Tracking developmental differences in real-world social attention across adolescence, young adulthood and older adulthood.

Detecting and responding appropriately to social information in one's environment is a vital part of everyday social interactions. Here, we report two preregistered experiments that examine how social attention develops across the lifespan, comparing adolescents (10-19 years old), young (20-40 years old) and older (60-80 years old) adults. In two real-world tasks, participants were immersed in different social interaction situations-a face-to-face conversation and navigating an environment-and their attention to social and non-social content was recorded using eye-tracking glasses. The results revealed that, compared with young adults, adolescents and older adults attended less to social information (that is, the face) during face-to-face conversation, and to people when navigating the real world. Thus, we provide evidence that real-world social attention undergoes age-related change, and these developmental differences might be a key mechanism that influences theory of mind among adolescents and older adults, with potential implications for predicting successful social interactions in daily life.

Visual attention towards food during unplanned purchases - A pilot study using mobile eye tracking technology.

This pilot study aims to investigate the relationships between consumers' weight status, energy density of food and visual attention towards food during unplanned purchase behavior in a real-world environment. After more than a decade of intensive experimental eye tracking research on food perception, this pilot study attempts to link experimental and field research in this area. Shopping trips of participants with different weight status were recorded with mobile eye tracking devices and their unplanned purchase behavior was identified and analyzed. Different eye movement measurements for initial orientation and maintained attention were analyzed. Differences in visual attention caused by energy density of food were found. There was a tendency across all participants to look at low energy density food longer and more often.

A novel eye-tracking paradigm for indexing social avoidance-related behavior in fragile X syndrome.

Fragile X syndrome (FXS) is characterized by hallmark features of gaze avoidance, reduced social approach, and social anxiety. The development of therapeutics to manage these symptoms has been hindered, in part, by the lack of sensitive outcome measures. This study investigated the utility of a novel eye-tracking paradigm for indexing social avoidance-related phenotypes. Adolescent/young adult-aged males with FXS (n = 24) and typical development (n = 23) participated in the study. Participants viewed faces displaying direct or averted gaze and the first fixation duration on the eyes was recorded as an index of initial stimulus registration. Fixation durations did not differ across the direction of gaze conditions in either group, although the control group showed longer initial fixations on the eyes relative to the FXS group. Shorter initial fixation on averted gaze in males with FXS was a robust predictor of the severity of their social avoidance behavior exhibited during a social greeting context, whereas parent-reported social avoidance symptoms were not related to performance in the semi-naturalistic context. This eye-tracking paradigm may represent a promising outcome measure for FXS clinical trials because it provides a quantitative index that closely maps onto core social avoidance phenotypes of FXS, can be completed in less than 20 min, and is suitable for use with individuals with low IQ.

Measuring visual attention to faces with cleft deformity.

BACKGROUND: Limited data are available regarding observers' visual attention to faces with congenital difference. We implemented eye tracking technology to examine this issue, as it pertains particularly to faces with cleft deformity. METHOD: Four hundred three observers assessed 273 clinical images, while their eye movements were unobtrusively tracked using an infrared sensor. Forty-one facial images of the repaired cleft lip, 137 images of other facial conditions, and 95 images of matched controls were assessed. Twenty facial regions of interest ("lookzones") were considered for all images observed. A separate cohort of 720 raters evaluated the images for attractiveness. Observer and image demographic information was collected. Visual fixation counts and durations were computed across all 20 lookzones for all images. The effect of a variety of variables on lookzone fixation was analyzed using factorial ANOVA testing. RESULTS: Cleft-repaired faces were rated as less attractive and drew observers' attention preferentially to the affected upper lip lookzone (p<.001). Images rated as less attractive garnered greater visual attention in the cleft-affected lookzones (p<.001). The eye tracking methodology demonstrated exquisite sensitivity to laterality of cleft deformity (p<.001). Individuals reporting a personal or a family history of facial deformity fixated more on the perioral region of cleft-repaired faces than did naïve observers (p<.001). CONCLUSION: These findings highlight the utility of eye tracking measures for understanding critical variables that influence the visual processing of faces with cleft deformity. The data may provide analytical tools for assessing surgical outcome and direct priority setting during surgeons' conversations with patients.

Applying Eye Tracking to Identify Autism Spectrum Disorder in Children.

Eye tracking (ET) holds potential for the early detection of autism spectrum disorder (ASD). To overcome the difficulties of working with young children, developing a short and informative paradigm is crucial for ET. We investigated the fixation times of 37 ASD and 37 typically developing (TD) children ages 4-6 watching a 10-second video of a female speaking. ASD children showed significant reductions in fixation time at six areas of interest. Furthermore, discriminant analysis revealed fixation times at the mouth and body could significantly discriminate ASD from TD with a classification accuracy of 85.1%, sensitivity of 86.5%, and specificity of 83.8%. Our study suggests that a short video clip may provide enough information to distinguish ASD from TD children.

