Visual marking and visual change.

Five experiments investigated the types of changes that disrupt the preview effect--the benefit gained in difficult search tasks from presenting some distractors earlier in time. A shape change with or without an overall luminance change at the location of an old item was found to disrupt the preview effect, whereas an equivalent luminance change alone or an isoluminant color change was not disruptive. Results suggest that (a) relatively low-level visual changes may not be sufficient to abolish the benefit, (b) the benefit most likely occurs through inhibition applied to locations within a location master map, and (c) inhibition need not be applied to surface features of objects. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Visual marking: Dissociating effects of new and old set size.

Visual marking makes it possible to ignore old items during search. In a typical study, old items are previewed 1 s before adding an equal number of new items, one of which is the target. Previewing half of the items reduces the search slope relating response time (RT) to overall set size by half. However, this manipulation sometimes only reduces overall RT but not search slope (Experiment 1). By orthogonally varying the numbers of old and new items, Experiment 2 shows that old and new set sizes interactively affect visual marking. Given a constant new set size, the size of the old set has negligible effect on RT. However, increasing the new set size reduces the preview benefit in overall RT. Experiment 3 shows that this reduction may be restricted to paradigms that use temporal segregation cues. Studies should vary old and new set size orthogonally to avoid missing a visual marking effect where one may be present. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

When visual marking meets the attentional blink: More evidence for top-down, limited-capacity inhibition.

An attentional blink (AB) paradigm was used to investigate the attentional resources necessary for visual marking. The results showed that distractors presented inside the AB cannot easily be ignored despite participants anticipating a future target display. This supports the hypothesis that attentional resources are required for visual marking. In addition, probe dots were better detected on blinked distractors than on successfully ignored distractors, but only when the task required new items to be prioritized. In a final experiment, a stronger negative carry-over effect on search occurred for targets identical to distractors presented outside rather than inside the AB. This suggests that at least part of the inhibitory processes involved in visual marking are nonspatial. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

When a reappearance is old news: Visual marking survives occlusion.

Performance in a visual search task becomes more efficient if half of the distractors are presented before the rest of the stimuli. This "preview benefit" may partly be due to inhibition of the old (previewed) items. The preview effect is abolished, however, if the old items offset briefly before reappearing (D. G. Watson & G. W. Humphreys, 1997). The authors examined whether this offset effect still occurred if the old item undergo occlusion. Results show that a preview benefit was found when the old items were occluded but not otherwise, consistent with the idea of top-down attentional inhibition being applied to the old items. The preview benefit is attenuated, however, by movement of the irrelevant stimuli in the displays. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

"Visual marking: Dissociating effects of new and old set size": Erratum.

Reports an error in the byline of the article by Y. Jiang et al (Journal of Experimental Psychology: Learning, Memory, and Cognition, 2002[Mar], Vol 28[2], 293-302). Y. Jiang's affiliations should have been listed as "Yale University and John B. Pierce Laboratory" and Lawrence E. Mark's affiliations should have been listed as "John B. Pierce Laboratory and Yale University." (The following abstract of the original article appeared in record 2002-00620-003.) Visual marking makes it possible to ignore old items during search. In a typical study, old items are previewed 1 s before adding an equal number of new items, one of which is the target. Previewing half of the items reduces the search slope relating response time (RT) to overall set size by half. However, this manipulation sometimes only reduces overall RT but not search slope (Experiment 1). By orthogonally varying the numbers of old and new items, Experiment 2 shows that old and new set sizes interactively affect visual marking. Given a constant new set size, the size of the old set has negligible effect on RT. However, increasing the new set size reduces the preview benefit in overall RT. Experiment 3 shows that this reduction may be restricted to paradigms that use temporal segregation cues. . . . (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Visual marking: Selective attention to asynchronous temporal groups.

In visual search, when a subset of distractors is previewed 1 s before the target and the remaining distractors, search speed is independent of the number of previewed items. This is visual marking. What allows old items to be marked? Four experiments show that marking is disrupted if the onset of the new items is accompanied by synchronous changes to the old items, but it is not disrupted by changes restricted to the background or by asynchronous changes to the old items. Further, behaviorally relevant old items can be prioritized over new items. Visual marking is based on temporal asynchrony between new and old items, which allows segregation of these items into 2 temporal groups. Attention is then selectively applied to 1 group. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Visual search for change in older adults.

Previous research has demonstrated that younger adults are surprisingly poor at detecting substantial changes to visual scenes. Little is known, however, about age differences in this phenomenon. In the 2 experiments reported here, older adults were slower than younger adults in detecting changes to simple visual stimuli. This age difference was beyond what would be expected given known age-related changes in processing speed. Examination of eye movement behavior during the search for change suggested that age-related changes in the useful field of view and degree of cautiousness play a significant role. Speed of processing and 3 age-related eye movement behaviors explained 85% of the variance in change detection latency, eliminating the effect of age. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

New objects dominate luminance transients in setting attentional priority.

