Multipurpose Bio-Monitored Integrated Circuit in a Contact Lens Eye-Tracker

We present the design, fabrication, and test of a multipurpose integrated circuit (Application Specific Integrated Circuit) in AMS 0.35 µm Complementary Metal Oxide Semiconductor technology. This circuit is embedded in a scleral contact lens, combined with photodiodes enabling the gaze direction detection when illuminated and wirelessly powered by an eyewear. The gaze direction is determined by means of a centroid computation from the measured photocurrents. The ASIC is used simultaneously to detect specific eye blinking sequences to validate target designations, for instance. Experimental measurements and validation are performed on a scleral contact lens prototype integrating four infrared photodiodes, mounted on a mock-up eyeball, and combined with an artificial eyelid. The eye-tracker has an accuracy of 0.2°, i.e., 2.5 times better than current mobile video-based eye-trackers, and is robust with respect to process variations, operating time, and supply voltage. Variations of the computed gaze direction transmitted to the eyewear, when the eyelid moves, are detected and can be interpreted as commands based on blink duration or using blinks alternation on both eyes.

Assessment of external interface of autonomous vehicles

The paper deals with the problem of a communication interface between autonomous vehicles (AV) and pedestrians. The introduced methodology for assessing new and existing e-HMI (external HMI) contributes to traffic safety in cities. The methodology is implemented in a pilot experiment with a scenario designed in virtual reality (VR). The simulated scene represents an urban zebra crossing with an approaching autonomous vehicle. The projection is implemented with the help of a head-up display – a headset with a built-in eye tracker. The suggested methodology analyses the pedestrian’s decision making based on the visual cues – the signals displayed on the autonomous vehicle. Furthermore, the decision making is correlated to subjects’ eye behaviour, based on gaze-direction data. The method presented in this paper contributes to the safety of a vehicle-pedestrian communication of autonomous vehicles and is a part of a research that shall further contribute to the design and assessment of external communication interfaces of AV in general.

Are You “Gazing” at Me? How Others' Gaze Direction and Facial Expression Influence Gaze Perception and Postural Control

In everyday life, interactions between humans are generally modulated by the value attributed to the situation, which partly relies on the partner's behavior. A pleasant or cooperating partner may trigger an approach behavior in the observer, while an unpleasant or threatening partner may trigger an avoidance behavior. In this context, the correct interpretation of other's intentions is crucial to achieve satisfying social interactions. Social cues such as gaze direction and facial expression are both fundamental and interrelated. Typically, whenever gaze direction and facial expression of others communicate the same intention, it enhances both the interlocutor's gaze direction and the perception of facial expressions (i.e., shared signal hypothesis). For instance, an angry face with a direct gaze is perceived as more intense since it represents a threat to the observer. In this study, we propose to examine how the combination of others' gaze direction (direct or deviated) and emotional facial expressions (i.e., happiness, fear, anger, sadness, disgust, and neutrality) influence the observer's gaze perception and postural control. Gaze perception was indexed by the cone of direct gaze (CoDG) referring to the width over which an observer feels someone's gaze is directed at them. A wider CoDG indicates that the observer perceived the face as looking at them over a wider range of gaze directions. Conversely, a narrower CoDG indicates a decrease in the range of gaze directions perceived as direct. Postural control was examined through the center of pressure displacements reflecting postural stability and approach-avoidance tendencies. We also investigated how both gaze perception and postural control may vary according to participants' personality traits and emotional states (e.g., openness, anxiety, etc.). Our results confirmed that gaze perception is influenced by emotional faces: a wider CoDGs was observed with angry and disgusted faces while a narrower CoDG was observed for fearful faces. Furthermore, facial expressions combined with gaze direction influence participants' postural stability but not approach-avoidance behaviors. Results are discussed in the light of the approach-avoidance model, by considering how some personality traits modulate the relation between emotion and posture.

