UNASSIGNED: Methamphetamine is frequently co-consumed with alcohol, yet combined effects on visually guided behaviours have not been experimentally assessed. This study examined whether methamphetamine and alcohol-induced changes in gaze behaviour can be accurately detected and indexed during a simulated driving task to establish characteristic patterns relevant to traffic safety.
UNASSIGNED: In a randomised, placebo-controlled, cross-over study design, the effects of acute oral methamphetamine (0.42 mg/kg) were assessed with and without low doses of alcohol (target 0.04% blood alcohol content) on gaze behaviour during driving. Twenty healthy adults (mean age 29.5 years (SD ± 4.9), 40% female) completed four, 1-h simulated drives with simultaneous eye monitoring using the SensoMotoric Instruments cap-mounted eye tracker over a 4-week experimental paradigm. Gaze entropy measures were used to quantify visual scanning efficiency, expressed as gaze transition entropy and stationary gaze entropy. Fixations, recorded as duration (milliseconds, ms) and rate (count) per minute, were examined in 10-min bins over the duration of the drive. Driving performance was assessed by the standard deviation of lateral position, standard deviation of speed and steering variability.
UNASSIGNED: Methamphetamine increased the rate and duration of fixations and produced a less dispersed but more disorganised pattern of gaze during highway driving while preserving performance. Alcohol alone impaired both oculomotor control and driving performance, even when consumed at levels well below the legal limit stipulated in many international jurisdictions.
UNASSIGNED: Methamphetamine-affected drivers display inefficient exploration in a limited visual range during driving. Eye-tracking metrics thus show potential for indexing intoxication due to psychoactive substance usage.

Infants\' motivation to engage with the social world depends on the interplay between individual brain\'s characteristics and previous exposure to social cues such as the parent\'s smile or eye contact. Different hypotheses about why specific combinations of emotional expressions and gaze direction engage children have been tested with group-level approaches rather than focusing on individual differences in the social brain development. Here, a novel Artificial Intelligence-enhanced brain-imaging approach, Neuroadaptive Bayesian Optimisation (NBO), was applied to infant electro-encephalography (EEG) to understand how selected neural signals encode social cues in individual infants. EEG data from 42 6- to 9-month-old infants looking at images of their parent\'s face were analysed in real-time and used by a Bayesian Optimisation algorithm to identify which combination of the parent\'s gaze/head direction and emotional expression produces the strongest brain activation in the child. This individualised approach supported the theory that the infant\'s brain is maximally engaged by communicative cues with a negative valence (angry faces with direct gaze). Infants attending preferentially to faces with direct gaze had increased positive affectivity and decreased negative affectivity. This work confirmed that infants\' attentional preferences for social cues are heterogeneous and shows the NBO\'s potential to study diversity in neurodevelopmental trajectories.

Word search puzzles are recognized as a valid word recognition task. Eye gaze patterns have been investigated during visual search and reading, but the word search puzzle requires both searching and word recognition. This paper will discuss findings from an eye-tracking study of word search puzzles in three languages, of varying fluency for the participants. Results indicated that participants employ a search strategy that is somewhat dependent on language fluency and varies from a rigid, structured search pattern to randomly searching for a target word. The majority of gaze measurements are not significantly influenced by either word length or fluency of presented language, although mean fixation durations are longer for shorter words.

This paper presents an analysis of space perception and how visual cues, such as landmarks and sound, are perceived and impact people\'s behaviour while exploring a given outdoor space. The primary goal of the research is to investigate how auditory sensations and visual stimuli influence people\'s behaviour in outdoor built environments. Our technique compares people\'s perception of the built environment in different conditions: the real world and a replicated virtual world. As a case study, a university campus was used, and four experimental conditions were designed. The study followed a between-subjects design, and the data collection included gaze data acquired from an eye-tracking device as well as self-reports. The study concludes that sound influences human behaviour in such settings. More specifically conclusions are that: i) human behaviour in virtual replications of the real space, including both visual and sound stimuli, is tendentially more similar to human behaviour in the real world than in simulations omitting sound; and ii) there is a difference in human behaviour when people explore the same virtually replicated outdoor space, by varying the presence of sound. This study is particularly useful for researchers working on the comparison between human behaviour in virtual and real environments, related to visual and sound stimuli.

