Dissertations / Theses on the topic 'Inattentional Blindne'

The influence of attention on perception is a much-discussed issue in the literature. Largely manifested in the Inattentional Blindness phenomenon (IB) (Mack & Rock, 1998; Most et al., 2005; Simons & Chabris, 1999), it has been extensively studied with respect of visual perception, but neglected in other sensory modalities like hearing. We investigated if IB could have an equivalent within the auditory modality: Inattentional Deafness (ID). Besides, we wonder how double-modality presentation of attended and unattended stimuli affects the presence and the extent of IB and ID. For these reasons we ran three different experiments, using the selective looking paradigm (Neisser, 1979); in every case the primary task was to count the bounces made by two teams passing two balls of different materials (making two different sounds) with wooden rackets. In experiments 1 and 2 the unattended stimulus was a black-dressed girl making a loud noise that crossed the visual field. In the last experiment the unattended stimulus was just auditory, thus the loud sound made by the girl, now invisible. Our data show that ID is a possible, strong and reliable phenomenon, and it can be increased in particular conditions, such as coupling the auditory modality of the primary task with the visual one (exp 1, 2 and 3) or pressing the space-bar in correspondence to the bounces (exp 2 and 3). We conclude that our results favor the existence of a non specific attentional system, shared between, and not within, modalities.

Inattentional blindness is a phenomenon in which people fail to notice stimuli appearing under their gaze when they are engaged with an attentionally demanding task. With our research we tried to understand what happens to the unattended stimulus when it is not seen; more precisely, we tried to understand if it is completely ignored or if it is elaborated, even if unconsciously. Moreover, we explored the novel possibility to generate inattentional blindness engaging participants with an auditory, rather than a visual, task.
La cecità da disattenzione è quel fenomeno per cui, quando stiamo prestando attenzione ad un oggetto o evento, accade che altri oggetti o eventi inattesi passino del tutto inosservati. L’obiettivo principale della mia attività di ricerca in questi tre anni è stato quello di approfondire il destino dello stimolo inatteso quando non visto. Abbiamo infatti indagato se venisse completamente ignorato o venisse comunque elaborato, anche se in modo non consapevole. Abbiamo inoltre studiato se vi fosse la possibilità di generare cecità da disattenzione utilizzando come compito target un compito presentato in modalità non visiva, e quindi non direttamente concorrente con la modalità coinvolta nella cecità da disattenzione.

A rapid serial visual presentation task (RSVP) was combined with the 'inattention' paradigm (Mack & Rock, 1998) to investigate the effect of cognitive load on the detection of an unexpected stimulus. In addition, the detection of an unexpected stimulus presented in conjunction with a distractor item, rather than target, was also investigated. Seventy four students of the University of Canterbury participated in one of five experiments. Participants either performed a high cognitive load version of the RSVP task, selecting items on the basis of colour and semantic category, or a low cognitive load version selecting items on the basis of colour only. On the final frame of the fourth and critical trial, an unexpected stimulus appeared in conjunction with either a target or distractor item. The level of inattentional blindness to the unexpected stimulus was the result of interest. No effect of cognitive load or presentation partner was found. The implications of the results for the load theory of attention and cognitive control are discussed, along with the potential future uses of the developed method.

When something is not attended to by a person, even when it is right before them, they wonâ t perceive it. This is known as inattentional blindness (Mack & Rock, 1998). Sometimes information missed due to inattentional blindness is trivial but inattentional blindness can become a problem when it hinders people from responding to something appropriately when a response is needed. When a visual cue is missed there can be an impact on decision-making. Variations in color luminance may also be a factor in oneâ s ability to attend to something. For example, if a person is attending to a number of objects that are one color shade (for instance, dark green), it may be possible that this person might not see an additional object appear in their field of view (FOV) if it is the same color and shade. Conversely, the opposite might be true that a person is more likely to attend to the additional object if it is the same dark green color, opposed to an object that is colored a lighter green. This research investigated whether some variations of luminance of the same color (for example, dark green to light green) can affect oneâ s ability to attend an additional object entering oneâ s FOV. A scenario was presented to tank gunners that required them to observe objects of one color (dark green) while an additional object was briefly presented to them colored either dark green or light green. In this between-subjects study, 48 participants observed four dark green and four light green enemy tanks moving about the battlefield. Each was given a task that involved monitoring the dark green tanks only. During their monitoring, an additional vehicle (M981A3 FIST-V) briefly entered and exited their FOV. The additional vehicle was presented to 24 participants colored dark green. For the other 24, it was presented colored light green. This research addressed whether there was an association between color luminance, FOV, or focused attention and detection of the FIST-V. The results did not indicate an association between FOV and detection of the FIST-V [÷2(1, N = 48) = 0.08, p = 1.0]. Nor was there an association between focused attention and detection of the FIST-V using the following self-reporting questionnaires for determining levels of focused attention: ETAS [÷2(1, N = 48) = 2.06, p = 0.20], the CFQ [÷2(1, N = 48) = 0.75, p = 0.56], and the DAPI [÷2(1, N = 47) = 1.39, p = 0.75]. In the same manner, there was also no association between field dependence and detection of the FIST-V [÷2(1, N = 43) = 0.34, p = 0.75]. There was, however, an association between color luminance and detection of the FIST-V [÷2(1, N = 48) = 36.80, p < 1.0e-8].
Master of Science

