We have a strong intuition that people's eyes are unique, socially informative stimuli. As such, it is reasonable to propose that humans have developed a fundamental tendency to preferentially attend to eyes in the environment. The empirical evidence to support this intuition is, however, remarkably thin. Over the course of eight chapters, the present thesis considers the area of social attention, and what special role (if any) the selection of eyes has in it. Chapters 2 and 3 demonstrate that when observers are shown complex natural scenes, they look at the eyes more frequently than any other region. This selection preference is enhanced when the social content and activity in the scene is high, and when the task is to report on the attentional states in the scene. Chapters 4 and 5 establish that the bias to select eyes extends to a variety of tasks, suggesting that it may be fundamental to human social attention. In addition, Chapter 5 shows that observers who are told that they will have to remember the scenes look more often at the eyes than observers who are unaware of the forthcoming memory test; moreover this difference between groups persists to scene recognition. Chapter 6 examines whether the preference for eyes can be explained by visual saliency. It cannot. Chapter 7 compares the selection of eyes to another socially communicative cue, the arrow. The results shed light on a recent controversy in the social attention field, and indicate again that there is a fundamental bias to select the eyes. Collectively the data suggest that for typically developing adults, eyes are rich, socially communicative stimuli that are preferentially attended to relative to other stimuli in the environment.

Thesis (Ph. D.)--University of Texas at Austin, 2007. / Vita. Includes bibliographical references.

Thesis (M. Sc. Med.)--Discipline of Medicine, Faculty of Medicine, University of Sydney, 2007. / Title from title screen (viewed June 20, 2007). Submitted in fulfilment of the requirements for the degree of Master of Science in Medicine to the Faculty of Medicine. Degree awarded 2007; thesis submitted 2005. Includes bibliography. Also issued in print.

Thesis (Ph.D.)--University of Western Australia, 2003.

Thesis (M. A. in Psychology)--Vanderbilt University, Aug. 2008. / Title from title screen. Includes bibliographical references.

Thesis (M.Eng.). / Title from title page of PDF (viewed 2008/01/30). Written for the Dept. of Biomedical Engineering. Includes bibliographical references.

Thesis (Ph. D.)--Northeastern University, 2008. / Title from title page (viewed March 3, 2009). Graduate School of Arts and Sciences, Dept. of Psychology. Includes bibliographical references (p. [80]-91).

Thesis (M. S.)--Psychology, Georgia Institute of Technology, 2009. / Committee Chair: Griffin, Zenzi; Committee Member: Blanchard-Fields, Fredda; Committee Member: Spieler, Daniel

There are different aims in this thesis. The primary aim is to investigate visual perception in Chinese orthography, from its fundamentally distinct unit, characters, to sentence reading. The first aim of the thesis is to investigate how a single Chinese character is processed in many ways. We have looked into an effect called orthographic satiation/decomposition (Cheng & Wu, 1994). It refers to the feeling of uncertainty about the composition of some characters when staring at a character for too long. Lee (2007) extended Cheng and Wu’s study (1996), and the results have showed that orthographic satiation occurred faster in females than males. We replicated Lee’s study (Experiment 1) (Chapter 3), and have found that: (1) there was no significant difference between male and female and (2) a radical that can stand alone as a single character makes characters in which it occurs resistant to satiation. Following orthographic satiation, in Chapter 4, we explored the preference for eye/hemisphere visual pathways in Chinese characters (Experiment 2 & 3) and words (Experiment 4). In English, researchers have reported a contralateral preference when four-letter words were presented very quickly using a haploscope (Obreg´on & Shillcock, 2012) . It raises the question of whether presenting Chinese characters and words will show similar results considering the complexity and the special characteristics of Chinese orthography. We presented Chinese characters and words to participants using a haploscope. Our results showed that: (1) the contralateral visual pathway was preferred in perceiving right-left structured Chinese characters and two-character words, (2) when a semantic radical is projected to the LH, participants are able to recognise the semantic component better, (3) neighbourhood size (NS) (Tsai, Lee, Lin, Tzeng & Hung, 2006) affects how participants recognise words, and(4) males do better than females recognising characters but not words. After investigating the recognition of Chinese characters and words, we analysed the eye-movements in Chinese and English reading corpora. The processes of reading are intuitively thought to be more complex than perceiving a single character or words. The last studies in the thesis focused on the reading behaviours in Chinese and English. The eye movement differences and similarities between reading Chinese and English were investigated. In Chapter 5, we showed that reading Chinese elicits more divergence of the eyes within a fixation, compared with reading English. We interpreted these data in terms of recent demonstrations that apparent size causes increases in visual sensitivity (Arnold & Schindel, 2010) and engages more cortical resource in V1 (Kersten & Murray, 2010). Our analyses were based on movement within exactly temporally synchronized binocular fixations in the reading of Chinese and English 5000-word multi-line texts, using monocular calibration, with EyeLink-2 technology. When faced with visually complex orthography, the oculomotor system ‘tricks’ the rest of the visual system into ‘zooming in’ on the text. We consolidated the relevant theorizing into the ‘Divergence Affects Reading’ (DOLLAR) Theory. In Chapter 6, we reported that (1) vertical movements within a fixation tend to be smaller than horizontal ones, and (2) vertical movements within a fixation tend to be upwards. We speculated that it is appropriate for the earlier part of the fixation to be associated with visual recognition and for the later part of the fixation to be associated with executive action. The tendency to move upwards also suggested that in real-world reading, the upper part of words/characters were informative. In the last chapter analysing the reading corpus (Chapter 7), we reported corrective saccades after return sweeps. We found that in English, there were more corrective saccades after return sweeps than in Chinese. We interpreted these data in terms of spatial coding (Kennedy & Murray, 1987). In terms of Chinese and English differences, the stimuli that were used in our corpus show that the length for each line was different in English. The length for each line in Chinese was less different. Though the first character of each line was at the same place for two languages, it was more difficult for English subjects to locate the correct place after return sweeps because the length of return sweeps was different. In short, this thesis investigated visual perception in Chinese orthography, in terms of characters, words, and real-world reading. Moreover, we compared the differences and similarities between languages (English and Chinese). Despite the fact that the orthographies of English and Chinese are very different, we still found similar effects (e.g., contralateral preference) between them. This thesis thus has contributed to a better understanding of the differences and similarities between English and Chinese in terms of the orthographies.

The aim of this thesis is to predict targets in a Multiple Object Tracking (MOT) task, in which subjects track multiple moving objects. We processed and analyzed data containing object and gaze position information from 1148 MOT trials completed by 20 subjects. We extracted multiple features from the raw data and designed a machine learning approach for the prediction of targets using neural networks and hidden Markov models. We assessed the performance of the models and features. The results of our experiments show that it is possible to train a machine learning model to predict targets with very high accuracy. 1