Vision, Volume 1, Issue 3 (September 2017) – 5 articles

Inherited retinal diseases are an extremely diverse group of genetically and phenotypically heterogeneous conditions characterized by variable maturation of retinal development, impairment of photoreceptor cell function and gradual loss of photoreceptor cells and vision. Significant progress has been made over the last two decades in identifying the many genes implicated in inherited retinal diseases and developing novel therapies to address the underlying genetic defects. Approximately one-quarter of exonic mutations related to human inherited diseases are likely to induce aberrant splicing products, providing opportunities for the development of novel therapeutics that target splicing processes. The feasibility of antisense oligomer mediated splice intervention to treat inherited diseases has been demonstrated in vitro, in vivo and in clinical trials. In this review, we will discuss therapeutic approaches to treat inherited retinal disease, including strategies to correct splicing and modify exon selection at the level of pre-mRNA. The challenges of clinical translation of this class of emerging therapeutics will also be discussed. Full article

In two experiments we investigated whether stimuli that elicit automatic orienting of attention (i.e., arrow or averted gaze) could drive apparent motion perception in one of two possible directions, modulating the effect of a low-level property (the orientation of elements along the motion direction). To this end, the competing motion paradigm was used, in which at time 1, a stimulus appears in the center of the display, and at time 2, two other stimuli appear in different spatial locations. Three kinds of stimuli with eight possible orientations were used in separate blocks; (1) a line; (2) an arrow; and, (3) an averted gaze. First, since the three stimuli present in the display at time 2 should be perceived to be located at the same distance (i.e., equidistant), the threshold for perceived equidistance was calculated for each participant and then used as the customized inter-stimulus distance. Participants were asked to press the button corresponding to the direction of the perceived motion. Results show a preference for collinear motion (motions between elements oriented along the motion direction), with a higher percentage of responses for gaze and arrow stimuli. In Experiment 1, a difference between gaze- and arrow-stimuli was observed. Apparent motion was seen towards the collinear position more often for gaze than for arrow when the stimulus was pointing to the vertical directions, while the opposite was true when the stimulus was pointing to the horizontal directions. In Experiment 2, where the lightness contrast between the gaze and the background was reduced, no difference between gaze- and arrow-stimuli emerged. We interpret our results as due to the social and biological value of gaze, which solved a possible ambiguity between gaze direction and the directions conveyed by the figural properties of the contrasted background in Experiment 1. These findings are consistent with the idea that stimuli known to automatically orient visual attention modulate motion perception. Full article

Diabetic retinopathy is a leading complication of diabetes. Death of capillary cells with resulting capillary degeneration is a central feature of this disease. Chronic low-grade inflammation has been linked to the development of retinal capillary degeneration in diabetes. CD40 is an upstream inducer of a broad range of inflammatory responses in the diabetic retina and is required for death of retinal capillary cells. Recent studies uncovered CD40 as a novel inducer of purinergic signaling and identified the CD40-ATP-P2X₇ pathway as having a key role in the induction of inflammation in the diabetic retina and programmed cell death of retinal endothelial cells. Full article

Humans spontaneously follow where others are looking. However, recent investigations suggest such gaze-following behavior during natural interactions occurs relatively infrequently, only in about a third of available instances. Here we investigated if a similar frequency of orienting is also found in laboratory tasks that measure covert attentional orienting using manual responses. To do so, in two experiments, we analyzed responses from a classic gaze cuing task, with arrow cues serving as control stimuli. We reasoned that the proportions of attentional benefits and costs, defined as responses falling outside of 1 standard deviation of the average performance for the neutral condition, would provide a good approximation of individual instances of attentional shifts. We found that although benefits and costs occurred in less than half of trials, benefits emerged on a greater proportion of validly cued relative to invalidly cued trials. This pattern of data held across two different measures of neutral performance, as assessed by Experiments 1 and 2, as well as across the two cue types. These results suggest that similarly to gaze-following in naturalistic settings, covert orienting within the cuing task also appears to occur relatively infrequently. Full article

Binocular rivalry is an important tool for measuring sensory eye dominance—the relative strength of sensory processing in an individual’s left and right eye. By dichoptically presenting images that lack corresponding visual features, one can induce perceptual alternations and measure the relative visibility of each eye’s image. Previous results indicate that observers demonstrate reliable preferences for several image features, and that these biases vary within the visual field. However, evidence about the persistence of these biases is mixed, with some suggesting they affect only the onset (i.e., first second) of rivalry, and others suggesting lasting effects during prolonged viewing. We directly investigated individuals’ rivalry biases for eye and color within the visual field and interestingly found results that mirrored the somewhat contradictory pattern in the literature. Each observer demonstrated idiosyncratic patterns of biases for both color and eye within the visual field, but consistent, prolonged biases only for the eye of presentation (sensory eye dominance, SED). Furthermore, the strength of eye biases predicted one’s performance on a stereoacuity task. This finding supports the idea that binocular rivalry and other binocular visual functions may rely on shared mechanisms, and emphasizes the importance of SED as a measure of binocular vision. Full article