Showing papers on "Attentional blink published in 2007"
TL;DR: This study shows that meditation, or mental training, affects the distribution of limited brain resources, and supports the idea that plasticity in brain and mental function exists throughout life and illustrates the usefulness of systematic mental training in the study of the human mind.
Abstract: The information processing capacity of the human mind is limited, as is evidenced by the so-called “attentional-blink” deficit: When two targets (T1 and T2) embedded in a rapid stream of events are presented in close temporal proximity, the second target is often not seen. This deficit is believed to result from competition between the two targets for limited attentional resources. Here we show, using performance in an attentional-blink task and scalp-recorded brain potentials, that meditation, or mental training, affects the distribution of limited brain resources. Three months of intensive mental training resulted in a smaller attentional blink and reduced brain-resource allocation to the first target, as reflected by a smaller T1-elicited P3b, a brain-potential index of resource allocation. Furthermore, those individuals that showed the largest decrease in brain-resource allocation to T1 generally showed the greatest reduction in attentional-blink size. These observations provide novel support for the view that the ability to accurately identify T2 depends upon the efficient deployment of resources to T1. The results also demonstrate that mental training can result in increased control over the distribution of limited brain resources. Our study supports the idea that plasticity in brain and mental function exists throughout life and illustrates the usefulness of systematic mental training in the study of the human mind.
696 citations
TL;DR: It is argued that for a stimulus to reach consciousness, two factors are jointly needed: (i) the input stimulus must have enough strength and (ii) it must receive top-down attention (which can be prevented by drawing attention to another stimulus or task).
Abstract: Understanding the extent and limits of non-conscious processing is an important step on the road to a thorough understanding of the cognitive and cerebral correlates of conscious perception. In this article, we present a critical review of research on subliminal perception during masking and other related experimental conditions. Although initially controversial, the possibility that a broad variety of processes can be activated by a non-reportable stimulus is now well established. Behavioural findings of subliminal priming indicate that a masked word or digit can have an influence on perceptual, lexical and semantic levels, while neuroimaging directly visualizes the brain activation that it evokes in several cortical areas. This activation is often attenuated under subliminal presentation conditions compared to consciously reportable conditions, but there are sufficiently many exceptions, in paradigms such as the attentional blink, to indicate that high activation, per se, is not a sufficient condition for conscious access to occur. We conclude by arguing that for a stimulus to reach consciousness, two factors are jointly needed: (i) the input stimulus must have enough strength (which can be prevented by masking) and (ii) it must receive top-down attention (which can be prevented by drawing attention to another stimulus or task). This view leads to a distinction between two types of non-conscious processes, which we call subliminal and preconscious. According to us, maintaining this distinction is essential in order to make sense of the growing neuroimaging data on the neural correlates of consciousness.
652 citations
TL;DR: The authors demonstrate that the ST2 model explains a spectrum of AB findings by modeling temporal attention results focused on the attentional blink (AB), and highlight a number of new temporal attention predictions arising from the ST1 theory.
Abstract: A detailed description of the simultaneous type, serial token (ST2) model is presented. ST2 is a model of temporal attention and working memory that encapsulates 5 principles: (a) M. M. Chun and M. C. Potter's (1995) 2-stage model, (b) a Stage 1 salience filter, (c) N. G. Kanwisher's (1987, 1991) types-tokens distinction, (d) a transient attentional enhancement, and (e) a mechanism for associating types with tokens called the binding pool. The authors instantiate this theoretical position in a connectionist implementation, called neural-ST2, which they illustrate by modeling temporal attention results focused on the attentional blink (AB). They demonstrate that the ST2 model explains a spectrum of AB findings. Furthermore, they highlight a number of new temporal attention predictions arising from the ST2 theory, which are tested in a series of behavioral experiments. Finally, the authors review major AB models and theories and compare them with ST2.
