Yes / Background: Past research has found cancellation tasks to be reliable markers of cognitive decline in Huntington’s disease (HD). Objective: The aim of this study was to extend previous findings by adopting the use of a dual task paradigm that paired cancellation and auditory tasks. Methods: We compared performance in 14 early stage HD participants and 14 healthy controls. HD participants were further divided into groups with and without cognitive impairment. Results: Results suggested that HD participants were not slower or less accurate compared with controls; however, HD participants showed greater dual task interference in terms of speed. In addition, HD participants with cognitive impairment were slower and less accurate than HD participants with no cognitive impairment, and showed greater dual task interference in terms of speed and accuracy. Conclusions: Our findings suggest that dual task measures may be a better measure of cognitive processing in HD compared with more traditional measures. / Supported by the School of Psychological Sciences, Monash University.

Benefit from the recent advancements of artificial intelligence (AI) methods, industrial automation has replaced human labors in many tasks. However, humans are still placed in the central role when visual searching tasks are highly involved for manufacturing decision-making. For example, highly customized products fabricated by additive manufacturing processes have posed significant challenges to AI methods in terms of their performance and generalizability. As a result, in practice, human visual searching tasks are still widely involved in manufacturing contexts (e.g., human resource management, quality inspection, etc.) based on various visualization techniques. Quantitatively modeling the visual searching behaviors and performance will not only contribute to the understanding of decision-making process in a visualization system, but also advance AI methods by incubating them with human expertise. In general, visual searching can be quantitatively understood from multiple scales, namely, 1) the population scale to treat individuals equally and model the general relationship between individual's physiological signals with visual searching decisions; 2) the individual scale to model the relationship between individual differences and visual searching decisions; and 3) the attention scale to model the relationship between individuals' attention in visual searching and visual searching decisions. The advancements of wearable sensing techniques enable such multiscale quantitative analytics of human visual searching performance. For example, by equipping human users with electroencephalogram (EEG) device, eye tracker, and logging system, the multiscale quantitative relationships among human physiological signals, behaviors and performance can be readily established. This dissertation attempts to quantify visual searching process from multiple scales by proposing (1) a data-fusion method to model the quantitative relationship between physiological signals and human's perceived task complexities (population scale, Chapter 2); (2) a recommender system to quantify and decompose the individual differences into explicit and implicit differences via personalized recommender system-based sensor analytics (individual scale, Chapter 3); and (3) a visual language processing modeling framework to identify and correlate visual cues (i.e., identified from fixations) with humans' quality inspection decisions in human visual searching tasks (attention scale, Chapter 4). Finally, Chapter 5 summarizes the contributions and proposes future research directions. The proposed methodologies can be readily extended to other applications and research studies to support multi-scale quantitative analytics. Besides, the quantitative understanding of human visual searching behaviors performance can also generate insights to further incubate AI methods with human expertise. Merits of the proposed methodologies are demonstrated in a visualization evaluation user study, and a cognitive hacking user study. Detailed notes to guide the implementation and deployment are provided for practitioners and researchers in each chapter. / Doctor of Philosophy / Existing industrial automation is limited by the performance and generalizability of artificial intelligence (AI) methods. Therefore, various human visual searching tasks are still widely involved in manufacturing contexts based on many visualization techniques, e.g., to searching for specific information, and to make decisions based on sequentially gathered information. Quantitatively modeling the visual searching performance will not only contribute to the understanding of human behaviors in a visualization system, but also advance the AI methods by incubating them with human expertise. In this dissertation, visual searching performance is characterized from multiple scales, namely, 1) the population scale to understand the visual searching performance in regardless of individual differences; 2) the individual scale to model the performance by quantifying individual differences; and 3) the attention scale to quantify the human visual searching-based decision-making process. Thanks to the advancements in wearable sensing techniques, this dissertation attempts to quantify visual searching process from multiple scales by proposing (1) a data-fusion method to model the quantitative relationship between physiological signals and human's perceived task complexities (population scale, Chapter 2); (2) a recommender system to suggest the best visualization design to the right person at the right time via sensor analytics (individual scale, Chapter 3); and (3) a visual language processing modeling framework to model humans' quality inspection decisions (attention scale, Chapter 4). Finally, Chapter 5 summarizes the contributions and proposes future research directions. Merits of the proposed methodologies are demonstrated in a visualization evaluation user study, and a cognitive hacking user study. The proposed methodologies can be readily extended to other applications and research studies to support multi-scale quantitative analytics.

