Language learning takes place in the context of social relationships. Yet, we know little about the mechanisms that link social interaction to word learning. This dissertation focuses on two aspects of that relationship, social contingency and eye gaze, and asks whether these cues may be a critical ingredient in the well established link between social support and language learning. Specifically, we investigate how toddlers learn novel verbs in one of three conditions. In one, training on four new words was conducted using live interaction. In the second, children were trained on the same words using a contingent screen condition (video-chat). Finally, in the third, they were taught the same words in a video condition that did not maintain social contingency (yoked video). Results suggest that children exposed to novel verbs via contingent screen condition learned these words to the same degree as children in the live condition and far exceeded their peers who were exposed to non-contingent video only. Analysis of looking patterns during training further suggests that children in contingent interactions rely on eye gaze during social interactions, which predicts language learning. Taken together, this dissertation begins to operationally define social cues and to illuminate the mechanism that links social interaction and language acquisition. It also speaks to the literature on learning through screen media as the first study to examine word learning through video chat technology. / Psychology

Emojis are pictographs added to messages on social media and websites. Researchers have observed that emojis representing kissing faces are often used to close instant messaging conversations. This has been interpreted as an imitation of cheek kissing, a common behavior in some cultural contexts. We analyze the use of seven types of kissing emojis in three corpora of WhatsApp chats, one from Spain (where cheek kisses in face-to-face interaction are commonplace in many situations), the other from Germany (where kisses are occasionally given), and the third from the German-speaking part of Switzerland (where cheek kisses are a common greeting between relatives and friends). To do so, we systematically categorize and compare the use of a sample of these emojis on WhatsApp. The analysis suggests that there are differences between the three corpora in the use of the kissing emojis. The emoji “face throwing a kiss” is often included in closing messages in the Spanish and Swiss-German data, while in the Federal German corpus kisses do not appear at the end of a conversation; using these emojis in openings is uncommon in all three corpora. This suggests that these emojis can exhibit cultural variation, but they do not clearly mirror face-to-face behavior.

This study investigates how visual cues can enhance player navigation in Metroidvania-style level design. This research aims to address the critical need for effective visual cues in improving player navigation within non-linear Metroidvania game levels. By delving into this aspect, we seek to not only enrich the gaming experience for players but also contribute valuable insights to game developers and researchers interested in improving their level design. Using a between-subjects design, we created a non-linear game prototype in Unity, representing the Metroidvania genre, along with three variants incorporating different levels of visual cue markedness, resulting in four versions in total. Data was collected through think-aloud protocols, observations, surveys, cued recall debriefs, and semi-structured interviews to assess participants' responses to the visual cues and their navigation strategies. The results indicate that integrated cues provided the clearest guidance, allowing players to quickly understand their objectives and navigate effectively. Subtle cues preserved the sense of discovery, while emphasized cues effectively highlighted specific items or secrets.

No / The luminance and colour gradients across an image are the result of complex interactions between object shape, material and illumination. Using such variations to infer object shape or surface colour is therefore a difficult problem for the visual system. We know that changes to the shape of an object can affect its perceived colour, and that shading gradients confer a sense of shape. Here we investigate if the visual system is able to effectively utilise these gradients as a cue to shape perception, even when additional cues are not available. We tested shape perception of a folded card object that contained illumination gradients in the form of shading and more subtle effects such as inter-reflections. Our results suggest that observers are able to use the gradients to make consistent shape judgements. In order to do this, observers must be given the opportunity to learn suitable assumptions about the lighting and scene. Using a variety of different training conditions, we demonstrate that learning can occur quickly and requires only coarse information. We also establish that learning does not deliver a trivial mapping between gradient and shape; rather learning leads to the acquisition of assumptions about lighting and scene parameters that subsequently allow for gradients to be used as a shape cue. The perceived shape is shown to be consistent for convex and concave versions of the object that exhibit very different shading, and also similar to that delivered by outline, a largely unrelated cue to shape. Overall our results indicate that, although gradients are less reliable than some other cues, the relationship between gradients and shape can be quickly assessed and the gradients therefore used effectively as a visual shape cue.

