Stream Of Distractors Research Articles

Decomposing the attentional blink.

The Attentional Blink (AB) refers to a deficit in reporting a second target (T2) embedded in a stream of distractors when presented 200-500 ms after a preceding target (T1). Several theories about the origin of the AB have been proposed; filter-based theories claim that the AB is the result of a temporarily closing of an attentional gate to avoid featural confusion for targets and distractors, while bottleneck theories propose that the AB is caused by a reduction in the capacity to either encode into or maintain information in visual short-term memory. In three experiments, we systematically vary the exposure duration and composition of the T2 display allowing us to decompose the T2 deficit into well-established parameter estimates based on the Theory of Visual Attention (TVA). As the different AB theories make specific predictions regarding which parameters should be affected during the AB, we are able to test their plausibility. All three experiments consistently show a lower capacity to process T2 during the AB, supporting theories hypothesizing a bottleneck at the encoding stage. No evidence is found supporting filter-based theories or theories placing the bottleneck at the maintenance stage. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Cat-astrophic effects of sudden interruptions on spatial auditory attention.

Salient interruptions draw attention involuntarily. Here, we explored whether this effect depends on the spatial and temporal relationships between a target stream and interrupter. In a series of online experiments, listeners focused spatial attention on a target stream of spoken syllables in the presence of an otherwise identical distractor stream from the opposite hemifield. On some random trials, an interrupter (a cat "MEOW") occurred. Experiment 1 established that the interrupter, which occurred randomly in 25% of the trials in the hemifield opposite the target, degraded target recall. Moreover, a majority of participants exhibited this degradation for the first target syllable, which finished before the interrupter began. Experiment 2 showed that the effect of an interrupter was similar whether it occurred in the opposite or the same hemifield as the target. Experiment 3 found that the interrupter degraded performance slightly if it occurred before the target stream began but had no effect if it began after the target stream ended. Experiment 4 showed decreased interruption effects when the interruption frequency increased (50% of the trials). These results demonstrate that a salient interrupter disrupts recall of a target stream, regardless of its direction, especially if it occurs during a target stream.

Age and Hearing Ability Influence Selective Attention During Childhood.

The purpose of the present study was to determine whether age and hearing ability influence selective attention during childhood. Specifically, we hypothesized that immaturity and disrupted auditory experience impede selective attention during childhood. Seventy-seven school-age children (5 to 12 years of age) participated in this study: 61 children with normal hearing and 16 children with bilateral hearing loss who use hearing aids and/or cochlear implants. Children performed selective attention-based behavioral change detection tasks comprised of target and distractor streams in the auditory and visual modalities. In the auditory modality, children were presented with two streams of single-syllable words spoken by a male and female talker. In the visual modality, children were presented with two streams of grayscale images. In each task, children were instructed to selectively attend to the target stream, inhibit attention to the distractor stream, and press a key as quickly as possible when they detected a frequency (auditory modality) or color (visual modality) deviant stimulus in the target, but not distractor, stream. Performance on the auditory and visual change detection tasks was quantified by response sensitivity, which reflects children's ability to selectively attend to deviants in the target stream and inhibit attention to those in the distractor stream. Children also completed a standardized measure of attention and inhibitory control. Younger children and children with hearing loss demonstrated lower response sensitivity, and therefore poorer selective attention, than older children and children with normal hearing, respectively. The effect of hearing ability on selective attention was observed across the auditory and visual modalities, although the extent of this group difference was greater in the auditory modality than the visual modality due to differences in children's response patterns. Additionally, children's performance on a standardized measure of attention and inhibitory control related to their performance during the auditory and visual change detection tasks. Overall, the findings from the present study suggest that age and hearing ability influence children's ability to selectively attend to a target stream in both the auditory and visual modalities. The observed differences in response patterns across modalities, however, reveal a complex interplay between hearing ability, task modality, and selective attention during childhood. While the effect of age on selective attention is expected to reflect the immaturity of cognitive and linguistic processes, the effect of hearing ability may reflect altered development of selective attention due to disrupted auditory experience early in life and/or a differential allocation of attentional resources to meet task demands.

