Abstract:
People with bilateral macular disease are known to exhibit much higher fixation instability when compared with people with a normal fovea. The increased fixation instability is attributed to larger amplitudes of ocular drifts and microsaccades. Poor fixation stability has been suggested as a major factor limiting visual performance for people with macular disease. However, given that most people with bilateral macular disease adopt a peripheral retinal location, the preferred retinal locus, for visual tasks, it is also possible that the increased fixation instability and the larger amplitude of ocular drifts and microsaccades are necessary to prevent visual stimuli from fading. To date, the functional consequences of fixational eye movements of people with macular disease remain unclear. In this talk, I will present several studies from my lab to summarize the characteristics of fixational eye movements for people with macular disease; evaluate the relationships between the characteristics of fixational eye movements and visual performance; and empirically determine whether increased or decreased fixation stability could benefit vision for people with macular disease.

Abstract:
Where we look not only reflects our information needs, but also guides our movements and actions in the world. As gaze is so central to our interactions, it has been studied as an input modality for human-computer interaction (HCI) for as long as we have had modern computer interfaces. However, in decades of research, the approach has been to isolate eye movement as input, and to treat it as separate from other movements of the body that we use for interaction with computers. In this talk I will highlight how closely the movement of our eyes is coupled with other movement, of objects in the visual field, and the movement of our hands, head and body, and discuss examples of novel interfaces that leverage eye movement in concert with other motion and modalities.

Abstract:
Attention has long been an unavoidable and highly controversial construct in cognitive science. Much of the controversy surrounding this topic, I argue, stems from a lack of theoretical frameworks describing “top-down” attention control – the mechanisms that align attention with behavioral goals. I will describe a novel theory proposing that attention – and, in monkeys and humans, saccades – are deployed to maximize expected information gains (EIG) – and a neurocomputational model of EIG-based saccadic control in the fronto-parietal and executive networks. I will discuss evidence supporting the model and some of its implications for mechanisms of uncertainty and EIG estimation in different contexts and tasks.

Abstract:
Given that words serve as the fundamental processing units in all languages, the initial stage of reading involves the parsing of natural text into discrete units of text, or word segmentation. Without proper word segmentation, readers cannot comprehend text accurately. While this process may appear straightforward in languages that employ explicit cues to demarcate words (e.g., inter-word spaces), it poses considerable challenges for languages where words lack explicit demarcation, as seen in Chinese. Unfortunately, this crucial aspect of reading has historically been overlooked. Traditional reading models, which were usually designed for spaced languages, word segmentation is not an issue at all because readers can easily do so with the aid of inter-word spaces. Nevertheless, these models encounter substantial difficulties when applied to unspaced languages. In this talk, I will report recent experimental findings on the cognitive mechanisms involved in word segmentation and eye-movement control during Chinese reading. Then I will introduce a computational model, called the Chinese reading model (CRM), which was designed to simulate reading processes during Chinese reading. Furthermore, I will report some eye-tracking studies that investigate how word segmentation interacts with higher-level language processing, including syntax, semantics, and pragmatics. Finally, I will discuss how research on languages using different word demarcation methods have informed our insights into universal and script-specific reading mechanisms.

Abstract:
Visual processing is not homogeneous across the visual field: acuity and contrast sensitivity peak at the fovea in the center of the visual field. The peripheral visual field allows for a large field of view at lower resolution. Despite these differences, humans typically do not notice changes in visual information that result from bringing an object from the periphery to the fovea with a saccadic eye movement. I will present a series of studies demonstrating where, when and how pre- and postsaccadic feature information can be integrated in a manner close to statistically optimal. The detection of feature changes is impaired across saccades but shows that appearance is in general well calibrated between peripheral and foveal vision. These findings support the view that peripheral and foveal vision are interrelated despite their functional specialization.