In everyday life, we are constantly surrounded by a huge amount of information.Since our attentional resources are limited, we need to select just the stimuli that we want to process. Despite our voluntary attempt to select a precise information, it often occurs that a salient stimulus or event automatically captures our attention, regardless its irrelevance. The fact that we are immediately and unintentionally attracted by sudden visual onsets provides a clear advantage for our survival. However, in spite of that, the possibility to counteract visual distraction is fundamental for an efficient interaction with the environment, particularly when a salient but irrelevant stimulation repeatedly affects our visual system. And then, how can we resist from being continuously distracted by irrelevant repetitive onsets? The current work is aimed to explore the mechanisms that we use to filter irrelevant information, with a focus on habituation, an ancestral form of learning that has recently been associated to the decrement of attentional capture observed in several studies. This experience-dependent learning process is defined as a behavioral response decrement that results from repeated stimulation and that does not involve sensory or motor fatigue. I will first provide the reader with a general introduction (Chapter 1) concerning the visual attention field, with a particular emphasis on attentional capture and the filtering of irrelevant information. I will then (Chapter 2) try to disentangle the two main accounts concerning the nature of the distractor filtering, the first claiming that filtering is accomplished to shield target processing from interference (top-down inhibitory control hypothesis), and the second stating that the passive exposure to a repeating visual onset is sufficient to trigger learning-dependent mechanisms to filter the unwanted stimulation (habituation hypothesis). After providing strong evidence in favor of the latter account, I will then examine (Chapter 3) to what extent the filtering of irrelevant information that we achieve through the mechanisms underlying habituation is affected by contextual cues, showing that this kind of filtering is context-dependent. Finally (Chapter 4), motivated by the existence of a strong functional and anatomical link between attention and the oculomotor system, I will explore whether habituation affects also the oculomotor capture triggered by an onset distractor, showing that the execution of reflexive saccades is subject to habituation, while the programming component is not. Taken together, the results of the present work give a strong contribution to the attentional capture field in showing that both attentional and oculomotor capture are subject to habituation, that this form of learning is context-specific and that it occurs also when we are passively exposed to a visual irrelevant stimulus.

There is more information in the visual environment than we can process at a given time, and as a result selective attention mechanisms have developed that allow us to focus on information that is relevant to us while ignoring information that is not. It is often assumed that our ability to overcome distraction by irrelevant information in the environment requires conscious, effortful processing, and traditional theories of selective attention have emphasized the role of an observer's explicit intentions in driving this control. At the same time, effortful control on the basis of explicit processes may be maladaptive when the behaviors to be executed are complex and dynamic, as is the case with many behaviors that we carry out on a daily basis. One way to increase the efficiency of this process would be to store information regarding past experiences with a distracting stimulus, and use this information to control distraction upon future encounters with that particular stimulus. The focus of the current thesis was to examine such a "learned control" view of distraction, where experience with particular stimuli is the critical factor determining whether or not a salient stimulus will capture attention and distract us in a given situation. In Chapters 2 through 4, I established a role for task-specific learning in the ability of observers to overcome attentional capture, showing that experience with particular attributes of distracting stimuli and the context in which the task was performed led to a predictable decrease in capture. In Chapter 5, I examined the neural basis of these learned control effects, and the results suggest that neocortical and medial temporal lobe learning mechanisms both contribute to the experience-dependent modulation of attentional capture observed in Chapters 2-4. Based on these results, a model of attentional capture was proposed in which experience with particular stimulus attributes and their context critically determine the ability of salient, task-irrelevant information to capture attention and cause distraction. I conclude that although explicit processes may play some role in this process under some conditions, much of our ability to overcome distraction results directly from past experience with the visual world.

