Fixation Location Research Articles

Visual attention during seeing for speaking in healthy aging.

As we age, we accumulate a wealth of information about the surrounding world. Evidence from visual search suggests that older adults retain intact knowledge for where objects tend to occur in everyday environments (semantic information) that allows them to successfully locate objects in scenes, but may overrely on semantic guidance. We investigated age differences in the allocation of attention to semantically informative and visually salient information in a task in which the eye movements of younger (N = 30, aged 18-24) and older (N = 30, aged 66-82) adults were tracked as they described real-world scenes. We measured the semantic information in scenes based on "meaning map" ratings from a norming sample of young and older adults, and image salience as graph-based visual saliency. Logistic mixed-effects modeling was used to determine whether, controlling for center bias, fixated scene locations differed in semantic informativeness and visual salience from locations that were not fixated, and whether these effects differed for young and older adults. Semantic informativeness predicted fixated locations well overall, as did image salience, although unique variance in the model was better explained by semantic informativeness than image salience. Older adults were less likely to fixate informative locations in scenes than young adults were, though the locations older adults' fixated were independently predicted well by informativeness. These results suggest young and older adults both use semantic information to guide attention in scenes and that older adults do not overrely on semantic information across the board. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Stimulus size modulates idiosyncratic neural face identity discrimination.

Humans show individual differences in neural facial identity discrimination (FID) responses across viewing positions. Critically, these variations have been shown to be reliable over time and to directly relate to observers' idiosyncratic preferences in facial information sampling. This functional signature in facial identity processing might relate to observer-specific diagnostic information processing. Although these individual differences are a valuable source of information for interpreting data, they can also be difficult to isolate when it is not possible to test many conditions. To address this potential issue, we explored whether reducing stimulus size would help decrease these interindividual variations in neural FID. We manipulated the size of face stimuli (covering 3°, 5°, 6.7°, 8.5°, and 12° of visual angle), as well as the fixation location (left eye, right eye, below the nasion, nose, and mouth) while recording electrophysiological responses. Same identity faces were presented with a base frequency of 6Hz. Different identity faces were periodically inserted within this sequence to trigger an objective index of neural FID. Our data show robust and consistent individual differences in neural face identity discrimination across viewing positions for all face sizes. Nevertheless, FID was optimal for a larger number of observers when faces subtended 6.7° of visual angle and fixation was below the nasion. This condition is the most suited to reduce natural interindividual variations in neural FID patterns, defining an important benchmark to measure neural FID when it is not possible to assess and control for observers' idiosyncrasies.

A Landmark-Based Technique for Determining an Isometric Femoral Attachment Site for Lateral Extraarticular Tenodesis is Inaccurate

To evaluate the reliability and accuracy of a method of placing the femoral fixation location for lateral extra-articular tenodesis (LET) within a safe isometric area using anatomic landmarks. Using a pilot cadaveric specimen, the center of the radiographic safe isometric area for femoral fixation of LET, defined as a 1 cm (proximal-distal) area located proximal to the metaphyseal flare and posterior to the posterior cortical extension line (PCEL), was located using fluoroscopy and found to be 20 mm directly proximal to the center of the fibular collateral ligament (FCL) origin. Using 10 additional specimens, the center of the FCL origin and a location 20 mm directly proximal was identified. K-wires were placed at each location. A lateral radiograph was obtained, and distances of the proximal K-wire relative to the PCEL and metaphyseal flare were measured. The location of the proximal K-wire relative to the radiographic safe isometric area was assessed by 2 independent observers. Intrarater and inter-rater reliability was calculated for all measurements using intraclass coefficients (ICCs). There was excellent intrarater and inter-rater reliability for all radiographic measurements (.908 to .975 and .968 to .988, respectively). In 5/10 specimens, the proximal K-wire was outside of the radiographic safe isometric area, with 4/5 anterior to the PCEL. Overall, the mean distance from the PCEL was 1 mm ± 4 mm (anterior), and the mean distance from the metaphyseal flare was 7.4 mm ± 2.9 mm (proximal). A landmark-based technique referencing the FCL origin was inaccurate in the placement of femoral fixation within a radiographic safe isometric area for LET. Therefore intraoperative imaging should be considered to ensure accurate placement. These findings may help to decrease the likelihood of misplacement of femoral fixation during LET by showing that landmark-based methods without intraoperative image guidance may be unreliable.