Yes / Motion-in-depth can be detected by using two different types of binocular cues: change of disparity (CD) and inter-ocular velocity differences (IOVD). To investigate the underlying detection mechanisms, stimuli can be constructed that isolate these cues or contain both (FULL cue). Two different methods to isolate the IOVD cue can be employed: anti-correlated (aIOVD) and de-correlated (dIOVD) motion signals. While both types of stimuli have been used in studies investigating the perception of motion-in-depth, for the first time, we explore whether both stimuli isolate the same mechanism and how they differ in their relative efficacy. Here, we set out to directly compare aIOVD and dIOVD sensitivity by measuring motion coherence thresholds. In accordance with previous results by Czuba et al. (2010), we found that motion coherence thresholds were similar for aIOVD and FULL cue stimuli for most participants. Thresholds for dIOVD stimuli, however, differed consistently from thresholds for the two other cues, suggesting that aIOVD and dIOVD stimuli could be driving different visual mechanisms.

Yes / Purpose: Although urgent primary eye care schemes exist in some areas of England, their current safety is unknown. Accordingly, the aim of the present study was to quantify the clinical safety and effectiveness of a COVID-19 Urgent Eyecare Service (CUES) across Luton, Bedford, Hull, East Riding of Yorkshire and Harrogate. Methods: Consenting patients with acute onset eye problems who had accessed the service were contacted to ascertain what the optometrist’s recommendation was, whether this worked, if they had to present elsewhere and how satisfied they were with the CUES. Results: 27% (170/629) and 6.3% (28/445) of patients managed virtually and in person, respectively, did not have their acute eye problem resolved. Regression analysis revealed that patients who attended a face-to-face consultation were 4.66 times more likely to be correctly managed (Exp (β) = 5.66), relative to those managed solely virtually. Optometrists phone consultations failed to detect conditions such as stroke, intracranial hypertension, suspected space occupying lesions, orbital cellulitis, scleritis, corneal ulcer, wet macular degeneration, uveitis with macular oedema and retinal detachment. Of referrals to hospital ophthalmology departments, in total, 19% were false-positives. Patients, however, were typically very satisfied with the service. Uptake was associated with socio-economic status. Conclusion: The present study found that a virtual assessment service providing optometrist teleconsultations was not effective at resolving patient’s acute-onset eye problems. The range and number of pathologies missed by teleconsultations suggests that the service model in the present study was detrimental to patient safety. To improve this, optometrists should follow evidence based guidance when attempting to manage patients virtually, or in person. For example, patients presenting with acute-onset symptoms of flashing lights and/or floaters require an urgent dilated fundus examination. Robust data collection on service safety is required on an ongoing basis. / The full-text of this article will be released for public view at the end of the publisher embargo on 10 Nov 2022.

Impairment of stereoacuity is common in the elderly population and is found to be a risk factor for falls. The purpose of these experiments was to extend knowledge regarding impairment of binocular vision and adaptive gait. Firstly using a 3D motion analysis system to measure how impairment of stereopsis affected adaptive gait during a negotiation of a step, secondly by determining which clinical stereotest was the most reliable for measuring stereoacuity in elderly subjects and finally investigating how manipulating the perceived height of a step in both binocular and monocular conditions affected negotiation of a step. In conditions of impaired stereopsis induced by acutely presented monocular blur, both young and elderly subjects adopted a safety strategy of increasing toe clearance of the step edge, even at low levels of monocular blur (+0.50DS) and the effect was greater when the dominant eye was blurred. The same adaptation was not found for individuals with chronic monocular blur, where vertical toe clearance did not change but variability of toe clearance increased compared to full binocular correction. Findings indicate stereopsis is important for accurately judging the height of a step, and offers support to epidemiological findings that impaired stereoacuity is a risk for falls. Poor agreement was found between clinical stereotests. The Frisby test was found to have the best repeatability. Finally, a visual illusion that caused a step to be perceived as taller led to increased toe elevation. This demonstrates a potential way of increasing toe clearance when stepping up and hence increase safety on stairs. / The Study data files are unavailable online.

