Showing papers on "Attentional blink published in 2000"

Recall of two visual targets embedded in RSVP streams of distractors depends on their temporal and spatial relationship.

Abstract: In the present study, I examined how the temporal and spatial relationship between two visual targets (T1 and T2) affects the recall of both targets when they are embedded in rapidly displayed distractors. Presented on a trial were two synchronized streams of characters, one to the left and the other to the right of the fixation. Independent of their spatial relationship, a U-shaped curve described the recall of the second target (T2) as a function of stimulus onset asynchrony (SOA) between T1 and T2. It indicated the presence of the attentional blink with a T2 deficit sparing up to about 150- to 200-msec SOA. However, T2 deficit was greater at short SOAs (up to about 250 msec) when T1 and T2 occurred at different locations than when they occurred at a common location. When SOA was short (100 msec or so), recall of T1 was impaired when T1 and T2 occurred at a common location, but not when they were at different locations. The present findings can be reconciled with existing models (e.g., the interference model and the two-stage model) by distinguishing automatic and controlled attention gating processes at the transfer of perceptual representations to a more durable storage (e.g., visual short-term memory).

Evidence for distinct attentional bottlenecks in attention switching and attentional blink tasks.

Abstract: E. Weichselgartner and G. A. Sperling (1987), using rapid serial visual presentation (RSVP), estimated that attention could be moved to a new spatial location within 300-400 ms. H. J. Muller and P. M. Rabbit (1989) used a spatial cuing task and found a similar time course for voluntarily redeploying attention. A separate phenomenon known as the attentional blink (AB) also follows a similar time course, yet occurs when participants attend to a single spatial location. The present study found that attention can be shifted more quickly than previously estimated and that part of the deficit observed during searches of spatially distinct RSVP streams is due to an AB. The results support some early and late selection accounts for the temporal dynamics of visual attention and suggest different bottlenecks during visual selection. The implications for visual search and visual processing are discussed.

Selective influence of second target exposure duration and Task1 load effects in the attentional blink phenomenon

Abstract: The purpose of the experiments was to constrain the locus of interference in the attentional blink (AB) paradigm. Two visual stimuli, T1 and T2, were shown 300 msec apart, and each was followed by a mask. T1 was an “H,” an “S,” an “ &, ” or a blank field; T2 consisted of five letters. In Task1, blank fields and & characters could be ignored, whereas Hs and Ss had to be identified and reported. Task2 was always to report as many letters as possible from T2. Task2 performance was lower when T1 had to be reported, as expected from the attentional blink phenomenon (AB). The exposure duration of T2 was also manipulated. More letters could be reported as exposure duration was increased. However, this effect was additive with manipulations of Task1 processing load that produced the AB effect. Log-linear analyses assuming that effects of T2 exposure duration and Task1 load effects occur at functionally distinct stages of processing provided satisfactory fits to the results, suggesting that none of the AB effect occurs as early as those of T2 exposure duration. The results suggest that the locus of the AB effect is later than the stage(s) of processing affected by exposure duration.

Development of multimodal attention in young infants: modification of the startle reflex by attention.

Abstract: This study examined the effect of attention engagement to compound auditory-visual stimuli on the modification of the startle blink reflex in infants. Infants at 8, 14, 20, or 26 weeks of age were presented with interesting audiovisual stimuli. After stimulus onset, at delays defined by heart rate changes known to be associated with sustained attention or attention disengagement, blink reflexes were elicited by visual or auditory stimuli. Blink amplitude to either visual or auditory stimuli was enhanced when the infants were engaged in attention to the foreground auditory-visual stimuli relative to control trials with no foreground patterns. This enhancement of the blink amplitude increased from 8 to 26 weeks of age. In contrast to selective modality enhancement for single-modality foreground stimuli, these results show that these multimodal stimuli engage both visual and auditory attention systems in this age range.

Direct estimates of processing delays in the attentional blink.

Abstract: When two targets (T1 and T2) are presented in rapid succession, identification of T2 is often impaired (attentional blink: AB). The two-stage model accounts for the AB deficit by assuming that: (a) T2 is delayed in Stage 1 while Stage 2 is busy processing T1, and (b) T2 is vulnerable to masking while delayed. We report converging evidence for the model by evaluating these assumptions independently of the AB deficit itself. The results show that: (a) response times for T2 identification decreased as the lag between T1 and T2 was increased; (b) response times for T2 decreased across lags only if T1 was masked; and (c) accuracy of T2 identification increased as the stimulus-onset asynchrony between T2 and the trailing mask was increased.