Predictability-Based Source Segregation and Sensory Deviance Detection in Auditory Aging.

When multiple sound sources are present at the same time, auditory perception is often challenged with disentangling the resulting mixture and focusing attention on the target source. It has been repeatedly demonstrated that background (distractor) sound sources are easier to ignore when their spectrotemporal signature is predictable. Prior evidence suggests that this ability to exploit predictability for foreground-background segregation degrades with age. On a theoretical level, this has been related with an impairment in elderly adults’ capabilities to detect certain types of sensory deviance in unattended sound sequences. Yet the link between those two capacities, deviance detection and predictability-based sound source segregation, has not been empirically demonstrated. Here we report on a combined behavioral-EEG study investigating the ability of elderly listeners (60–75 years of age) to use predictability as a cue for sound source segregation, as well as their sensory deviance detection capacities. Listeners performed a detection task on a target stream that can only be solved when a concurrent distractor stream is successfully ignored. We contrast two conditions whose distractor streams differ in their predictability. The ability to benefit from predictability was operationalized as performance difference between the two conditions. Results show that elderly listeners can use predictability for sound source segregation at group level, yet with a high degree of inter-individual variation in this ability. In a further, passive-listening control condition, we measured correlates of deviance detection in the event-related brain potential (ERP) elicited by occasional deviations from the same spectrotemporal pattern as used for the predictable distractor sequence during the behavioral task. ERP results confirmed neural signatures of deviance detection in terms of mismatch negativity (MMN) at group level. Correlation analyses at single-subject level provide no evidence for the hypothesis that deviance detection ability (measured by MMN amplitude) is related to the ability to benefit from predictability for sound source segregation. These results are discussed in the frameworks of sensory deviance detection and predictive coding.

The effect of fearful faces on the attentional blink is modulated by emotional task relevance: An event-related potential study

A fearful face as second visual target (T2) was detected better than a neutral T2 in a Rapid Serial Visual Presentation (RSVP) task. The advantage of fear over neutral emotion was originally attributed to a limited-capacity mechanism, in which fearful stimuli are prioritized for attention over neutral stimuli. However, more recent studies have shown that the prioritization of the processing of fear is strongly dependent on the emotional task relevance. Combining the RSVP task and Garner's paradigm, by varying the expression (fearful and neutral faces) and the emotional task relevance of the T2 (relevance: emotion classification task; irrelevance: gender classification task), this study aims to investigate the role of emotional task relevance on the advantage of fear during an RSVP task in which participants have to identify two visual targets in a stream of distractors. The behavioral results revealed that there was no significant effect of the expression on the task performance in the gender classification task. Fearful faces were easier to detect than neutral faces, but the T2 accuracy of fearful faces was lower than that of neutral faces in the emotion classification task. Furthermore, we found that the vertex positive potential and P100 components were enhanced for fearful faces compared to neutral faces independent of the emotional task relevance. For the P300 component, there was no significant difference in the gender classification task, but fearful faces elicited enhanced P300 amplitudes compared to neutral faces in the emotion classification task. These results indicated that the early processing of fear is automatic, while the late processing of fear is dependent on the emotional task relevance under limited attentional resources.

Time course of the unmasked attentional blink.

The Attentional Blink (AB) usually refers to the impaired report of a second target (T2) if it appears within 200-500ms after a first target within a rapid sequence of distractors. The present study focused on a less studied AB variant known as the unmasked AB, where T2 is the last item of the sequence and T2 report is unaffected. This aspect of the unmasked AB holds promise for an experimental paradigm in which measures of on-going event-related processing are unconfounded by differences in late-stage processing. To fully characterize the unmasked AB paradigm, we used a randomization statistics approach to comprehensively examine the electroencephalographic signature of the unmasked AB. We examined the unmasked AB with auditory and visual T2s-participants attended to either the auditory or visual information within a sequence of paired auditory-visual stimuli, and reported targets within the attended modality stream while ignoring the other. As predicted, T2 report was unaffected by the unmasked AB. The visual AB was associated with delayed but intact N2 and P3 components, and a suppressed N1. We suggest that this N1 is linked to auditory processing of the distractor stream, and reflects the cognitive system prioritizing the processing of visual targets over auditory distractors in response to AB-related processing load. The auditory AB only indicated a delayed but intact P3. Collectively, these findings support the view that the AB limits the entry of information into consciousness via a late-stage modal bottleneck, and suggest an ongoing compensatory response at early latencies.