No / The importance of peripheral visual cues in the control of minimum-foot-clearance during overground locomotion on a clear path was investigated. Eleven subjects walked at their natural speed whilst wearing goggles providing four different visual conditions: upper occlusion, lower occlusion, circumferential–peripheral occlusion and full vision. Results showed that under circumferential– peripheral occlusion, subjects were more cautious and increased minimum-foot-clearance and decreased walking speed and step length. The minimum-foot-clearance increase can be interpreted as a motor control strategy aiming to safely clear the ground when online visual exproprioceptive cues from the body are not available. The lack of minimum-foot-clearance increase in lower occlusion suggests that the view of a clear pathway from beyond two steps combined with visual exproprioception and optic flow in the upper field were adequate to guide gait. A suggested accompanying safety strategy of reducing the amount of variability of minimum-foot-clearance under circumferential–peripheral occlusion conditions was not found, likely due to the lack of online visual exproprioceptive cues provided by the peripheral visual field for fine-tuning foot trajectory.

La schizophrénie est caractérisée par un ensemble de symptômes positifs et négatifs ainsi que par des déficits cognitifs dont les éléments les plus handicapants sont les troubles mnésiques. La métamémoire, qui est la connaissance sur la mémoire, est un champ d’investigation prometteur pour la compréhension et la remédiation de ce trouble. La métamémoire est composée d’un processus évaluatif et d’un processus de régulation du comportement qui sont en interaction. Les études précédentes ont montré que l’évaluation serait préservée dans la schizophrénie alors que la régulation serait déficitaire. Cependant, les relations entre ces processus n’ont pas été examinées alors qu’elles pourraient permettre decompenser le déficit mnésique. Les objectifs de ce travail étaient donc d’une part, d’observer ces relations entre évaluation et régulation dans la schizophrénie, ainsi que les ressources cognitives liées à ces processus. D’autre part, afin d’étendre les connaissances fondamentales sur la métamémoire, nous souhaitions observer l’utilisation de différents types de matériels etde stratégies d’apprentissage chez des participants sains. Les deux premières expériences ont permis de montrer que les patients schizophrènes étaient capables d’utiliser l’évaluation de leur apprentissage pour adapter leur stratégie de mémorisation et que leurs déficits en mémoire étaient liés à d’autres fonctions cognitives. Les cinq expériences suivantes ont confirmé que les participants sains ne prenaient pas en compte de la même manière les caractéristiques intrinsèques et extrinsèques du matériel dans leurs jugements et leurs stratégies. Ces données sont discutées et indiquent que davantage de recherches sur la métamémoire dans la schizophrénie seraient d’un grand intérêt pour la prise en charge des troubles mnésiques de ces patients. / Schizophrenia is characterized by a range of positive and negative symptoms and bycognitive deficits including the most disabling one, memory. Metamemory, which is knowledge about memory is of particular interest for the understanding and remediation of this trouble. It involves a monitoring and a control process, which would be in interaction.Previous studies have shown that monitoring is spared whereas control is impaired. However,these relations between these processes have not been examined whereas they could compensate for memory deficit. The aims of this work were to observe these relations between monitoring and control in schizophrenia and cognitive resources linked to these processes on the one hand. On the other hand, we wished to observe the use of different kinds of materials and learning strategies in healthy participants to get better fundamental knowledge about metamemory. Two experiments showed that patients were able to use monitoring to adapt their learning strategy and also that their memory deficits were linked too ther cognitive functions. Five following experiments confirmed that healthy participants do not use intrinsic and extrinsic characteristics of the materials in the same way when makin gjudgments and using strategies. These data are discussed and point out that more research about metamemory in schizophrenia is of interest for the remediation of memory deficits inschizophrenia patients.

The aim of this thesis is to describe, by means of compounding disciplines of Computer Mediated Communication and Human-Computer Interaction, how interpersonal communication is transformed by the read recepit function which occurs in contemporary Instant Messaging applications. Besides the impact of the function itself on interpersonal communication, this thesis also explores the effect of other Awareness Cues on its acceptance and interpretation.