Computational intelligence approaches to robotics, automation, and control [Volume guest editors]

No abstract available

Change blindness: eradication of gestalt strategies

Arrays of eight, texture-defined rectangles were used as stimuli in a one-shot change blindness (CB) task where there was a 50% chance that one rectangle would change orientation between two successive presentations separated by an interval. CB was eliminated by cueing the target rectangle in the first stimulus, reduced by cueing in the interval and unaffected by cueing in the second presentation. This supports the idea that a representation was formed that persisted through the interval before being 'overwritten' by the second presentation (Landman et al, 2003 Vision Research 43149–164]. Another possibility is that participants used some kind of grouping or Gestalt strategy. To test this we changed the spatial position of the rectangles in the second presentation by shifting them along imaginary spokes (by ±1 degree) emanating from the central fixation point. There was no significant difference seen in performance between this and the standard task [F(1,4)=2.565, p=0.185]. This may suggest two things: (i) Gestalt grouping is not used as a strategy in these tasks, and (ii) it gives further weight to the argument that objects may be stored and retrieved from a pre-attentional store during this task

The Effect of Incentives on Pupil Dilation During Recognition Memory: An Attentional Saliency Account of the Pupil Old/New Effect

Another interesting feature of this OMS circuit is the strong surround suppression occurring in the inner retina, which enables both VG3-ACs and W3-RGCs to remain silent to the global image motion. Pharmacological evidence suggested wide-field and/or spiking ACs are the source of the inhibition. The specific AC types, however, have not been identified. To address this question, in chapter 3, I explored candidate cell types using transgenic mouse lines expressing Cre recombinase, mainly tyrosine hydroxylase (TH)-Cre transgenic mice. In 2-photon guided patch clamp recordings, response patterns of TH2-ACs to object motion visual stimuli corresponded to inhibitory inputs of both VG3-ACs and W3-RGCs. Through optogenetics, functional connectivity of TH2-ACs to VG3-ACs and W3-RGCs is tested. Then, in order to understand how TH2-ACs contribute to the OMS circuit, I generated conditional knockouts of the vesicular inhibitory amino acid transporter (VIAAT) and evaluate responses of VG3-ACs and W3-RGCs to motion visual stimuli

Dwell-free input methods for people with motor impairments

Millions of individuals affected by disorders or injuries that cause severe motor impairments have difficulty performing compound manipulations using traditional input devices. This thesis first explores how effective various assistive technologies are for people with motor impairments. The following questions are studied: (1) What activities are performed? (2) What tools are used to support these activities? (3) What are the advantages and limitations of these tools? (4) How do users learn about and choose assistive technologies? (5) Why do users adopt or abandon certain tools? A qualitative study of fifteen people with motor impairments indicates that users have strong needs for efficient text entry and communication tools that are not met by existing technologies. To address these needs, this thesis proposes three dwell-free input methods, designed to improve the efficacy of target selection and text entry based on eye-tracking and head-tracking systems. They yield: (1) the Target Reverse Crossing selection mechanism, (2) the EyeSwipe eye-typing interface, and (3) the HGaze Typing interface. With Target Reverse Crossing, a user moves the cursor into a target and reverses over a goal to select it. This mechanism is significantly more efficient than dwell-time selection. Target Reverse Crossing is then adapted in EyeSwipe to delineate the start and end of a word that is eye-typed with a gaze path connecting the intermediate characters (as with traditional gesture typing). When compared with a dwell-based virtual keyboard, EyeSwipe affords higher text entry rates and a more comfortable interaction. Finally, HGaze Typing adds head gestures to gaze-path-based text entry to enable simple and explicit command activations. Results from a user study demonstrate that HGaze Typing has better performance and user satisfaction than a dwell-time method

Evaluating the role of social attention in the causal path to Autism Spectrum Disorder

This thesis evaluated the evidence for the hypothesis that early disruptions in social attention are involved in the causal pathway to Autism Spectrum Disorder (ASD). The sample included infants at high and low familial risk for neurodevelopmental disorders participating in a prospective longitudinal study, and their family members. Five studies were conducted to test whether social attention atypicalities precede the onset of behavioural symptoms and whether they are related to familial, genetic and epigenetic burden for ASD. Chapter 2 examined neural correlates of attention measured with multi-channel electroencephalography in 8-month-old infants attending to faces and non-social stimuli, in relation to outcomes at age 3. Chapter 3 used structural equation modelling to investigate whether disruptions in neural response have cascading effects on learning from the environment via looking behaviour. Next, to further understand whether disruptions in social attention lie between genetic risk and ASD phenotype, Chapter 4 examined the association between ability to detect eye-gaze direction in a familial sample, severity of ASD symptoms and polygenic risk for ASD. Chapter 5 explored these patterns earlier in development, looking at the relationship between social attention at 14 months of age and familial burden, polygenic risk and parentreport traits of ASD and ADHD. Finally, Chapter 6, leveraging DNA methylation data, explored whether epigenetic signals were associated with early neural and behavioural correlates of social attention as well as developmental change leading to atypical outcome. Taken together, this work examined in depth the multifaceted nature of social attention, pointing to neural and behavioural atypicalities at critical time points as promising targets for cognitive and affective interventions. Furthermore, it pioneers future work integrating genetics, epigenetics and early neurocognitive measures of social attention in large prospective longitudinal studies of individuals at increased vulnerability for neurodevelopmental disorders, to shed light on the developmental mechanisms underlying the emergence of ASD