Boosted visual performance after eye blinks.

We blink more often than required for maintaining the corneal tear film. Whether there are perceptual or cognitive consequences of blinks that may justify their high frequency is unclear. Previous findings showed that blinks may indicate switches between large-scale cortical networks, such as dorsal attention and default-mode networks. Thus, blinks may trigger a refresh of visual attention. Yet, this has so far not been confirmed behaviorally. Here, we tested the effect of blinks on visual performance in a series of rapid serial visual presentation tasks. In Experiment 1, participants had to identify a target digit embedded in a random stream of letter distractors, presented foveally for 60 ms each. Participants blinked once during the presentation stream. In a separate condition, blinks were simulated by shutter glasses. Detection performance was enhanced (up to 13% point increase in accuracy) for targets appearing up to 300 ms after eye blinks. Performance boosts were stronger for voluntary blinks than artificial blinks. This performance boost was also replicated with more naturalistic stimuli (Experiment 2). We conclude that eye blinks lead to attentional benefits for object recognition in the period after reopening of the eyelids and may be used strategically for temporarily boosting visual performance.

A modification of the scale illusion into a detection task for assessment of binaural streaming.

Binaural streaming by frequency-proximity was investigated without subjective listener-feedback by modifying the scale illusion of Deutsch [J. Acoust. Soc. Am. 57, 1156-1160 (1975)] into a detection-task. Nineteen listeners had to detect one deviation within a repeating melody stream, while simultaneously presented with a randomized distractor stream. Every second note in each stream was presented to the opposite ear, requiring binaural streaming to detect the deviant. Listeners performed well in this test but adding interaural delay or timbre-difference let the listeners group by lateralization instead. This confirms the grouping by frequency-proximity. The method could be used to investigate binaural streaming in hearing-impaired patients, where interaural percepts might differ.

Kanizsa-figure object completion gates selection in the attentional blink.

Previous work has demonstrated that perceptual grouping modulates the selectivity of attention across space. By contrast, how grouping influences the allocation of attention over time is much less clear. This study investigated this issue, using an attentional blink (AB) paradigm to test how grouping influences the initial selection and the subsequent short-term memory consolidation of a target. On a given trial, two red Kanizsa-type targets (T1 and T2) with varying grouping strength were embedded in a rapid serial visual presentation stream of irrelevant distractors. Our results showed the typical AB finding: impaired identification of T2 when presented close in time following T1. Moreover, the AB was modulated by the T2 grouping-independently of the T1 structure-with stronger grouping leading to a decreased AB and overall higher performance. Conversely, a reversed pattern, namely an increased AB with increasing grouping strength was observed when the Kanizsa figure was not task-relevant. Together, these findings suggest that the grouping benefit emerges at early perceptual stages, automatically drawing attentional resources, thereby leading to either sustained benefits or transient costs-depending on the task-relevance of the grouped object. This indicates that grouping modulates processing of objects in time.

The effects of distractor set-size on neural tracking of attended speech

Attention is crucial to speech comprehension in real-world, noisy environments. Selective phase-tracking between low-frequency brain dynamics and the envelope of target speech is a proposed mechanism to reject competing distractors. Studies have supported this theory in the case of a single distractor, but have not considered how tracking is systematically affected by varying distractor set sizes. We recorded electroencephalography (EEG) during selective listening to both natural and vocoded speech as distractor set-size varied from two to six voices. Increasing set-size reduced performance and attenuated EEG tracking of target speech. Further, we found that intrusions of distractor speech into perception were not accompanied by sustained tracking of the distractor stream. Our results support the theory that tracking of speech dynamics is a mechanism for selective attention, and that the mechanism of distraction is not simple stimulus-driven capture of sustained entrainment of auditory mechanisms by the acoustics of distracting speech.