Feigned ADHD Associated Cognitive Impairment: Utility of Integrating an Eye-trAcker and the MOXO-dCPT

Objective: The current study assessed the utility of eye-movements measures, gathered while participants performed a commercially available Continuous Performance Test (CPT), to detect feigned ADHD-associated cognitive impairment. Method: Healthy simulators ( n = 37), ADHD patients ( n = 33), and healthy controls ( n = 36) performed an eye-tracker integrated MOXO-dCPT and a stand-alone validity indicator. Results: Simulators gazed significantly longer at regions that were irrelevant for successful MOXO-dCPT performance compared to ADHD patients and healthy controls. This eye-movement measure, however, had lower sensitivity than traditional MOXO-dCPT indices. Discussion: Gaze direction measures, gathered while performing a CPT, show initial promise as validity indicators. Traditional CPT measures, however, are more sensitive and therefore offer a more promising path for the establishment of CPT-based validity indicators. The current study is an initial exploration of the issue and further evaluation of both theoretical and practical aspects is mandated.

Bupivacaine-lidocaine versus Ropivacaine-lidocaine Retrobulbar Anesthesia in Vitreoretinal Surgery

Purpose: To compare efficacies of bupivacaine-lidocaine and ropivacaine-lidocaine mixtures in terms of inducing retrobulbar anesthesia during vitrectomy.Methods: Sixty patients who underwent retrobulbar anesthesia during vitrectomy were divided into two groups. Patients in group 1 received a mixture of bupivacaine and lidocaine (n = 30); patients in group 2 received a mixture of ropivacaine and lidocaine (n = 30). The effects of the two combinations were retrospectively compared and analyzed. The onset times of analgesia and akinesia were measured. Two hours after surgery, sensory blockade was assessed by touching the corneas with cotton swabs and by communicating with patients. Ocular movement was evaluated in four gaze direction quadrants. A 10-point visual analog pain scale was used to assess pain during and 2 hours after surgery. Intra- and postoperative complications were recorded.Results: The mean analgesia onset times in groups 1 and 2 were 94.62 ± 28.87 and 92.32 ± 35.53 seconds, respectively (p = 0.071); the mean akinesia onset times were 147.89 ± 59.35 and 132.57 ± 76.38 seconds (p = 0.223), respectively. Patients in group 2 reported significantly less postoperative pain and exhibited less postoperative ocular movement, compared with patients in group 1 (both p = 0.002). One patient in group 1 experienced respiratory depression after retrobulbar blockade.Conclusions: When retrobulbar anesthesia is required during vitrectomy, a ropivacaine-lidocaine mixture and a bupivacaine-lidocaine mixture induce anesthesia with similar rapidity. However, the ropivacaine-lidocaine mixture is safer and affords better-quality intra- and postoperative anesthesia.

Eye Tracking in Driver Attention Research—How Gaze Data Interpretations Influence What We Learn

Eye tracking (ET) has been used extensively in driver attention research. Amongst other findings, ET data have increased our knowledge about what drivers look at in different traffic environments and how they distribute their glances when interacting with non-driving related tasks. Eye tracking is also the go-to method when determining driver distraction via glance target classification. At the same time, eye trackers are limited in the sense that they can only objectively measure the gaze direction. To learn more about why drivers look where they do, what information they acquire foveally and peripherally, how the road environment and traffic situation affect their behavior, and how their own expertise influences their actions, it is necessary to go beyond counting the targets that the driver foveates. In this perspective paper, we suggest a glance analysis approach that classifies glances based on their purpose. The main idea is to consider not only the intention behind each glance, but to also account for what is relevant in the surrounding scene, regardless of whether the driver has looked there or not. In essence, the old approaches, unaware as they are of the larger context or motivation behind eye movements, have taken us as far as they can. We propose this more integrative approach to gain a better understanding of the complexity of drivers' informational needs and how they satisfy them in the moment.

