Visual Search

When searching for one object among distracting objects, observers make use of a limited set of stimulus attributes to guide the deployment of their attention. Thus, if asked to search for ripe strawberries, an observer will use color information to guide covert attention as well as overt movements of eye and hand. While color is an unambiguous source of such guidance, there is no universally agreed list of all such sources. This chapter reviews the methods for determining if a property can guide the deployment of attention. Candidate sources of guidance are listed found in a table.

Seventy-five left and right brain-damaged patients, with or without hemispatial neglect, and 40 age-matched control subjects were tested on cancellation tasks with two different visual textures modeled after Julesz (1981). In one condition (''preattentive''), target elements segregated easily from background elements and were perceived effortlessly. In the other (''attentive''), target elements did not segregate easily and could be detected only after prolonged focal scrutiny. Both controls and patients were more accurate and faster on the preattentive than attentive texture. However, only neglect patients were disproportionately impaired on the attentive texture, thus suggesting that unilateral neglect is exacerbated by the low visual salience of the stimuli and a higher engagement of focal attention. Thus, a simple bedside test may help to tell apart the level of visual information processing maximally impaired in neglect patients.

At work and at leisure people perform various visual search tasks, e.g. they search for a particular icon in software tools, on Web sites or on mobile phones. With an increasing number of items, visual search becomes difficult. Recently, it has been suggested that the so-called contextual cueing effect, which is known from psychological experiments, can be applied to improve visual search performance. Contextual cueing leads to decreased search times for target objects within familiar context configurations. It is assumed that associations between context configurations and target locations are learned implicitly and then used to guide the allocation of attention to the relevant object. In accordance with demands for interface consistency, this mechanism could be interesting for the development of user interfaces. The present study investigated which object features (e.g. color or orientation) can establish the learning process. The results show that implicit learning of color and orientation arrangements are possible, but the transfer to configuration with changed features depends on the recent learning history. Implications of these results are discussed with respect to the design of user interfaces.

Multimedia data is generally stored in compressed form in order to efficiently utilize the available storage facilities. Access to archives is dependent on our ability to browse compressed multimedia information-retrieval and tracking from coded video databases. In this paper, a novel visual search engine for video retrieval and tracking from compressed multimedia databases is proposed. The goal of the project is the implementation of a visual browser that operates in a distributed environment where users initiate video searches and retrieve relevant video information simultaneously from multiple video archives. Being presented with a query in the form of template images of objects, the system operates on the compressed video to find the images or video sequences where those objects are present and their positions in the image. Upon user's request, the system will decompress and display only the video sequences of interest.

An attempt was made to determine why evidence for perceptual selectivity based on conceptual category (e.g., digits vs. letters) has been found in some experiments but not in others. Experiments using the partial-report paradigm find no partial-report superiority when the report is cued by category, whereas, in recent visual search studies, evidence for perceptual selectivity has been obtained for arrays containing a single item that was categorically different from the other items (e.g., a digit among letters). Using a search task, Experiment 1 investigated the possibility that the number of categorically different items in the arrays could be a determinant of selectivity. One, two, or three digits and a variable number of letters were presented on each trial, and subjects determined if a particular digit was present. No evidence of selectivity was obtained, even for the one-digit condition. Experiment 2 verified this result, and Experiment 3 extended the failure of selectivity to a search task in which the possible targets differed in color from the distractor items. In Experiment 4, subjects counted the number of digits or red letters in arrays in which black letters were the distractor items. The counting task was used to eliminate the requirement in our previous tasks that the subjects search forspecific items. Evidence was obtained in the counting task for selectivity based on the color difference but not on the categorical difference. The color stimuli used in the counting task were essentially the same as those that did not yield any evidence of selectivity in the search task. The results suggest that task demands are an important determinant of whether or not perceptual selectivity will occur.