Pupillometry as an Objective Measure of Sustained Attention in Young and Older Listeners.

The ability to sustain attention on a task-relevant sound source while avoiding distraction from concurrent sounds is fundamental to listening in crowded environments. We aimed to (a) devise an experimental paradigm with which this aspect of listening can be isolated and (b) evaluate the applicability of pupillometry as an objective measure of sustained attention in young and older populations. We designed a paradigm that continuously measured behavioral responses and pupillometry during 25-s trials. Stimuli contained a number of concurrent, spectrally distinct tone streams. On each trial, participants detected gaps in one of the streams while resisting distraction from the others. Behavior demonstrated increasing difficulty with time-on-task and with number/proximity of distractor streams. In young listeners (N = 20; aged 18 to 35 years), pupil diameter (on the group and individual level) was dynamically modulated by instantaneous task difficulty: Periods where behavioral performance revealed a strain on sustained attention were accompanied by increased pupil diameter. Only trials on which participants performed successfully were included in the pupillometry analysis so that the observed effects reflect task demands as opposed to failure to attend. In line with existing reports, we observed global changes to pupil dynamics in the older group (N = 19; aged 63 to 79 years) including decreased pupil diameter, limited dilation range, and reduced temporal variability. However, despite these changes, older listeners showed similar effects of attentive tracking to those observed in the young listeners. Overall, our results demonstrate that pupillometry can be a reliable and time-sensitive measure of attentive tracking over long durations in both young and (with caveats) older listeners.

Using Temporal Expectation to Assess Auditory Streaming in Mice.

Auditory streaming is the process by which environmental sound is segregated into discrete perceptual objects. The auditory system has a remarkable capability in this regard as revealed in psychophysical experiments in humans and other primates. However, little is known about the underlying neuronal mechanisms, in part because of the lack of suitable behavioural paradigms in non-primate species. The mouse is an increasingly popular model for studying the neural mechanisms of perception and action because of the range of molecular tools enabling precise manipulation of neural circuitry. Here we present a novel behavioural task that can be used to assess perceptual aspects of auditory streaming in head-fixed mice. Animals were trained to detect a target sound in a one of two simultaneously presented, isochronous pure tone sequences. Temporal expectation was manipulated by presenting the target sound in a particular stream either early (~2 s) or late (~4 s) with respect to trial onset in blocks of 25–30 trials. Animals reached high performance on this task (d' > 1 overall), and notably their false alarms were very instructive of their behavioural state. Indeed, false alarm timing was markedly delayed for late blocks compared to early ones, indicating that the animals associated a different context to an otherwise identical stimulus. More finely, we observed that the false alarms were timed to the onset of the sounds present in the target stream. This suggests that the animals could selectively follow the target stream despite the presence of a distractor stream. Extracellular electrophysiological recordings during the task revealed that sound processing is flexibly modulated in a manner consistent with the optimisation of behavioural outcome. Together, these results indicate that the perceptual streaming can be inferred via the timing of false alarms in mice, and provide a new paradigm with which to investigate neuronal mechanisms of selective attention.

Auditory Stream Segregation and Selective Attention for Cochlear Implant Listeners: Evidence From Behavioral Measures and Event-Related Potentials.