Both the sudden appearance of an object and sudden changes in existing object features influence priority in visual search. However, direct comparisons of these influences have not been made under controlled conditions. In 5 visual search experiments, new object onsets were compared directly with changes in the luminance of old objects. Factors included the luminance contrast of items against the background, the magnitude of luminance change, and the probability that these changes were associated with the target item. New objects were consistently more effective in guiding search, such that a new item with very low luminance contrast was equivalent to an old item undergoing a large change in luminance. An important exception was an old item changing in contrast and polarity, which was as effective as the appearance of a new object. This indicates that search priority is biased toward object rather than situational changes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Characteristics of covert and overt visual orienting: Evidence from attentional and oculomotor capture.

Five visual search experiments found oculomotor and attentional capture consistent with predictions of contingent orienting, contrary to claims that oculomotor capture is purely stimulus driven. Separate saccade and attend-only conditions contained a color target appearing either singly, with an onset or color distractor, or both. In singleton mode, onsets produced oculomotor and attentional capture. In feature mode, capture was absent or greatly reduced, providing evidence for top-down modulation of both types of capture. Although attentional capture by color abstractors was present throughout, oculomotor capture by color occurred only when accompanied by transient change, providing evidence for a dissociation between oculomotor and attentional capture. Oculomotor and attentional capture appear to be mediated by top-down attentional control settings, but transient change may be necessary for oculomotor capture. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Alcohol-related attentional bias in problem drinkers with the flicker change blindness paradigm.

The authors used a flicker paradigm for inducing change blindness as a more direct method of measuring attentional bias in problem drinkers in treatment than the previously used, modified Stroop, Posner, and dual-task paradigms. First, in an artificially constructed visual scene comprising digitized photographs of real alcohol-related and neutral objects, problem drinkers detected a change made to an alcohol-related object more quickly than to a neutral object. Age- and gender-matched social drinkers showed no such difference. Second, problem drinkers given the alcohol-related change to detect showed a negative correlation between the speed with which the change was detected and the problem severity as measured by the number of times previously treated. Coupled with other data from heavy and light social drinkers, the data support a graded continuity of attentional bias underpinning the length of the consumption continuum. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Grasp preparation improves change detection for congruent objects.

A series of experiments provided converging support for the hypothesis that action preparation biases selective attention to action-congruent object features. When visual transients are masked in so-called change-blindness scenes, viewers are blind to substantial changes between 2 otherwise identical pictures that flick back and forth. The authors report data in which participants planned a grasp prior to the onset of a change-blindness scene in which 1 of 12 objects changed identity. Change blindness was substantially reduced for grasp-congruent objects (e.g., planning a whole-hand grasp reduced change blindness to a changing apple). A series of follow-up experiments ruled out an alternative explanation that this reduction had resulted from a labeling or strategizing of responses and provided converging support that the effect genuinely arose from grasp planning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Visual search in a multi-element asynchronous dynamic (MAD) world.

In visual search tasks participants search for a target among distractors in strictly controlled displays. We show that visual search principles observed in these tasks do not necessarily apply in more ecologically valid search conditions, using dynamic and complex displays. A multi-element asynchronous dynamic (MAD) visual search was developed in which the stimuli could either be moving, stationary, and/or changing in luminance. The set sizes were high and participants did not know the specific target template. Experiments 1 through 4 showed that, contrary to previous studies, search for moving items was less efficient than search for static items and targets were missed a high percentage of the time. However, error rates were reduced when participants knew the exact target template (Experiment 5) and the difference in search efficiency for moving and stationary targets disappeared when lower set sizes were used (Experiment 6). In all experiments there was no benefit to finding targets defined by a luminance change. The data show that visual search principles previously shown in the literature do not apply to these more complex and “realistically” driven displays. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Attentional capture of objects referred to by spoken language.

Participants saw a small number of objects in a visual display and performed a visual detection or visual-discrimination task in the context of task-irrelevant spoken distractors. In each experiment, a visual cue was presented 400 ms after the onset of a spoken word. In experiments 1 and 2, the cue was an isoluminant color change and participants generated an eye movement to the target object. In experiment 1, responses were slower when the spoken word referred to the distractor object than when it referred to the target object. In experiment 2, responses were slower when the spoken word referred to a distractor object than when it referred to an object not in the display. In experiment 3, the cue was a small shift in location of the target object and participants indicated the direction of the shift. Responses were slowest when the word referred to the distractor object, faster when the word did not have a referent, and fastest when the word referred to the target object. Taken together, the results demonstrate that referents of spoken words capture attention. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Feature-based memory-driven attentional capture: Visual working memory content affects visual attention.

In 7 experiments, the authors explored whether visual attention (the ability to select relevant visual information) and visual working memory (the ability to retain relevant visual information) share the same content representations. The presence of singleton distractors interfered more strongly with a visual search task when it was accompanied by an additional memory task. Singleton distractors interfered even more when they were identical or related to the object held in memory, but only when it was difficult to verbalize the memory content. Furthermore, this content-specific interaction occurred for features that were relevant to the memory task but not for irrelevant features of the same object or for once-remembered objects that could be forgotten. Finally, memory-related distractors attracted more eye movements but did not result in longer fixations. The results demonstrate memory-driven attentional capture on the basis of content-specific representations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

When something old becomes something new: Spatiotemporal object continuity and attentional capture.