In adults, the availability of certain kinds of cues prior to a recognition task facilitates performance (often called “priming”). Studies have found that conceptual and perceptual priming improves neural efficiency and thus shortens response time in adults. In infant research, various visual and auditory/visual events are used as attention getters to orient the infant to a screen and alert them to upcoming information for their detection, discrimination, and/or recognition. However, the influence of attention-getters on infants’ performance has rarely been systematically evaluated, even though these attention cues could be acting as perceptual/conceptual primes. This study investigated the effect of priming on infants’ preferences for infant-directed speech (IDS) compared to adult-directed speech (ADS). IDS, an inherently social event, can be described as a moderator between attention systems and later language development. Thus, if the attentional network is primed in advance of hearing IDS, it is possible that the magnitude of the IDS preference may change. In this study, 20, 12- to 18-month old infants were provided with either a nonsocial or social prime in an infant-controlled, speech preference procedure with both IDS and ADS speech types. The infant’s total looking duration to IDS relative to ADS was compared for the social versus nonsocial prime condition. Results indicated a main effect for speech and overall IDS preference. However, no significant effect of prime was detected. Results are discussed in terms of future directions to investigate social priming of language in infancy. / Master of Science / In infant research, short duration events are used before the task of interest to orient infants to the screen, increase their attention, and prepare them for the following information to come. These events are called “attention getters” in developmental research, and are used internationally as a way to garner infants’ attention before the main test of interest. Labs use different attention getters based on their prior experience of what works best, and these attention getters vary in content (e.g., social, nonsocial), and format (e.g., audio, visual, audiovisual). The effect of the content of the attention getter on infants’ subsequent performance has never previously been studied, although the content could be acting as a prime for the following task. This study investigated the effect of a social, as opposed to nonsocial, attention getter on infants’ subsequent performance on a speech preference task. Infants (N = 20, 12- to 18-month olds) received both infant-directed speech (IDS; or how caregivers speak to their infants, characterized by shorter sentences, slower rate of speech, and exaggerated vowels) and adult-directed speech (ADS; or how adults speak to other adults, characterized by complex grammar, faster rates of speech, and shorter vowel sounds) which were preceded by either a social (woman saying “Hi Baby” in IDS) or nonsocial (swirling target with chimes) attention getter to investigate their preferences for speech type. It was predicted that infants who received a social prime would demonstrate a stronger preference for IDS over ADS relative to infants who received the nonsocial prime. Results indicated a main effect for speech and overall IDS preference. However, no significant effect of attention getter was detected, and the interaction between speech type and attention getter was not significant. Thus, our predicted results were not supported; the content of the attention getter did not attenuate or augment infants’ speech type preferences. Results are discussed in terms of future directions to better detect social priming in infancy.

Much research has examined how rate affects visual preferences in human infants and auditory preferences in avian infants. In the visual domain, it seems that human infants prefer stimuli (e.g., flashing displays) presented at faster relative rates. Research using avian species has shown that ducklings, for example, prefer their species- specific maternal call only when it is presented at values close to the species-typical mean. These studies have shown that experience affects ducklings'­ preferences for rate in auditory events. Researchers in the areas of human infant preferences for visual rate and avian infant preferences for auditory rate have suggested that an effective window of frequencies exists for which infants show maximal attention. Unlike these two areas, little research has addressed how rate affects human infants' preferences for auditory events. A study by Cooper and Cooper (1997) was the first to find that infants attend to rates of speaking infant directed (ID) speech. Specifically, infants preferred ID speech at its normal rate to ID speech at a faster rate. The present study was intended to further investigate how rate of speaking affected infants' preferences for ID speech. More specifically, this study sought to determine whether a window of effective rates also exists for infant preferences for rate in ID speech. Using an infant-controlled preference procedure, 20 six- to eight-week old infants were presented with ID-normal speech (ID speech as its normal rate) and ID- slow speech (ID speech slowed to half the normal rate). It was found that infants looked longer to a visual display when it was paired with ID-slow speech than when it was paired with ID-normal speech. How these results relate to research and theory on visual rate preferences in human infants and auditory rate in avian species is discussed, as well as future directions for this line of research. / Master of Science

The objective of this study was to examine attentional bias for threat in relation to social anxiety. It is well known that socially anxious individuals are likely to exhibit this bias, and this phenomenon may be clearly separated into two subsections: facilitation and disengagement. Facilitation, or vigilance, is the initial drawing of attention toward threat, and disengagement is the process of drawing attention away from threat. Past research focuses only on individuals ranked in the lowest and highest percentiles of any particular social anxiety measure, however, and fails to consider those having median scores. The current study included participants representing the full range of socially anxious individuals. In order to do this, the Fear of Negative Evaluations Scale (FNE) was distributed to undergraduate students (N = 230). A portion of these students was then drawn from each of six scoring ranges on the FNE. Participants in this new sample (N = 19) were asked to complete a computerized dot-probe detection task measuring attentional bias. The face stimuli for the current version of the computerized task included disgusted, happy, and neutral faces. Results of the correlational analyses showed a statistically significant positive correlation between FNE score and disengagement bias for disgust faces. There also was a statistically significant negative correlation between FNE score and vigilance bias for disgust faces. There was no suggestion of a statistically significant correlation between FNE score and vigilance or disengagement biases with happy faces.