Exploration of Relations between Belief-Tracking and Motor Processing using a new Ecologically-Valid Helping Task for Adults

<p>Three experiments investigated efficient belief tracking as described by the two-systems theory of human mindreading (Apperly & Butterfill, 2009) whereupon mindreading implies the operation of a flexible system that is slow to develop and cognitively effortful, and an efficient system which develops early but subject to signature limits. Signature limits have been evidenced by children’s and adults’ difficulty anticipating how someone with a false belief (FB) about an object’s identity, will act. In a recent investigation of signature limits, erroneous pre-activation of the motor system was detected when adults predicted the actions of an agent with an identity FB, suggesting that efficient mindreading and motor processes are linked (Edwards & Low, 2017). Moreover, young children differentiated between true and FBs about an object’s location, but not identity, as revealed by the object children retrieved in an active helping task (Fizke et al., 2017). The aim of the present thesis was to provide new evidence of signature limits in adults, and of the recent conjecture that efficient mindreading and motor processes interact. In helping tasks, participants’ interpretation of another’s actions is crucial to how they coordinate their helping response. Therefore, an ecologically valid helping task was adapted to investigate the proposed interface between efficient mindreading and motor processes. The present work measured adults’ eye movements made prior to helping, and their helping actions across a set of distinct directional full-body movements (around which side of a desk they swerved, which compartment they approached, toward which compartment they reached, and which object they retrieved). In this way, it was possible to investigate whether gaze direction correlated with full-body movements and whether adults’ gaze differed when the agent’s FB was about an object’s location or identity. Results from Experiment 1 indicated that efficient belief tracking is equipped to process location but not identity FBs, and that - in the location scenario - gaze direction correlated with the immediate stage of participants’ helping action (the direction they swerved). To investigate this correlation further, Experiment 2 drew upon research suggesting that temporarily tying an observer’s hands behind their backs impaired their ability to predict the outcome of hand actions (Ambrosini et al., 2012). Results showed that tying adults’ hands behind their back had a negative effect on their gaze behavior and severed the correlation between gaze and swerving, suggesting that the link between efficient mindreading and motor processes is fragile. Experiment 3 tested an alternative interpretation for Experiment 2’s findings (that restraining participants’ hands applied a domain-general distraction, rather than a specific detriment to belief tracking) by tying up participants’ feet. Results were ambiguous: the gaze behavior of participants whose feet were tied did not differ from those who were unrestrained, nor from those whose hands were bound. These findings support the two-systems theory and provide suggestive evidence of a connection between efficient mindreading and motor processes. However, the investigation highlights new methodological challenges for designing naturalistic helping tasks for adult participants.</p>

Exploration of Relations between Belief-Tracking and Motor Processing using a new Ecologically-Valid Helping Task for Adults

<p>Three experiments investigated efficient belief tracking as described by the two-systems theory of human mindreading (Apperly & Butterfill, 2009) whereupon mindreading implies the operation of a flexible system that is slow to develop and cognitively effortful, and an efficient system which develops early but subject to signature limits. Signature limits have been evidenced by children’s and adults’ difficulty anticipating how someone with a false belief (FB) about an object’s identity, will act. In a recent investigation of signature limits, erroneous pre-activation of the motor system was detected when adults predicted the actions of an agent with an identity FB, suggesting that efficient mindreading and motor processes are linked (Edwards & Low, 2017). Moreover, young children differentiated between true and FBs about an object’s location, but not identity, as revealed by the object children retrieved in an active helping task (Fizke et al., 2017). The aim of the present thesis was to provide new evidence of signature limits in adults, and of the recent conjecture that efficient mindreading and motor processes interact. In helping tasks, participants’ interpretation of another’s actions is crucial to how they coordinate their helping response. Therefore, an ecologically valid helping task was adapted to investigate the proposed interface between efficient mindreading and motor processes. The present work measured adults’ eye movements made prior to helping, and their helping actions across a set of distinct directional full-body movements (around which side of a desk they swerved, which compartment they approached, toward which compartment they reached, and which object they retrieved). In this way, it was possible to investigate whether gaze direction correlated with full-body movements and whether adults’ gaze differed when the agent’s FB was about an object’s location or identity. Results from Experiment 1 indicated that efficient belief tracking is equipped to process location but not identity FBs, and that - in the location scenario - gaze direction correlated with the immediate stage of participants’ helping action (the direction they swerved). To investigate this correlation further, Experiment 2 drew upon research suggesting that temporarily tying an observer’s hands behind their backs impaired their ability to predict the outcome of hand actions (Ambrosini et al., 2012). Results showed that tying adults’ hands behind their back had a negative effect on their gaze behavior and severed the correlation between gaze and swerving, suggesting that the link between efficient mindreading and motor processes is fragile. Experiment 3 tested an alternative interpretation for Experiment 2’s findings (that restraining participants’ hands applied a domain-general distraction, rather than a specific detriment to belief tracking) by tying up participants’ feet. Results were ambiguous: the gaze behavior of participants whose feet were tied did not differ from those who were unrestrained, nor from those whose hands were bound. These findings support the two-systems theory and provide suggestive evidence of a connection between efficient mindreading and motor processes. However, the investigation highlights new methodological challenges for designing naturalistic helping tasks for adult participants.</p>

