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.

In this article, we review eye-tracking studies with dogs (Canis familiaris) with a threefold goal; we highlight the achievements in the field of canine perception and cognition using eye tracking, then discuss the challenges that arise in the application of a technology that has been developed in human psychophysics, and finally propose new avenues in dog eye-tracking research. For the first goal, we present studies that investigated dogs\' perception of humans, mainly faces, but also hands, gaze, emotions, communicative signals, goal-directed movements, and social interactions, as well as the perception of animations representing possible and impossible physical processes and animacy cues. We then discuss the present challenges of eye tracking with dogs, like doubtful picture-object equivalence, extensive training, small sample sizes, difficult calibration, and artificial stimuli and settings. We suggest possible improvements and solutions for these problems in order to achieve better stimulus and data quality. Finally, we propose the use of dynamic stimuli, pupillometry, arrival time analyses, mobile eye tracking, and combinations with behavioral and neuroimaging methods to further advance canine research and open up new scientific fields in this highly dynamic branch of comparative cognition.

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.

Many video-based eye trackers rely on detecting and tracking ocular features, a task that can be negatively affected by a number of individual or environmental factors. In this context, the aim of this study was to practically evaluate how the use of a scleral contact lens with two integrated nearinfrared lasers (denoted CLP) could improve the tracking robustness in difficult lighting conditions, particularly outdoor ones. We assessed the ability of the CLP (on a model eye) to detect the lasers and to deduce a gaze position with an accuracy better than 1° under four lighting conditions (1 lx, 250 lx, 50 klux and alternating 1lx /250 lx) on an artificial eye. These results were compared to the ability of a commercial eye tracker (Pupil Core) to detect the pupil on human eyes with a confidence score equal to or greater than 0.9. CLP provided good results in all conditions (tracking accuracy and detection rates). In comparison, the Pupil Core performed well in all indoor conditions (99% detection) but failed in outdoor conditions (9.85% detection). In conclusion, the CLP presents strong potential to improve the reliability of video-based eyetrackers in outdoor conditions by providing easy trackable feature.

Background: Automated eye tracking data correction algorithms such as Dynamic-Time Warp always made a trade-off between the ability to handle regressions (jumps back) and distortions (fixation drift). At the same time, eye movement in code reading is characterized by non-linearity and regressions. Objective: In this paper, we present a family of hybrid algorithms that aim to handle both regressions and distortions with high accuracy. Method: Through simulations with synthetic data, we replicate known eye movement phenomena to assess our algorithms against Warp algorithm as a baseline. Furthermore, we utilize two real datasets to evaluate the algorithms in correcting data from reading source code and see if the proposed algorithms generalize to correcting data from reading natural language text. Results: Our results demonstrate that most proposed algorithms match or outperform baseline Warp in correcting both synthetic and real data. Also, we show the prevalence of regressions in reading source code. Conclusion: Our results highlight our hybrid algorithms as an improvement to Dynamic-Time Warp in handling regressions.

Individuals\' gaze on an object usually leads others to prefer that object, which is called the gaze-liking effect. However, it is still unclear whether this effect is driven by social factors (i.e., visual perspective-taking) or the domain-general processing (i.e., attention cueing). This research explored the mechanism of the gaze-liking effect by manipulating the objects\' visibility to an avatar in six online one-shot experiments. The results showed that participants\' affective evaluation for the object was modulated by the avatar\'s visual perspective. Specifically, the visible object to the avatar received a higher rating of liking degree. However, when the avatar was replaced with a non-social stimulus, the experimental effect was absent. Furthermore, the gaze-liking effect was robust while controlling for confounding factors such as the distance between the object and the avatar or type of stimuli. These findings provided convincing evidence that the gaze-liking effect involves a process of the other\'s visual experience and is not merely a by-product of the gaze-cueing effect.

