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526
Perceptual load as a necessary condition for selective attention
- Journal of Experimental Psychology: Human Perception and Performance
, 1995
"... The early and late selection debate may be resolved if perceptual load of relevant information determines the selective processing of irrelevant information. This hypothesis was tested in 3 studies; all used a variation of the response competition paradigm to measure irrelevant processing when load ..."
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Cited by 318 (18 self)
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The early and late selection debate may be resolved if perceptual load of relevant information determines the selective processing of irrelevant information. This hypothesis was tested in 3 studies; all used a variation of the response competition paradigm to measure irrelevant processing when load in the relevant processing was varied. Perceptual load was manipulated by relevant display set size or by different processing requirements for identical displays. These included the requirement to process conjunctions versus isolated features and the requirement to perform simple detection of a character's presence versus difficult identifi-cation of its size and position. Distractors ' interference was found only under low-load conditions. Because the distractor was usually clearly distinct from the target, it is concluded that physical separation is not a sufficient condition for selective perception; overloading perception is also required. This allows a compromise between early and late selection views and resolves apparent discrepancies in previous work. While no one disputes the importance of selective mech-anisms in mental processing, the locus of selection in the sequence of processing from perception to action remains to
Sustained and transient components of focal visual attention
- Vision Research
, 1989
"... Abstract-Human observers fixated the center of a search array and were required to discriminate the color of an odd target if it was present. The array consisted of horizontal or vertical black or white bars. In the simple case, only orientation was necessary to define the odd target, whereas in the ..."
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Cited by 245 (2 self)
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Abstract-Human observers fixated the center of a search array and were required to discriminate the color of an odd target if it was present. The array consisted of horizontal or vertical black or white bars. In the simple case, only orientation was necessary to define the odd target, whereas in the conjunctive case, both orientation and color were necessary. A cue located at the critical target position was either visible all the time (sustained cuing) or it appeared at a short variable delay before the array presentation (transient cuing). Sustained visual cuing enhanced perception greatly in the conjunctive, but not in the simple condition. Perception of the odd target in the conjunctive display was improved even further by transient cuing, and peak discrimination performance occurred if the cue preceded the target array by 70-150 msec. Longer delays led to a marked downturn in performance. Control experiments indicated that this transient attentional component was independent of the observers ’ prior knowledge of target position and was not subject to voluntary control. We provide evidence to suggest hat the transient component does not originate at the earliest stages of visual processing, since it could not be extended in duration by flickering the cue, nor did it require a local sensory transient o trigger its onset. Neither the variation in retinal eccentricity nor changing the paradigm to a vernier acuity task altered the basic pattern of results. Our findings indicate the existence of a sustained and a transient component of attention, and we hypothesize that of the two, the transient component is operative at an earlier stage of visual cortical processing. Focal attention Visual search Pattern recognition Vernier acuity
Conjunction search revisited
- Journal of Experimental Psychology: Human Perception and Performance
, 1990
"... Search for conjunctions of highly discriminable features can be rapid or even parallel. This article explores, three possible accounts based on (a) perceptual segregation, (b) conjunction detectors, and (c) inhibition controlled separately by two or more distractor features. Search rates for conjunc ..."
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Cited by 212 (3 self)
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Search for conjunctions of highly discriminable features can be rapid or even parallel. This article explores, three possible accounts based on (a) perceptual segregation, (b) conjunction detectors, and (c) inhibition controlled separately by two or more distractor features. Search rates for conjunctions of color, size, orientation, and direction of motion correlated closely with an independent measure of perceptual segregation. However, they appeared unrelated to the physi-ology of single-unit responses. Each dimension contributed additively to conjunction search rates, suggesting that each was checked independently of the others. Unknown targets appear to be found only by serial search for each in turn. Searching through 4 sets of distractors was slower than searching through 2. The results suggest a modification of feature integration theory, in which attention is controlled not only by a unitary "window " but also by a form of feature-based inhibition. Objects in the real world vary in a large number of prop-erties, at least some of which appear to be coded by special-ized, independent channels or modules in the perceptual
Objects and attention: the state of the art
- Cognition
, 2001
"... What are the units of attention? In addition to standard models holding that attention can select spatial regions and visual features, recent work suggests that in some cases attention can directly select discrete objects. This paper reviews the state of the art with regard to such `object-based &ap ..."
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Cited by 199 (14 self)
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What are the units of attention? In addition to standard models holding that attention can select spatial regions and visual features, recent work suggests that in some cases attention can directly select discrete objects. This paper reviews the state of the art with regard to such `object-based ' attention, and explores how objects of attention relate to locations, reference frames, perceptual groups, surfaces, parts, and features. Also discussed are the dynamic aspects of objecthood, including the question of how attended objects are individuated in time, and the possibility of attending to simple dynamic motions and events. The ®nal sections of this review generalize these issues beyond vision science, to other modalities and ®elds such as auditory objects of attention and the infant's `object concept'. q 2001 Elsevier Science B.V. All rights reserved.
Shifting visual attention between objects and locations: Evidence from normal and parietal lesion subjects
- Journal of Experimental Psychology: General
, 1994
"... Space- and object-based attention components were examined in neurologically normal and ..."