Multi-method laboratory user evaluation of an actionable clinical performance information system: Implications for usability and patient safety.

INTRODUCTION: Electronic audit and feedback (e-A&F) systems are used worldwide for care quality improvement. They measure health professionals' performance against clinical guidelines, and some systems suggest improvement actions. However, little is known about optimal interface designs for e-A&F, in particular how to present suggested actions for improvement. We developed a novel theory-informed system for primary care (the Performance Improvement plaN GeneratoR; PINGR) that covers the four principal interface components: clinical performance summaries; patient lists; detailed patient-level information; and suggested actions. As far as we are aware, this is the first report of an e-A&F system with all four interface components. OBJECTIVES: (1) Use a combination of quantitative and qualitative methods to evaluate the usability of PINGR with target end-users; (2) refine existing design recommendations for e-A&F systems; (3) determine the implications of these recommendations for patient safety. METHODS: We recruited seven primary care physicians to perform seven tasks with PINGR, during which we measured on-screen behaviour and eye movements. Participants subsequently completed usability questionnaires, and were interviewed in-depth. Data were integrated to: gain a more complete understanding of usability issues; enhance and explain each other's findings; and triangulate results to increase validity. RESULTS: Participants committed a median of 10 errors (range 8-21) when using PINGR's interface, and completed a median of five out of seven tasks (range 4-7). Errors violated six usability heuristics: clear response options; perceptual grouping and data relationships; representational formats; unambiguous description; visually distinct screens for confusable items; and workflow integration. Eye movement analysis revealed the integration of components largely supported effective user workflow, although the modular design of clinical performance summaries unnecessarily increased cognitive load. Interviews and questionnaires revealed PINGR is user-friendly, and that improved information prioritisation could further promote useful user action. CONCLUSIONS: Comparing our results with the wider usability literature we refine a previously published set of interface design recommendations for e-A&F. The implications for patient safety are significant regarding: user engagement; actionability; and information prioritisation. Our results also support adopting multi-method approaches in usability studies to maximise issue discovery and the credibility of findings.

A Screening Tool to Measure Eye Contact Avoidance in Boys with Fragile X Syndrome.

We examined the reliability, validity and factor structure of the Eye Contact Avoidance Scale (ECAS), a new 15-item screening tool designed to measure eye contact avoidance in individuals with fragile X syndrome (FXS). Internal consistency of the scale was acceptable to excellent and convergent validity with the Social Responsiveness Scale, Second Edition (SRS-2) and the Anxiety, Depression, and Mood Scale (ADAMS) was good. Boys with a comorbid ASD diagnosis obtained significantly higher scores on the ECAS compared to boys without ASD, when controlling for communication ability. A confirmatory factor analysis indicated that a two-factor model (avoidance and aversion) provided an excellent fit to the data. The ECAS appears to be a promising reliable and valid tool that could be employed as an outcome measure in future pharmacological/behavioral treatment trials for FXS.

Flipping the stimulus: Effects on scanpath coherence?

In experiments investigating dynamic tasks, it is often useful to examine eye movement scan patterns. We can present trials repeatedly and compute within-subjects/conditions similarity in order to distinguish between signal and noise in gaze data. To avoid obvious repetitions of trials, filler trials must be added to the experimental protocol, resulting in long experiments. Alternatively, trials can be modified to reduce the chances that the participant will notice the repetition, while avoiding significant changes in the scan patterns. In tasks in which the stimuli can be geometrically transformed without any loss of meaning, flipping the stimuli around either of the axes represents a candidate modification. In this study, we examined whether flipping of stimulus object trajectories around the x- and y-axes resulted in comparable scan patterns in a multiple object tracking task. We developed two new strategies for the statistical comparison of similarity between two groups of scan patterns, and then tested those strategies on artificial data. Our results suggest that although the scan patterns in flipped trials differ significantly from those in the original trials, this difference is small (as little as a 13 % increase of overall distance). Therefore, researchers could use geometric transformations to test more complex hypotheses regarding scan pattern coherence while retaining the same duration for experiments.

Social attention in ASD: A review and meta-analysis of eye-tracking studies.

