Mechanisms of attentional priority.

When a single abrupt onset occurs in a multielement visual display, it captures attention, possibly by generating an attentional interrupt that designates onsets as being of high priority. In 3 experiments, the mechanisms subserving attentional priority setting were investigated. A total of 56 Ss searched for a prespecified target letter among multiple distractor letters, half of which had abrupt onsets and half of which did not. The target, when present, was equally often an onset element and a no-onset element. Several models for attentional priority, differing in how many onset elements have priority over no-onset elements, were assessed. The data support a model in which approximately 4 onset stimuli are processed before any no-onset stimuli are processed. Two attentional priority mechanisms are proposed: (1) queuing of a limited number of high-priority elements and (2) temporally modulated decay of attentional priority tags. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Perceptual grouping in space and time: evidence from the Ternus display

Persistence of the brain and kidney Na+,K(+)-ATPase isozymes to SDS inactivation under different time and temperature conditions of microsome extraction with the detergent was compared. In contrast to enzyme preparations from medulla oblongata the higher sensitivity of the Na+,K(+)-ATPase alpha-isoform (in comparison to alpha +) to SDS inactivation accompanied by its, at least, partial removal from the membrane was found in the preparations from cerebral cortex. This difference in the sensitivity to SDS was eliminated after extraction of microsomes with the detergent at 37 degrees C. The interpretation of the results is based on the assumed differences in the structural organization of the boundary lipids of the neuronal Na+,K(+)-ATPase catalytic subunit isoforms.     

Stimulus-driven attentional capture: Evidence from equiluminant visual objects.

Previous work has shown that abrupt visual onsets capture attention. Possible mechanisms for this phenomenon include (1) luminance-change detection system and (2) a mechanism that detects the appearance of new perceptual objects. Exps 1 and 2 revealed that attention is captured in visual search by the appearance of a new perceptual object even when the object is equiluminant with its background and thus exhibits no luminance change when it appears. Exp 3 showed that a highly salient luminance increment alone is not sufficient to capture attention. These findings suggest that attentional capture is mediated by a mechanism that detects the appearance of new perceptual objects. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Amount of information about the attitude object and attitude–behavior consistency.

The synthesis of 2 separate lines of inquiry—research on information integration and longitudinal studies of attitudes—prompted the hypothesis that the degree of consistency between attitudes and behavior will increase as a function of the amount of information available about the attitude object. This hypothesis was tested in 3 longitudinal studies, ranging in length from 4 days to 4 mo, that investigated the following behaviors: voting for candidates for political office, voting for 2 social-policy election initiatives, and having an influenza vaccination. Ss were 62 undergraduates (Study 1), 270 undergraduates (Study 2), and 299 27–92 yr old veterans (Study 3). In support of the hypothesis, amount of information moderated the consistency between attitudes and behavior in each study, and the significance of this relation remained even after controlling for the effects of other potential moderators, including prior direct behavioral experience with the attitude object and attitude certainty. Consistent with previous research, direct behavioral experience was also a determinant of attitude–behavior consistency, and this relation was independent of the effect of amount of information for the behavior of having an influenza vaccination. Discussion focuses on the interrelation among moderators of attitude–behavior consistency and on the theoretical implications of the findings. (52 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Stimulus-driven attentional capture and attentional control settings.

J. Jonides and S. Yantis (1988) found that abrupt-onset singletons capture attention in visual search when onset is orthogonal to the target's defining and reported attributes and that color and brightness singletons do not. They concluded that abrupt onset may be unique in capturing visual attention. C. L. Folk et al (1992) challenge this conclusion and argue that (1) the occurrence of attentional capture is contingent on the adoption of an appropriate attentional control setting by the observer and (2) properties other than onset (in particular, color) can capture attention involuntarily. In this article, each of these claims is critically evaluated, and it is argued that the results by Folk et al, though important, do not definitively corroborate either one. The available evidence concerning stimulus-driven attentional capture is summarized, and 3 empirical generalizations that characterize the evidence are advanced. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

On the distinction between visual salience and stimulus-driven attentional capture.

It is often assumed that the efficient detection of salient visual objects in search reflects stimulus-driven attentional capture. Evidence for this assumption, however, comes from tasks in which the salient object is task relevant and therefore may elicit a deliberate deployment of attention. In 9 experiments, participants searched for a nonsalient target (vertical among tilted bars). In each display, 1 bar was highly salient in a different dimension (e.g., color or motion). When the target and salient elements coincided only rarely, reducing the incentive to attend deliberately to the salient stimuli, response times depended little on whether the target was salient, although some interesting exceptions were observed. It is concluded that efficient selection of an element in visual search does not constitute evidence that the element captures attention in a purely stimulus-driven fashion. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Abrupt visual onsets and selective attention: Voluntary versus automatic allocation.

The hypothesis that abrupt visual onsets capture attention automatically, as suggested by S. Yantis and J. Jonides (see record 1985-19225-001), was tested in four experiments. A centrally located cue directed attention to one of several stimulus positions in preparation for the identification of a target letter embedded in an array of distractor letters. In all experiments, one stimulus (either the target or one of the distractors) had an abrupt onset; the remaining letters did not. The effectiveness of the cue was manipulated (varying either its duration or its predictive validity) to test whether abrupt onsets capture attention even when subjects are in a highly focused attentional state. Results showed that onsets do not necessarily capture attention in violation of an observer's intentions. A mechanism for partially automatic attentional capture by abrupt onset is proposed, and the diagnosticity of the intentionality criterion for automaticity is discussed. (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)     

On the continuity of perceptual experience: Implications for perception and attention.

When an observer views a real-world scene, some objects in the scene are partly occluded by intervening surfaces. Similarly, as the observer moves through the environment, some objects are temporarily occluded and revealed. Yet, although the retinal image is fragmented in space and time, perceptual experience is coherent and continuous. Continuity of experience is achieved by perceptual organization mechanisms, which have their effect before attention. Several experiments are described to illustrate the close interaction between perceptual organization and attention. This interaction determines the representational basis for selection, and is therefore a crucial precursor to understanding object-based mechanisms of visual selection. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Attentional capture by abrupt onsets: New perceptual objects or visual masking?

The authors have shown that an object appearing abruptly in a previously blank location is efficiently detected in visual search when it is embedded in an array of objects without abrupt onset (termed no-onset stimuli). In these experiments, no-onset stimuli appeared well before the onset stimulus but were camouflaged by additional line segments rendering the stimuli unidentifiable. B. S. Gibson (see record 1997-06229-001) claims that the availability of the no-onset stimuli was delayed relative to that of the abrupt onset stimulus because of forward masking. The authors show that forward masking is unlikely to be a significant factor in their experiments, and 3 new experiments are reported that undermine Gibson's masking account. Observed differences in the efficiency with which onset and no-onset stimuli are processed in visual search are due to attentional capture by new perceptual objects and to a relatively sluggish process of updating existing object representations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)