This paper describes a series of visual search experiments for targets defined by their hinocular characteristics. In searches for targets defined by binocular rivalry among fused distractors, or vice versa, the rivalrous items do not "pop out" (reaction time [RT] increases with number of distractors). Binocular luster, a variety of rivalry, is an exception. Luster, an important property of visible surfaces, behaves like a basic feature or "texton" (RT independent of the number of nonlustrous distractors). Searches for targets defined exclusively by eye-of-origin information are virtually impossible. Subjects respond randomly, suggesting that purely monocular information is not available for visual search. Searches for cyclopean (but nonstereoscopic) features are easy, with RTs independent of set size, suggesting that some purely binocular information is available for visual search.

Social threat captures attention and is processed rapidly and eYciently, with many lines of research showing involvement of the amygdala. Visual search paradigms looking at social threat have shown angry faces 'pop-out' in a crowd, compared to happy faces. Autism and Asperger Syndrome (AS) are neurodevelopmental conditions characterised by social deWcits, abnormal face processing, and amygdala dysfunction. We tested adults with high-functioning autism (HFA) and AS using a facial visual search paradigm with schematic neutral and emotional faces. We found, contrary to predictions, that people with HFA/AS performed similarly to controls in many conditions. However, the eVect was reduced in the HFA/AS group when using widely varying crowd sizes and when faces were inverted, suggesting a diVerence in face-processing style may be evident even with simple schematic faces. We conclude there are intact threat detection mechanisms in AS, under simple and predictable conditions, but that like other face-perception tasks, the visual search of threat faces task reveals atypical face-processing in HFA/AS.

This study tested the hypotheses that visual search impairments in schizophrenia are due to a delay in initiation of search or a slow rate of serial search. We determined the specificity of these impairments by comparing children with schizophrenia to children with attention-deficit hyperactivity disorder (ADHD) and age-matched normal children. The hypotheses were tested within the framework of feature integration

In seven experiments, observers searched for a scrambled object among normal objects. The critical comparison was between repeated search in which the same set of stimuli remained present in fixed positions in the display for many (> 100) trials and unrepeated conditions in which new stimuli were presented on each trial. In repeated search conditions, observers monitored an essentially stable display for the disruption of a clearly visible object. This is an extension of repeated search experiments in which subjects ...

Research focusing on perceptual-cognitive skill in sport is abundant. However, the existing qualitative syntheses of this research lack the quantitative detail necessary to determine the magnitude of differences between groups of varying levels of skills, thereby limiting the theoretical and practical contribution of this body of literature. We present a meta-analytic review focusing on perceptual-cognitive skill in sport (N = 42 studies, 388 effect sizes) with the primary aim of quantifying expertise differences. Effects were calculated for a variety of dependent measures (i.e., response accuracy, response time, number of visual fixations, visual fixation duration, and quiet eye period) using point-biserial correlation. Results indicated that experts are better than nonexperts in picking up perceptual cues, as revealed by measures of response accuracy and response time. Systematic differences in visual search behaviors were also observed, with experts using fewer fixations of longer duration, including prolonged quiet eye periods, compared with nonexperts. Several factors (e.g., sport type, research paradigm employed, and stimulus presentation modality) significantly moderated the relationship between level of expertise and perceptual-cognitive skill. Practical and theoretical implications are presented and suggestions for empirical work are provided.

Medical-grade monochrome monitors typically display 8 bits of data. This study determined if 11-bit displays could improve observer performance and decrease use of window/level. 8and 11-bit displays from three manufacturers were used at three sites. Six radiologists at each site viewed 100 DR chest images (half with a pulmonary nodule) on both displays. Decisions, confidence, nodule location, viewing time, and window/level use were recorded. There was no significant difference in ROC Az as a function of bit depth. The average Az with 8 bits was 0.8284 and with 11 bits was 0.8253. There was a significant difference in viewing time favoring the 11-bit displays. Window/level use did not differ. Eye position was recorded on a subset of images at one site. Cumulative dwell times for each decision category were lower with the 11-bit than with the 8-bit display. When tested with t-tests for paired observations, the TP (t = 1.452, p = 0.1507), FN (t = 0.050, p = 0.9609), and FP (t = 0.042, p = 0.9676) were not statistically significant. The difference in the TN decisions was statistically significant (t = 1.926, p = 0.05). 8-bit displays will not impact negatively diagnostic accuracy, but using 11-bit displays may improve workflow efficiency.

