Grabbing Your Attention: The Impact of Finding a First Target in Multiple-Target Search

For over 50 years, the Satisfaction of Search effect, and more recently known as the Subsequent Search Miss (SSM) effect, has plagued the field of radiology. Defined as a decrease in additional target accuracy after detecting a prior target in a visual search, SSM errors are known to underlie both real-world search errors (e.g., a radiologist is more likely to miss a tumor if a different tumor was previously detected) and more simplified, lab-based search errors (e.g., an observer is more likely to miss a target ‘T’ if a different target ‘T’ was previously detected). Unfortunately, little was known about this phenomenon’s cognitive underpinnings and SSM errors have proven difficult to eliminate. However, more recently, experimental research has provided evidence for three different theories of SSM errors: the Satisfaction account, the Perceptual Set account, and the Resource Depletion account. A series of studies examined performance in a multiple-target visual search and aimed to provide support for the Resource Depletion account—a first target consumes cognitive resources leaving less available to process additional targets.

To assess a potential mechanism underlying SSM errors, eye movements were recorded in a multiple-target visual search and were used to explore whether a first target may result in an immediate decrease in second-target accuracy, which is known as an attentional blink. To determine whether other known attentional distractions amplified the effects of finding a first target has on second-target detection, distractors within the immediate vicinity of the targets (i.e., clutter) were measured and compared to accuracy for a second target. To better understand which characteristics of attention were impacted by detecting a first target, individual differences within four characteristics of attention were compared to second-target misses in a multiple-target visual search.

The results demonstrated that an attentional blink underlies SSM errors with a decrease in second-target accuracy from 135ms-405ms after detection or re-fixating a first target. The effects of clutter were exacerbated after finding a first target causing a greater decrease in second-target accuracy as clutter increased around a second-target. The attentional characteristics of modulation and vigilance were correlated with second- target misses and suggest that worse attentional modulation and vigilance are predictive of more second-target misses. Taken together, these result are used as the foundation to support a new theory of SSM errors, the Flux Capacitor theory. The Flux Capacitor theory predicts that once a target is found, it is maintained as an attentional template in working memory, which consumes attentional resources that could otherwise be used to detect additional targets. This theory not only proposes why attentional resources are consumed by a first target, but encompasses the research in support of all three SSM theories in an effort to establish a grand, unified theory of SSM errors.

A busca visual da cor, como medida avaliadora do funcionamento do sistema visual: um estudo exploratório a propósito da objetividade da felicidade em crianças

Este estudo, procura explicar a modularidade da mente humana, como um conjunto de módulos, permitindo desta forma contribuir para o estudo das ciências cognitivas. Estes módulos da arquitetura mental, permitem que a nossa mente interprete a cor resultante do sistema visual e das longitudes de ondas do espetro eletromagnético refratado dos objetos. Tendo por base o estudo do sistema visual, as células sensíveis, designadas por fotorrecetores percorrem o nervo ótico até atingir o encéfalo, localizando-se aí o sistema percetivo, permitindo desta forma realizar o estudo sobre busca visual da cor, como medida avaliadora do funcionamento do sistema visual, um estudo exploratório a propósito da objetividade da felicidade em crianças, que visa explorar a busca visual disjuntiva da cor como medida objetiva do bom funcionamento mental, do bem-estar subjetivo, como construto da felicidade. A amostra foi constituída por um grupo de 49 crianças não institucionalizadas e por um grupo de 16 crianças institucionalizadas, de ambos os sexos. Para a concretização deste estudo, foi necessária a utilização de uma tarefa de busca visual disjuntiva, que utilizou as simetrias de cores pertencentes ao mesmo par oponente e cores pertencentes a diferentes pares oponentes. Os resultados sugerem que não há qualquer interferência da institucionalização no funcionamento mental, logo no bem-estar subjetivo nas crianças; ABSTRACT: This study seeks to explain the modularity of the human mind, as a set of modules, giving this way a contribution to the study of the cognitive sciences. These modules of the mental architecture, allow our mind to interpret the resulting color of the visual system and the wavelengths of the electromagnetic spectrum refracted from the objects. Based on the study of our visual system, sensitive cells known as photoreceptors, which run along the optic nerve to the encephalon, being the perceptive system located there, allowing in this way to carry out the study on visual search of colour, as an assessment measure of the functioning of the visual system, an exploratory study concerning the objectivity of happiness in children, which aims to explore the disjunctive visual search of color as an objective measure of good mental functioning, of subjective well-being, as a construct of happiness. The sample consisted of a group of 49 non institutionalized children and of a group of 16 institutionalized children from both sexes. For the implementation of this study it was necessary to use a disjunctive visual search task, which used the Symmetry of colours belonging to the same opponent pair, and colours belonging to different opponent pairs. The results suggest that there is no interference from the institutionalization in mental functioning, therefore in the children’s subjective well being.