Evidence gathered from major fraud investigations over the last decade has revealed that auditors in these cases failed to attend to fraud red flags within the substantive testing evidence. Research in psychology regarding inattentional blindness (IB) provides a theoretical framework for explaining why auditors may be prone to missing fraud red flags. This study examines the presence of IB during the performance of substantive testing and proposes two distinct interventions. Each intervention is predicted to improve auditor fraud detection. In a scenario involving fraudulent revenue transactions, findings show that a slight modification to the standard audit procedures significantly improves an auditor’s detection of red flags indicative of fraud. A second intervention involving the performance of a strategic reasoning task did not yield significant results. Overall, the results suggest that audit firms should consider making a cost effective adjustment to their standard audit program to improve fraud detection.

When attention is focused elsewhere, individuals may fail to notice unexpected events in plain sight, a phenomenon known as inattentional blindness (IB: Mack & Rock, 1998). In legal settings, eyewitnesses may experience IB and fail to notice entire crimes occurring (Hyman, 2016). The current thesis aimed to assess the impact of IB on eyewitness safety, memory, and credibility. In the first two studies, IB for an assault crime was measured. The presence of a weapon was manipulated (Study 1), and memory for the crime was assessed (Study 1 & Study 2). The results showed that weapon presence did not impact rates of IB. Study 1 found that IB impacted the quantity, but not quality, of witness memory. However, when manipulating the recall instructions in Study 2, IB negatively affected both the quantity and quality of memory. Given that witnesses who experience IB may testify in court, subsequent studies were conducted to explore perceptions of eyewitness IB. In Study 3, lawyers, psychology students, and members of the public were surveyed regarding their beliefs about IB in legal scenarios. All populations overestimated visual detection across most legal scenarios. In Studies 4 and 5, mock-jurors read a trial containing two key witnesses: one who saw the crime, and one who experienced IB. Both studies showed that the witness who experienced IB was perceived as less credible than the witness who saw the crime. In Study 5, several factors (witness role, witness familiarity with defendant, and expert testimony) did not influence the negative perceptions of IB. Therefore, Studies 6 and 7 aimed to determine whether demonstrating IB and providing expert testimony on IB would improve perceptions of witness IB. Neither demonstrating IB nor expert testimony rectified the negative perceptions of witness IB. The findings within this thesis indicate that IB among eyewitnesses presents a unique challenge in criminal settings.

This thesis investigates the allocation of visual processing resources to stimuli perceived as being threatening by individuals with an increased fear of spiders. The literature in the broad field of cognitive psychopathology suggests that, throughout a number of subtypes of anxiety, there is a visual processing bias that causes anxious individuals to rapidly notice threatening objects in their environment. It is further suggested that individuals with low or normal levels of anxiety do not display the same pattern of attentional allocation. The thesis reviews the range of theories and the experimental paradigms that have informed them and suggests that in the majority of cases methodological limitations lead to different interpretations of the results. Additionally, alternative interpretations of the findings, namely that of the delayed disengagement hypothesis, which suggests that anxious individuals are not faster at detecting images than low anxious control participants, but rather they display a bias where they are unable to rapidly disengage their attention from threatening stimuli when they have been noticed, are explored. The thesis then investigates the use of a method from the perception and attention literature, called inattentional blindness. It is proposed that the inattentional blindness experiment is able to overcome the methodological difficulties associated with current methods in cognitive psychopathology. A series of experiments are detailed investigating the allocation of attention to neutral and spider images in individuals with increased fear of spiders. The first series of experiments suggests that, relative to control participants with low levels of spider fear, individuals with an increased fear of spiders do rapidly allocate attention to spiders appearing in their left visual field. The thesis also examines whether heightened anxiety causes a general hypervigilance of the attentional system. However, the results do not confirm this prediction. Two additional experiments were conducted. Firstly, one investigating whether individuals with a fear of spiders display difficulties disengaging their attention from spider stimuli. The results from this experiment do not confirm the delayed disengagement hypothesis. Secondly, an experiment using the dynamic inattentional blindness paradigm was developed to investigate attentional allocation to spider stimuli in individuals with high and low spider fear. The results provide partial support for the hypothesis that the high, but not the low, fear group, notice moving spiders when they are presented against expectation. The implications of these results are discussed.

