RESUMEN

Precise perception of three-dimensional (3D) images is crucial for a rewarding experience when using novel displays. However, the capability of the human visual system to perceive binocular disparities varies across the visual field meaning that depth perception might be affected by the two-dimensional (2D) layout of items on the screen. Nevertheless, potential difficulties in perceiving 3D images during free viewing have received only a little attention so far, limiting opportunities to enhance visual effectiveness of information presentation. The aim of this study was to elucidate how the 2D layout of items in 3D images impacts visual search and distribution of maintaining attention based on the analysis of the viewer's gaze. Participants were searching for a target which was projected one plane closer to the viewer compared to distractors on a multi-plane display. The 2D layout of items was manipulated by changing the item distance from the center of the display plane from 2° to 8°. As a result, the targets were identified correctly when the items were displayed close to the center of the display plane, however, the number of errors grew with an increase in distance. Moreover, correct responses were given more often when subjects paid more attention to targets compared to other items on the screen. However, a more balanced distribution of attention over time across all items was characteristic of the incorrectly completed trials. Thus, our results suggest that items should be displayed close to each other in a 2D layout to facilitate precise perception of 3D images and considering distribution of attention maintenance based on eye-tracking might be useful in the objective assessment of user experience for novel displays.

RESUMEN

(1) Background: Saccadic eye movements are rapid eye movements aimed to position the object image on the central retina, ensuring high-resolution data sampling across the visual field. Although saccadic eye movements are studied extensively, different experimental settings applied across different studies have left an open question of whether and how stimulus parameters can affect the saccadic performance. The current study aims to explore the effect of stimulus contrast and spatial position on saccadic eye movement latency, peak velocity and accuracy measurements. (2) Methods: Saccadic eye movement targets of different contrast levels were presented at four different spatial positions. The eye movements were recorded with a Tobii Pro Fusion video-oculograph (250 Hz). (3) Results: The results demonstrate a significant effect of stimulus spatial position on the latency and peak velocity measurements at a medium grey background, 30 cd/m2 (negative and positive stimulus polarity), light grey background, 90 cd/m2 (negative polarity), and black background, 3 cd/m2 (positive polarity). A significant effect of the stimulus spatial position was observed on the accuracy measurements when the saccadic eye movement stimuli were presented on a medium grey background (negative polarity) and on a black background. No significant effect of stimulus contrast was observed on the peak velocity measurements under all conditions. A significant stimulus contrast effect on latency and accuracy was observed only on a light grey background. (4) Conclusions: The best saccadic eye movement performance (lowest latency, highest peak velocity and accuracy measurements) can be observed when the saccades are oriented to the right and left from the central fixation point. Furthermore, when presenting the stimulus on a light grey background, a very low contrast stimuli should be considered carefully.

RESUMEN

New visualization approaches are being actively developed aiming to mitigate the effect of vergence-accommodation conflict in stereoscopic augmented reality; however, high interindividual variability in spatial performance makes it difficult to predict user gain. To address this issue, we investigated the effects of consistent and inconsistent binocular and focus cues on perceptual matching in the stereoscopic environment of augmented reality using a head-mounted display that was driven in multifocal and single focal plane modes. Participants matched the distance of a real object with images projected at three viewing distances, concordant with the display focal planes when driven in the multifocal mode. As a result, consistency of depth cues facilitated faster perceptual judgments on spatial relations. Moreover, the individuals with mild binocular and accommodative disorders benefited from the visualization of information on the focal planes corresponding to image planes more than individuals with normal vision, which was reflected in performance accuracy. Because symptoms and complaints may be absent when the functionality of the sensorimotor system is reduced, the results indicate the need for a detailed assessment of visual functions in research on spatial performance. This study highlights that the development of a visualization system that reduces visual stress and improves user performance should be a priority for the successful implementation of augmented reality displays.

Asunto(s)

Realidad Aumentada , Acomodación Ocular , Señales (Psicología) , Emetropía , Humanos

RESUMEN

This study explores perceptual organisation and shape perception when viewing a tetragon and an additional element (a dot) that is located at varying positions and distances next to the tetragon. The aim of the study is to determine the factors that can alter the interpretation of object configuration and impact whether the presented tetragon is perceived as a diamond or a square. Methods used in this study are a forced-choice task as a subjective measurement and eye tracking as an objective measurement of perceptual processes. Overall, 31 stimuli were presented to the participants: a tetragon in two different sizes with an additional element (a dot) located inside or outside the object at three different positions at three distances. The results indicate significant changes in shape perception, depending on the location of the additional element. The results are complemented with eye movement analysis indicating that as the distance between the elements increases, there is a higher probability of either of the two shape interpretations and the gaze is less likely to be directed to the area between the stimuli. Furthermore, the subjective perception of shape is codetermined by the shape perception when the tetragon is presented without the additional element.