Determining whether social attention is reduced in Autism Spectrum Disorder (ASD) and what factors influence social attention is important to our theoretical understanding of developmental trajectories of ASD and to designing targeted interventions for ASD. This meta-analysis examines data from 38 articles that used eye-tracking methods to compare individuals with ASD and TD controls. In this paper, the impact of eight factors on the size of the effect for the difference in social attention between these two groups are evaluated: age, non-verbal IQ matching, verbal IQ matching, motion, social content, ecological validity, audio input and attention bids. Results show that individuals with ASD spend less time attending to social stimuli than typically developing (TD) controls, with a mean effect size of 0.55. Social attention in ASD was most impacted when stimuli had a high social content (showed more than one person). This meta-analysis provides an opportunity to survey the eye-tracking research on social attention in ASD and to outline potential future research directions, more specifically research of social attention in the context of stimuli with high social content.

The politics of the face-in-the-crowd.

Recent work indicates that the more conservative one is, the faster one is to fixate on negative stimuli, whereas the less conservative one is, the faster one is to fixate on positive stimuli. The present series of experiments used the face-in-the-crowd paradigm to examine whether variability in the efficiency with which positive and negative stimuli are detected underlies such speed differences. Participants searched for a discrepant facial expression (happy or angry) amid a varying number of neutral distractors (Experiments 1 and 4). A combination of response time and eye movement analyses indicated that variability in search efficiency explained speed differences for happy expressions, whereas variability in post-selectional processes explained speed differences for angry expressions. These results appear to be emotionally mediated as search performance did not vary with political temperament when displays were inverted (Experiment 2) or when controlled processing was required for successful task performance (Experiment 3). Taken together, the present results suggest political temperament is at least partially instantiated by attentional biases for emotional material.

Accommodation to uncomfortable patterns.

Grating patterns can cause discomfort and perceptual distortions. Individuals who experience discomfort and are susceptible to these distortions generally show weaker accommodation than those who are less susceptible. We measured the accommodative response to grating patterns known to differ in the discomfort they evoke because of differences in their colour, motion, or spatial frequency. The parameters known to affect discomfort and distortion had no influence on the mean or variance in the accommodative response, even when accommodative demand was manipulated systematically and the accommodative response varied as expected.

The attraction of yellow corn: reduced attentional constraints on coding learned conjunctive relations.

Physiological evidence indicates that different visual features are computed quasi-independently. The subsequent step of binding features, to generate coherent perception, is typically considered a major rate-limiting process, confined to one location at a time and taking 25 ms per item or longer (A. Treisman & S. Gormican, 1988, Feature analysis in early vision: Evidence from search asymmetries, Psychological Review, Vol. 95, pp. 15-48). We examined whether these processing limitations remain once bindings are learned for familiar objects. Participants searched for objects that could appear either in familiar or unfamiliar colors. Objects in familiar colors were detected efficiently at rates consistent with simultaneous binding across multiple stimuli. Processing limitations were evident for objects in unfamiliar colors. The advantage for the learned color for known targets was eliminated when participants searched for geometric shapes carrying the object colors and when the colors fell in local background areas around the shapes. The effect occurred irrespective of whether the nontargets had familiar colors, but was largest when nontargets had incorrect colors. The efficient search for targets in familiar colors held, even when the search was biased to favor objects in unfamiliar colors. The data indicate that learned bindings can be computed with minimal attentional limitations, consistent with the direct activation of learned conjunctive representations in vision.

The flexibility of letter-position flexibility: evidence from eye movements in reading Hebrew.

Hebrew provides an intriguing contrast to European languages. On the one hand, like any European language, it has an alphabetic script. On the other hand, being a Semitic language, it differs in the structure of base words. By monitoring eye movements, we examined the time-course of processing letter transpositions in Hebrew and assessed their impact on reading different types of Hebrew words that differ in their internal structure. We found that letter transposition resulted in dramatic reading costs for words with Semitic word structure, and much smaller costs for non-Semitic words. Moreover, the strongest impact of transposition occurred where root-letter transposition resulted in a pseudo-root, where significant interference emerged already in first fixation duration. Our findings thus suggest that Hebrew readers differentiate between Semitic and non-Semitic forms already at first fixation, at the early phase of word recognition. Moreover, letters are differentially processed across the visual array, given their morphological structure and their contribution to recovering semantic meaning. We conclude that flexibility or rigidity in encoding letter position is determined by cues regarding the internal structure of printed words.

Coordination of word recognition and oculomotor control during reading: the role of implicit lexical decisions.