Cognitive assessment in closed head injury : stability, validity and parallel forms for two neuropsychological measures of recovery

Investigated the psychometric properties of the original and alternate sets of the Trail Making Test (TMT) and the Controlled Oral Word Association Test (COWAT; A. L. Benton and D. Hamsher, 1978) in 50 orthopedic and 15 closed head injured (1 yr after trauma) patients (aged 15–59 yrs). Although the alternate forms of both measures proved to be stable and consistent with each other in both groups, only the parallel sets of TMT reliably discriminated the clinical group from controls. Practice effects in the head injured were significant only for Trail B of TMT. Factor analysis of the control group's results identified Verbal Knowledge as a major contributor to performance on COWAT, whereas TMT was more dependent on Rapid Visual Search and Visuomotor Sequencing.

Different cognitive profiles for single compared with recurrent fallers without Dementia

Relationships between self-reported retrospective falls and cognitive measures (executive function, reaction time, processing speed, working memory, visual attention) were examined in a population based sample of older adults (n = 658). Two of the choice reaction time tests involved inhibiting responses to either targets of a specific color or location with hand and foot responses. Potentially confounding demographic variables, medical conditions and postural sway were controlled for in logistic regression models, excluding participants with possible cognitive impairment. A factor analysis of cognitive measures extracted factors measuring reaction time, accuracy and inhibition, and visual search. Single fallers did not differ from non-fallers in terms of health, sway or cognitive function, except that they performed worse on accuracy and inhibition. In contrast, recurrent fallers performed worse than non-fallers on all measures. Results suggest that occasional falls in late life may be associated with subtle age-related changes in the pre-frontal cortex leading to failures of executive control, whereas recurrent falling may result from more advanced brain ageing that is associated with generalized cognitive decline.

Sensitivity of the lane change test as a measure of in-vehicle system demand

The Lane Change Test (LCT) is one of the growing number of methods developed to quantify driving performance degradation brought about by the use of in-vehicle devices. Beyond its validity and reliability, for such a test to be of practical use, it must also be sensitive to the varied demands of individual tasks. The current study evaluated the ability of several recent LCT lateral control and event detection parameters to discriminate between visual-manual and cognitive surrogate In-Vehicle Information System tasks with different levels of demand. Twenty-seven participants (mean age 24.4 years) completed a PC version of the LCT while performing visual search and math problem solving tasks. A number of the lateral control metrics were found to be sensitive to task differences, but the event detection metrics were less able to discriminate between tasks. The mean deviation and lane excursion measures were able to distinguish between the visual and cognitive tasks, but were less sensitive to the different levels of task demand. The other LCT metrics examined were less sensitive to task differences. A major factor influencing the sensitivity of at least some of the LCT metrics could be the type of lane change instructions given to participants. The provision of clear and explicit lane change instructions and further refinement of its metrics will be essential for increasing the utility of the LCT as an evaluation tool.

Do drinking and riding mix? Effects of legal doses of alcohol on balance ability in experienced motorcyclists

The appropriateness of applying drink driving legislation to motorcycle riding has been questioned as there may be fundamental differences in the effects of alcohol on these two activities. For example, while the distribution of blood alcohol content (BAC) levels among fatally injured male drivers compared to riders is similar, a greater proportion of motorcycle fatalities involve levels in the lower (0 to .10% BAC) range. Several psychomotor and higher-order cognitive skills underpinning riding performance appear to be significantly influenced by low levels of alcohol. For example, at low levels (.02 to .046% BAC), riders show significant increases in reaction time to hazardous stimuli, inattention to the riding task, performance errors such as leaving the roadway and a reduced ability to complete a timed course. It has been suggested that alcohol may redirect riders’ focus from higher-order cognitive skills to more physical skills such as maintaining balance. As part of a research program to investigate the potential benefits of introducing a zero, or reduced, BAC for all riders in Queensland regardless of their licence status, the effects of low doses of alcohol on balance ability were investigated in a laboratory setting. The static balance of ten experienced riders was measured while they performed either no secondary task, a visual search task, or a cognitive (arithmetic) task following the administration of alcohol (0; 0.02, and 0.05% BAC). Subjective ratings of intoxication and balance impairment increased in a dose-dependent manner; however, objective measures of static balance were negatively affected only at the .05% BAC dose. Performance on a concurrent secondary visual search task, but not a purely cognitive (arithmetic) task, improved postural stability across all BAC levels. Finally, the .05% BAC dose was associated with impaired performance on the cognitive (arithmetic) task, but not the visual search task, when participants were balancing, but neither task was impaired by alcohol when participants were standing on the floor. Implications for road safety and future ‘drink riding’ policy considerations are discussed.