Effect of benzodiazepine on temporal integration in object perception.

Abstract: Rationale: Though various psychometrical tests indicate that benzodiazepines affect vigilance, few studies have been conducted to assess the effect of benzodiazepines on attentional processes. Objective: We used a RSVP (Rapid Serial Visual Presentation) procedure to investigate the effect of benzodiazepines on the attentional blink effect. It refers to the difficulty in detecting a probe following identification of a target within a temporal window of 500 ms. Method: Three experimental groups were tested (placebo, lorazepam and diazepam). Sequences of 15 pictures were centrally displayed for 50 ms each. In a dual-task condition, observers were instructed (1) to identify the target (the single picture on a blue background) and (2) to detect the presence of a probe. In the single-task condition, subjects were asked to detect the probe. The serial position of the probe relative to the target was varied. Results: Performance was equivalent for the three groups in the single-task condition. In the dual-task condition, the attentional blink was increased in magnitude and duration for benzodiazepine-treated subjects, especially diazepam, than for placebo-treated subjects. A large number of intrusions (a tendency to report as target the name of a picture preceding the target) were observed in the benzodiazepine-treated groups. Conclusion: The results indicate that benzodiazepines impair visual integration in the temporal domain. This extends previous findings that benzodiazepine impairs visual integration in the spatial domain. The results also suggest that benzodiazepine increase time to disengage attention from a first to a second target.

Change Blindness: Theory or Paradigm?

Abstract: The present paper examines a number of recent findings from the induced change blindness literature in an attempt to determine what these findings reveal about the role of attention in perception. The conclusion is drawn that change blindness research reveals that attention is necessary to raise a stimulus to a level of awareness (e.g. verbal report), as has been shown in related literatures, e.g. eye movement, masking, and the attentional blink. Some research possibilities employing the change blindness paradigm are suggested, which may prove useful in future research efforts.

The effects of change in lead stimulus modality on the modulation of acoustic blink startle

Abstract: In two experiments we investigated the effect of generalized orienting induced by changing the modality of the lead stimulus on the modulation of blink reflexes elicited by acoustic stimuli In Experiment 1 (n = 32), participants were presented with acoustic or visual change stimuli after habituation training with tactile lead stimuli In Experiment 2 (n = 64), modality of the lead stimulus (acoustic vs visual) was crossed with experimental condition (change vs no change) Lead stimulus change resulted in increased electrodermal orienting in both experiments Blink latency shortening and blink magnitude facilitation increased from habituation to change trials regardless of whether the change stimulus was presented in the same or in a different modality as the reflex-eliciting stimulus These results are not consistent with modality-specific accounts of attentional startle modulation

Dissociating the effects of featural and conceptual interference on multiple target processing in rapid serial visual presentation

Abstract: Attentional blink (AB) describes the finding that, when subjects attend to a specified target in a rapidly presented visual stream, they show a decreased ability to process a subsequent probe item for up to 600 msec. In the present study, the roles of featural and conceptual interference in the processing of targets and probes in a rapid serial visual presentation stream were examined. In Experiment 1, featurally more complex T + l items produced larger AB even when the physical energy of the stimulus (e.g., the number of pixels) was held constant. In Experiment 2, the conceptual category of the T + l item affected target identification but not AB magnitude. These results suggest that featural interference is a major determinant of AB magnitude, whereas featural and conceptual interference both affect target identification.

Failure to identify the target does not prevent the attentional blink effect.

Abstract: The attentional blink has been attributed to capacity limitations at a central level of processing. We tested whether failure to identify the target would eliminate the blink. Two agnostic patients were presented with streams of letters, which they were able to identify, and streams of pictures, which they were unable to identify. The dual-task involved identification of a target and detection of a probe. With letters the duration of the blink was equivalent to that of the control subjects. A prolonged blink was observed in both patients for pictures irrespective of whether the target was identified. This result indicates that failure to identify the target does nevertheless mobilize attentional resources sufficiently to prevent detection of a second target stimulus.