In two studies we investigate the role of affective factors and top-down processes underlying production and deliberate control of emotional facial expressions and its neural underpinnings. In Study 1 we examine facial expressions of joy, fear and disgust depending on the emotional content of the visual stimuli (upright faces, inverted faces, emotion inducing pictures without faces). In Study 2 we focus on expressions of joy and disgust depending on gaze direction (with and without eye contact) in a more natural setting with a real person as stimulus. We hypothesized that the more automatic processes are induced by stimuli (e.g., arousal, mimicry or social cues like eye contact) the harder it is to control facial expressions; particularly expressions of joy compared to fear and disgust. In both studies we used go/no-go tasks and showed faster RTs for conditions with upright faces or eye contact, respectively. We also found faster RTs for expressions of joy than of fear and disgust. In Study 1 participants showed more errors in no-go trials for expressions of joy than for expressions of fear and disgust, indicating worse top-down control for expressions of joy than of fear or disgust. An ERP analysis of the no-go P3 in Study 1 revealed larger amplitudes for upright faces compared with both inverted faces and emotion inducing pictures and larger amplitudes for expressions of joy than for disgust. This indicates greater demand of top-down control when automatic mimicry processes are activated and some degree of specificity to particular facial expressions. In Study 2 more errors in no-go trials in conditions with eye contact only for expressions of joy indicate mimicry could be larger for expressions with high affiliative intent like expressions of joy, and reduced mimicry for negative expressions. All results indicate that facial expressions buffered by automatic processes (e.g., mimicry) have a greater need for top-down control, especially expressions of joy compared to expressions of fear and disgust.

Eye contact is essential for human interactions. We investigated whether humans are able to avoid eye contact while navigating crowds. At a science festival, we fitted 62 participants with a wearable eye tracker and instructed them to walk a route. Half of the participants were further instructed to avoid eye contact. We report that humans can flexibly allocate their gaze while navigating crowds and avoid eye contact primarily by orienting their head and eyes towards the floor. We discuss implications for crowd navigation and gaze behavior. In addition, we address a number of issues encountered in such field studies with regard to data quality, control of the environment, and participant adherence to instructions. We stress that methodological innovation and scientific progress are strongly interrelated.

Differences in visual attention have been documented in ASD, and appear linked to clinical symptoms. However, most research has been conducted in Western cultures. Because striking differences in visual attention patterns have been documented in other cultures, it is important to understand how culture may influence attentional patterns in ASD. This study compared differences in visual attention in ASD across Western and East Asian cultures, where differences in attention to contextual and global information have been repeatedly demonstrated, to investigate potential culturally-specific ASD phenotypes. One hundred thirty-two total participants included individuals with ASD (n = 24) and controls (n = 47) from Hong Kong (HK), along with a previously studied group of age- and IQ-comparable participants from the United States (n = 26 ASD; n = 35 control). Gaze was tracked while participants completed two narrative tasks that differed in social-emotional complexity. Proportions of fixations to face, bodies, and setting were examined across groups using linear mixed-effect models and a series of growth curve models. Cultural differences were found across tasks and groups. Both the ASD and control HK groups attended more to global contextual setting information, more to the body regions, and less toward faces of characters compared to US groups. Growth curve models indicated that these differences attenuated over time in certain stimuli. ASD-related effects were only observed in the more complex stimuli depicting characters with ambiguous facial expressions. Findings indicate a notable cultural influence on visual attention patterns in ASD, and underscore the importance of stimuli complexity in differentiating cultural versus diagnostic effects on attentional styles.

