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<p>In the first chapter, I conduct an eye-tracking experiment to measure how subjects allocate attention over a price chart while they predict future stock returns. I confirm that the attention allocation reflects how subjects form expectations from past price information. The measure of expectation based on eye-tracking quantitatively fits the actual forecasts submitted by subjects. Easily recognizable patterns in data receive disproportionately more attention: Subjects spend much more time reading recent as well as extreme trends and price levels. Such heuristics in information acquisition are heterogeneous across subjects and lead to inferior forecast precision. Overall, the results provide direct evidence for investor beliefs hypothesized by theories of return extrapolation. </p> <p><br></p> <p>In the second chapter, co-authored by Sergey Chernenko and Huseyin Gulen, we use data on scrip dividends, which give shareholders the option to receive additional shares instead of cash dividends, to investigate how investors form expectations of future returns. Shareholders are more likely to elect to receive dividends in shares when recent past returns are higher, especially when returns are positive and volatile. Actions based on extrapolative beliefs are stronger in small firms, growth firms, and firms with low institutional ownership. Finally, take-up rates of scrip dividends negatively predict both short- and long-run future returns.</p>

付記する学位プログラム名: 霊長類学・ワイルドライフサイエンス・リーディング大学院 / 京都大学 / 新制・課程博士 / 博士(理学) / 甲第23747号 / 理博第4837号 / 新制||理||1692(附属図書館) / 京都大学大学院理学研究科生物科学専攻 / (主査)教授 平田 聡, 教授 伊谷 原一, 教授 村山 美穂 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DFAM

This study utilized eye-tracking to investigate 63 intermediate-level university Chinese foreign language (CFL) learners' real-time radical preferences. Radicals are components of Chinese characters and give clues to the meanings and pronunciations of the character. This study aimed to answer the following research questions: (1) What type of radicals (semantic/phonetic) do CFL readers most rely on when reading characters? (2) Does reliance on one type of radical (semantic/phonetic) correlate with accuracy in character recognition? (3) Does awareness of semantic/phonetic radicals affect the accuracy of character recognition or reliance on radicals in real-time processing? The results found that participants demonstrated a phonetic bias in that they had more proportion of looks on phonetic over semantic radicals in real-time reading. Furthermore, participants' radical awareness and radical identification scores positively correlated with accurate character recognition. Pedagogical applications drawn from this study suggest that future instructors should explicitly teach radical identification to CFL learners to facilitate character decoding.

Yes / It has been proposed that mentalising involves retrodicting as well as predicting behaviour, by inferring previous mental states of a target. This study investigated whether retrodiction is impaired in individuals with Autism Spectrum Disorders (ASD). Participants watched videos of real people reacting to the researcher behaving in one of four possible ways. Their task was to decide which of these four “scenarios” each person responded to. Participants’ eye movements were recorded. Participants with ASD were poorer than comparison participants at identifying the scenario to which people in the videos were responding. There were no group differences in time spent looking at the eyes or mouth. The findings imply those with ASD are impaired in using mentalising skills for retrodiction.

The broad autism phenotype (BAP) has been defined both behaviorally and biologically. There has been little research on the association of the BAP, behaviorally defined, with neural or cognitive biomarkers typically associated with Autism Spectrum Disorder (ASD). People diagnosed with ASD tend to show reduced gaze fixation toward the eye region, but much less eye-tracking research has been done related to the BAP (Boraston & Blakemore, 2007). In this study, we sought to assess eye gaze patterns in people with the behaviorally defined BAP, as defined by a score of 30 or above on the Autism Spectrum Quotient (AQ; Baron-Cohen et al., 2001). It was hypothesized that the BAP group participants would exhibit longer average fixation duration to the eye region during an emotion recognition condition, relative to a free-viewing condition, whereas the comparison group participants (defined as an AQ score of 24 and below) would not show a difference in fixation duration to the eye region between conditions. Nine hundred and thirty-nine undergraduates completed an online survey, and 45 of these students (15 BAP group and 30 comparison group) participated in the eye-tracking session, where they viewed a series of human faces, each presented twice within a condition. Results revealed a significant negative relationship between social anxiety and eye region fixation duration in the free-viewing condition, for both presentations of faces. Contrary to expectation, BAP predicted longer eye region fixation duration in the free-viewing condition, for the second presentation of faces. Possible explanations for these surprising findings are discussed. / Master of Science