Two Inattentional Blindness type experiments involving 446 participants were performed in order to examine how unexpected objects are noticed. Perception of these unexpected objects was measured using explicit and implicit measurements. Despite initial difficulty in determining implicit perception, results showed a dissociation between implicit measurements and explicit measurements, providing strong evidence for unconscious processing. Research into attention capture often emphasizes the role of either expectations or stimulus properties in attention capture; the current research examines both. Critical objects presented were either of a colour that participants were familiar with, or of a new colour. The different patterns of results for these two categories of objects provide evidence for two separate mechanisms of attention capture: a parallel process driven by the features of objects, and a serial process, driven by the intentions of the observer. Predications of the recent theoretical work produced by Most, Scholl, Clifford & Simons, (2005) are examined, and support is obtained for their theoretical formulation.

Introduction: Medical errors are major hazards, and lapses in non-technical skills such as situational awareness contribute to most incidents. Risks are concentrated in acute care, and in crisis situations clinicians can apparently ignore vital information. Poor workplace ergonomics contributes to risk. Existing work into perceptual errors offers insights, but these phenomena have been little researched in medicine. This thesis considers medical non-technical skills and how they are taught, and explores vulnerability to inattentional and change blindness. Methods: Medical human factors and the psychology of perceptual error were reviewed, and a mixed-methods assessment of postgraduate medical curricula completed. Experiments assessed clinicians' interaction with clinical monitoring devices using eye-tracking, and studies were conducted exposing clinicians to various perceptual error stimuli using non-clinical and clinical videos, and simulation. A survey was also conducted to assess clinicians' insight into the phenomena of perceptual error. Results: Non-technical skills feature poorly in medical curricula, and equipment is poorly standardised in critical care areas. Unfamiliar devices slow response times and increase error rate. Clinical training confers no generalisable advantage in perceptual reliability. Even expert clinicians miss important events. Two out of every three life-support instructors for example missed a critical failure in the patient's oxygen supply when watching a recorded emergency simulation. The insight and understanding healthcare staff have of perceptual errors is poor, leading to significant overestimates of perceptual reliability that could have consequences for clinical practice. Conclusions: Perceptual errors represent a latent risk factor contributing to loss of situational awareness. High rates of perceptual error were observed in the video-based experiment. Although lower rates were observed in simulation, important events were still missed by participants that could have serious consequences. The incidence of perceptual error appears sensitive to the method used to test for it, and this has important implications for the design of future experiments testing for these phenomena. Mitigating perceptual error is likely to be challenging, but relatively simple adjustments to team practices in emergency situations may be fruitful.

Inattentional blindness refers to a failure to detect visible objects when attention is engaged in a task. Despite the central role for attention implied by its name, there is surprisingly little evidence that inattentional blindness indeed results from inattention. In this thesis I provide such evidence in demonstrating that rates of inattentional blindness critically depend on the extent to which a relevant task exhausts attentional capacity (under high perceptual load) or leaves spare capacity (under low perceptual load) for determining awareness of task-irrelevant stimuli. This was found when load was increased by requiring a more subtle line-length judgment in the traditional inattentional blindness cross-task, or by increasing the number of items in a visual search task. Further experiments generalised the effects of perceptual load on awareness across simple shapes and meaningful objects, and for irrelevant stimuli appearing in the periphery and at fixation. By contrast, upright (but not inverted) faces reached awareness regardless of the level of perceptual load in the relevant task. These findings are consistent with previous behavioural perceptual load studies using reaction time (RT) measures of task-irrelevant processing (Lavie, 1995 Lavie, Ro & Russell, 2003 see Lavie, 2005 for review) and support the conclusion that perceptual load determines conscious awareness. The experiments also found no advantage for awareness at fixation versus awareness at the periphery, highlighting a potential dissociation between awareness measures and distracter effects on RTs (which have previously shown such an advantage, Beck & Lavie, 2005). Finally, this thesis presents a preliminary investigation of the development of awareness as measured by rates of inattentional blindness under different levels of task load in children and in adults. Results demonstrated a clear pattern of increasing awareness with increasing age, and lend partial support to the notion that the development of attentional capacity underlies this trend in awareness.