The role of the spatial separation between the stimulating electrodes (electrode separation) in sequential stream segregation was explored in cochlear implant (CI) listeners using a deviant detection task. Twelve CI listeners were instructed to attend to a series of target sounds in the presence of interleaved distractor sounds. A deviant was randomly introduced in the target stream either at the beginning, middle or end of each trial. The listeners were asked to detect sequences that contained a deviant and to report its location within the trial. The perceptual segregation of the streams should, therefore, improve deviant detection performance. The electrode range for the distractor sounds was varied, resulting in different amounts of overlap between the target and the distractor streams. For the largest electrode separation condition, event-related potentials (ERPs) were recorded under active and passive listening conditions. The listeners were asked to perform the behavioral task for the active listening condition and encouraged to watch a muted movie for the passive listening condition. Deviant detection performance improved with increasing electrode separation between the streams, suggesting that larger electrode differences facilitate the segregation of the streams. Deviant detection performance was best for deviants happening late in the sequence, indicating that a segregated percept builds up over time. The analysis of the ERP waveforms revealed that auditory selective attention modulates the ERP responses in CI listeners. Specifically, the responses to the target stream were, overall, larger in the active relative to the passive listening condition. Conversely, the ERP responses to the distractor stream were not affected by selective attention. However, no significant correlation was observed between the behavioral performance and the amount of attentional modulation. Overall, the findings from the present study suggest that CI listeners can use electrode separation to perceptually group sequential sounds. Moreover, selective attention can be deployed on the resulting auditory objects, as reflected by the attentional modulation of the ERPs at the group level.

Entrainment for attentional selection in Parkinson's disease

Neural entrainment plays a crucial role in perception and action, especially when stimuli possess a certain temporal regularity, and is also suggested to serve as a neural process to select and attend the relevant stream in situations where there are competing stimulus streams. Beneficial effects of entrainment have led to the suggestion that rhythmic stimuli can improve motor function in patients with Parkinson's disease (PD). Behavioural studies support this suggestion, but neurophysiological studies have shown reduced entrainment of motor areas in PD. However, oscillatory entrainment in PD has only been tested in paradigms with a single isochronous stimulus stream, whereas entrainment has an enhanced benefit in situations where one rhythmic stimulus stream has to be segregated from distractor stimuli. Therefore, we here used an intermodal selective attention task with concurrent auditory and visual stimulus streams while recording oscillatory brain activity with Magnetoencephalography (MEG). We aimed to (i) replicate earlier findings of deficient motor entrainment in PD patients in conditions where there is a single stimulus stream, and (ii) to evaluate whether increasing the benefit of entrainment by introducing a distractor stream would lead to entrainment in PD patients not seen otherwise. Contrary to this hypothesis, PD patients showed reduced motor entrainment compared to controls during both conditions, as indexed by beta oscillatory activity. These results suggest that entrainment in PD patients is deficient, even under conditions that encourage entrainment.

Adaptability and specificity of inhibition processes in distractor-induced blindness.

In a rapid serial visual presentation task, inhibition processes cumulatively impair processing of a target possessing distractor properties. This phenomenon-known as distractor-induced blindness-has thus far only been elicited using dynamic visual features, such as motion and orientation changes. In three ERP experiments, we used a visual object feature-color-to test for the adaptability and specificity of the effect. In Experiment I, participants responded to a color change (target) in the periphery whose onset was signaled by a central cue. Presentation of irrelevant color changes prior to the cue (distractors) led to reduced target detection, accompanied by a frontal ERP negativity that increased with increasing number of distractors, similar to the effects previously found for dynamic targets. This suggests that distractor-induced blindness is adaptable to color features. In Experiment II, the target consisted of coherent motion contrasting the color distractors. Correlates of distractor-induced blindness were found neither in the behavioral nor in the ERP data, indicating a feature specificity of the process. Experiment III confirmed the strict distinction between congruent and incongruent distractors: A single color distractor was embedded in a stream of motion distractors with the target consisting of a coherent motion. While behavioral performance was affected by the distractors, the color distractor did not elicit a frontal negativity. The experiments show that distractor-induced blindness is also triggered by visual stimuli predominantly processed in the ventral stream. The strict specificity of the central inhibition process also applies to these stimulus features.

Contributions of the Ventral Striatum to Conscious Perception: An Intracranial EEG Study of the Attentional Blink.