The coordination of word-recognition and oculomotor processes during reading was evaluated in eye-tracking experiments that examined how word skipping, where a word is not fixated during first-pass reading, is affected by the lexical status of a letter string in the parafovea and ease of recognizing that string. Ease of lexical recognition was manipulated through target-word frequency (Experiment 1) and through repetition priming between prime-target pairs embedded in a sentence (Experiment 2). Using the gaze-contingent boundary technique the target word appeared in the parafovea either with full preview or with transposed-letter (TL) preview. The TL preview strings were nonwords in Experiment 1 (e.g., bilnk created from the target blink), but were words in Experiment 2 (e.g., sacred created from the target scared). Experiment 1 showed greater skipping for high-frequency than low-frequency target words in the full preview condition, but not in the TL preview (nonword) condition. Experiment 2 showed greater skipping for target words that repeated an earlier prime word than for those that did not, with this repetition priming occurring both with preview of the full target and with preview of the target's TL neighbor word. However, time to progress from the word after the target was greater following skips of the TL preview word, whose meaning was anomalous in the sentence context, than following skips of the full preview word whose meaning fit sensibly into the sentence context. Together, the results support the idea that coordination between word-recognition and oculomotor processes occurs at the level of implicit lexical decisions.

Visual assessment of camouflaged targets with different background similarities.

The study investigated the effectiveness of different camouflage designs using a computational image quality index. Camouflaged human targets were presented on a natural landscape and the targets were designed to be similar to the landscape background with different levels of background similarity as estimated by the image index. The targets were presented in front of the observer (central 0 degrees) or at different angles in the left (-7 degrees, -14 degrees, -21 degrees) or right (+7 degrees, +14 degrees, +21 degrees) visual fields. The observer had to detect the target using peripheral vision if the target appeared in the left and right visual fields. The camouflage effectiveness was assessed by detection hit rates, detection times, and subjective ratings on detection confidence and task difficulty. The study showed that the psychophysical measures correlated well with the image similarity index, suggesting a potentially more efficient camouflage effectiveness assessment tool if the relationship between the psychophysical results and the index can be quantified in the future.

Impact of dynamic bottom-up features and top-down control on the visual exploration of moving real-world scenes in hemispatial neglect.

Patients with hemispatial neglect are severely impaired in orienting their attention to contralesional hemispace. Although motion is one of the strongest attentional cues in humans, it is still unknown how neglect patients visually explore their moving real-world environment. We therefore recorded eye movements at bedside in 19 patients with hemispatial neglect following acute right hemisphere stroke, 14 right-brain damaged patients without neglect and 21 healthy control subjects. Videos of naturalistic real-world scenes were presented first in a free viewing condition together with static images, and subsequently in a visual search condition. We analyzed number and amplitude of saccades, fixation durations and horizontal fixation distributions. Novel computational tools allowed us to assess the impact of different scene features (static and dynamic contrast, colour, brightness) on patients' gaze. Independent of the different stimulus conditions, neglect patients showed decreased numbers of fixations in contralesional hemispace (ipsilesional fixation bias) and increased fixation durations in ipsilesional hemispace (disengagement deficit). However, in videos left-hemifield fixations of neglect patients landed on regions with particularly high dynamic contrast. Furthermore, dynamic scenes with few salient objects led to a significant reduction of the pathological ipsilesional fixation bias. In visual search, moving targets in the neglected hemifield were more frequently detected than stationary ones. The top-down influence (search instruction) could neither reduce the ipsilesional fixation bias nor the impact of bottom-up features. Our results provide evidence for a strong impact of dynamic bottom-up features on neglect patients' scanning behaviour. They support the neglect model of an attentional priority map in the brain being imbalanced towards ipsilesional hemispace, which can be counterbalanced by strong contralateral motion cues. Taking into account the lack of top-down control in neglect patients, bottom-up stimulation with moving real-world stimuli may be a promising candidate for future neglect rehabilitation schemes.

Updating the premotor theory: the allocation of attention is not always accompanied by saccade preparation.

There is an ongoing controversy regarding the relationship between covert attention and saccadic eye movements. While there is quite some evidence that the preparation of a saccade is obligatory preceded by a shift of covert attention, the reverse is not clear: Is allocation of attention always accompanied by saccade preparation? Recently, a shifting and maintenance account was proposed suggesting that shifting and maintenance components of covert attention differ in their relation to the oculomotor system. Specifically, it was argued that a shift of covert attention is always accompanied by activation of the oculomotor program, while maintaining covert attention at a location can be accompanied either by activation or suppression of oculomotor program, depending on the probability of executing an eye movement to the attended location. In the present study we tested whether there is such an obligatory coupling between shifting of attention and saccade preparation and how quickly saccade preparation gets suppressed. The results showed that attention shifting was always accompanied by saccade preparation whenever covert attention had to be shifted during visual search, as well as in response to exogenous or endogenous cues. However, for the endogenous cues the saccade program to the attended location was suppressed very soon after the attention shift was completed. The current findings support the shifting and maintenance account and indicate that the premotor theory needs to be updated to include a shifting and maintenance component for the cases in which covert shifts of attention are made without the intention to execute a saccade.