We investigated whether the effect of covert attention on information accrual varies with eccentricity (4°vs 9°) and the complexity of the visual search task (feature vs conjunction). We used speed-accuracy tradeoff procedures to derive conjoint measures of the speed of information processing and accuracy in each search task. Information processing was slower with more complex conjunction searches than with simpler feature searches, and overall it was faster at peripheral (9°) than parafoveal (4°) locations in both search types. Covert attention increased discriminability and accelerated information accrual at both eccentricities, and the magnitude of this attentional effect was the same for both feature (simple) and conjunction (complex) searches. Interestingly, in contrast to the compensatory effect of covert attention on information processing at iso-eccentric locations (temporal performance fields), covert attention did not eliminate speed differences across eccentricity.

— In this paper, we propose a multi-modal search engine for interior design that combines visual and textual queries. The goal of our engine is to retrieve interior objects, e.g. furniture or wall clocks, that share visual and aesthetic similarities with the query. Our search engine allows the user to take a photo of a room and retrieve with a high recall a list of items identical or visually similar to those present in the photo. Additionally, it allows to return other items that aesthetically and stylistically fit well together. To achieve this goal, our system blends the results obtained using textual and visual modalities. Thanks to this blending strategy, we increase the average style similarity score of the retrieved items by 11%. Our work is implemented as a Web-based application and it is planned to be opened to the public.

Web standards such as RDF (Resource Description Framework) facilitate data integration over large number of sources. The resulting interlinked datasets describe objects, their attributes and links to other objects. Such datasets are amenable for queries beyond traditional keyword search and for visualisation beyond a simple list of links to documents. Given that data integrated from the open web exhibits enormous variety in scope and structure, the mechanisms for interacting with such data have to be generic and agnostic to the vocabularies used. Ideally, a system operating on web data is easy to use without upfront training. To this end, we present VisiNav, a system based on an interaction model designed to easily search and navigate large amounts of web data (the current system contains over 18.5m RDF triples aggregated from 70k sources). In this paper we introduce a formal query model comprising four atomic operations over object-structured datasets: keyword search, object focus, path traversal, and facet specification. From these atomic operations, users incrementally assemble complex queries that yield trees of objects as result. These results can then be either directly visualised or exported to application programs or online services for further processing. The current system provides detail, list, and table views for arbitrary types of objects; and timeline and map visualisations for temporal and spatial aspects of objects.

Patients with spatial neglect do not explore contralateral space effectively. Although cancellation tasks are used widely to assess this visual search deficit, their methods of analysis are not well established. We introduce logistic regression analyses for cancellation tasks in 7 patients with left neglect. We investigated the influences of spatial location, stimuli number, and target discriminability on the probability of canceling a target. As a group, neglect patients showed left and near neglect. They also explored and canceled targets further into contralateral space on arrays with fewer visual stimuli. Individual analyses revealed exceptions to these group patterns, such as two patients with far rather than near neglect. Only patients with relatively mild neglect canceled more targets when they were more easily discriminated from distracters. Logistic regression models accounted for 0.68 the variance in cancellation performances of the entire group. Shifting the unit of analysis from the proportion of targets canceled to the probability of detecting individual targets offers a powerful parametric method to analyze group and individual performances on cancellation tasks and can reveal functional dissociations in neglect.