Experienced nursery teachers gaze longer at children during play than do novice teachers: an eye-tracking study

Despite the widespread recognition of the significance of outdoor play in early childhood development, centers for early childhood education (ECE) face the challenge of striking a balance between active play activities and safety concerns. Thus, the visual attention of teachers is critical. Studies that compare the visual attention of novice and experienced teachers traditionally focus on instructional settings instead of recreational play. This study examines the effect of experience on the attentional focus of teachers on children’s play in ECE settings in Japan. Eye-tracking data were collected from 10 novices and 10 relatively experienced ECE staff members to compare fixation location, number of fixation, and fixation duration while groups of 3-year-old children played in a sandbox. The results of the independent sample t tests revealed that experienced teachers gazed at the children more frequently than did novice teachers; however, the mean fixation duration was significantly shorter among relatively experienced teachers across all participants. Similarly, although experienced teachers spent more time overall than did novice teachers in observing the children and peripheral areas of the play area as they played, the mean fixation duration was significantly shorter than that of novice teachers. The findings support other studies that highlight the heightened ability of experienced teachers to assess conditions more quickly and draw conclusions regarding the activities of children. In addition, the findings support research that reports that the level of supervision and control imposed by ECE teachers on children’s play and safety are closely related to their level of experience.

Evaluation of long-term performance of an intraperitoneal biomaterial in the treatment of ventral hernias

BackgroundOne-year device safety and clinical outcomes of ventral hernia repair with the GORE® SYNECOR Intraperitoneal Biomaterial, a hybrid composite mesh was evaluated.MethodsThis retrospective, multicenter, case review analyzed device/procedure endpoints and patient-reported outcomes in patients treated for hernia repair ≥ 1 year from study enrollment.ResultsIncluded were 459 patients (with 469 ventral hernias) with a mean age of 58 ± 15 years; 77.1% met Ventral Hernia Working Group 2 (VHWG2) classification. Mean hernia size was 18.9 cm2 and 57.3% of hernias were incisional. Laparoscopic or robotic approach was utilized in 95.4% of patients. Mesh location was intraperitoneal for 75.6% and bridging repair was performed in 57.3%. Procedure-related adverse events within 30-days occurred in 5.0% of patients and included surgical site infection (SSI), surgical site occurrence (SSO), ileus, readmission, and re-operation. Procedure-related SSI or SSO events were 3.8% through 12 months. SSO events requiring procedural intervention (SSOPI) were 2.6% through 24 months. Four patients (0.9%) had confirmed hernia recurrence through the study (the mean follow-up was 32-months, range 14–53 months). Subgroup comparisons were conducted for all type recurrence; only diabetes was found to be statistically significant (p = .0506).ConclusionIn this analysis, ventral hernia repair with hybrid, composite mesh results in successful outcomes in most patients. This study represents a heterogeneous patient population undergoing repair using various approaches, mesh fixation, and mesh placement locations. These data appear to confirm long-term acceptable safety and device performance with a low rate of recurrence in a predominantly VHWG2 population.

Right-dominant contextual cueing for global configuration cues, but not local position cues

Contextual cueing can depend on global configuration or local item position. We investigated the role of these two kinds of cues in the lateralization of contextual cueing effects. Cueing by item position was tested by recombining two previously learned displays, keeping the individual item locations intact, but destroying the global configuration. In contrast, cueing by configuration was investigated by rotating learned displays, thereby keeping the configuration intact but changing all item positions. We observed faster search for targets in the left display half, both for repeated and new displays, along with more first fixation locations on the left. Both position and configuration cues led to faster search, but the search time reduction compared to new displays due to position cues was comparable in the left and right display half. In contrast, configural cues led to increased search time reduction for right half targets. We conclude that only configural cues enabled memory-guided search for targets across the whole search display, whereas position cueing guided search only to targets in the vicinity of the fixation. The right-biased configural cueing effect is a consequence of the initial leftward search bias and does not indicate hemispheric dominance for configural cueing.

Individual differences in the tuning of the face adaptation aftereffect to the preferred fixation location on the face

Individual differences in the tuning of the face adaptation aftereffect to the preferred fixation location on the face

Look twice: A generalist computational model predicts return fixations across tasks and species.