This article examines the possibility that the visual system treats dynamic cues as instances of new perceptual objects under some circumstances. Using the contingent capture paradigm (C. L. Folk, R. W. Remington, & J. C. Johnston, 1992), the author compared luminance change cues of different magnitude for their ability to capture attention when participants were set for new objects. Whereas small luminance changes failed to produce attentional capture, large luminance changes indeed captured attention, suggesting that they were treated as compatible with the participants' attentional set for new objects. It is argued that sufficiently large luminance transients led to a disruption of spatiotemporal object continuity and precipitated the emergence of a new perceptual object. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Attention set for number: Expectation and perceptual load in inattentional blindness.

Inattentional blindness is the failure to detect unexpected events when attention is otherwise engaged. Previous research indicates that inattentional blindness increases as perceptual demands intensify. The authors present 6 cuing experiments that manipulated both the perceptual demands of a primary letter-naming task and the expectations of the individual. Inattentional blindness was greatest for individuals who held a numerical expectation that was consistent with the number of primary-task items presented. Expectation also affected detection differentially at various levels of perceptual load: Detection at moderate and high perceptual load was significantly affected by expectation, whereas detection at low perceptual load was not. The authors suggest that at moderate to high levels of perceptual load, individuals whose numerical expectations are fulfilled terminate processing when the primary task is complete, at the expense of the unexpected visual event. These experiments provide compelling evidence that expectations do affect detection of an unexpected stimulus, and they are the first to demonstrate that individuals set their attention for the number of items to be detected and are vulnerable to inattentional blindness whenever their primary-task numerical expectation is fulfilled. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

When danger lurks in the background: Attentional capture by animal fear-relevant distractors is specific and selectively enhanced by animal fear.

Across 2 experiments, a new experimental procedure was used to investigate attentional capture by animal fear-relevant stimuli. In Experiment 1 (N = 34), unselected participants were slower to detect a neutral target animal in the presence of a spider than a cockroach distractor and in the presence of a snake than a large lizard distractor. This result confirms that phylogenetically fear-relevant animals capture attention specifically and to a larger extent than do non-fear-relevant animals. In Experiment 2 (N = 86), detection of a neutral target animal was slowed more in the presence of a feared fear-relevant distractor (e.g., a snake for snake-fearful participants) than in presence of a not-feared fear-relevant distractor (e.g., a spider for snake-fearful participants). These results indicate preferential attentional capture that is specific to phylogenetically fear-relevant stimuli and is selectively enhanced in individuals who fear these animals. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Surprise-induced blindness: A stimulus-driven attentional limit to conscious perception.

The cost of attending to a visual event can be the failure to consciously detect other events. This processing limitation is well illustrated by the attentional blink paradigm, in which searching for and attending to a target presented in a rapid serial visual presentation stream of distractors can impair one's ability to detect a second target presented soon thereafter. The attentional blink critically depends on 'top-down' attentional settings, for it does not occur if participants are asked to ignore the first target. Here we show that 'bottom-up' attention can also lead to a profound but ephemeral deficit in conscious perception: Presentation of a novel, unexpected, and task-irrelevant stimulus virtually abolishes conscious detection of a target presented within half a second after the 'Surprise' stimulus, but only for its earliest occurrences (generally 1 to 2 presentations). This powerful but short-lived deficit contrasts with a milder but more enduring form of attentional capture that accompanies singleton presentations in rapid serial visual presentations. We conclude that the capture of stimulus-driven attention alone can limit explicit perception. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Fractionating the preview benefit in search: Dual-task decomposition of visual marking by timing and modality.

Providing participants with a preview of half the distractors in a visual search task facilitates performance. The present study examined the effects of secondary tasks on the preview benefit in search. Participants had to attend to a visual or an auditory stream of digits that began either (a) at the onset of the preview or (b) after the preview. Secondary tasks that onset with the preview disrupted the preview benefit irrespective of their modality. Only visual secondary tasks disrupted the benefit in the delayed condition. These selective interference effects suggest that the preview benefit can be fractionated into 2 components: an initialization component that involves modality-independent resources and a maintenance component that depends on visual resources. Results are discussed in relation to theoretical accounts of the preview benefit in search. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The time course of attentional and oculomotor capture reveals a common cause.

Eye movements are often misdirected toward a distractor when it appears abruptly, an effect known as oculomotor capture. Fundamental differences between eye movements and attention have led to questions about the relationship of oculomotor capture to the more general effect of sudden onsets on performance, known as attentional capture. This study explores that issue by examining the time course of eye movements and manual localization responses to targets in the presence of sudden-onset distractors. The results demonstrate that for both response types, the proportion of trials on which responses are erroneously directed to sudden onsets reflects the quality of information about the visual display at a given point in time. Oculomotor capture appears to be a specific instance of a more general attentional capture effect. Differences and similarities between the two types of capture can be explained by the critical idea that the quality of information about a visual display changes over time and that different response systems tend to access this information at different moments in time. (PsycINFO Database Record (c) 2010 APA, all rights reserved)