Reklam anses vara lika gammal som mänskligheten och lika universell som kultur. Ur den synvinkeln är reklam en del av det sociala livet, där människor gör utbyten som gynnar båda parterna. Under de senaste decennierna har samma mänsklighet upplevt den digitala världens intensiva tillväxt, där idag nästan allt går att finna. Det har aldrig varit lättare för företag att inte enbart marknadsföra sig globalt men även ha omedelbara interaktioner med deras konsumenter. På andra sidan spektrumet spåras alla internetanvändare genom sin digitala resa med företag och organisationer som tittar på deras varje steg för att sedan presentera personligt anpassade annonser. Denna utveckling i teknik och annonser på internet har lett till att påträngande annonser har blivit ett frekvent klagomål kring internetmarknadsföring. Adblock är ett filtreringsverktyg (tillägg) som kan appliceras för att blockera reklam på webben. Verktyget kom till vid sekelskiftet och har snabbt blivit ett populärt tillägg till webbläsare. Många har kommit att ta del av dess fördelar med att blockera banderoller, pop-ups och videoannonser. Samtidigt som reklamundvikande inte enbart orsakar företagen enorma förluster kan det ytterligare skada webbplatserna samt alla andra parter inblandade. Dessutom kan en fortsatt ökning av annonsblockerare i slutändan leda till slutet av gratis digitalt innehåll. Vidare kan ett reklamundvikande ske kognitivt, beteendemässigt eller mekaniskt utan att nyttja annonsblockerare. Detta kan också resultera i kostnader för företag som producerar reklam på internet. Därav ansågs en studie utförd på icke-annonsblockerarnas synpunkt vara nödvändig för att förstå vilka faktorer det är som gör att man inte installerar och använder en annonsblockerare.   Syftet med denna studie är att kartlägga och belysa individers bakomliggande faktorer till varför de inte installerar annonsblockerare. Teorigenomgången av denna studie omfattar ämnen om varför människor installerar eller avböjer från att installera applikationer, automaticity, approach-avoidance theory, inattentional blindness, och banner blindness theory. Den analyserade data i studien samlades in genom en kvalitativ metod med 18 semistrukturerade intervjuer med individer som har en kännedom om annonsblockerare och som även har medvetet valt att inte tillämpa tillägget på webben. Studien avgränsade sig till att undersöka människors uppfattning och upplevelse mot banderoller, pop-ups och videoannonser på endast datorer. Studien har upptäckt att respondenterna bland annat inte upplever reklam som störande, att de är tekniskt okunniga eller att reklam upplevs som intressanta. Vidare undviker dock respondenterna redan reklam genom en vana och erfarenhet. Dessutom att de fokuserar på sina behov som huvudändamålet när de besöker webbsidor. Vidare hade webbsidors design och miljö en påverkan i närmande och undvikande av reklam. Denna data tolkades och sedan analyserades vara faktorer till varför man inte blockerar reklam. Slutligen har studien även upptäckt att banderoller beroende på dess design eller budskap är den mest positivt mottagna annonstypen.
Advertisement is considered as old as mankind and as universal as culture. In that sense it is a part of social life itself, where mutually beneficial exchanges are made. During the last couple of decades that same mankind has experienced the intense growth of the digital world, where today almost anything and everything can be found. It has never been easier for companies to not only market themselves globally but have instant interactions with their consumers. On the other side of the spectrum, all internet users are tracked throughout their digital journey with companies and organizations watching their every move to then present personalized advertisement. Thus, intrusion have become a frequent complaint associated with online marketing. Adblock is a filtering tool (extension) that can be applied to block out advertisement on the web. This tool came to be at the turn of the century and have rapidly become a popular addition to browsers. Many have come to take part of its benefits of blocking out banners, pop-ups and video ads alike. While ad avoidance is not only causing companies tremendous amounts of loss, it could further harm the websites that carry them, and all other parties involved. Furthermore, a continued increase of ad blockers could ultimately lead to the end of free digital contents altogether. Moreover, ad avoidance can still take place cognitively, behaviourally or mechanically without the use of an adblocker. This can also cause losses for the companies producing ads on the internet. Thereof, a study executed upon the non-ad blockers’ point of view is deemed necessary in order to understand what factors prevent the installation or use of an adblocker.    The purpose of this study is to map out and highlight individuals’ underlying factors to why they do not install ad blockers. The literature review of this study covers the subjects of why people install or reject applications, automaticity, approach-avoidance theory, inattentional blindness, and banner blindness theory. The analysed data in the study was collected through a qualitative method with 18 semi-structured interviews with individuals who are not only aware of the existence of ad blockers but who have deliberately chosen not to make use of the extension. The study delimited itself to studying people’s perception and experience of banners, pop-ups and video ads through computers only. The study found that the respondents for instance do not experience ads as disruptive, that they are technologically inexpert or that ads are perceived as interesting. However, the respondents already do avoid ads through their habit and experience. Moreover, that they focus on their needs as their main purpose of visiting websites. Furthermore, websites’ design and environment did influence approaching or avoiding ads. This data was interpreted and analysed to be factors as to why people do not block ads. Finally, the study finds that banners depending on their design or message were the most positively received ad form.