BACKGROUND: The ability to recognize and respond appropriately to threat is critical to survival, and the neural substrates subserving attention to threat may be probed using depictions of media violence. Whether neural responses to potential threat differ in Down syndrome is not known. METHODS: We performed functional MRI scans of 15 adolescent and adult Down syndrome and 14 typically developing individuals, group matched by age and gender, during 50 min of passive cartoon viewing. Brain activation to auditory and visual features, violence, and presence of the protagonist and antagonist were compared across cartoon segments. fMRI signal from the brain's dorsal attention network was compared to thematic and violent events within the cartoons between Down syndrome and control samples. RESULTS: We found that in typical development, the brain's dorsal attention network was most active during violent scenes in the cartoons and that this was significantly and specifically reduced in Down syndrome. When the antagonist was on screen, there was significantly less activation in the left medial temporal lobe of individuals with Down syndrome. As scenes represented greater relative threat, the disparity between attentional brain activation in Down syndrome and control individuals increased. There was a reduction in the temporal autocorrelation of the dorsal attention network, consistent with a shortened attention span in Down syndrome. Individuals with Down syndrome exhibited significantly reduced activation in primary sensory cortices, and such perceptual impairments may constrain their ability to respond to more complex social cues such as violence. CONCLUSIONS: These findings may indicate a relative deficit in emotive perception of violence in Down syndrome, possibly mediated by impaired sensory perception and hypoactivation of medial temporal structures in response to threats, with relative preservation of activity in pro-social brain regions. These findings indicate that specific genetic differences associated with Down syndrome can modulate the brain's response to violence and other complex emotive ideas.

The present research examines three central issues in the context of ADIHD. First, a theory of attribution proposing that parents' causal attributions affect ADIHD children's locus of control is assessed. Second, ADIHD children's locus of control is linked to their psychological profiles. Finally, ADIHD is looked at from a cross-cultural perspective norms, highlighting the significance of parents' knowledge versus ignorance of the disorder. The main population of interest consists of unmedicated and untreated ADIHD children in Greece whose parents had no prior knowledge of the disorder. Initially, the impact of Greek parents' causal attributions about their ADIHD children's academic performance and behaviour on those children's locus of control is examined. Qualitative and quantitative analyses of the attributions made by parents were found to be associated with specific patterns of locus of control beliefs in their children. In-depth measures of the children's psychological profiles were found to be associated with their locus of control, and a detailed discussion compares these results with other research findings linking internalising and extemalising behaviours with biases in locus of control and attributional style. Then the possible implications of knowledge and socio-cultural beliefs are discussed in relation to the findings on two socio-culturally different populations - Greek and British ADIHD children's locus of control. Finally in an attempt to compare attributional differences, the role of locus of control is examined in an experimental test of task persistence and children's self-evaluations before and after a failure experience. It is concluded that socio-cultural norms influence the ways in which parents formulate causal explanations for their children's behaviour, which, in turn, influence the locus of control, the psychological profiles, the task persistence, and the self-evaluations of ADIHD children.

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Precognition can be defined as an anomalous correlation between current cognitive activity and a future event. Using behavioural and physiological measures, a number of previous studies have reported evidence for unconscious precognition during a variety of task conditions. The current thesis presents five experiments that were designed to test for unconscious precognition in the visual attention system while participants were engaged in a short term visual memory task. Each trial consisted of a study and test phase. In the study phase, participants were required to memorise an array of four stimuli while their eye movements were recorded. After a brief retention interval, a probe stimulus was presented for a yes/no recognition test. Two conditions were employed and were randomly determined. In the old condition, the probe was a stimulus viewed during study, termed the target. In the new condition, the probe was a novel stimulus. Experiments tested for the presence of precognition by examining whether there was a difference in the degree to which visual attention was allocated to items during the study phase of old and new trials. Two further studies were also carried out involving simulations that aimed to establish the extent to which a previously described artefact, termed the expectation bias, may impact on the results. Experiment 1 suggested that participants spent more time attending to target stimuli in old compared to new trials, a result that appeared to provide evidence for precognition. However, the data was considered unreliable due to inadequate randomisation. An exact replication of Experiment 1 was carried out in Experiment 2 with adequate randomisation, but failed to find evidence for precognition. Experiment 3A was a further attempt to replicate the preliminary results of Experiment 1 using more extensive randomisation procedures while Experiment 3B explored the potential role of the probe stimulus in generating a precognitive effect. However, no support for the precognitive hypothesis was found in either experiment. A fully balanced design was employed in Experiment 4 in order to control for potential confounds such as position and saliency effects. The results supported the precognitive hypothesis and suggested that less attention was allocated to targets in the old condition. An exploratory analysis also examined the relationship between several standardised stimulus variables and the apparent precognitive effect observed in Experiment 4. The results revealed a suggestive relationship between the size of the effect and item ratings of familiarity and visual complexity. Simulations of an expectation bias in Experiments 5A and 5B together with post-hoc examination of the data from the current series of experiments suggest that this artefact is not a plausible explanation for the observed effects. The thesis ends with a discussion of several methodological issues that may impact on both the interpretation of positive results and the conclusions that may be reached from this body of data as a whole. Finally, suggestions for further work are made.

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