What determines whether we become aware of a piece of information or not? Conscious access has been robustly associated with activity within a distributed network of cortical regions. Using intracranial electrophysiological recordings during an attentional blink task, we tested the idea that the ventral striatum, because of its ability to modulate cortical information flow, may contribute to conscious perception. We find that conscious perception is influenced and signaled by ventral striatal activity. Short-latency (80-140 ms) striatal responses to a first target determined conscious perception of a second target. Moreover, conscious perception of the second target was signaled by longer-latency (200-400 ms) striatal activity. These results suggest that the ventral striatum may be part of a subcortical network that influences conscious experience.

Lag-1 sparing in the attentional blink with multiple RSVP streams

When two targets are presented in a rapid stream of distractors, the accuracy of identifying the second target is impaired when the temporal lag between the targets is brief (attentional blink; AB). When the second target is presented immediately after the first target, the AB deficit is considerably reduced, a phenomenon called Lag 1 sparing. A recent study (Kristjansson & Nakayama, 2002) however, reported that Lag 1 sparing did not occur when multiple distractor streams were presented, al-though it had occurred in other studies (e.g., Peterson & Juola, 2000). The present study found that specific target attributes were the key for this inconsistency. When two targets in the same stream appear to be similar and are distinctive from the distractors, the first target is masked by the second. This masking of the first target increases the AB deficit, and Lag-1 sparing does not occur. Introduction We often encounter difficulties in processing two consecutive events in a brief interval. For example, when catching a cab, if we notice that the first approaching cab is occupied, it is highly likely that we will miss a second cab that appears immediately afterwards. Similarly, in the laboratory, when first and second targets (T1 and T2, respectively) are embedded in a rapid stream of distractors, T2 is frequently missed when the temporal lag between the two targets is short, although T1 is identified correctly. Successful T2 identification improves progressively as the temporal lag increases up to 700 ms. Poor identification of T2 in a rapid serial visual presentation (RSVP) is known as the attentional blink (AB; Raymond, Shapiro, & Arnell, 1992). The general consensus from studies of the AB is that this deficit derives from insufficient processing resources available for T2, because most of the available resources are used to process T1 when the temporal lag is brief (e.g., Shapiro, Arnell, & Raymond, 1997). As T1 processing releases more resources with increased lag time, T2 performance recovers. It is, however, not possible to explain the AB solely in terms of such resource depletion. Under the resource depletion scenario, T2 performance should be most impaired when T2 is presented directly after T1 (i.e., at Lag 1), but this was found to be the case in only approximately half of the experiments in the extant AB literature. In the remaining half, T2 performance at Lag 1 was not impaired. Potter, Chun, Banks, & Muckenhoupt (1998) termed this “Lag-1 sparing.” To understand this phenomenon, Visser, Bischof, & Di Lollo (1999) conducted a meta-analysis of previous AB studies. They defined Lag-1 sparing as the case in which identification of T2 at Lag 1 exceeded the lowest level of performance at the other lags by more than 5%. Visser, Bischof et al. (1999) found that changing spatial locations between T1 and T2 plays a critical role in determining whether Lag-1 sparing occurs. Their analysis indicated that T2 performance at Lag 1 is unimpaired when two targets appear in the same location. In contrast, when the two targets appear in different locations, Lag-1 sparing does not occur; the AB deficit is most severe at Lag 1. Based on this analysis, Visser, Zuvic, Bischof, & Di Lollo (1999) used a single RSVP stream and showed that Lag-1 sparing occurred when there was no spatial switching between the targets, but that it did not occur when there was spatial switching. However, when there are two or more RSVP streams, the situation is more complex. For example, Peterson & Juola (2000) used three concurrent RSVP streams and showed that Lag-1 sparing occurred when the two targets appeared in the same stream, but not when the targets appeared in different streams. On the other hand, Kristjansson & Nakayama (2002) used seven RSVP streams and reported that there was no Lag-1 sparing even when the two targets were presented in the same stream. This apparent inconsistency cannot be explained solely by the effect on Lag-1 sparing of spatial switching between the targets when using multiple RSVP streams, and the purpose of the present study is to determine the source of the inconsistency. We believe that it is important to understand the mechanisms for Lag-1 sparing, because it is one of the outstanding questions in AB studies (Shapiro et al., 1997) and because information about Lag-1 sparing will provide cues to characterize the temporal aspects of attention (Kawahara, 2003). The two studies that reported inconsistent results in Lag-1 sparing differ in three important ways. First, temporal parameters, especially stimulus-onset asynchrony (SOA) between the This is a preprint version of the article published at The Japanese Journal of Psychonomic Science