Visual motion information plays an important role in the control of movements in sports. Skilled ball players are thought to acquire accurate visual information by using an effective visual search strategy with eye and head movements. However, differences in catching ability and gaze movements due to sports experience and expertise have not been clarified. Therefore, the purpose of this study was to determine the characteristics of gaze strategies based on eye and head movements during a ball-catching task in athlete and novice groups. Participants were softball and tennis players and college students who were not experienced in ball sports (novice). They performed a one-handed catching task using a tennis ball-shooting machine, which was placed at 9 m in front of the participants, and two conditions were set depending on the height of the ball trajectory (high and low conditions). Their head and eye velocities were detected using a gyroscope and electrooculography (EOG) during the task. Our results showed that the upward head velocity and the downward eye velocity were lower in the softball group than in the tennis and novice groups. When the head was pitched upward, the downward eye velocity was induced from the vestibulo-ocular reflex (VOR) during ball catching. Therefore, it is suggested that skilled ball players have relatively stable head and eye movements, which may lead to an effective gaze strategy. An advantage of the stationary gaze in the softball group could be to acquire visual information about the surroundings other than the ball.

The visual cues of lexical tones are more implicit and much less investigated than consonants and vowels, and it is still unclear what facial areas contribute to facial tones identification. This study investigated Chinese and English speakers\' eye movements when they were asked to identify audiovisual Mandarin lexical tones. The Chinese and English speakers were presented with an audiovisual clip of Mandarin monosyllables (for instance, /ă/, /à/, /ĭ/, /ì/) and were asked to identify whether the syllables were a dipping tone (/ă/, / ĭ/) or a falling tone (/ à/, /ì/). These audiovisual syllables were presented in clear, noisy and silent (absence of audio signal) conditions. An eye-tracker recorded the participants\' eye movements. Results showed that the participants gazed more at the mouth than the eyes. In addition, when acoustic conditions became adverse, both the Chinese and English speakers increased their gaze duration at the mouth rather than at the eyes. The findings suggested that the mouth is the primary area that listeners utilise in their perception of audiovisual lexical tones. The similar eye movements between the Chinese and English speakers imply that the mouth acts as a perceptual cue that provides articulatory information, as opposed to social and pragmatic information.

UNASSIGNED: Neck pain is a common musculoskeletal disorder, the most common type being non-specific chronic neck pain. It usually involves postural or mechanical causes. In Individuals with neck pain, a notable prevalence of visual complaints has been predominantly reported. It can be linked to the mismatch in the cervical afferent output.
UNASSIGNED: This study aimed to assess the effect of oculomotor exercises on neck pain, neck disability, gaze stability and visual complaints among individuals with non-specific chronic neck pain and associated visual complaints.
UNASSIGNED: A total of 32 individuals with non-specific chronic neck pain and associated visual complaints were equally randomised into two groups. To receive either: stretching to the sternocleidomastoid and anterior scalene along with neck Isometric exercises (Group A, conventional) or the conventional protocol along with oculomotor exercises (Group B, experimental). The protocol was given for three alternate days a week for three weeks, a total of nine sessions. The outcome measures were the Visual Analogue Scale (VAS) for pain, Neck Disability Index (NDI) for disability, Dynamic Visual Acuity (DVA) test for gaze stability and Visual Complaints Index (VCI) for visual complaints.
UNASSIGNED: Significant results were seen for the DVA (p=0.002) and VCI (p=0.024), suggesting improvements in gaze stability and visual complaints using oculomotor exercises.
UNASSIGNED: From this study, we highlighted that oculomotor exercises along with conventional treatment led to improvement in visual complaints and gaze stability in patients with non-specific chronic neck pain and associated visual complaints.

In a spatial Stroop task, eye-gaze targets produce a reversed congruency effect (RCE) with faster responses when gaze direction and location are incongruent than congruent. On the other hand, non-social directional targets (e.g., arrows) elicit a spatial Stroop effect (SSE). The present study examined whether other social stimuli, such as head orientation, trigger the RCE. Participants judged the target direction of the head or the gaze while ignoring its location. While the gaze target replicated the RCE, the head target produced the SSE. Moreover, the head target facilitated the overall responses relative to the gaze target. These results suggest that the head, a salient directional feature, overrides the social significance. The RCE may be specific to gaze stimuli, not to social stimuli in general. The head and gaze information differentially affect our attentional mechanisms and enable us to bring about smooth social interactions.