A new hypothesis about the role of focused attention is proposed. The feature-integration theory of attention suggests that attention must be directed serially to each stimulus in a display whenever conjunctions of more than one separable feature are needed to characterize or distinguish the possible objects presented. A number of predictions were tested in a variety of paradigms including visual search, texture segregation, identification and localization, and using both separable dimensions (shape and color) and local elements or parts of figures (lines, curves, etc. in letters) as the features to be integrated into complex wholes. The results were in general consistent with the hypothesis. They offer a new set of criteria for distinguishing separable from integral features and a new rationale for predicting which tasks will show attention limits and which will not.

Cette recherche porte sur le rôle que peuvent jouer les humeurs sur, premièrement, les processus attentionnels fondamentaux lors d’une tâche de détection visuelle simple, puis sur ces mêmes mécanismes activés lors de la perception de stimuli complexes. Notre première expérience nous a permis de vérifier notre hypothèse reposant sur la théorie de Fredrickson (2004) et qui propose une facilitation de la détection d’une cible en humeur positive. Des affiches de campagnes de prévention « Stop Sida » ont été le support de notre deuxième expérience. Ces analyses, effectuées au moyen d’une mesure des mouvements oculaires, n’ont révélé aucune influence de l’humeur sur la manière de percevoir des affiches de prévention, que ce soit sur la totalité des campagnes ou sur certaines en particulier. Nous avons par contre pu définir quelles sont les campagnes qui ont le plus attiré l’attention de nos sujets. De plus, les liens trouvés entre des dimensions d’ouverture émotionnelle et la perception de quelques campagnes nous ont aidée à comprendre pourquoi certaines affiches ont été inspectées différemment.

We raise the new possibility that people diagnosed with developmental dyslexia (DD) are specialized in explorative cognitive search, and rather than having a neurocognitive disorder, play an essential role in human adaptation. Most DD research has studied educational difficulties, with theories framing differences in neurocognitive processes as deficits. However, people with DD are also often proposed to have certain strengths – particularly in realms like discovery, invention, and creativity – that deficit-centered theories cannot explain. We investigate whether these strengths reflect an underlying explorative specialization. We re-examine experimental studies in psychology and neuroscience using the framework of cognitive search, whereby many psychological processes involve a trade-off between exploration and exploitation. We report evidence of an explorative bias in DD-associated cognitive strategies. High DD prevalence and an attendant explorative bias across multiple areas of cognition suggest the existence of explorative specialization. An evolutionary perspective explains the combination of findings and challenges the view that individuals with DD have a disorder. In cooperating groups, individual specialization is favored when features that confer fitness benefits are functionally incompatible. Evidence for search specialization suggests that, as with some other social organisms, humans mediate the exploration–exploitation trade-off by specializing in complementary strategies. The existence of a system of collective cognitive search that emerges through collaboration would help to explain our species’ exceptional adaptiveness. It also aligns with evidence for substantial variability during our evolutionary history and the notion that humans are adapted not to a particular habitat but to variability itself. Specialization creates interdependence and necessitates balancing complementary strategies. Reframing DD therefore underscores the urgency of changing certain cultural practices to ensure we do not inhibit adaptation. Key improvements would remove cultural barriers to exploration and nurture explorative learning in education, academia, and the workplace, as well as emphasize collaboration over competition. Specialization in complementary search abilities represents a meta-adaptation; through collaboration, this likely enables human groups (as a species and as cultural systems) to successfully adapt. Cultural change to support this system of collaborative search may therefore be essential in confronting the challenges humanity now faces.

Schematic threatening, friendly, and neutral faces were used to test the hypothesis that humans preferentially orient their attention toward threat. Using a visual search paradigm, participants searched for discrepant faces in matrices of otherwise identical faces. Across 5 experiments, results consistently showed faster and more accurate detection of threatening than friendly targets. The threat advantage was obvious regardless of whether the conditions favored parallel or serial search (i.e., involved neutral or emotional distractors), and it was valid for inverted faces. Threatening angry faces were more quickly and accurately detected than were other negative faces (sad or "scheming"), which suggests that the threat advantage can be attributed to threat rather than to the negative valence or the uniqueness of the target display.

