Digitized by Kansas Correctional Industries

Digitized by Kansas Correctional Industries

The visual system integrates information over space to see surfaces, contours and edges. This integration can be described by a divisive normalization framework in which surrounding contextual information normalizes response to a central target. We ran a set of studies examining perceptual illusions with the intention of better understanding the neural mechanisms responsible for how the visual system integrates information over space. We measured surround integration using the Simultaneous Tilt Illusion. In the first study, we determined the extent to which the probability that different surround regions were co-assigned to the same object as the center impacts how much they are integrated. We found that the magnitude of the illusion was a sum of regional surround effects weighted by their dependency to the center. These results are consistent with a system that uses prior experience with natural scene statistics to integrate regions of space. In the second study, we measured the relationship between individual differences in spatial integration and autistic traits. We found no evidence for reduced normalization in people who score high on autistic traits. In the third study, we determined the extent to which arousal modulates spatial integration. Although we did not observe an effect of natural fluctuations in arousal, as indexed by pupil diameter, we observed a reduction in the magnitude of the illusion following an alerting tone. While more work is still needed to verify this effect, it suggests that we context information less under moderately alert states. We interpret these results in the context of the neural and perceptual mechanisms underlying spatial integration. Specifically, these results seem to indicate that the normalization process is gated by our expectancies about the structure of a scene and by our internal brain state. These results are consistent with a system that uses prior experience with scene statistics to represent patterns more efficiently.

The lateral line organ in fish and amphibians transforms fluid motion in the animal's surroundings into a representation of its hydrodynamic environment. This sense is involved in complex behaviors, ranging from rheotaxis to schooling. The primary sensory neurons are hair cells, each of which can tonically transmit a graded ‘analog' signal to afferent neurons, via highly specialized ‘ribbon' synapses. Many questions about this first step in sensory coding remain to be answered. For example: What is the relationship between the biologically relevant stimulus and hair cell output? How do the synaptic properties of different hair cells contribute to the signal that is sent to the brain? And how are these signals modulated by top-down (efferent) projections? The first chapter of this thesis describes a newly established preparation including an overview of transgenic fish lines, some of which were newly generated, to study the processing of mechanical information in larval zebrafish at various stages, from the periphery to the hindbrain. The second chapter contains a detailed characterization of the relationship between cupula deflection and hair-cell glutamate release. We show that the population of hair cells in the lateral line is highly heterogeneous in terms of their sensitivity, dynamic range and adaptive properties and that this heterogeneity has functional implications for downstream processing. These results are unique because of how well the biophysical, anatomical and physiological context of the actual sensory transduction is maintained. The third chapter describes the effects of (fictive) locomotion on the processing of mechanical information. We show that an efferent signal, which is highly correlated with motor neuron activity, is present in the neuromast and leads to a strong suppression of mechanically induced activity of afferent neurons. This efference copy appears to selectively reduce the gain to hair cells sensitive to posterior cupula deflections.