Primates constantly explore their surroundings via saccadic eye movements that bring different parts of an image into high resolution. In addition to exploring new regions in the visual field, primates also make frequent return fixations, revisiting previously foveated locations. We systematically studied a total of 44,328 return fixations out of 217,440 fixations. Return fixations were ubiquitous across different behavioral tasks, in monkeys and humans, both when subjects viewed static images and when subjects performed natural behaviors. Return fixations locations were consistent across subjects, tended to occur within short temporal offsets, and typically followed a 180-degree turn in saccadic direction. To understand the origin of return fixations, we propose a proof-of-principle, biologically-inspired and image-computable neural network model. The model combines five key modules: an image feature extractor, bottom-up saliency cues, task-relevant visual features, finite inhibition-of-return, and saccade size constraints. Even though there are no free parameters that are fine-tuned for each specific task, species, or condition, the model produces fixation sequences resembling the universal properties of return fixations. These results provide initial steps towards a mechanistic understanding of the trade-off between rapid foveal recognition and the need to scrutinize previous fixation locations.

Drivers’ Eye Movement Characteristics in a Combined Bridge-Tunnel Scenario on a Mountainous Urban Expressway: A Realistic Study

Combined bridge-tunnel scenarios of driving on mountainous city expressways occur when bridges and tunnels frequently alternate during driving. The complex nature of these driving scenarios imposes crucial requirements on the drivers’ eye movement characteristics. This paper attempts to clarify these characteristics using descriptive statistics and the box graph method, registering the pupil diameter, blink duration, fixation, saccades, and fixation loci at different tunnel locations, bridges, and ramps. Realistic driving experiments were performed on the road segment spanning from the Nanchang tunnel to the Liujiatai tunnel freeway in Chongqing, China. Eye movement data were collected for 21 drivers. The experimental results showed that, while driving in the tunnel, the maximal pupil diameter of the participating drivers was approximately 4.0 mm as the driving mileage and the number of tunnels increased, and the maximal visual load on the drivers in the tunnel tended to be stable. At the second tunnel exit, the ramp, the middle section of the first bridge, and the third tunnel exit, the driving load was the highest, while the fixation duration was shorter for nighttime driving. The fixation duration was the longest for the diversion road of bridge B1 to the ramp during the day, and the fixation times were the longest at the beginning and end of the test road. The drivers more often paid attention to the speed dashboard while entering tunnels during daytime driving (compared with nighttime driving).

Gaze Fixation and Visual Searching Behaviors during an Immersive Virtual Reality Social Skills Training Experience for Children and Youth with Autism Spectrum Disorder: A Pilot Study.

Children and youth with Autism Spectrum Disorder (ASD) display difficulties recognizing and interacting with behavioral expressions of emotion, a deficit that makes social interaction problematic. Social skills training is foundational to the treatment of ASD, yet this intervention is costly, time-consuming, lacks objectivity, and is difficult to deliver in real-world settings. This pilot project investigated the use of an immersive virtual reality (IVR) headset to simulate real-world social interactions for children/youth with ASD. The primary objective was to describe gaze fixation and visual search behaviors during the simulated activity. Ten participants were enrolled and completed one social-skills training session in the IVR. The results demonstrate differential patterns between participants with mild, moderate, and severe ASD in the location and duration of gaze fixation as well as the patterns of visual searching. Although the results are preliminary, these differences may shed light on phenotypes within the continuum of ASD. Additionally, there may be value in quantifying gaze and visual search behaviors as an objective metric of interventional effectiveness for social-skills training therapy.