Intertarget Distractors and Input Filter Compatibility in the Attentional Blink

The Attentional Blink (AB) refers to the impairment in report accuracy of a second target when presented shortly after a first target in a stream of distractors. The main goal of the present study was to understand the nature of intertarget distractor interference in the AB by manipulating the compatibility of the distractor immediately trailing the first target and the attentional filter set to select targets preferentially for conscious report. Results show that distractor/filter compatibil - ity had no impact on the AB, except when the distractor was of the same response category as the targets. In these conditions, the AB was larger in compatible than incompatible conditions, an effect that could be explained by an increase in misselection errors. Results are discussed in relation to extant theories of the AB.

Perception of temporal order during the attentional blink: Using stimulus salience to modulate prior entry.

When multiple targets are presented in rapid sequence, observers frequently confuse the order in which they were presented. The probability of order reversals is known to vary throughout the period of the attentional blink (AB), which refers to impairment in the perception of the second of two targets when it is presented within approximately 500ms from the first. Our objective was to examine the principle of prior entry (in which perception of temporal order is said to be affected by the relative latency at which each target is processed) as a determinant of the perception of temporal order throughout the AB. In two experiments, three letter targets (T1, T2, T3) were inserted in a stream of digit distractors, with T3 always presented directly after T2. The T1-T2 lag was varied to assess the perception of T2-T3 temporal order throughout the period of the AB. Processing latency was manipulated by means of salience. In Experiment 1, salience of T2 and T3 was manipulated exogenously by coloring the salient target red with all other stimuli being green. In Experiment 2, salience was modulated endogenously by manipulating which of the two targets matched the contents of working memory. Consistent with the principle of prior entry, perception of temporal order in both experiments was enhanced throughout the period of the AB when T2 was salient, and impaired when T3 was salient. Simulations based on the Episodic Simultaneous Type, Serial Token (eSTST) model that incorporates prior-entry, matched the empirical results.

An individual differences approach to multiple-target search errors: Errors correlate with attentional deficits

Multiple-target visual searches, where more than one target can be present within a single search array, are especially error-prone such that a second target is more likely to be missed after a first target has been detected. This is a serious concern for many critical searches (e.g., radiology, baggage screening) and also raises interesting theoretical questions. Increasingly, evidence supports a resource depletion account of these errors-a first target consumes attentional resources leaving less available to process additional targets. The current study tested this account by comparing 60 participants' multiple-target search performance to two other attention-demanding tasks: attentional blink (AB) and vigilance. The multiple-target search task had 1 or 2 targets per trial intermixed with distractors, and participants clicked on each target they found. The AB task presented two targets (letters) 100-800ms apart in a rapid serial visual presentation (RSVP) stream of distractors (numbers), and participants reported which targets they saw. The vigilance task presented targets (the letter O) in a RSVP stream with distractors (forward or backwards letter Ds) on top of a noise mask, and participants were to indicate every time the target appeared. Second target accuracy in the multiple-target search task significantly correlated with (1) a measure of how long it took second target accuracy in an AB task to recover from the blink, and (2) sensitivity (d') in the vigilance task. Participants who took longer to recover from an AB and who were less vigilant had more second-target misses in a multiple-target search task. Taken together, these results support a resource depletion account of multiple-target search errors in that they highlight an attentional underpinning; errors in AB and vigilance tasks are believed to reflect a deficit in attentional resources and the magnitude of these deficits significantly related to the magnitude of the multiple-target search errors. Meeting abstract presented at VSS 2015. Language: en