同客体效应通常被用来支持基于物体的注意分配这一理论观点，该效应已被广大研究者所证实。但是，与之同时，有些研究者报告发现与同客体效应完全相反的效应---异客体效应。因此，本文旨在探究为何这两种看似矛盾的效应会在不同的研究中出现，从而解决由这两类效应引发的冲突。研究一通过6个实验并且采用不同的刺激、任务以及研究范式来检验异客体效应的稳定性以及普遍性。研究结果表明，正如已被广泛探究和验证的同客体效应一样，异客体效应同样也是一种有效稳定并且普遍存在的效应，该效应可以在不同的实验情境下出现。这些结果激发了研究二中探讨的一系列新的问题。即，既然异客体效应也是一种有效稳定并且普遍存在的效应，而并非只是一些特定方法的产物，那为什么该效应会发生，其内在的心理机制是什么？此外，假如同客体与异客体这两种效应都是有效稳定的效应，那么这两种效应分别会在什么时候出现，以及哪些因素可以预测决定这两种效应的出现。研究二通过5个实验并且调控两个目标子之间的一致性来探究以上问题。结果发现，当两个目标子是相同的刺激（甚至当两个目标子只是在身份上一样而物理特征上不一样），异客体效应出现；而当两个目标子是不同刺激时，则同客体效应出现。此外，这些结果已经被证明并不仅仅是由于被试的反应偏差所导致的。总得来说，本次研究结果证明 1）异客体效应与同客体效应一样，也是一种有效稳定并且普遍存在的效应； 2）两目标子之间的一致性可以预测决定同客体或是异客体效应的出现。 / The same-object advantage (SOA) effect is usually cited as evidence favoring the view of object-based attention. However, the different-object advantage (DOA) effect, which appears to be the opposite of the SOA effect, has also been reported by some researchers. The present study was designed to resolve this apparent inconsistency. In Study 1, I tested the robustness and generality of the DOA effect through a series of six experiments (Experiments 1-6) by exploiting different stimuli, tasks and paradigms. The results demonstrated that, as the well-documented SOA effect, the DOA effect was also a robust effect that can emerge under numerous circumstances, rather than just the byproducts of certain methods. These findings motived the second study in which I attempted to investigate the mechanism underlie DOA effect, as well as to explore critical factors that can predict the presences of SOA and DOA effects. Specifically, with a series of another five experiments (Experiments 7-11), I manipulated the identicality between two targets and found the SOA effect when the targets were different but the DOA effect when they were identical (even when the targets just share a common identity but different physical formats). These findings have been proved not just arose from any possible response bias. Taken together, the results of the present study demonstrate that 1) the DOA effect was also a robust effect as the SOA effect, and 2) the occurrences of SOA versus DOA effects can be critically determined by the identicality between targets. / Detailed summary in vernacular field only. / Chen, Hui. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2013. / Includes bibliographical references (leaves 96-103). / Abstracts also in Chinese. / Abstract --- p.II / Chinese Abstract --- p.IV / Acknowledgements --- p.V / Contents --- p.VII / Chapter Chapter 1. --- Introduction --- p.1 / Chapter 1.1. --- Previous studies on the SOA effect --- p.2 / Chapter 1.1.1. --- SOA effect based on divided-attention paradigm: --- p.2 / Chapter 1.1.2. --- SOA effect based on spatial-cuing paradigm --- p.5 / Chapter 1.2. --- Theories of SOA effect --- p.6 / Chapter 1.2.1 --- Sensory enhancement hypothesis --- p.7 / Chapter 1.2.2. --- Attentional shifting hypothesis --- p.9 / Chapter 1.2.3. --- Attentional prioritization hypothesis --- p.11 / Chapter 1.3. --- The factors that can affect SOA effect --- p.14 / Chapter 1.3.1. --- Cue-target stimulus onset asynchrony --- p.15 / Chapter 1.3.2. --- Object preview time --- p.16 / Chapter 1.3.3. --- Goodness of the object --- p.17 / Chapter 1.3.4. --- Spatial extent of attention --- p.18 / Chapter 1.4. --- Previous studies on the DOA effect --- p.19 / Chapter Chapter 2. --- The current study --- p.23 / Chapter 2.1. --- Aim of the present study --- p.23 / Chapter 2.2. --- Overview of the present study --- p.23 / Chapter Chapter 3. --- Study 1: The robustness and generality of the DOA effect --- p.25 / Chapter 3.1. --- Experiment 1 --- p.25 / Chapter 3.1.1. --- Method --- p.25 / Chapter 3.1.2. --- Results --- p.27 / Chapter 3.1.3. --- Discussion --- p.29 / Chapter 3.2. --- Experiment 2 --- p.30 / Chapter 3.2.1. --- Method --- p.30 / Chapter 3.2.2. --- Results --- p.31 / Chapter 3.2.3. --- Discussion --- p.33 / Chapter 3.3. --- Experiment 3 --- p.34 / Chapter 3.3.1. --- Method --- p.34 / Chapter 3.3.2. --- Results --- p.36 / Chapter 3.3.3. --- Discussion --- p.37 / Chapter 3.4. --- Experiment 4 --- p.38 / Chapter 3.4.1. --- Method --- p.39 / Chapter 3.4.2. --- Results --- p.40 / Chapter 3.4.3. --- Discussion --- p.43 / Chapter 3.5. --- Experiment 5 --- p.44 / Chapter 3.5.1. --- Method --- p.44 / Chapter 3.5.2. --- Results --- p.46 / Chapter 3.5.3. --- Discussion --- p.47 / Chapter 3.6 --- Experiment 6 --- p.48 / Chapter 3.6.1. --- Method --- p.48 / Chapter 3.6.2. --- Results --- p.51 / Chapter 3.6.3. --- Discussion --- p.53 / Chapter Chapter 4. --- Study 2: The mechanism underlie DOA effect and the factor that determine the occurrence of SOA vs. DOA effect --- p.55 / Chapter 4.1 --- Experiment 7 --- p.57 / Chapter 4.1.1. --- Method --- p.57 / Chapter 4.1.2. --- Results --- p.59 / Chapter 4.1.3. --- Discussion --- p.61 / Chapter 4.2 --- Experiment 8 --- p.61 / Chapter 4.2.1. --- Method --- p.62 / Chapter 4.2.2. --- Results --- p.63 / Chapter 4.2.3. --- Discussion --- p.64 / Chapter 4.3 --- Experiment 9 --- p.65 / Chapter 4.3.1. --- Method --- p.66 / Chapter 4.3.2. --- Results --- p.67 / Chapter 4.3.3. --- Discussion --- p.69 / Chapter 4.4 --- Experiment 10 --- p.69 / Chapter 4.4.1. --- Method --- p.70 / Chapter 4.4.2. --- Results --- p.71 / Chapter 4.4.3. --- Discussion --- p.72 / Chapter 4.5 --- Experiment 11 --- p.74 / Chapter 4.5.1. --- Method --- p.74 / Chapter 4.5.2. --- Results --- p.76 / Chapter 4.5.3. --- Discussion --- p.78 / Chapter Chapter 5. --- General discussion --- p.79 / Chapter 5.1 --- Overview of present findings --- p.79 / Chapter 5.2 --- When can SOA effect happen? --- p.81 / Chapter 5.2.1 --- The initial distribution of attention --- p.82 / Chapter 5.2.2 --- The relationship between targets and objects --- p.84 / Chapter 5.3 --- When can DOA effect happen? --- p.86 / Chapter 5.4 --- How can SOA effect happen? --- p.88 / Chapter 5.5 --- How can DOA effect happen? --- p.90 / Chapter 5.6 --- The possible relationships between SOA and DOA effects --- p.92 / Chapter 5.7 --- Limitations and future directions --- p.93 / BIBLIOGRAPHY --- p.96

草圖繪製是創意產業最早期的一個工序。研究發現，草圖不但表達了畫家的想法，在繪製的過程，草圖也能為畫家帶來新靈感，所以草圖繪製是不可缺少的工序。然而，原始的草圖包含許多不必要的筆觸，所以進行後期製作前，必須用線重新勾畫。傳統上，這個過程是費時和繁瑣的，畫家必須人手把每一條需要的線都重新勾畫出來。當應用到動畫創作的時候，由於涉及的草圖數量龐大，情況會變得更壊，所以有必要把整個過程自動化。現有的研究都視草圖勾勒為一個線條分組和曲線擬合的過程，他們會把相近而順暢的筆觸組合在一起，形成單一線條。然而，他們都忽略了視覺感知上的一個重要法則──格式塔理論中的閉合原理。格式塔理論是一個知名的心理學理論，解釋人類如何透過整合理解各種視覺元素。根據格式塔理論中的閉合原理，我們往往把各種分隔的視覺元素整合為一個封閉的形狀。在這篇論文中，我提出閉合原理比格式塔理論中的其他原理更能幫助我們理解草圖，從而提出了一種基於區域的方法來勾勒草圖。實驗結果發現，我的方法在保有草圖上封閉形狀的能力上比現有的方法更優勝。 / Sketching is the earliest stage of production in art and design. Sketches are useful in conveying and developing ideas. However, raw sketches contain unnecessary strokes and must be converted to neat and tidy drawings before moving onto later stage of production. Traditionally, this conversion process is time-consuming and tedious since it is performed stroke by stroke manually. The situation is even worse when it comes to animation production which involves a huge number of sketches, so there is a strong motivation to automate the conversion process. Existing works formulate the conversion process as stroke grouping and curve fitting processes, in which close and continuous strokes are grouped together to form single strokes in the resulting image. Nevertheless, previous works overlooked an important law of visual perception: the law of closure in Gestalt principles. Gestalt principles concluded from early visual perception studies demonstrate how human perceive visual elements as different groups of lines and shapes. It states that we tend to group elements into closed shape even when a gap exists. In this thesis, we utilize the idea of law of closure and propose a region-based approach to refine sketches. Experiment result shows that this method outperforms the existing methods in terms of the capability of preserving salient regions in sketches. / Detailed summary in vernacular field only. / Wong, Ka Wing. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 59-61). / Abstracts also in Chinese. / Chapter 1 --- Introduction --- p.6 / Chapter 2 --- Background --- p.8 / Chapter 2.1 --- Role of Sketch in Art and Design --- p.8 / Chapter 2.2 --- Characteristics of Raw Sketches --- p.10 / Chapter 2.3 --- Related Works --- p.11 / Chapter 2.3.1 --- Methods for Raster Image --- p.12 / Chapter 2.3.2 --- Methods for Vector Image --- p.14 / Chapter 2.3.3 --- Deficiency --- p.17 / Chapter 3 --- Gestalt Principles and Its Application --- p.18 / Chapter 3.1 --- Introduction to Gestalt Principles --- p.18 / Chapter 3.2 --- Existing Computational Model of Gestalt Principles --- p.20 / Chapter 3.3 --- Gestalt Principles for Outline Tracing --- p.22 / Chapter 3.3.1 --- Similarity --- p.23 / Chapter 3.3.2 --- Proximity --- p.23 / Chapter 3.3.3 --- Continuity --- p.24 / Chapter 3.3.4 --- Regularity --- p.25 / Chapter 3.3.5 --- Closure --- p.25 / Chapter 4 --- Proposed Method --- p.27 / Chapter 4.1 --- Multi-scale Region Retrieval --- p.28 / Chapter 4.1.1 --- Construction of Region Hierarchy --- p.29 / Chapter 4.1.2 --- Region Refinement --- p.31 / Chapter 4.2 --- Salient Region Retrieval --- p.32 / Chapter 4.2.1 --- Flattening of Region Hierarchy --- p.32 / Chapter 4.2.2 --- Region Merging --- p.33 / Chapter 4.2.3 --- Region Pruning --- p.37 / Chapter 4.2.4 --- Region Merging by User --- p.41 / Chapter 4.3 --- Outline Synthesis --- p.43 / Chapter 4.3.1 --- Outline Synthesis of Region-boundary Strokes --- p.44 / Chapter 4.3.2 --- Smoothing of Region-boundary Strokes --- p.45 / Chapter 4.3.3 --- Outline Synthesis of Feature Strokes --- p.48 / Chapter 4.4 --- Curve Fitting --- p.50 / Chapter 5 --- Result and Discussion --- p.52 / Chapter 6 --- Conclusion --- p.58 / Chapter 7 --- Reference --- p.59

First, although there is some evidence suggesting IOR influences nonspatial attribute-based visual search, the effects observed have been small and inconsistent, have not followed the same time course as more standard IOR, and there is some evidence that the effect may depend on presenting a "neutral attractor" between the cue and target. In Experiments 1(1a,1b) and Experiment 2(2a), participants ii demonstrated a robust color-, and shape-based inhibitory effect that, unlike previous findings, followed a time course similar to that for location-based IOR. Moreover, the effect does not seem to require the presentation of a neural attractor. Experiment 3 and Experiment 2b demonstrated that less or no attribute-based IOR appeared if the cue and target were less salient. The results showed that if the stimuli offer featural differences that are salient enough, the perceptual system uses them to encode the displays, and IOR can be applied to those features. / Inhibition of return (IOR) has been reported when a target is preceded by an irrelevant stimulus (cue) at the same location: Target detection is slowed, relative to uncued locations. It is suggested that IOR is a general phenomenon that helps to provide a broad sampling of stimuli in the environment. In recent years, however, the generality of the IOR phenomenon has been questioned. Although there is considerable research demonstrating inhibition of cued locations, and a mountain of evidence for inhibition of cued objects, inhibition of cued nonspatial attributes, like color, shape and orientation, has rarely been explicitly demonstrated. Using a paradigm that has shown robust location-based IOR when relatively richer displays are presented, the present thesis addresses three noticeable gaps in the IOR literature relating to nonspatial feature visual search. / Second, the nonspatial-based IOR effect does not seem to be independent