This study examines the impact of Cognitive Awareness training on transaction processing accuracy rates within the US Financial Services Industry. Grounded in the theories of Inattentional Blindness and Error Management Culture, this paper supports and extends both theories through the development of a new theoretical construct. The ACE Construct is a novel approach that combines cognitive science, organizational development, and operational efficiency practices into a single approach designed to improve transaction processing accuracy. The study involved the design and implementation of a novel training program, with performance data observations sampled over seven months, to evaluate the impact of Cognitive Awareness training on accuracy. The researcher was able to partner with a global financial services firm to conduct experiments within three of their US based locations. It involved over 150 agents as they processed live-client transactions requests in real time. The similarities between agent populations, training practices, systems and procedures, and work types, allowed for analysis and interpretation of independent variables related to gender, proficiency/experience of the agent, and location. As expected, analysis of pre-treatment conditions suggest that accuracy is largely dependent on experience. Analysis of post-treatment accuracy results favor improvement in both accuracy measures and organization climate and culture dynamics as a result of Cognitive Awareness Training. Statistically significant improvements to both accuracy and organizational climate, related to type of Cognitive Awareness treatment introduced, and tenure, were discovered in the agent populations who were present during the entirety of the study. However, there was an absence of statistical support for a direct relationship between Cognitive Awareness Training as an independent variable and accuracy improvement. Furthermore, I was unable to detect a correlation between improvements in Error Management Culture and transaction processing accuracy. The results suggest the possibility of positive effects on transaction processing accuracy in practice, and open the door for continued research in this field.

Forskning visar att 65 procent av konsumenternas köpbeslut av dagligvaror fattas i butikerna. Denna studie syftade till att studera konsumenters medvetenhet om tv-reklam i dagligvarubutik, hur deras köpbeteende påverkas, och i vilken grad kognitiva och perceptuella faktorer inverkar på om tv-reklam medvetet uppfattas av konsumenten eller inte. Endast fyra av 120 konsumenter upptäckte den tv-skärm som de stått intill och ingen mindes vad tv-skärmen visat, en stark indikation på att konsumentens uppmärksamhet kan vara mycket svårfångad. Huruvida visad reklamfilm var försedd med ljud och prisuppgift eller inte tycktes inte ha någon effekt på konsumenternas medvetenhet och ingen försäljningseffekt kunde påvisas men generella slutsatser kräver ytterligare forskning. Fortsatt forskning kan även undersöka konsumentens mottaglighet för tv-reklam på olika platser i butiken.