Layperson Bias and Empathy Influence Visual Attention Toward Patients with Hemifacial Microsomia: A Prospective Eye-tracking Study

INTRODUCTION: Facial attractiveness influences our perceptions of others, with beautiful faces reaping societal rewards and anomalous faces encountering penalties. Previous work with functional magnetic resonance imaging (fMRI) has demonstrate implication of certain neuroanatomic structures in visual pathways when viewing others with facial anomalies. For example, laypersons with high levels of implicit bias toward those with facial anomalies demonstrated increased amygdala reactivity. This study aimed to characterize associations between visual attention patterns and implicit biases (attitudes toward groups of people without conscious awareness), explicit biases (attitudes toward groups of people with conscious awareness), and social dispositions toward people with facial anomalies. METHODS: Participants completed an implicit bias association test (IAT), an explicit bias questionnaire (EBQ), and several social disposition tests (e.g. empathic concern and perspective taking) prior to viewing publicly available images of pre- and postoperative patients with hemifacial microsomia (HFM). Eye-tracking was used to register visual fixations. Four areas of interest (AOIs) were defined on each face: cheek and ear, forehead and orbit, mandible and chin, and nose and lips. Linear mixed effects models (LMEMs) in R Studio tested whether locations of participant fixations were affected by surgical correction of HFM and influenced by IAT, EBQ, or social disposition scores. RESULTS: Sixty participants (38 women) were prospectively enrolled. LMEMs revealed participants with higher IAT scores fixated significantly less on the cheek and ear region preoperatively compared to postoperatively (β = 0.115, SE = 0.040, z = 2.855, p = 0.004). Participants with higher scores on empathic concern fixated more on the forehead and orbit preoperatively compared to postoperatively (β = -0.107, SE = 0.053, z = -2.007, p = 0.045) and participants with higher scores in perspective taking fixated more on the nose and lips (β = -0.085, SE = 0.038, z = -2.215, p = 0.027) preoperatively compared to postoperatively. EBQ scores and other social disposition scores did not significantly influence visual fixations in any AOIs based on better fit to the null models. CONCLUSION: Levels of biases, empathic concern, and other social dispositions may influence visual attention toward people with facial anomalies. Those with higher levels of implicit bias may avoid looking at anomalous anatomy, while those with higher levels of empathic concern and perspective taking do not show similar avoidance behaviors. These findings may have neural underpinnings with amygdala reactivity modulating visual activity in response to facial anomalies. This study has implications for the experience of patients with craniofacial anomalies and for characterizing neurologic mechanisms of the ‘beauty-is-good’ and ‘anomalous-is-bad’ biases.

A meta-analysis on the effect of visual attention on choice.

Decision makers attend more to preferred choice options and to the ultimately chosen option, but does visual attention influence preferences and choice? Several theories suggest that attention has a causal effect on preferences and choice and a growing number of studies have examined the question with experimental methods. However, the evidence for an effect of attention on choice is mixed and highly contended. To advance the debate on the role of attention in decision making, we meta-analyze studies that manipulate attention-to-choice options and measure the effect on 2-alternative preferential choices. We identify 3 different methods for manipulating attention and find that studies manipulating total exposure time enhance choices the most, P = .541, 95% CI [.523, .560], p < .001, followed by studies controlling the location of the last fixation, P = .532, 95% CI [.518, .547], p < .001. Studies manipulating the location of the first fixation do not differ from chance level choice proportions, P = .507, 95% CI [0.497, 0.516], p = .18. The PET-PEESE analysis suggests a small degree of publication bias which results in a slight reduction of effect sizes. A meta-regression with absolute attention difference as predictor confirms the robustness of the findings. Our findings show the relevance of assuming an effect of attention on choice, but also indicate a need for further model development to account for the complete pattern of attention effects. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

80.3 The Behavioral Health Avatar for Automatic Nonverbal Behavioral Analysis for Personalizing Treatment of Bipolar Disorder

Improving diagnostic accuracy of bipolar spectrum disorder (BSD) is clearly indicated to better inform treatment decisions. This proof-of-concept study aims to advance and improve treatment options for youth with BSD. This innovative proposal introduces the Behavioral Health AVATAR (BHA), which is an embodied conversational agent (ECA) that conducts natural and noncontact diagnostic interviews. During the interview, the BHA measures pupil dilation, eye fixation location, facial expression, body rigidity, vocal acoustics, and linguistic content.

Are predictive saccades linked to the processing of peripheral information?