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Cited by 198 (1 self)
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Space- and object-based attention components were examined in neurologically normal and
Reflexive and voluntary orienting of visual attention: Time course of activation and resistance to interruption
- JOURNAL OF EXPERIMENTAL PSYCHOLOGY: HUMAN PERCEPTION AND PERFORMANCE
, 1989
"... To study the mechanisms underlying covert orienting of attention in visual space, subjects were given advance cues indicating the probable locations of targets that they had to discriminate and localize. Direct peripheral cues (brightening of one of four boxes in peripheral vision) and symbolic cent ..."
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Cited by 184 (0 self)
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To study the mechanisms underlying covert orienting of attention in visual space, subjects were given advance cues indicating the probable locations of targets that they had to discriminate and localize. Direct peripheral cues (brightening of one of four boxes in peripheral vision) and symbolic central cues (an arrow at the fixation point indicating a probable peripheral box) were compared. Peripheral and central cues are believed to activate different reflexive and voluntary modes of orienting (Jonides, 1981; Posner, 1980). Experiment 1 showed that the time courses of facilitation and inhibition from peripheral and central cues were characteristic and different. Experiment 2 showed that voluntary orienting in response to symbolic central cues is interrupted by reflexive orienting to random peripheral flashes. Experiment 3 showed that irrelevant peripheral flashes also compete with relevant peripheral cues. The amount of interference varied systematically with the interval between the onset of the relevant cue and of the distracting flash (cue-flash onset asynchrony) and with the cuing condition. Taken together, these effects support a model for spatial attention with distinct but interacting reflexive and voluntary orienting mechanisms.
Visual indexes, preconceptual objects, and situated vision
- Cognition
, 2001
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The Spatial Resolution of Visual Attention
- Cognitive Psychology
, 1997
"... Two tasks were used to evaluate the grain of visual attention, the minimum spacing at which attention can select individual items. First, observers performed a tracking task at many viewing distances. Performance dropped to chance levels at small display sizes even though, in all conditions, observe ..."
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Cited by 131 (11 self)
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Two tasks were used to evaluate the grain of visual attention, the minimum spacing at which attention can select individual items. First, observers performed a tracking task at many viewing distances. Performance dropped to chance levels at small display sizes even though, in all conditions, observers could easily resolve the items and their motions. The limiting size for selection was roughly the same whether tracking one or three targets, suggesting that the resolution limit acts independently of the capacity limit of attention. Second, the closest spacing that still allowed individuation of single items in dense, static displays was examined. This critical spacing was about 50% coarser in the radial direction compared to the tangential direction, and was coarser in the upper as opposed to the lower visual field. The results suggest that no more than about 72 items can be arrayed in the central 30 degrees of the visual field while still allowing attentional access to each individuall...
Multielement visual tracking: Attention and perceptual organization
- Cognitive Psychology
, 1992
"... Two types of theories have been advanced to account for how attention is allocated in performing goal-directed visual tasks. According to location-based theories, visual attention is allocated to spatial locations in the image; according to object-based theories, attention is allocated to perceptual ..."
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Cited by 129 (4 self)
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Two types of theories have been advanced to account for how attention is allocated in performing goal-directed visual tasks. According to location-based theories, visual attention is allocated to spatial locations in the image; according to object-based theories, attention is allocated to perceptual objects. Evidence for the latter view comes from experiments demonstrating the importance of perceptual grouping in selective-attention tasks. This article provides further evidence concerning the importance of perceptual organization in attending to objects. In seven experiments, observers tracked multiple randomly moving visual elements under a variety of conditions. Ten elements moved continuously about the display for several seconds; one to five of them were designated as targets before movement initiation. At the end of movement, one element was highlighted, and subjects indicated whether or not it was a target. The ease with which the elements in the target set could be perceptually grouped was systematically manipulated. In Experiments l-3, factors that influenced the initial formation of a perceptual group were manipulated; this affected performance, but only early in practice. In
Tracking multiple items through occlusion: Clues to visual objecthood
- Cognitive Psychology
, 1999
"... In three experiments, subjects attempted to track multiple items as they moved independently and unpredictably about a display. Performance was not impaired when the items were briefly (but completely) occluded at various times during their motion, suggesting that occlusion is taken into account whe ..."
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Cited by 123 (20 self)
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In three experiments, subjects attempted to track multiple items as they moved independently and unpredictably about a display. Performance was not impaired when the items were briefly (but completely) occluded at various times during their motion, suggesting that occlusion is taken into account when computing enduring perceptual objecthood. Unimpaired performance required the presence of accretion and deletion cues along fixed contours at the occluding boundaries. Performance was impaired when items were present on the visual field at the same times and to the same degrees as in the occlusion conditions, but disappeared and reappeared in ways which did not implicate the presence of occluding surfaces (e.g., by imploding and exploding into and out of existence instead of accreting and deleting along a fixed contour). Unimpaired performance did not require visible occluders (i.e., Michotte’s tunnel effect) or globally consistent occluder positions. We discuss impli-cations of these results for theories of objecthood in visual attention. ª 1999 Academic Press What is an object? This is a question which draws together researchers