碩士
中國科技大學
土木與防災設計系
103
In this study, the method for easing the situation on construction workers of inattentional blindness due to over-concentration on work will be discussed. To start with, related papers were collected and summarized so to thoroughly understand the circumstances that may lead to the induction of inattentional blindness, and also the easing methods for such situation. At the same time, questionnaires and videos were produced based on the template designed by Chia-Wen Liao , Jane Cheng Yu (2014) for this study. The study includes two experiments. After completion of two experiments, the results were compared with those from the experiment conducted by Chia-Wen Liao (2014), so to investigate the effectiveness of the methods, and determine which method is more effective. In the experiment, the participants were first informed about the matters need attention. After that, participants watched the mock video of construction site, followed by filling in the questionnaires. The study targeted students from The China University of Technology. 71 questionnaires were distributed, 100% of the questionnaires were collected and 100% of the questionnaires were valid. Based on the collected questionnaires, analysis on credibility, Chi-square test were carried out and descriptive statistics were studied.After series of experiments and analysis, the results could be concluded as below: Different methods for easing the situation of inattentional blindness were used in the two experiments (light-reflecting line and warning sign). However, from the experimental result, light-reflecting line did not show expected effect in easing the situation of inattentional blindness. On the other hand, warning sign could reduce the happening of inattentional blindness. The result shows that warning sign is more effective than light-reflecting line in easing the situation of inattentional blindness.

碩士
臺灣大學
心理學研究所
95
Past studies have demonstrated visual-auditory interactions such as the McGurk effect (McGurk & MacDonald, 1976) and the sound-induced-flash illusion (Shams, Kamitani, & Shimojo, 2002). However, visual stimuli in these studies were well attended by the observers, and it remains unknown whether visual-auditory interactions also occur when the observers are unaware of the existence of the visual stimuli. We used the modified inattentional blindness paradigm of Moore and Egeth (1997) by adding a synchronous sound to examine whether sound can affect processing of unattended visual background. Experiment 1 used a texture segregation task in which the unattended background pattern was formed by texture segregation of different oriented Gabors to render the railroad track as in the Ponzo illusion. The participants were asked to judge the length of the two horizontal lines. Half of the trials were accompanied with a beep sound, and the other half were not. Results showed that in trials with beep sounds, the Ponzo illusion occurred; however, no Ponzo illusion was observed without beep sounds. In Experiments 2, 3, and 4, we tested 3 hypotheses about the mechanism and our results suggested that it was due to visual-auditory integration. Further, in Experiments 5 and 6, a response-end processing, accessory-stimulus Simon effect was examined, and we found that response-end processing also occurred in synchronous sound condition when observers were unattended to the accessory stimulus. These results suggest that adding a synchronous sound can speed up the low-level unattended visual processing (texture segregation) and make the high-level response-end processing (the Simon effect) possible. Thus, unattended visual-auditory integration can occur at different loci through the processing stream.

Consciousness has remained one of the most perplexing enigmas of science and philosophy. Modern neuroscientific research seeks to understand how consciousness emerges within biological systems through identifying the necessary mechanisms that enable sensory information to be consciously experienced. Inattentional blindness (IB), the failure to notice something right in front of you, offers a profound means of studying consciousness, as it highlights the indistinct boundary between the conscious and the unconscious. The primary goal of the current thesis was to contribute to a scientific understanding of consciousness through advancing knowledge on IB. To this end, two reviews and four empirical studies were conducted. The first review provides a qualitative synthesis of empirical literature on IB that has employed neuroscientific methodology. Findings suggest that neural correlates of consciousness under conditions of IB may favour early sensory views of consciousness, however more research is needed. The second review provides a systematic review of the behavioural literature on IB, with focus on its two leading theories. Findings highlight that no theory can yet fully account for IB, and a model of IB is proposed based on the partial awareness hypothesis. Study one investigates the relation between alpha-band neural activity and IB via electroencephalography (EEG). Results indicate that a reduction in alpha activity in the pre- and post-stimulus interval correlates with consciousness of the critical stimulus during IB. Study two employs transcranial alternating current stimulation (tACS) to examine a causal role of alpha activity in IB. Findings indicate that, relative to control conditions, those stimulated at alpha frequency were more likely to be subject to IB. Study three extends on study two by implementing auditory tone trains at various frequencies during IB. Results show no difference in rates of IB based on auditory tone frequency. Study four then addresses the degree to which semantic processing, as indexed via the N400, can occur under conditions of IB. Findings show that no significant N400 activity is observed when the eliciting stimuli are rendered unconscious via IB. Overall, the implications of the current thesis are that alpha activity has a reliable, and potentially causal, relationship with IB; that a coherent explanation of IB is yet to exist, but may be found in reconsidering the traditional view of visual consciousness more broadly; and that the endowment of meaning to sensory information may be a key function of consciousness.