The environment is abundant with visual information. Each moment, this information competes for representation in the brain. From billboards and pop-up ads to smart phones and flat screens, in modern society our attention is constantly drawn from one salient object to the next. Learning how to focus on the objects that are most important for the current task is a major developmental hurdle. Fortunately, rewards help us to learn what is important by providing feedback signals to the brain. Sometimes, in adolescence for example, reward seeking can become the pre-potent response. This can ultimately lead to risky and impulsive behaviors that have devastating consequences. Until recently, little has been known about how rewards operate to influence the focus of attention. In this document, I first demonstrate the robustness of various behavioral paradigms designed to measure reward processing in vision. I found that even mundane rewards, such as images of money, are effective enough to prime the attentional system on the basis of value. Remarkably, this effect extended to images of Monopoly money. This observation suggests that whole classes of visual stimuli, such as food, pornography, commercial logos, corporate brands, or money, each with its own reward salience value, are likely vying for representation in the brain. This work has implications for the growing digital economy as it suggests that novel value systems, such as the digital currency Bitcoin, could eventually become as psychologically relevant as physical currency provided sufficient use and exposure. Likewise, this work has implications for gamification in the industrial setting. Next, I examined the sensitivity of the system to make optimal economic decisions. When faced with an economic choice normative theories of decision-making suggest that the economic actor will choose the response that affords the greatest expected utility. Contrary to this account, I developed a new behavioral paradigm (reward contingent capture) and reveal that the attentional homunculus is a fuzzy mathematician. Specifically, I found that low-level attentional processes conform to the same probability distortions observed in prospect theory. This finding supports a unified value learning mechanism across several domains of cognition and converges with evidence from monkey models. Then, I demonstrate the influence of rewards on high-order search parameters. I found that images of money can implicitly encourage observers to preferentially adopt one of two search strategies – one that values salience versus one that values goals. Together, my results expose two distinct ways in which the very same rewards can affect attentional behavior – by tuning the salience of specific features and by shaping global search mode settings. Lastly, I draw from my empirical results to present a unified model of the manifold role of rewards on visual attention. This model makes clear predictions for clinical applications of rewarded attention paradigms because it incorporates a dimension of complexity upon which learning processes can operate on attention. Thus, future work should acknowledge how individual traits such as developmental trajectory, impulsivity, and risk-seeking factors differentially interact with low- and high-level attentional processes. In sum, this document puts forward the notion that rewards serve a compelling role in visual awareness. The key point however is not that rewards can have an effect on attention but that due to the nature of visual processing, reward signals are likely always tuning attention. In this way we can consider reward salience an attentional currency. This means then that deciding where to attend is a matter of gains and losses.

Complex behaviors require selectively attending to task-relevant items, and ignoring conspicuous, irrelevant items. For example, driving requires selectively attending to other cars on the road while ignoring flashing billboards. Dominant models of attentional control posit that we avoid distraction by biasing attention towards task-relevant items, and our ability to avoid distraction depends on the strength and specificity of this bias. I find that a strong, specific bias towards task-relevant items is insufficient for preventing distraction. Instead, preventing distraction also requires past experience ignoring distractors. I also find that long-term memory systems, rather than visual short-term memory or priming memory systems, maintain this experience. Based upon these findings, I propose that effective attentional control not only demands a strong, specific bias towards task-relevant items, but also requires that observers learn to ignore conspicuous, irrelevant items.

In this study the mechanisms that control attention in natural scenes was examined. It was explored whether familiarity with the environment makes participants more sensitive to changes or novel events in the scene. Previous investigation of this issue has been based on viewing 2D pictures/images of simple objects or of natural scenes, a situation which does not accurately reflect the challenges of natural vision. In order to examine this issue, as well as the differences between 2D and 3D environments, two experiments were designed in which the general task demands could be manipulated. The results revealed that familiarity with the environment significantly increased the time spent fixating regions in the scene where a change had occurred. The results support the hypothesis that we learn the structure of natural scenes over time, and that attention is attracted by deviations from the stored scene representation. Such a mechanism would allow attention to objects or events that were not explicitly on the current cognitive agenda.

In the study of covert visual attention, two event-related potential (ERP) components have been identified by earlier research. The N2 posterior contralateral (N2pc) component has been suggested to index the enhancement of attention to a specific lateralized target item. The distractor positivity (PD) component has been suggested to index the suppression of distractors appearing in the same search array. Earlier studies have reported different latencies for the PD component depending on the task and experiment. Furthermore, the N2pc and the PD component are not always elicited in the same experiment. Relative target-to-difficult-distractor placement have been shown to affect the mean amplitude of the N2pc. Less is known about how different relative placements affect the PD component. The aim of the present study was to try and elicit both an N2pc and a PD component in the same visual search paradigm. The PD was recorded later time-window which previous studies have suggested to indicate the ending of attention to a previously attended target. Three relative placements were analysed, horizontally opposite, vertically opposite and diagonally opposite. When combining all three relative placements an N2pc component was elicited contralateral to the target. No PD component was found when combining all relative placements. A larger mean amplitude N2pc was measured for the vertically opposite condition. The results are not in line with previous research, that have found the N2pc to be smaller in conditions where both target and distractor are on the same side of the visual field. However, when comparing upper and lower visual field targets the N2pc was found to be larger for lower visual field stimuli, which is in line with previous research. A larger mean amplitude for the PD was found in the diagonally opposite condition. Earlier research has suggested that when difficult distractor and target are located on separate sides of the visual field, this leads to successful inhibition, indexed by the PD component. In contrast to earlier research a larger PD component was not found for upper visual field stimuli. The present study differs from previous studies in the way the target and difficult distractor were placed and analysed. By separating what has previously been called “opposite side” condition into two separate conditions diagonally opposite and horizontally opposite the results from the present study seem to suggest that these two conditions are not synonymous. However, the results should be regarded with caution due to the small sample size. Furthermore, the horizontally opposite side condition also differs from previous studies with regards to relative target and distractor distances, which could have had an effect on the results.

