1,720,969 research outputs found
The attention cascade model and attentional blink
No full textAn attention cascade model is proposed to account for attentional blinks in rapid serial visual presentation (RSVP) of stimuli. Data were collected using single characters in a single RSVP stream at 10 Hz (from Shih & Reeves, 2007), and single words, in both single and dual RSVP streams at 19 Hz (from Potter, Staub, & O'Connor, 2002). The model adopts similar architecture of the cognitive accounts of attentional blinks and employs computational details from theories of attention gating. The model has elaborated working memory and attention control mechanism. Both bottom-up and top-down salience are explicit in the model. Quantitative fits are good and the model parameters have plausible values. The model handles stimulus competition, lag 1 sparing, intrusion errors, and magnitude of the dip; it also accounts for commonly observed effects such as stimulus similarities (local and global), target+1 blank, and stimulus salience
Using the attention cascade model to probe cognitive aging
No full textYoung and older adults searched for two digit targets among black letter distractors in rapid serial visual presentation. Unsurprisingly, relative to the young, the old performed worse on both targets and exhibited greater and longer attentional blink. The data of each group were computationally accounted for by the attention cascade model (Shih, 2008) with seven parameters; the optimum values and 95% confidence intervals of the parameters were based on 10,000 bootstrap samples. There was no age effect on the width of the attention window, or the capacity of the consolidation processor. However, relative to the young, the old suffered more masking effect of the salient (and brighter) stimulus, required longer consolidation duration, and had greater and more spread decision noise. The processing rate prior to working memory was numerically slower in the old. Both age groups adopted inefficient strategy during the task – engaging the consolidation processor unnecessarily long. Further simulations suggest that varying the duration can emulate strong, weak, or non-blinkers. The attention cascade model appears a useful tool for the investigation of cognitive aging and other comparative studies
Using the attention cascade model to computationally account for the age differences in an Attentional Blink (AB) task
No full textThe attention cascade model (Shih, 2008) is a general, mathematical model of attention and working memory. It is applied here to characterize cognitive aging
Searching for multiple targets without an attentional blink
No full textParticipants searched for four red target letters in rapid serial visual presentation (RSVP). On each trial, targets were consecutive or interleaved with distractors, and RSVP speed was slow or fast (7.5 or 12 Hz). Green distractors were also letters in one experiment, but digits in another. More targets were reported when distractors were digits than letters, speed was slow than fast, targets were consecutive than interleaved. More important, an attentional blink (AB: a sharp reduction in report probability from the first to subsequent targets) was absent in all but one condition -- fast RSVP, interleaved targets, and letter distractors -- and its occurrence was attributed to intrusions from interleaved distractors. Conclusions: an attention window is much wider in the present than conventional AB task; attention-gated distractors affect target processing in working memory only if they share target-defining features (e.g., category membership)
Attentional blink session
No full textParticipants searched for four red target letters in rapid serial visual presentation (RSVP). On each trial, targets were consecutive or interleaved with distractors, and RSVP speed was slow or fast (7.5 or 12 Hz). Green distractors were also letters in one experiment, but digits in another. More targets were reported when distractors were digits than letters, speed was slow than fast, targets were consecutive than interleaved. More important, an attentional blink (AB: a sharp reduction in report probability from the first to subsequent targets) was absent in all but one condition -- fast RSVP, interleaved targets, and letter distractors -- and its occurrence was attributed to intrusions from interleaved distractors. Conclusions: an attention window is much wider in the present than conventional AB task; attention-gated distractors affect target processing in working memory only if they share target-defining features (e.g., category membership)
Attentional capture in rapid serial visual presentation
No full textWe examined whether attentional capture can occur during an attentional blink (AB). If attention were 'locked up' during an AB, capture should not occur. To test for capture, we varied the salience of the two targets (T1 and T2) or of a distractor. Salience was controlled by adjusting chromaticity at equiluminance to equate simple reaction times. Experiment 1 demonstrated that the extent of AB varied almost entirely with T2 salience, not with T1 salience. In Experiment 2, a salient distractor between T1 and T2 reduced the AB without affecting its temporal profile; a salient distractor after T2 had no effect on AB. We conclude that attentional capture can occur during the AB, and stimulus salience modulates, rather than overriding, the AB. Independent of the post-attentional (consolidation) mechanism primarily responsible for the AB, stimulus salience affects how an attention gate is triggere
Is there feature-based attentional selection in visual search?
No full textA new paradigm combines attentional cuing and rapid serial visual presentation to disentangle the effects of perceptual filtering and location selection. Observers search successive, superimposed arrays, in which feature values are alternated for a target numeral among letters. Two dimensions, size (small, large) and color (red, green) are tested. Selective attention to feature values is jointly manipulated by instructions, presentation probabilities, and payoffs. In Experiment 1, the attended feature provides temporal, not spatial, information; observers show no attentional costs or benefits in response accuracy. In Experiment 2, the attended feature indicates a unique location; observers show consistent attentional costs and benefits. Selective attention to a particular size or color does not cause perceptual exclusion or admission of items containing that feature; it acts by guiding search processes to spatial locations that contain the to-be-attended feature
Measuring and modelling the trajectories of visual spatial attention
No full textn a novel choice attention-gating paradigm, observers monitor a stream of 3x3 letter arrays until a tonal cue directs them to report 1 row. Analyses of the particular arrays from which reported letters are chosen and of the joint probabilities of reporting pairs of letters are used to derive a theory of attention dynamics. An attention window opens 0.15 s following a cue to attend to a location, remains open (minimally) 0.2 s, and admits information simultaneously from all the newly attended locations. The window dynamics are independent of the distance moved. The theory accounts for about 90% of the variance from the over 400 data points obtained from each of the observers in the 3 experiments reported here. With minor elaborations, it applies to all the principal paradigms used to study the dynamics of visual spatial attention
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