Perception-driven approaches to real-time remote immersive visualization

In remote immersive visualization systems, real-time 3D perception through RGB-D cameras, combined with modern Virtual Reality (VR) interfaces, enhances the user’s sense of presence in a remote scene through 3D reconstruction rendered in a remote immersive visualization system. Particularly, in situations when there is a need to visualize, explore and perform tasks in inaccessible environments, too hazardous or distant. However, a remote visualization system requires the entire pipeline from 3D data acquisition to VR rendering satisfies the speed, throughput, and high visual realism. Mainly when using point-cloud, there is a fundamental quality difference between the acquired data of the physical world and the displayed data because of network latency and throughput limitations that negatively impact the sense of presence and provoke cybersickness. This thesis presents state-of-the-art research to address these problems by taking the human visual system as inspiration, from sensor data acquisition to VR rendering. The human visual system does not have a uniform vision across the field of view; It has the sharpest visual acuity at the center of the field of view. The acuity falls off towards the periphery. The peripheral vision provides lower resolution to guide the eye movements so that the central vision visits all the interesting crucial parts. As a first contribution, the thesis developed remote visualization strategies that utilize the acuity fall-off to facilitate the processing, transmission, buffering, and rendering in VR of 3D reconstructed scenes while simultaneously reducing throughput requirements and latency. As a second contribution, the thesis looked into attentional mechanisms to select and draw user engagement to specific information from the dynamic spatio-temporal environment. It proposed a strategy to analyze the remote scene concerning the 3D structure of the scene, its layout, and the spatial, functional, and semantic relationships between objects in the scene. The strategy primarily focuses on analyzing the scene with models the human visual perception uses. It sets a more significant proportion of computational resources on objects of interest and creates a more realistic visualization. As a supplementary contribution, A new volumetric point-cloud density-based Peak Signal-to-Noise Ratio (PSNR) metric is proposed to evaluate the introduced techniques. An in-depth evaluation of the presented systems, comparative examination of the proposed point cloud metric, user studies, and experiments demonstrated that the methods introduced in this thesis are visually superior while significantly reducing latency and throughput

The dynamic interplay of external and internal attention

During natural behaviour, our attention is in constant flux, seamlessly transitioning between information available in the external environment and internal representations stored in working memory. However, as past research has primarily investigated external and internal attention in isolation, relatively little is known regarding the dynamic interplay between these two attentional domains. In this doctoral thesis, I explore scenarios where individuals encounter both external and internal information in quick succession, necessitating rapid shifts between perception and working memory. The experimental work in this thesis can be divided into two main branches. The first branch explores cross-domain attentional modulations; that is, how attention within one domain influences attention within the alternative domain. The second branch takes a deeper dive into the intricacies of shifting attention between domains. To provide an overview of previous contributions, Chapter 1 reviews past studies on external and internal attention, both as independent facets of attention and as interdependent phenomena. Building on this, Chapter 2 investigates the behavioural consequences of attentional shifts and examines how these can be modulated. Chapter 3 explores between-domain shifts by employing neural measures to examine the timing of reactivating internal representations following engagement in an external task. To understand the overarching nature of between-domain shifts, Chapters 4 and 5 introduce a novel, combined perception and working-memory task that allows within- and between-domain shifts to be contrasted in each respective domain. While Chapter 4 focusses on the behavioural correlates of between-domain shifts, Chapter 5 investigates the neural signatures associated with these transitions. Finally, in Chapter 6, I discuss the implications of my results and suggest potential avenues for future research. The findings of my doctoral research reveal that the dynamic interplay between attentional domains imposes behavioural costs; however, these costs are not immutable and can be influenced by various modulatory factors from multiple sources. Further, I demonstrate that prompt (but not always complete) shifts between attentional domains can be triggered by various events. Taken together, this thesis advocates for a holistic approach to examining external and internal attention