We propose WindowScape, a window manager that uses a photograph metaphor for lightweight, post hoc task management. This is the first task management windowing model to provide intuitive accessibility while allowing windows to exist simultaneously in multiple tasks. WindowScape exploits users' spatial and visual memories by providing a stable thumbnail layout in which to search for windows. A function is provided to let users search the window space while maintaining a largely consistent screen image to minimize distractions. A novel keyboard interaction technique is also presented.

Scanning of the visual scene is an important selective process in visual perception. In this article we argue that eye-movement data provide an excellent on-line indication of the cognitive processes underlying visual search and reading. We outline some recent advances from physiological investigations of saccadic eye-movement control before focusing on eye-movement behaviour in visual search and reading studies. We consider factors that can affect the duration of fixations and the choice of saccade targets, emphasising continuities between biological and cognitive descriptions. We discuss different ways of measuring cognitive processing time from an eye-movement record and the relationship between attention and eye movements.

Human Computer Interaction (HCI) is a discipline that has progressed to establish a smooth understanding between humans and computers for effective visual searchability, accessibility and usability. With a lot of advancements in the search engines, only a few studies examined how the results are viewed from the perspective of end users from different regions. The main aim of this research is to investigate and explore whether there are cultural variations in visual search behaviour and eye movements on Search Engine Results Page (SERP) between two different cultures (Arabic and English), using the eye-tracking method in order to provide insights for global implementation of search engines. This research also aims to explore to what extent users with different language and cultural background differ in their visual search behaviour, performance and satisfaction when they are searching SERP with different layout and tasks. As a preliminary work, a controlled eye-tracking experiment was conducted to explore and evaluate the visual search behaviour of Arabs and English when searching through the Google Pages. The preliminary results provide new insights into the differences in visual search behaviours and eye movements between members from the Middle East and United Kingdom.

In the fall of 1987 Mobius began fieldwork, under a license from the Bahamian Government, to carry out an archaeological survey in an area of the Grand Bahama Banks encompassing some 579.15 square miles  (1500 sq. km).  This report compares the Remote Viewing, electronic remote sensing, and visual search process used to locate the wreck site of a previously undiscovered armed American merchantman believed to be the Brig Leander, which was found in a sub-section of the License Area known as Consensus Zone C; an area of 11.81 sq. miles (30.59 sq. km) of water.  It concludes that Remote Viewing was the source of information which led to the site’s location, and that electronic remote sensing was not useful in this instance. Leander was under the Command of Captain William Johnson when she sank for unknown reasons near Beaks Cay on  6 April 1834,  while returning from Manzanilla, Cuba to her homeport in Boston, Massachusetts.  In addition to location information, a total of 193 conceptu...

“Weak central coherence” refers to the detail-focused processing style proposed to characterise autism spectrum disorders (ASD). The original suggestion of a core deficit in central processing resulting in failure to extract global form/meaning, has been challenged in three ways. First, it may represent an outcome of superiority in local processing. Second, it may be a processing bias, rather than deficit. Third, weak coherence may occur alongside, rather than explain, deficits in social cognition. A review of over 50 empirical studies of coherence suggests robust findings of local bias in ASD, with mixed findings regarding weak global processing. Local bias appears not to be a mere side-effect of executive dysfunction, and may be independent of theory of mind deficits. Possible computational and neural models are discussed.

Anticipation skill in tennis was examined using realistic film simulations, movement-based response measures, and a portable eye movement recording system. Skilled players were faster than their less skilled counterparts in anticipating the direction of opponents' tennis strokes, with this superior performance being based, at least in part, on more effective visual search behaviors. The processes mediating superior performance were then modeled in groups of recreational tennis players using video simulation, instruction, and feedback. Players who received perceptual training improved their performance on laboratory-and field-based tests of anticipation when compared with matched placebo and control groups that did not receive any instruction regarding expert performance strategies. The approach used may have practical utility in a variety of performance contexts.