UNASSIGNED: Eye-tracking devices are an innovative tool to understand providers\' attention during stressful medical tasks. The knowledge about what gaze behaviors improve (or harm) the quality of clinical care can substantially improve medical training. The aim of this study is to identify gaze behaviors that are related to the quality of pediatric resuscitation.
UNASSIGNED: Forty students and healthcare providers performed a simulated pediatric life support scenario, consisting of a chest compression task and a ventilation task, while wearing eye-tracking glasses. Skill Reporter software measured chest compression (CC) quality and Neo Training software measured ventilation quality. Main eye-tracking parameters were ratio [the number of participants who attended a certain area of interest (AOI)], dwell time (total amount of time a participant attended an AOI), the number of revisits (how often a participant returned his gaze to an AOI), and the number of transitions between AOIs.
UNASSIGNED: The most salient AOIs were infant chest and ventilation mask (ratio = 100%). During CC task, 41% of participants also focused on ventilation bag and 59% on study nurse. During ventilation task, the ratio was 61% for ventilation bag and 36% for study nurse. Percentage of correct CC rate was positively correlated with dwell time on infant chest (p = 0.044), while the overall CC quality was negatively correlated with dwelling outside of pre-defined task-relevant AOIs (p = 0.018). Furthermore, more dwell time on infant chest predicted lower leakage (p = 0.042). The number of transitions between AOIs was unrelated to CC parameters, but correlated negatively with mask leak during ventilations (p = 0.014). Participants with high leakage shifted their gaze more often between ventilation bag, ventilation mask, and task-irrelevant environment.
UNASSIGNED: Infant chest and ventilation mask are the most salient AOIs in pediatric basic life support. Especially the infant chest AOI gives beneficial information for the resuscitation provider. In contrast, attention to task-irrelevant environment and frequent gaze shifts seem to harm the quality of care.

UNASSIGNED: Acute sleep loss increases the brain\'s reactivity toward positive and negative affective stimuli. Thus, despite well-known reduced attention due to acute sleep loss, we hypothesized that humans would gaze longer on happy, angry, and fearful faces than neutral faces when sleep-deprived. We also examined if facial expressions are differently perceived after acute sleep loss.
UNASSIGNED: In the present, within-subjects study, 45 young adults participated in one night of total sleep deprivation and one night with an 8-hour sleep opportunity. On the morning after each night, an eye tracker was used to measure participants\' time spent fixating images of happy, angry, fearful, and neutral faces. Participants also evaluated faces\' attractiveness, trustworthiness, and healthiness on a 100-mm visual analog scale.
UNASSIGNED: Following sleep loss, participants struggled more fixating the faces than after sleep. The decrease in total fixation duration ranged from 6.3% to 10.6% after sleep loss (P<0.001). Contrary to our hypothesis, the reduction in total fixation duration occurred irrespective of the displayed emotion (P=0.235 for sleep*emotion interaction) and was also present for the upper (P<0.001) but not the lower part of the faces (except for the lower part of angry faces). Overall, faces were evaluated as less trustworthy (-2.6 mm) and attractive (-3.6 mm) after sleep loss (p<0.05).
UNASSIGNED: Facial expressions are crucial for social interactions. Thus, spending less time fixating on faces after acute sleep loss may come along with several problems for social interactions, eg, inaccurate and delayed judgment of the emotional state of others. In addition, more negative social impressions of others may lead to social withdrawal in sleep-deprived humans.

BACKGROUND: Television viewing among children is associated with developmental and health outcomes, yet measurement techniques for television viewing are prone to errors, biases, or both.
OBJECTIVE: This study aims to develop a system to objectively and passively measure children\'s television viewing time.
METHODS: The Family Level Assessment of Screen Use in the Home-Television (FLASH-TV) system includes three sequential algorithms applied to video data collected in front of a television screen: face detection, face verification, and gaze estimation. A total of 21 families of diverse race and ethnicity were enrolled in 1 of 4 design studies to train the algorithms and provide proof of concept testing for the integrated FLASH-TV system. Video data were collected from each family in a laboratory mimicking a living room or in the child\'s home. Staff coded the video data for the target child as the gold standard. The accuracy, sensitivity, specificity, positive predictive value, and negative predictive value were calculated for each algorithm, as compared with the gold standard. Prevalence and biased adjusted κ scores and an intraclass correlation using a generalized linear mixed model compared FLASH-TV\'s estimation of television viewing duration to the gold standard.
RESULTS: FLASH-TV demonstrated high sensitivity for detecting faces (95.5%-97.9%) and performed well on face verification when the child\'s gaze was on the television. Each of the metrics for estimating the child\'s gaze on the screen was moderate to good (range: 55.1% negative predictive value to 91.2% specificity). When combining the 3 sequential steps, FLASH-TV estimation of the child\'s screen viewing was overall good, with an intraclass correlation for an overall time watching television of 0.725 across conditions.
CONCLUSIONS: FLASH-TV offers a critical step forward in improving the assessment of children\'s television viewing.