碩士
國立中正大學
心理學所
95
Inattentional blindness refers to failures detect the appearance of an unexpected object in the visual field when attention is otherwise engaged. Most, Scholl, Clifford & Simons (2005) consider that a person’s own attentional set is the important factor to influence noticing of unexpected objects. Experiment 1 replicated the result of Most et al. (2005). When the dimension of an unexpected object was same to people’s attentional set, a great number of participants could notice it appearance. Experiment 2 and Experiment 3 studied the effects of fixation position on inattentional blindness. Eye movement was measured during the experiment. We found that eye movement data could be an index to measure whether participants notice an unexpected stimulus. The hypothesis of perceptual cycle framework which was argued by Most et al. (2005) supported by our eye movement data. Attentional set was an important role on the processing from unconscious to awareness of an unexpected stimulus. Experiment 3 also showed that the dimension of attentional set was variable or invariable would be an influential factor on inattentional blindness. When dimension of attentional set was variable, the ratio of inattentional blindness was affected by consistence or inconsistence of the attentional set. When dimension of attentional set was invariable, whether the attentional set was consistent or not, it would not be influence the ratio of inattentional blindness.

These three experiments examined noticing rates of an unexpected object (UO) that appeared during a dynamic aircraft threat evaluation task that required participants to shift their visual attention between multiple task-relevant locations. Experiment 1 manipulated the location at which the UO appeared; no effects on noticing rates were found. However, eye-tracking data revealed trends for UOs to be noticed more when participants were looking at locations closer to where the UO appeared, or when they were making more eye-movements while the UO was present. Eye-tracking data also showed a strong link between making an eye movement to the UO and noticing it. Experiment 2 manipulated the color, direction and speed of the UO to make it more or less similar to task-relevant objects. Also, to-be-ignored (TBI) aircraft were either present or absent for each participant. An interaction between the color of the UO and the presence of TBI aircraft was found with noticing rates being greater for uniquely-colored UO's only when no TBI aircraft were present. No overall effect of UO and target aircraft similarity was found. Experiment 3 manipulated the visual complexity and cognitive difficulty of the task. Noticing rates were higher only in the visually-simple, cognitively-easy, task pairing. These findings reveal the importance of participants' task strategies, attentional set and the interaction with task complexity unexplored by current theories of visual attention and prior findings from research on inattentional blindness. Also discussed are the implications for designers of human-machine systems.