Examining Gaze Cone Shape and Size

Another person's looking behavior is used by observers to judge gaze direction and fixation points. An important task in this context is the judgement of direct gaze, that is, the perception of being looked at. The cone of gaze can be defined as the range of fixation points that support direct gaze. The cone concept implies that this range lawfully increases with distance, but that the cone angle is constant. The present experiment tested the concept with a larger number and a more extended range of distances than previously done, and took care of possible directional errors. The gaze cone was found to be roughly linear, and stable between 1.6 m and 7.9 m – an almost perfect cone. The mean cone size subtended 5.2° in diameter when averaged over ascending and descending series. Measures differed, however, in ascending and descending series, consistent with a conservative bias. Also, the variability of judgements increased slightly with distance. Results are discussed considering whether cone size is actually smaller than often reported in the literature.

A Bird's-Eye View: Core Knowledge in Wild North Island Robins of New Zealand

<p>A prominent psychological theory on early cognitive development is Spelke’s Core Knowledge (CK) hypothesis (Spelke, Breinlinger, Macomber, & Jacobson, 1992), which posits that human infants, and possibly other species, are guided by innate understandings of how object movements, classification and quantification are governed by physical laws and, further, how agents are capable of perceptions and purposive action. CK is a set of cognitive building blocks, which serve as the foundation for more complex cognition such as acquisition and use of symbol systems pertaining to language and mathematics (Spelke, 2000). Evidence points to four core systems of knowledge: representation of number, object, space (or geometry) and agency. Investigation of spontaneous CK in nonhuman species in the wild is fundamental to understanding the ecological validity and evolutionary context for a set of systems that is proposed to be universally embedded. The bold, inquisitive manner, naïve fearlessness and unique insect caching behaviour of wild North Island robins (Petroica longipes) presents a unique opportunity to identify and characterise CK in a new model system. Six studies were conducted with the aim of investigating core developmental cognition in robins. The first three studies focused on perception of numerical quantity. Study 1 investigated the ability to discriminate between both large and small quantities, finding that robins successfully discriminate between unusually large quantities independent of ratio. Study 2 explored quantity discrimination in which summation of items is spatially distributed across an array, and found that while robins perform successfully with small numbers, the task presented substantially more cognitive demand. Study 3 measured robins’ reactions to computation by presenting simple addition and subtraction problems in a Violation of Expectancy (VoE) paradigm, finding that robins search longer when presented with a mathematically incongruent scenario. The last three studies focused on perception of agency. Study 4 investigated robins’ response to gaze direction in humans in a competitive paradigm, and found that they were sensitive to human gaze direction in all conditions but one. Study 5 explored perception of physical capability in humans, and results indicated that limb visibility significantly influences pilfering choice. Study 6 examined robins’ perception of animacy in prey, finding that in a VoE paradigm, robins’ expectation of hidden prey continuity varies depending on mobility and animacy. Taken together, the results of these six studies suggest that while supportive of fundamental characteristics defining basic Core Knowledge in many ways, some unique results in the cognitive abilities of this biologically naïve species shed new light on our growing understanding of the shared basis of cognition. A deeper look at avian performance in core developmental tasks, especially in a naïve wild population, can offer new insights into sweeping evolutionary theories that underpin basic cognitive mechanisms.</p>