Prior research has shown that both emotion recognition and expression in children with Autism Spectrum Disorder (ASD) differs from that of typically developing children, and that these differences may contribute to observed social impairment. This study extends prior research in this area with an integrated examination of both expression and recognition of emotion, and evaluation of spontaneous generation of emotional expression in response to another person's emotion, a behavior that is characteristically deficient in ASD. The aim of this study was to assess eye gaze patterns during scripted and spontaneous emotion expression tasks, and to assess quality of emotional expression in relation to gaze patterns. Youth with ASD fixated less to the eye region of stimuli showing surprise (F(1,19.88) = 4.76, p = .04 for spontaneous task; F(1,19.88) = 3.93, p = .06 for the recognition task), and they expressed emotion less clearly than did the typically developing sample (F(1, 35) = 6.38, p = .02) in the spontaneous task, but there was not a significant group difference in the scripted task across the emotions. Results do not, however, suggest altered eye gaze as a candidate mechanism for decreased ability to express an emotion. Findings from this research inform our understanding of the social difficulties associated with emotion recognition and expression deficits. / Master of Science

Previous research on emotion identification in Autism Spectrum Disorders (ASD) has demonstrated inconsistent results. While some studies have cited a deficit in emotion identification for individuals with ASD compared to controls, others have failed to find a difference. Many studies have used static photographs that do not capture subtle details of dynamic, real-life facial expressions that characterize authentic social interactions, and therefore have not been able to provide complete information regarding emotion identification. The current study aimed to build upon prior research by using dynamic, talking videos where the speaker expresses emotions of happiness, sadness, fear, anger, and excitement, both with and without a voice track. Participants included 10 children with ASD between the ages of four and 12, and 10 gender- and mental age-matched children with typical development between six and 12. Overall, both ASD and typically developing groups performed similarly in their accuracy, though the group with typical development benefited more from the addition of voice. Eye tracking analyses considered the eye region and mouth as areas of interest (AOIs). Eye tracking data from accurately identified trials resulted in significant main effects for group (longer and more fixations for participants with typical development) and condition (longer and more fixations on voiced emotions), and a significant condition by AOI interaction, where participants fixated longer and more on the eye region in the voiced condition compared to the silent condition, but fixated on the mouth approximately the same in both conditions. Treatment implications and directions for future research are discussed. / Master of Science

Emerging research suggests that many adults with Autism Spectrum Disorder (ASD) experience impairing Social Anxiety Disorder (SAD) or social anxiety symptoms (e.g., Joshi et al., 2013; Kleinhans et al., 2010), yet there is little guidance or agreement about how to best assess social anxiety in this population. Direct examination of overt eye gaze patterns may help determine if the attentional biases often reported in people with SAD also operate in those with ASD and co-occurring social anxiety. This study sought to assess the influence of social anxiety on gaze patterns in adults with ASD. An exploratory aim was to better understand the phenomenology of SAD within ASD. Three groups of participants were included: adults with ASD (n = 25), adults with SAD (n = 25), and adults without ASD or SAD (n = 25). As hypothesized, a large subset (n = 11; 44%) of the participants with ASD met diagnostic criteria for SAD. Contrary to study hypotheses related to gaze patterns, however, there was no evidence for gaze vigilance followed by avoidance for socially threatening stimuli in either the ASD or SAD groups, and there was no relationship between fear of negative evaluation and gaze duration toward socially threatening stimuli within the ASD group. Possible reasons for these null findings are considered. Clinical implications and suggestions for future research are also discussed. / Ph. D.