of location, as it only occurs when cue and target share not only features, but location. The results suggest that attentional selection can be applied to stimulus properties such as color, shape, and orientation, but that the attentional operations are specified in location-based coordinates. Given location-based IOR appeared in all experiments, repetition of nonspatial features may reflect an additional phenomenon. When the cue and the target do not share location, they can not be the same object, indicating featural IOR is rather object based. / Third, in Experiment 4, 5 and 6, when attribute discrimination tasks were required, the attribute-based IOR was gone. So far, there have been a limited number of studies examing the attribute-based discrimination research, and the results of them are mixed. Our results clearly indicated that the attribute-based inhibitory effect does not generalize to higher mental demanding tasks. We suggested that this type of cuing effects can be considered as different manifestations of attentional capture on non-spatial attributes processing, that is, under attribute-based higher demanding tasks observers allocate attestation to locations, rather than to attributes; hence IOR is predominantly location-based. / To conclude, these findings shed considerable light on IOR: nonspaital attribute-based IOR can be demonstrated under certain conditions, with rich displays, and with enough stimulus salience. Critically, the effect of inhibition directed to an attribute is tied to the location of the prior stimulus. The effect also depends on the difficulty of the target processing (simple detection task vs. discrimination task). / Hu, Kesong. / Adviser: Agnes S.Chan. / Source: Dissertation Abstracts International, Volume: 72-11, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves 108-122). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.

This thesis used pupillometry to investigate whether pupils respond differently to faces that differ in familiarity. We aimed to see whether pupillometry measures cognitive processes involved in face processing, and whether it could be applied forensically. We started by evaluating three explanations for pupillary changes that occur when processing faces. The first was cognitive load (mental effort), because faces that have only been seen briefly are more difficult to recognise than well-known faces. The second was cognitive engagement (interest), because faces contain socially-important information. The third was memory strength (forensically applicable), as eyewitnesses have to recall a perpetrator's face in an attempt to identify them if they appear in a lineup. While pupillary responses reflected cognitive engagement to some extent, cognitive load best accounted for decreasing pupil sizes when learning new faces, and memory strength explained the pupillary changes seen in lineups. The theories all had some influence on pupil sizes, but their influence varied according to context, saliency, and the task at hand. Then we investigated whether pupillometry measured implicit recognition of a perpetrator in a lineup, and found that it did. Pupil sizes reflected memory strength in participants who believed their memory to be strong: there were differences in pupil sizes (between looking at the perpetrator and the distractors) in participants who identified him, but not in those who did not. The pupillary responses of participants who 'guessed' indicated that they were indeed guessing. There were no pupillary changes when the perpetrator was not in the lineup, even when participants misidentified a distractor. We concluded that pupillary responses are independent of explicit identification responses, and could be used forensically to support traditional measures of eyewitness identification and credibility.

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