Detection of object onset and offset in naturalistic scenes

The present study was conducted to investigate whether ob- servers are equally prone to overlook any kinds of visual events in change blindness. Capitalizing on the finding from visual search studies that abrupt appearance of an object effectively captures observers' attention, the onset of a new object and the offset of an existing object were contrasted regarding their detectability when they occurred in a naturalistic scene. In an experiment, participants viewed a series of photograph pairs in which layouts of seven or eight objects were depicted. One object either appeared in or disappeared from the layout, and participants tried to detect this change. Results showed that onsets were detected more quickly than offsets, while they were detected with equivalent ac- curacy. This suggests that the primacy of onset over offset is a robust phenomenon that likely makes onsets more resistant to change blindness under natural viewing conditions.

Final report of Working Group 2: Traffic psychology [A COST Action TU1101 / HOPE collaboration]

BACKGROUND The workgroup of Traffic Psychology is concerned with the social, behavioral, and perceptual aspects that are associated with use and non-use of bicycle helmets, in their various forms and under various cycling conditions. OBJECTIVES The objectives of WG2 are to (1) share current knowledge among the people already working in the field, (2) suggest new ideas for research on and evaluation of the design of bicycle helmets, and (3) discuss options for funding of such research within the individual frameworks of the participants. Areas for research include 3.1. The patterns of use of helmets among different users: children, adults, and sports enthusiasts. 3.2. The use of helmets in different environments: rural roads, urban streets, and bike trails. 3.3. Concerns bicyclists have relative to their safety and convenience and the perceived impact of using helmets on comfort and convenience. 3.4. The benefit of helmets for enhancing visibility, and how variations in helmet design and colors affect daytime, nighttime, and dusktime visibility. 3.5. The role of helmets in the acceptance of city-wide pickup-and-drop-off bicycles. 3.6. The impact of helmets on visual search behaviour of bicyclists.

视觉搜索中注意捕获的控制机制

Theories of Visual search generally differentiate between bottom-up control and top-down control. Bottom-up control occurs when visual selection is determined by the stimulus properties in the search field. Top-down control takes place when observers are able to select those stimuli that are in line with their attentional sets. Pure stimulus-driven capture and contingent capture are two main theories on attentional capture by now, in which, theory of pure capture more emphasize bottom-up control, while theory of contingent capture more emphasize top-down control. Besides those two theories, Perceptual load theory of attention provides completely new perspective to explain attentional capture. The aim of this study is to investigate the mechanism of attentional capture in visual search on the basis of the existing theory of attentional capture and Perceptual load theory of attention. Three aspects of questions were explored in this study, which includes: the modulation role of perceptual load on attentional capture; the influence of search mode on attentional capture; and the influence of stimuli’s spatial and temporal characteristics on attentional capture. The results showed that: (1) Attentional capture was modulated by perceptual load in both conditions in which perceptual load manipulated either by amount of stimuli or similarity of stimuli. (2) Search mode did influence attentional capture, but more important, which was also modulated by perceptual load. (3) The spatial characteristics of congruent and incongruent distractor did influence attentional capture, specifically, the further the distractor from the target, the more interference effect the distractor had on visual search. (4) The temporal characteristics of distractor did influence attentional capture, specifically, the pattern of results from the study in which distractor were presented after the search display, were similar to those from the study in which distractors were presented before the search display. In sum, the results indicated that attentional capture are controlled not only by bottom-up factors, top-down factors but also modulated by available attention resources. These findings contribute to resolve the controversy for mechanism of attentional capture. And the potential application of this research was discussed.

线索位置和搜索方式对视觉搜索绩效的影响

By two different cue paradigms to cue target’s location or locations of all stimuli, this study is to discuss the search efficiency in different search modes. The research includes three experiments. The main results are as follows: The first experiment explores whether cueing target’s location has impact on vis-ual search performance under different search modes (parallel search and serial search). The results are: cueing target’s location has no facilitation effect in parallel search condition while has facilitation effect in serial search condition, the effect reflects the diffidence in slope of reaction time. In the second experiment, we want to explore whether cueing all stimuli’s loca-tions has impact on visual search performance under different search modes. The re-sults show that: cueing all stimuli’s locations has no facilitation effect in parallel search condition but has facilitation effect in serial search condition, the effect reflects the diffidence in intercept of reaction time. The third experiment is to explore the time course of facilitation effect in serial search. The result shows that only a 50ms which cueing all stimuli’s locations has fa-cilitation effect, with the longer cueing time, the more facilitation effect.

