Cultural differences in attention: Eye movement evidence from a comparative visual search task.

Individual differences in visual attention have been linked to thinking style: analytic thinking (common in individualistic cultures) is thought to promote attention to detail and focus on the most important part of a scene, whereas holistic thinking (common in collectivist cultures) promotes attention to the global structure of a scene and the relationship between its parts. However, this theory is primarily based on relatively simple judgement tasks. We compared groups from Great Britain (an individualist culture) and Saudi Arabia (a collectivist culture) on a more complex comparative visual search task, using simple natural scenes.

Attentional Differences in a Driving Hazard Perception Task in Adults with Autism Spectrum Disorders.

The current study explored attentional processing of social and non-social stimuli in ASD within the context of a driving hazard perception task. Participants watched videos of road scenes and detected hazards while their eye movements were recorded. Although individuals with ASD demonstrated relatively good detection of driving hazards, they were slower to orient to hazards.

Safety in numbers: target prevalence affects the detection of vehicles during simulated driving.

The "low-prevalence effect" refers to the fact that observers often fail to detect rare targets (<5 % prevalence) during visual search tasks. Previous research has demonstrated robust prevalence effects in real-world tasks that employ static images, such as airport luggage screening. No published research has examined prevalence effects in dynamic tasks, such as driving.

On-road behaviour of younger and older novices during the first six months of driving.

Newly qualified drivers are known to have greater crash involvement than more experienced drivers, but does the on-road driving behaviour of young novices differ from that of older novices who might be expected to be more mature and to have different driving needs? Both younger and older novices were compared with experienced drivers in their behaviour driving an instrumented car on three occasions. The three drives were conducted within the novices' first few months of becoming qualified. All drivers, including both groups of novices, increased their average road speed over the three drives, and all increased their tendency to cut across the central lane marker on bends.

Salience of the lambs: a test of the saliency map hypothesis with pictures of emotive objects.

Humans have an ability to rapidly detect emotive stimuli. However, many emotional objects in a scene are also highly visually salient, which raises the question of how dependent the effects of emotionality are on visual saliency and whether the presence of an emotional object changes the power of a more visually salient object in attracting attention. Participants were shown a set of positive, negative, and neutral pictures and completed recall and recognition memory tests.

Some hazards are more attractive than others: drivers of varying experience respond differently to different types of hazard.

The ability to detect hazards in video clips of driving has been inconsistently linked to driving experience and skill. One potential reason for the lack of consistency is the failure to understand the structural differences between those hazards that discriminate between safe and unsafe drivers, and those that do not. The current study used a car simulator to test drivers of differing levels of experience on approach to a series of hazards that were categorized a priori according to their underlying structure.

Decisions about objects in real-world scenes are influenced by visual saliency before and during their inspection.

Evidence from eye-tracking experiments has provided mixed support for saliency map models of inspection, with the task set for the viewer accounting for some of the discrepancies between predictions and observations. In the present experiment viewers inspected pictures of road scenes with the task being to decide whether or not they would enter a highway from a junction. Road safety observations have concluded that highly visible road users are less likely to be involved in crashes, suggesting that saliency is important in real-world tasks.

Encoding time and signs exposure time in the representation of diagrammatic deontic meanings.

It has been proposed that prohibition and obligation be represented in different ways in reasoning with deontic information (Bucciarelli & Johnson-Laird, 2005). Obligations are salient in permissible situations and prohibitions in impermissible situations. In some specific cases, differential initial representations are also consistently predicted from the comprehension of negations, if prohibition is considered as the negation of an obligation.

Modeling eye movements in visual agnosia with a saliency map approach: bottom-up guidance or top-down strategy?

Two recent papers (Foulsham, Barton, Kingstone, Dewhurst, & Underwood, 2009; Mannan, Kennard, & Husain, 2009) report that neuropsychological patients with a profound object recognition problem (visual agnosic subjects) show differences from healthy observers in the way their eye movements are controlled when looking at images. The interpretation of these papers is that eye movements can be modeled as the selection of points on a saliency map, and that agnosic subjects show an increased reliance on visual saliency, i.e.

Visual strategies used for time-to-arrival judgments in driving.

To investigate the sources of visual information that are involved in the anticipation of collisions we recorded eye movements while participants made relative timing judgments about approaching vehicles at a junction. The avoidance of collisions is a critical aspect in driving, particularly where cars enter a line of traffic from a side road, and the present study required judgments about animations in a virtual driving environment. In two experiments we investigated the effects of (i) the angle of approach of the vehicle and the type of path (straight or curved) of the observer, and (ii) the speed of both the observer and the approaching car.

The potency of people in pictures: evidence from sequences of eye fixations.

Does the presence of people in a natural scene affect the way that we inspect that picture? Previous research suggests that we have a natural tendency to look at the social information before other items in a scene. There is also evidence that accuracy of visual memory and the way we move our eyes are related. This experiment investigated whether eye movements differed when participants correctly and incorrectly identified stimuli at recognition, and how this is affected by the presence of people.