Saccadic abnormalities in frontotemporal dementia.

OBJECTIVE: To characterize saccadic eye movements, as a marker of decision-making processes, in frontotemporal dementia (FTD). METHODS: Saccadometry was performed on a cross-section of patients with FTD, using a portable saccadometer, and results compared to matched control subjects. We used the Linear Approach to Threshold with Ergodic Rate model to generate measures of decision-making speed and incidence of early saccades. Patterns of cortical atrophy were related to decision-making processes using voxel-based morphometry (VBM) analysis. RESULTS: A total of 45 subjects (22 FTD: 10 with behavioral variant FTD and 12 with primary progressive aphasia, and 23 controls) were studied. A measure of decision-making speed, µ, was reduced in FTD, resulting in prolonged saccadic latency, but the incidence of early saccades was increased compared to controls. In addition, performance on an antisaccade task was poor in FTD compared to controls. Decision-making speed and the incidence of early saccades were independently correlated with atrophy of the left frontal eye field, and decision-making speed also correlated with atrophy of the left cingulate eye field. CONCLUSION: Saccades are abnormal in FTD, reflecting reduced decision-making speed, and these abnormalities related to atrophy of the left frontal eye field. In addition, patients with FTD had an increased incidence of early saccades, which may be due to reduced inhibition of primitive responses.

Diagnostic accuracy of eye movements in assessing pedophilia.

INTRODUCTION: Given that recurrent sexual interest in prepubescent children is one of the strongest single predictors for pedosexual offense recidivism, valid and reliable diagnosis of pedophilia is of particular importance. Nevertheless, current assessment methods still fail to fulfill psychometric quality criteria. AIMS: The aim of the study was to evaluate the diagnostic accuracy of eye-movement parameters in regard to pedophilic sexual preferences. METHOD: Eye movements were measured while 22 pedophiles (according to ICD-10 F65.4 diagnosis), 8 non-pedophilic forensic controls, and 52 healthy controls simultaneously viewed the picture of a child and the picture of an adult. Fixation latency was assessed as a parameter for automatic attentional processes and relative fixation time to account for controlled attentional processes. MAIN OUTCOME MEASURES: Receiver operating characteristic (ROC) analyses, which are based on calculated age-preference indices, were carried out to determine the classifier performance. Cross-validation using the leave-one-out method was used to test the validity of classifiers. RESULTS: Pedophiles showed significantly shorter fixation latencies and significantly longer relative fixation times for child stimuli than either of the control groups. Classifier performance analysis revealed an area under the curve (AUC) = 0.902 for fixation latency and an AUC = 0.828 for relative fixation time. The eye-tracking method based on fixation latency discriminated between pedophiles and non-pedophiles with a sensitivity of 86.4% and a specificity of 90.0%. Cross-validation demonstrated good validity of eye-movement parameters. CONCLUSIONS: Despite some methodological limitations, measuring eye movements seems to be a promising approach to assess deviant pedophilic interests. Eye movements, which represent automatic attentional processes, demonstrated high diagnostic accuracy.

Evidence for delayed parafoveal-on-foveal effects from word n+2 in reading.

During reading information is acquired from word(s) beyond the word that is currently looked at. It is still an open question whether such parafoveal information can influence the current viewing of a word, and if so, whether such parafoveal-on-foveal effects are attributable to distributed processing or to mislocated fixations which occur when the eyes are directed at a parafoveal word but land on another word instead. In two display-change experiments, we orthogonally manipulated the preview and target difficulty of word n+2 to investigate the role of mislocated fixations on the previous word n+1. When the eyes left word n, an easy or difficult word n+2 preview was replaced by an easy or difficult n+2 target word. In Experiment 1, n+2 processing difficulty was manipulated by means of word frequency (i.e., easy high-frequency vs. difficult low-frequency word n+2). In Experiment 2, we varied the visual familiarity of word n+2 (i.e., easy lower-case vs. difficult alternating-case writing). Fixations on the short word n+1, which were likely to be mislocated, were nevertheless not influenced by the difficulty of the adjacent word n+2, the hypothesized target of the mislocated fixation. Instead word n+1 was influenced by the preview difficulty of word n+2, representing a delayed parafoveal-on-foveal effect. The results challenge the mislocated-fixation hypothesis as an explanation of parafoveal-on-foveal effects and provide new insight into the complex spatial and temporal effect structure of processing inside the perceptual span during reading.