High-level athletes can predict the actions of an opposing player. Interestingly, such predictions are also reflected by the athlete’s gaze behavior. In cricket, for example, players first pursue the ball with their eyes before they very often initiate two predictive saccades: one to the predicted ball-bounce point and a second to the predicted ball-bat-contact point. That means, they move their eyes ahead of the ball and “wait” for the ball at the new fixation location, potentially using their peripheral vision to update information about the ball’s trajectory. In this study, we investigated whether predictive saccades are linked to the processing of information in peripheral vision and if predictive saccades are superior to continuously following the ball with foveal vision using smooth-pursuit eye-movements (SPEMs). In the first two experiments, we evoked the typical eye-movements observed in cricket and showed that the information gathered during SPEMs is sufficient to predict when the moving object will hit the target location and that (additional) peripheral monitoring of the object does not help to improve performance. In a third experiment, we show that it could actually be beneficial to use SPEMs rather than predictive saccades to improve performance. Thus, predictive saccades ahead of a target are unlikely to be performed to enhance the peripheral monitoring of target.

Effects of visual span on Chinese reading performance in normal peripheral vision

The current study examined the relationships among temporal processing speed, spatial visual span and Chinese character reading speed in normal central and peripheral vision. Maximum reading speed (MRS) and critical print size (CPS) of 26 native Chinese readers (13 young and 13 older adults) were determined at three visual field locations: central vision, 10° left and 10° below fixation using a rapid serial visual presentation (RSVP) task. Temporal processing speed was measured using trigrams of randomly selected Chinese characters presented at a range of exposure durations, while spatial visual span was measured using trigrams presented at different spatial positions. It was found that shorter temporal processing speed and larger spatial visual span were associated with faster MRS at the central and inferior visual field locations, but not at the left of fixation location. As expected, reading and visual span metrics were better in central vision compared to both peripheral locations. In addition, reading, temporal processing, and spatial visual span metrics were better in the young than older subjects (except for similar temporal processing speed at two peripheral locations). The results for central and inferior presentation locations support the hypothesis that temporal processing speed and spatial visual span were associated with Chinese character reading speed. Surprisingly, no correlation was observed for the 10° left of the fixation location, suggesting that the factors affecting reading speed might differ for inferior and lateral peripheral viewing locations.

Assessment of photoreceptor function with ultrafast retinal densitometry.

The optical density of visual pigment can be measured by imaging the dark-adapted eye while bleaching with visible light. This measurement can be made for individual photoreceptor cells using adaptive optics; however, activation of the phototransduction cascade imparts rapid changes in phase that modulate the signal via optical interference. This limits utility because data must be averaged over many experimental runs. Here we used a "flood" illuminated adaptive optics system at 4000 fps, bright light to achieve rapid bleaching, and broad illumination bandwidth to mitigate interference effects. Data were super-resolved using the natural motion of the eye to overcome the reduced pixel resolution of the ultrafast camera. This approach was applied to classify the trichromatic cone photoreceptor mosaic at a single fixation locus within the foveal region of 3 healthy subjects. Subjects were dark adapted for 6 minutes to replenish cone photopigment. This was followed either directly by imaging at 555 ± 50 nm, or by first pre-adapting the retina to 700 nm light to preferentially deplete "L" cone pigment. A total of 3,252 cones were classified as either "S", "M", or "L" type based on clustering of the intensity data observed under these two conditions. Mean classification probability ranged from 99.3 to 99.8%, with individual cell probabilities exceeding 95% in 97.0 to 99.2% of cones. Accuracy of cone classification peaked when using the first 10-30 ms of data, with significant reductions in accuracy noted with the inclusion of data from later times. Our results show that rapid bleaching and data acquisition significantly improve the robustness of cell-resolved densitometry.

The Alleviation of Perceptual Blindness During Driving in Urban Areas Guided by Saccades Recommendation

In advanced industrial applications, computational visual attention models (CVAMs) could predict visual attention very similarly to actual human attention allocation. This has been used as a very important component of technology in advanced driver assistance systems (ADAS). Given that the biological inspiration of the driving-related CVAMs could be obtained from skilled drivers in complex driving conditions, in which the driver’s attention is constantly directed at various salient and informative visual stimuli by alternating the eye fixations via saccades to drive safely, this paper proposes a saccade recommendation strategy to enhance the driving safety under urban road environment, particularly when the driver’s vision is often impaired by the visual crowding. The altered and directed saccades are collected and optimized by extracting four innate features from human dynamic vision. A neural network isdesigned to classify preferable saccades to reduce perceptual blindness due to visual crowding under urban scenes. A state-of-the-art CVAM is firstly adopted to localize the predicted eye fixation locations (EFLs) in driving video clips. Besides, human subjects’ gaze at the recommended EFLs is measured via an eye-tracker. The time delays between the predicted EFLs and drivers’ EFLs are analyzed under different driving conditions, followed by the time delays between the predicted EFLs and the driver’s hand control. The visually safe margin is then measured by mediating the driving speed and the total delay. Experimental results demonstrate that the recommended saccades can effectively reduce the amount of perceptual blindness, which is known to be of help to further improve road driving safety.