Social anxiety disorder is the third most common mental disorder with the lifetime prevalence rate of 13.3% in the US population. Typically, it causes significant impairment in a wide range of functioning and follows a chronic, unremitting course if untreated. Over the past two decades, there has been a dramatic increase in clinical research aimed at examining underlying mechanisms maintaining social anxiety. One line of research has investigated attentional biases in social anxiety, using various cognitive experiment paradigms, including the emotional Stroop and the modified dotprobe tasks. However, overall findings are equivocal about the nature of attentional biases in social anxiety and several methodological problems limit the interpretability of the data. The present study examined attentional biases associated with social anxiety using a new research paradigm in the field of anxiety disorders: the inattentional blindness paradigm. This paradigm presents a social cue in the absence of the subjects’ expectation while they are engaged in a cognitively demanding task, thereby enabling the more purely attentional aspect of information processing to be examined reducing the influence of potential response biases or effortful strategies. Two independent experiments were conducted using nonclinical student samples consisting of individuals high in social anxiety (HSAs) versus individuals low in social anxiety (LSAs) based on the static and sustained inattentional blindness tasks. Overall, results revealed that HSAs were more likely to detect or identify a socially-threatening cue, relative to LSAs; whereas LSAs were more likely to detect or identify a non-threatening social cue, relative to HSAs. These findings were observed only in the presence of a bogus-speech manipulation. These data suggest the promising utility of the inattentional blindness paradigm in investigating attentional biases in social anxiety and perhaps other psychopathological conditions. Theoretical and clinical implications are discussed.
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Inattentional blindness (IB) occurs when an individual does not notice a salient but unexpected object or event because their attention is engaged by another task. Previous research into IB predominantly focused on how manipulating stimulus characteristics or task demands affects rates of lB. This thesis extends existing research by examining IB in relation to other phenomena including eye movements and cross-modal attention, and examining the effect of individual differences in general attentional processes. There are six empirical chapters addressing various aspects of IB research. The first empirical chapter investigates whether IB knowledge predicts the incidence of lB. Most prior research excluded participants with any knowledge of IB, claiming they would "expect the unexpected". This chapter demonstrates that it is possible to use non-na{u00EF}ve participants in IB experiments under certain circumstances, which is relevant since most potential participants possess some knowledge of lB. The second empirical chapter used a video eye tracker to investigate the role of eye movements in lB. The results reveal that eye movements do not predict IB; in both experiments several participants failed to notice the unexpected stimulus despite directly fixating on its location, while other participants detected the stimulus without fixating on or near it. The third and fourth empirical chapters investigate the effects of crossmodal attention on lB. These chapters address the effects of listening to concurrent audio stimuli and talking on a cellular telephone during IB tasks. Conversing on a hands-free phone significantly impairs observers' ability to detect a highly salient stimulus. Simply talking without a conversation partner (e.g., leaving a voicemail message) also significantly increases lB. In contrast, simply listening to audio stimuli (e.g., voicemail, short stories, music) typically has no effect on IB but can actually decrease IB under some conditions, particularly when the primary visual task has low perceptual load. The fifth and sixth empirical chapters examine individual differences in lB. The fifth empirical chapter examines the relationship between IB and attentional blink (AB), another failure of visual awareness. Observers who experienced IB also experienced AB, suggesting that some people are generally more susceptible to failures of conscious awareness regardless of whether they result from the distribution of attention across space (IB) or time (AB). The sixth empirical chapter explores whether specific cognitive traits or processing styles predispose individuals to experiencing lB. Self-report measures of distractibility and immersion do not predict IB, however, individual tendencies towards rumination and task-unrelated thoughts do predict lB. Together these studies help situate IB within the broader framework of attention research and theory. Previous research tended to look at IB in isolation, with few links to other cognitive phenomena. Past studies also involved a strong stimulus focus, which gave us insight into which unexpected events were most likely to be noticed. The current thesis extends past research and forms part of a new programme of IB research, which is focused more on individual observers and providing insight into who is most likely to notice unexpected objects and why, with consideration given to both personal and characteristics.

碩士
國立交通大學
工業工程與管理系所
107
Inattentional blindness refers to the phenomena that attention is too focused on the target to detect the unexpected object in the environment. The purpose of the present study is to examine the effects of the number of goal setting and the number of reoccurrence of the unexpected object on inattentional blindness. Two hundred and two participants were randomly assigned to the number of goal (2) × the number of reoccurrence of the unexpected object (3) conditions. Their primary task was to calculate the number of rebounds of the target object in the computer screen. Unexpected objects appeared in a particular critical trial three or five times. Some participant's detection of the unexpected object were probed by questions after the 11th trial or 18th trial. The number of goal setting was manipulated by the instruction before the experiment. Data showed that the instruction to keep alert to the unexpected items in the environment could reduce the limiting effect of goal setting and enhance the detect in rate of the unexpected objects. Dual goal setting could alert to promote the accuracy of the counting performance. When participants were probed about the unexpected object of trial 11, or having experienced the unexpected object five times with dual goal settings, their detection rate and accuracy score on unexpected object detection were both enhanced, but their counting performance was hampered.

abstract: Magicians are informal cognitive scientists who regularly test their hypotheses in the real world. As such, they can provide scientists with novel hypotheses for formal psychological research as well as a real-world context in which to study them. One domain where magic can directly inform science is the deployment of attention in time and across modalities. Both magicians and scientists have an incomplete understanding of how attention operates in time, rather than in space. However, magicians have highlighted a set of variables that can create moments of visual attentional suppression, which they call "off-beats," and these variables can speak to modern models of temporal attention. The current research examines two of these variables under conditions ranging from artificial laboratory tasks to the (almost) natural viewing of magic tricks. Across three experiments, I show that the detection of subtle dot probes in a noisy visual display and pieces of sleight of hand in magic tricks can be influenced by the seemingly irrelevant rhythmic qualities of auditory stimuli (cross-modal attentional entrainment) and processes of working memory updating (akin to the attentional blink).
Dissertation/Thesis
Ph.D. Psychology 2013