Vision, Instruction, and Action

This thesis describes Sonja, a system which uses instructions in the course of visually-guided activity. The thesis explores an integration of research in vision, activity, and natural language pragmatics. Sonja's visual system demonstrates the use of several intermediate visual processes, particularly visual search and routines, previously proposed on psychophysical grounds. The computations Sonja performs are compatible with the constraints imposed by neuroscientifically plausible hardware. Although Sonja can operate autonomously, it can also make flexible use of instructions provided by a human advisor. The system grounds its understanding of these instructions in perception and action.

A Solution of the Figure-ground Problem for Biological Vision

A neural network model of 3-D visual perception and figure-ground separation by visual cortex is introduced. The theory provides a unified explanation of how a 2-D image may generate a 3-D percept; how figures pop-out from cluttered backgrounds; how spatially sparse disparity cues can generate continuous surface representations at different perceived depths; how representations of occluded regions can be completed and recognized without usually being seen; how occluded regions can sometimes be seen during percepts of transparency; how high spatial frequency parts of an image may appear closer than low spatial frequency parts; how sharp targets are detected better against a figure and blurred targets are detector better against a background; how low spatial frequency parts of an image may be fused while high spatial frequency parts are rivalrous; how sparse blue cones can generate vivid blue surface percepts; how 3-D neon color spreading, visual phantoms, and tissue contrast percepts are generated; how conjunctions of color-and-depth may rapidly pop-out during visual search. These explanations arise derived from an ecological analysis of how monocularly viewed parts of an image inherit the appropriate depth from contiguous binocularly viewed parts, as during DaVinci stereopsis. The model predicts the functional role and ordering of multiple interactions within and between the two parvocellular processing streams that join LGN to prestriate area V4. Interactions from cells representing larger scales and disparities to cells representing smaller scales and disparities are of particular importance.

Spider monkey home ranges: A comparison of radio telemetry and direct observation

The ranging patterns of two male and five female spider monkeys (Ateles geoffroyi) were studied with the use of radio telemetry in Santa Rosa National Park, Costa Rica. The average size of a spider monkey home range was 62.4 hectares; however, range size varied with sex, and, for females, with the presence of a dependent infant. The probability of encountering a radio‐collared spider monkey in a three‐hour search using radio telemetry (0.91) was much greater than using a visual search (0.20), and telemetric data resulted in a larger estimate of mean home range size than did observational data, when all subjects were compared. However, the difference appeared to be owing to the presence of male ranges in the telemetric, but not the observational, data. When the size of home ranges derived from radio‐tracking data for adult females was compared to size of ranges for adult females derived from observations, the results were not significantly different. Adult males had larger home ranges than adult females, thus lending support to the hypothesis that males have adapted to the dispersion of females by occupying a large home range that overlaps the ranges of several adult females. The smallest home ranges were occupied by low‐weight females with dependent infants, perhaps reflecting social and energetic constraints. Copyright © 1988 Wiley‐Liss, Inc., A Wiley Company

Brief Report: Faces cause less distraction in Autism

Individuals with autism have difficulties interpreting face cues that contribute to deficits of social communication.When faces need to be processed for meaning they fail to capture and hold the attention of individuals with autism. In the current study we illustrate that faces fail to capture attention in a typical manner even when they are non-functional to task completion. In a visual search task with a present butterfly target an irrelevant face distractersignificantly slows performance of typical individuals.However, participants with autism (n = 28; mean 10 years 4 months) of comparable non-verbal ability are not distracted by the faces. Interestingly, there is a significant relationship between level of functioning on the autism spectrum and degree of face capture or distraction.

Étude électrophysiologique de l’impact de la couleur dans le déploiement attentionnel

L’influence de la couleur dans les mécanismes perceptuels et attentionnels a été étudiée. Quatre couleurs (le rouge, le vert, le bleu et le jaune) ont été calibrées individuellement à travers la technique heterochromatic flicker photometry. Suivant cela, les participants ont déployé leur attention à une cible (un cercle de couleur avec une ligne orientée). Les données électrophysiologiques ont été enregistrées pendant que les sujets performaient la tâche de recherche visuelle, et les analyses ont été basées sur les potentiels évoqués (PÉs). Trois composantes des PÉs ont été examinées : la posterior contralateral positivity (Ppc); la N2pc, reflétant le déploiement de l’attention visuo-spatiale et la temporal and contralateral positivity (Ptc). Des conditions dans lesquelles la cible était bleu ou rouge, lorsque comparées à des conditions avec une cible jaune ou verte suscitaient une N2pc plus précoce. Une amplitude plus élevée est aussi observée pour les cibles rouges pour les composantes Ppc et Ptc, reflétant une sélectivité pré-attentionelle. Ces résultats suggèrent de la prudence dans l’interprétation de données comparant des cibles de différentes couleurs dans des tâches de PÉs, et ce même lorsque les couleurs sont équiluminantes.