Saccades during visual search in macular degeneration

Macular degeneration (MD) compromises both high-acuity vision and eye movements when the foveal regions of both eyes are affected. Individuals with MD adapt to central field loss by adopting a preferred retinal locus (PRL) for fixation. Here, we investigate how individuals with bilateral MD use eye movements to search for targets in a visual scene under realistic binocular viewing conditions. Five individuals with binocular scotomata, 3 individuals with monocular scotomata and 6 age-matched controls participated in our study. We first extensively mapped the binocular scotoma with an eyetracker, while fixation was carefully monitored (Vullings & Verghese, 2020). Participants then completed a visual search task where 0, 1, or 2 Gaussian blobs were distributed randomly across a natural scene. Participants were given 10 s to actively search the display and report the number of blobs. An analysis of saccade characteristics showed that individuals with binocular scotomata made more saccades in the direction of their scotoma than controls for the same directions. Saccades in the direction of the scotoma were typically of small amplitude, and did not fully uncover the region previously hidden by the scotoma. Rather than make more saccades to explore this hidden region, participants frequently made saccades back toward newly uncovered regions. Backward saccades likely serve a similar purpose to regressive saccades exhibited during reading in MD, by inspecting previously covered regions near the direction of gaze. Our analysis suggests that the higher prevalence of backward saccades in individuals with binocular scotomata might be related to the PRL being adjacent to the scotoma.

Transient attention equally reduces visual crowding in radial and tangential axes.

Crowding refers to the failure to identify a peripheral object due to its proximity to other objects (flankers). This phenomenon can lead to reading and object recognition impairments and is associated with macular degeneration, amblyopia, and dyslexia. Crucially, the maximal target–flanker spacing required for the crowding interference (critical spacing) increases with eccentricity. This spacing is also larger when target and flankers appear along the horizontal meridian (radial arrangement) than when the flankers appear above and below the target (tangential arrangement). This phenomenon is known as radial–tangential anisotropy. Previous studies have demonstrated that transient attention can reduce crowding interference; however, it is still unclear whether and how attention interacts with radial–tangential anisotropy. To address this issue, we manipulated transient attention by using a cue at either the target (valid) or the fixation (neutral) location, in both radial and tangential target–flanker arrangements. Results showed that critical spacing was larger in the radial than in the tangential arrangement and that cueing the target location improved performance and reduced the critical spacing for both radial and tangential arrangements to the same extent. Together, our findings suggest that transient spatial attention plays an essential role in crowding but not in radial–tangential anisotropy.

Scene inversion reveals distinct patterns of attention to semantically interpreted and uninterpreted features

Semantic guidance theories propose that attention in real-world scenes is strongly associated with semantically informative scene regions. That is, we look where there are recognizable and informative objects that help us make sense of our visual environment. In contrast, image guidance theories propose that local differences in semantically uninterpreted image features such as luminance, color, and edge orientation primarily determine where we look in scenes. While it is clear that both semantic guidance and image guidance play a role in where we look in scenes, the degree of their relative contributions and how they interact with each other remains poorly understood. In the current study, we presented real-world scenes in upright and inverted orientations and used general linear mixed effects models to understand how semantic guidance, image guidance, and observer center bias were associated with fixation location and fixation duration. We observed distinct patterns of change under inversion. Semantic guidance was severely disrupted by scene inversion, while image guidance was mildly impaired and observer center bias was enhanced. In addition, we found that fixation durations for semantically rich regions decreased when viewing inverted scenes relative to upright scene viewing, while fixation durations for image salience and center bias were unaffected by inversion. Together these results provide important new constraints on theories and computational models of attention in real-world scenes.