Depuis une vingtaine d’années, la littérature scientifique traitant de la capture attentionnelle a mis en évidence, à l’aide de paradigmes expérimentaux testés en laboratoire, un certain nombre de processus attentionnels fondamentaux. Bien que les résultats obtenus « en laboratoire » à partir de stimuli visuellement « simples » méritent encore d’être investigués, depuis quelques années se pose la question de la « transposabilité » de ces observations à des objets et des situations issus du monde réel. Les phénomènes observés en laboratoire à partir d’un matériel visuellement simple sont-ils transposables à des situations, complexes, de la vie quotidienne ? Afin de répondre à cette question, nous avons créé et testé différentes conditions proches de celles du monde réel,notamment en expérimentant en situation de double-tâche, en utilisant un matériel visuellement complexe extrait du monde réel (c.-à-d. des photographies de conduite automobile), en faisant varier la fréquence d’apparition de l’élément distracteur ou bien encore en testant une nouvelle caractéristique du distracteur, la dimension sémantique. Nos résultats révèlent les conditions d’apparition du phénomène de capture attentionnelle dans des situations s’approchant de celles du monde réel. Nous avons tout particulièrement détaillé dans cet ouvrage le cas de l’effet de capture attentionnelle contingente, phénomène majeur et robuste de la capture attentionnelle, y compris dans des situations visuellement complexes. / During the last two decades, studies about attentional capture revealed some major basic attentional processes by using several experimental paradigms. While further investigations need to be conducted by using simple visual stimuli, a raising question concerns the possibility to generalize laboratory findings to much more complex real-world situations. Indeed, basic attentional capture studies usually use simple stimuli while real-world displays are generally rich in visual information. To answer this issue, we conducted several experiments under close to real-world conditions, such as testingdual task situations, using complex visual stimuli from real-world situations (e.g. driving-scenes photographs), modulating the distractor frequency or testing attentional capture at a semantic and conceptual dimension. Our results revealed the conditions in which the attentional capture phenomenon occurs in close to real-world situations. We particularly discussed in our work the contingent attentional capture phenomenon which appears to be a strong and robust effect, in both laboratory and close to real-world situations.

Visual attentional capture is a form of visual attentional selection that is automatic and involuntary in nature, and is of high adaptive value as it allows visual attention to be oriented in a reflexive manner towards visual information without necessarily being guided by pre-existing knowledge, goals, and plans. According to the load-hypothesis (Lavie & De Fockert, 2005), attentional capture of salient stimuli increases under load on working memory due to disruption of stimulus-processing priorities. Moreover, it has been proposed that maintenance of task-irrelevant verbal information increases distractor interference in singleton search by increasing attentional capture of salient, but task-irrelevant, color singletons. This hypothesis was tested in the present study by having participants complete several succeeding trials of singleton search while simultaneously maintaining digits in working memory. The presence of task-irrelevant color singletons in the search array of a singleton search task led to increased response times, indicating attentional capture. However, the cost to response times associated with distractor presence did not increase under load on working memory, indicating that distractor interference may not be affected by load on working memory when task-irrelevant verbal information is maintained over an extended period of time. Individual differences in action video game playing and trait anxiety were considered and excluded as possible confounders.

Ringing phones are common in work space environments in the 21th century and while capturing the attention of the call-taker they also tend to disrupt people in the surrounding environment. This study aims to investigate the attentional capturing effect of ringtones by comparing sudden and increasing onsets with quiet and noise masking conditions while participants undertook a test of short-term memory for serial order (serial recall). The experiment presented new evidence that increasing ringtone sounds have a disruptive effect on serial recall processing. A masking noise background, however, successfully eliminated the effect of the increasing ringtone sound.  In contrary to what was anticipated, the ringtone with the sudden onset did not cause an attentional capture effect, suggesting at least in behavioural terms, it was successfully ignored. The results are discussed in relation to the literature on looking effects. Increasing ringtone sounds may appear looming, with sudden onset sounds decreasing in volume appearing receding. The central idea is that looming sounds are more disruptive to serial recall because they cause a diversion of attention from the serial recall task so as to react to the apparently approaching sound. The disruption attributable to looming sounds may be a form of attentional capture that is more specific than those triggered by deviant events within a to-be-ignored stream of sounds.

This paper describes a sequence of experiments addressing basic questions about the control of visual attention and the relationship between attention and object recognition. This work reviews compelling findings addressing attentional control on the basis of high-level perceptual properties. In five experiments observers were presented with a rapid sequence of object photographs and instructed to either detect or selectively encode a verbally cued object category. When these object categories (e.g. "baseball") were preceded by contextual images associated with a given object category (e.g. "baseball diamond"), observers were less likely to accurately report information about the target item. This effect obtained with both detection and discrimination measures. This evidence of attentional capture is particularly strong because associated contexts typically enhance object detection or discrimination, whereas here they harmed performance. These findings demonstrate that observers use relatively abstract and elaborated representations when selecting visual objects on the basis of category. Further, even when observers attempt to ignore depictions of associated contexts these images engage perceptual processing. That is, while participants were able to determine the target of their search categorically, they had relatively little control over the specific types of representations and information employed when performing an object search task. After reviewing these five experiments, conclusions regarding the use of object-context association knowledge in vision are addressed.