequency (flicker) and other randomly according to a white noise distribution (random broadband flicker, rbbf). On each trial, observer instructed attend annulus detect target (a triangle) that...

Stereopsis, the perception of depth based on disparity images projected to retinas two eyes, is an important process in our three-dimensional world; however, 3–5% population stereoblind or has seriously impaired stereovision. Here we provide evidence for recovery stereopsis through perceptual learning, repetitive practice a demanding visual task, human adults long deprived normal binocular vision. We used training paradigm that combines monocular cues were correlated perfectly with cues....

We investigated suprathreshold binocular combination in humans with abnormal visual experience early life. In the first experiment we presented two eyes equal but opposite phase shifted sine waves and measured perceived of cyclopean wave. Normal observers have balanced vision between when eyes' images contrast (i.e., both contribute equally to image = 0°). However, strabismus and/or amblyopia, requires a higher nondominant eye (NDE) than dominant (DE). This asymmetry is larger predicted from...

Stereopsis is the rich impression of three-dimensionality, based on binocular disparity—the differences between two retinal images same world. However, a substantial proportion population stereo-deficient, and relies mostly monocular cues to judge relative depth or distance objects in environment. Here we trained adults who were stereo blind stereo-deficient owing strabismus and/or amblyopia natural visuomotor task—a ‘bug squashing’ game—in virtual reality The subjects' task was squash...

Abstract We analyzed models of volume conduction and magnetic field spread to account for aspects spatial structure in electroencephalographic (EEG) magnetoencephalographic (MEG) coherence. The head model consisted three confocal ellipsoids, representing layers (brain, skull, scalp) with different tissue conductivities, while the follows from Biot–Savart law a spherically symmetric medium. Source were constructed based on resonance imaging data subjects, approximating neocortical current...

We investigated suprathreshold binocular combination, measuring both the perceived phase and contrast of a cyclopean sine wave. used paradigm adapted from Ding Sperling (2006, 2007) to measure by indicating apparent location (phase) dark trough in horizontal wave relative black reference line, we same stimuli matching combined standard presented one eye. found that under normal viewing conditions (high long stimulus duration), is constant, independent interocular ratio difference, while...

Abstract Purpose Humans with amblyopia have an asymmetry in binocular vision: neural signals from the amblyopic eye are suppressed cortex by fellow eye. The purpose of this study was to develop new models and methods for rebalancing asymmetric vision manipulating contrast luminance two eyes. Methods We measured perceived phase a cyclopean sinewave asking normal observers indicate apparent location (phase) dark trough horizontal sine wave relative black reference line, used same stimuli...

The present study showed that anodal and cathodal transcranial direct current stimulation (tDCS) can respectively increase decrease the amplitude of visually evoked field potentials in stimulated visual cortex cats, with effect lasting for ∼60-70 min. We directly measured tDCS-induced changes concentration inhibitory excitatory neurotransmitters using enzyme-linked immunosorbent assay method tDCS selectively GABA glutamate cortical area. Anodal inhibit synthesis by suppressing expression...

Although most instances of object recognition during natural viewing occur in the presence saccades, neural correlates objection have almost exclusively been examined fixation. Recent studies indicated that there are post-saccadic modulations activity immediately following eye movement landing; however, whether affect relatively late occurring cognitive components such as P3 has not explored. The conventionally measured at fixation is commonly used brain computer interfaces, hence...

We develop and test a new two-dimensional model for binocular combination of the two eyes' luminance profiles. For first-order stimuli, assumes that one eye's profile first goes through compressor, receives gain-control gain-enhancement from other eye, then linearly combines output profile. second-order rectification is added in signal path before site. Both total contrast energies, weighted sums over both space spatial-frequency domains, were used interocular gain-control, while only energy...

When two sine waves that differ slightly in orientation are presented to the eyes separately, a single cyclopean wave is perceived. However, it unclear how brain calculates its orientation. Here, we used signal detection rating method estimate perceived when were with Gabor patches differed both and contrast. We found nearly linear combination of targets had same binocular percept shifted away from prediction towards higher contrast, depending on base contrast ratio. stimuli combined into...

The effects of signal and noise on contrast discrimination are difficult to separate because a singularity in the signal-detection-theory model two-alternative forced-choice (Katkov, Tsodyks, & Sagi, 2006). In this article, we show that it is possible eliminate by combining with binocular combination fit monocular, dichoptic, discrimination. We performed three experiments using identical stimuli measure perceived phase, contrast, cyclopean sine wave. absence fixation point, found advantage...

The purpose of this study was (1) to implement a test for binocular imbalance in Virtual Reality headset, (2) assess its testability, reliability and outcomes population clinical patients (3) evaluate the relationships interocular acuity difference, stereoacuity amblyogenic risk factors. 100 volunteers (6 70 years old, mean 21.2 ± 16.2), 21 with no factors 79 amblyopia or history participated. Participants were classified by factor (24 anisometropic, 25 strabismic 30 mixed) and, those...

Background.Individual measures and previous composite of subclinical vascular disease defined high risk for cardiovascular events, but did not detect low modest risk. A different approach might better describe the spectrum from to

Abnormal early visual development can result in a constellation of neural and deficits collectively known as amblyopia. Among the many deficits, common finding is that both saccadic manual reaction times to targets presented amblyopic eye are substantially delayed when compared fellow or normal eyes. Given well-known contrast sensitivity eye, natural question whether prolonged simply consequence reduced stimulus visibility. To address this question, Experiment 1 we measure (RT) perifoveal...

Previous studies indicate that top-down influence plays a critical role in visual information processing and perceptual detection. However, the substrate carries remains poorly understood. Using combined technique of retrograde neuronal tracing immunofluorescent double labeling, we characterized distribution cell type feedback neurons cat’s high-level cortical areas send direct connections to primary cortex (V1: area 17). Our results showed: (1) 21a at ventral stream PMLS dorsal have similar...

Augmented reality (AR) devices seek to create compelling visual experiences that merge virtual imagery with the natural world. These often rely on wearable near-eye display systems can optically overlay digital images left and right eyes of user separately. Ideally, two should be shown minimal radiometric differences (e.g., same overall luminance, contrast, color in both eyes), but achieving this binocular equality challenging stringent demands weight size. Basic vision research has a...

To explore the relative contributions of higher-order and primary visual cortex (V1) to perception, we compared cats' behavioral V1 neuronal contrast sensitivity functions (CSF) threshold versus external noise (TvC) before after top-down influence area 7 (A7) was modulated with transcranial direct current stimulation (tDCS). We found that suppressing A7 cathode-tDCS, but not sham-tDCS, reduced in same range spatial frequencies increased thresholds levels. The CSF TvC were highly correlated...

Abstract Luminance and contrast are two major attributes of objects in the visual scene. information received by neurons often updated simultaneously. We examined temporal response properties primary cortex (V1) to stimuli whose luminance were simultaneously changed 50 Hz. found that tuning changes precedes V1. For most V1 neurons, onset time was shorter than changes. Most carried early stage, while all both late stage. The suggests cortical processing for is not as slow previously thought.