Brief report: driving hazard perception in autism.

This study investigated whether individuals with ASD (autistic spectrum disorders) are able to identify driving hazards, given their difficulties processing social information, Klin et al. (Archives of General Psychiatry 59: 809-816, 2002). Twenty-three adult males with ASD and 21 comparison participants viewed 10 video clips containing driving hazards.

Fixation and saliency during search of natural scenes: the case of visual agnosia.

Models of eye movement control in natural scenes often distinguish between stimulus-driven processes (which guide the eyes to visually salient regions) and those based on task and object knowledge (which depend on expectations or identification of objects and scene gist). In the present investigation, the eye movements of a patient with visual agnosia were recorded while she searched for objects within photographs of natural scenes and compared to those made by students and age-matched controls. Agnosia is assumed to disrupt the top-down knowledge available in this task, and so may increase the reliance on bottom-up cues.

Does conspicuity enhance distraction? Saliency and eye landing position when searching for objects.

While visual saliency may sometimes capture attention, the guidance of eye movements in search is often dominated by knowledge of the target. How is the search for an object influenced by the saliency of an adjacent distractor? Participants searched for a target amongst an array of objects, with distractor saliency having an effect on response time and on the speed at which targets were found. Saliency did not predict the order in which objects in target-absent trials were fixated.

Domain knowledge moderates the influence of visual saliency in scene recognition.

Is the sequence of eye-movements made when viewing a picture related to encoding the image into memory? The suggestion of a relationship is supported by studies that have found that scanpaths are more similar over multiple viewings of a stimulus than would be expected by chance. It has also been found that low-level visual saliency contributes to the initial formation of these scanpaths, and has lead to formation of theories such as the saliency map hypothesis. However, bottom-up processes such as these can be overridden by top-down cognitive knowledge in the form of domain proficiency.

Turning the world around: patterns in saccade direction vary with picture orientation.

The eye movements made by viewers of natural images often feature a predominance of horizontal saccades. Can this behaviour be explained by the distribution of saliency around the horizon, low-level oculomotor factors, top-down control or laboratory artefacts? Two experiments explored this bias by recording saccades whilst subjects viewed photographs rotated to varying extents, but within a constant square frame. The findings show that the dominant saccade direction follows the orientation of the scene, though this pattern varies in interiors and during recognition of previously seen pictures.

Attentional and automatic processes in line tracing: is tracing obligatory?

When comparing two target elements placed on the same convoluted curve, response times are dependent on the distance between the targets along the curve, despite being separated by a constant Euclidean distance. The present study assessed whether such line tracing is obligatory across the whole of the line even when the task demands do not require it, or whether it is an optional strategy that can be disregarded when the circumstances favor a different method of attentional deployment. Three experiments were conducted to assess whether attention can select only a portion of a curve to trace when it is strategically sensible to do so.

Does attention move or spread during mental curve tracing?

There are two theories that attempt to explain how attention is deployed when lines are traced. Initially, it was believed that a covert zoom lens moved along the line. Recent evidence has, however, suggested that attention spreads along the line, rather than moving along it, perhaps as part of an effortful object-parsing process.

What can saliency models predict about eye movements? Spatial and sequential aspects of fixations during encoding and recognition.

Saliency map models account for a small but significant amount of the variance in where people fixate, but evaluating these models with natural stimuli has led to mixed results. In the present study, the eye movements of participants were recorded while they viewed color photographs of natural scenes in preparation for a memory test (encoding) and when recognizing them later. These eye movements were then compared to the predictions of a well defined saliency map model (L.

Sensing without seeing in comparative visual search.

Rensink [Rensink, R. A. (2004).

Low-level visual saliency does not predict change detection in natural scenes.

Saliency models of eye guidance during scene perception suggest that attention is drawn to visually conspicuous areas having high visual salience. Despite such low-level visual processes controlling the allocation of attention, higher level information gained from scene knowledge may also control eye movements. This is supported by the findings of eye-tracking studies demonstrating that scene-inconsistent objects are often fixated earlier than their consistent counterparts.

How does the purpose of inspection influence the potency of visual salience in scene perception?

Salience-map models have been taken to suggest that the locations of eye fixations are determined by the extent of the low-level discontinuities in an image. While such models have found some support, an increasing emphasis on the task viewers are performing implies that these models must combine with cognitive demands to describe how the eyes are guided efficiently. An experiment is reported in which eye movements to objects in photographs were examined while viewers performed a memory-encoding task or one of two search tasks.

Previous attentional set can induce an attentional blink with task-irrelevant initial targets.

Identification of a second target is often impaired by the requirement to process a prior target in a rapid serial visual presentation (RSVP). This is termed the attentional blink. Even when the first target is task irrelevant an attentional blink may occur providing this first target shares similar features with the second target (contingent capture).