Novice drivers have been found in previous studies to display a limited search of the immediate environment, relative to experienced drivers, when manoeuvring on a dual-carriageway road. The present study investigated whether this reduction in the variance of search along the horizontal plane was a product of less frequent glancing in the car's mirrors. Novice and experienced drivers were observed as they made lane changes in relatively unobstructed conditions and when they needed to move into a lane already occupied by tra c. Novice drivers were found to rely more than experienced drivers upon their internal mirror, even when the lane-changing manoeuvre required information about tra c in the lane best re¯ected in the external, door-mounted mirror. Novices did increase their use of the external mirror in response to driving needs, suggesting that they did have an awareness of the situation that required inter-weaving with tra c in their destination lane. Their reliance upon the internal mirror may be a product of a habit acquired speci®cally for the driver licensing examination, in which exaggerated inspection of the internal mirror is regarded as being desirable.

The main objective of this paper was to investigate the effects of a computer screen interface design and its related geometrical characteristics of 36 graphical objects on a user's task efficiency. A total of 490 subjects took part in laboratory experiments that focused on the direct manipulation of a visual dialogue between a user and a computer. The subjects were asked to select an object from among a group of items randomly placed on the computer screen that were visible exclusively during the visual search process. A model expressing the mean object acquisition time as a function of graphical object size and the configuration was developed and statistically validated. The model showed an influence of geometrical design characteristics of the graphical objects (icons) and their groupings (icon structures) on the observed task efficiency. The reported results can be used at those stages of a software lifecycle that concentrate on prototyping, designing, and implementing graphical solutions for the efficient graphical user-computer interface. r

To examine how visual attentional resources are allocated when learning from a complex animation about the cardiovascular system, eye movements were registered in the absence and presence of visual cues. Cognitive processing was assessed using cued retrospective reporting, whereas comprehension and transfer tests measured the quality of the constructed representation. Within the framework of Cognitive Load Theory, visual cues highlighting the subsystems of the heart were hypothesized to guide attention, reduce visual search and extraneous cognitive load, and enhance learning. As predicted, learners looked more often and longer at cued parts. However, we found no effects of cueing on visual search and cognitive load. With respect to cognitive processing, performance differences were found on the number of statements in the learners’ verbal reports. These findings suggest that visual cueing can guide attention in an animation, but other factors are also important in determining the effectiveness of visual cues on learning.

Previous research has noted that novice drivers are at greatest risk of an accident. One reason that has been reported for this is that they have not developed the optimum visual search strategies of their more experienced counterparts. One might expect that new drivers might be taught the appropriate visual skills while learning to drive, though this requires instructors to have introspection into their own visual skills before they can be passed on to the student. In addition novice drivers should be able to acquire the instructed skills. This study used an image-based questionnaire to assess driving instructors’ and novice drivers’ priority ratings for attending to different areas of the driving scene across nine scenarios. It was predicted that if instructors and novices have introspection into the relative importance of these different areas, there should be agreement across the sample of participants. Additionally it was considered important to assess which areas of the visual scene are important across all different scenarios and which areas change in priority with a change in scenario. Results showed that for both groups the opinions regarding visual field prioritisation were highly consistent when compared to chance. Despite the rating consistencies, group differences were found, across all scenarios with “Rear View Mirrors” being the visual field with the most frequent observed group differences. Certain categories (“Road Ahead” and “Mirrors”) were highly ranked across all scenarios, while other categories were more scenario specific. We conclude that both groups have insight into some elements of visual search. However, in many occasions the prioritisation was different between driving instructors and novice drivers. It appears that during the learning process the novice drivers did not adopt the prioritisation strategies seen in driving instructors. This has important implications for the teaching of visual skills in driving.

A leftward spatial bias has been observed with visuospatial attention tasks, including line bisection and the greyscales task. Upper and lower visual field differences have been observed on various tasks, with a lower visual field advantage occurring for motion, global processing and coordinate spatial judgments. Upper visual field advantages occur for visual search, local processing and categorical judgments. In perceptual

& The purpose of the present study was to investigate the effect of harmonic expectancy violations on emotions. Subjective response measures for tension and emotionality, as well as electrodermal activity (EDA) and heart rate (HR), were recorded from 24 subjects (12 musicians and 12 nonmusicians) to observe the effect of expectancy violations on subjective and physiological measures of emotions. In addition, an electroencephalogram was recorded to observe the neural correlates for detecting these violations. Stimuli consisted of three matched versions of six Bach chorales, which differed only in terms of one chord (harmonically either expected, unexpected or very unexpected). Musicians' and nonmusicians' responses were also compared. Tension, overall subjective emotionality, and EDA increased with an increase in harmonic unexpectedness. Analysis of the event-related potentials revealed an early negativity (EN) for both the unexpected and the very unexpected harmonies, taken to reflect the detection of the unexpected event. The EN in response to very unexpected chords was significantly larger in amplitude than the EN in response to merely unexpected harmonic events. The ENs did not differ in amplitude between the two groups but peaked earlier for musicians than for nonmusicians. Both groups also showed a P3 component in response to the very unexpected harmonies, which was considerably larger for musicians and may reflect the processing of stylistic violations of Western classical music. & D

Change blindness (CB), the inability to detect changes in visual scenes, may increase with age and early Alzheimer's disease (AD). To test this hypothesis, participants were asked to localize changes in natural scenes. Dependent measures were response time (RT), hit rate, false positives (FP), and true sensitivity (d′). Increased age correlated with increased sensitivity and RT; AD predicted even slower RT. Accuracy and RT were negatively correlated. Differences in FP were nonsignificant. CB correlated with impaired attention, working memory, and executive function. Advanced age and AD were associated with increased CB, perhaps due to declining memory and attention. CB could affect real-world tasks, like automobile driving.

This study tested whether adverse effects of state anxiety on attention and performance may be modulated by experience. Sixteen experienced and eleven inexperienced drivers drove in a simulator under low-and highstress conditions. Anxiety was manipulated by competition, the presence of an evaluator, external video camera, and traffic noise. Most drivers showed greater anxiety scores and higher mean heart rates following manipulation. In both groups increased state anxiety decreased car speed control and caused more collisions, accompanied by fewer fixations of longer duration towards the driving lane across a horizontally narrower region. Inexperienced drivers increased the number of short fixations towards cars, while experienced drivers increased the number of short fixations on the speedometer. Although anxiety impairs processing efficiency and performance effectiveness for both groups, attentional changes differ as a function of experience. Inexperienced drivers tended to shift attention to threatening stimuli, while experienced drives were more likely to consciously monitor task goal.

Barn owls are nocturnal predators which have evolved specific sensory and morphological adaptations to a life in dim light. Here, some of the most fundamental properties of spatial vision in barn owls are reviewed. The eye with its tubular shape is rigidly integrated in the skull so that eye movements are very much restricted. The eyes are oriented frontally, allowing for a large binocular overlap. Accommodation, but not pupil dilation, is coupled between the two eyes. The retina is rod dominated and lacks a visible fovea. Retinal ganglion cells form a marked region of highest density that extends to a horizontally oriented visual streak. Behavioural visual acuity and contrast sensitivity are poor, although the optical quality of the ocular media is excellent. A low f-number allows high image quality at low light levels. Vernier acuity was found to be a hyperacute percept. Owls have global stereopsis with hyperacute stereo acuity thresholds. Neurons of the visual Wulst are sensitive to binocular disparities. Orientation based saliency was demonstrated in a visual-search experiment, and higher cognitive abilities were shown when the owl's were able to use illusory contours for object discrimination.