293 citations
TL;DR: It is shown that increasing the number of targets in the stream can lead to remarkable improvements as long as there are no intervening distractors and a strong role for attentional control processes that may be overzealously applied.
Abstract: The identification of the second of two targets presented in close succession is often impaired--a phenomenon referred to as the attentional blink. Extending earlier work (Di Lollo, Kawahara, Ghorashi, and Enns, in Psychological Research 69:191-200, 2005), the present study shows that increasing the number of targets in the stream can lead to remarkable improvements as long as there are no intervening distractors. In addition, items may even recover from an already induced blink whenever they are preceded by another target. It is shown that limited memory resources contribute to overall performance, but independent of the attentional blink. The findings argue against a limited-capacity account of the blink and suggest a strong role for attentional control processes that may be overzealously applied.
205 citations
TL;DR: In this paper, the authors show that sexual words involuntarily capture attention and enter awareness at the expense of goal-driven targets, at least in the context of laboratory experiments performed by young university participants who might have high impact and relevance.
Abstract: Participants are usually able to search rapid serial visual presentation (RSVP) streams and report a single target, given that RSVP distractors do not typically deplete attention required for target identification. Here, participants performed single target search, but the target was preceded by a to-be-ignored distractor varying in valence and arousal. When the critical distractor was a sexual word, lower target accuracy was observed, particularly at short distractor-target stimulus onset asynchronies, even when participants were shown the critical distractors beforehand and told to ignore them. No reduction in target accuracy was evidenced when the critical distractor was negative, positive, threatening, or emotionally neutral. Target accuracy was predicted by participants' arousal ratings to the critical distractor words and by their memory for them, but not by their valence ratings. Memory for critical distractors mediated the relationship between arousal and target accuracy. The results provide evidence that arousing sexual words involuntarily capture attention and enter awareness at the expense of goal-driven targets, at least in the context of laboratory experiments performed by young university participants for whom sexual material might have high impact and relevance.
173 citations
TL;DR: It is concluded that the resources allocated to first and second target processing are directly mirrored by the P3 component and, moreover, that brain states before and during stimulus presentation, as reflected by oscillatory brain activity, strongly determine the access to consciousness.
135 citations
TL;DR: The results support the idea that individual processing limitations (with regard to either attentional allocation policies or the speed of global cortical integration processes) play a key role in the AB.
Abstract: The attentional blink (AB) is often attributed to resource limitations, but the nature of these resources is commonly underspecified. Recent observations rule out access to short-term memory or storage capacity as limiting factors, but operation bottlenecks are still an option. We considered the operation span of working memory (WM) as a possible factor and investigated the relationship between individual WM operation span (as measured by OSPAN), fluid intelligence (as measures by Raven's SPM), and the size of the AB. WM operation span was negatively correlated with the AB, whereas fluid intelligence was associated with higher overall accuracy but not with AB magnitude. These results support the idea that individual processing limitations (with regard to either attentional allocation policies or the speed of global cortical integration processes) play a key role in the AB.
98 citations
01 Jan 2007
TL;DR: The authors show that an attentional blink occurs even in the absence of distractors, with 2 letter targets separated by a blank interval, and show that the root cause of the blink lies in the difficulty of engaging attention twice within a short period of time for 2 temporally discrete target events.
Abstract: When asked to identify 2 visual targets (T1 and T2 for the 1st and 2nd targets, respectively) embedded in a sequence of distractors, observers will often fail to identify T2 when it appears within 200-500 ms of T1--an effect called the attentional blink. Recent work shows that attention does not blink when the task is to encode a sequence of consecutive targets, suggesting that distractor interference plays a causal role in the attentional blink. Here, however, the authors show that an attentional blink occurs even in the absence of distractors, with 2 letter targets separated by a blank interval. In addition, the authors found that the impairment for identification of the 2nd of 2 targets separated by a blank interval is substantially attenuated either when the intertarget interval is filled with additional target items or when the 2nd target is precued by an additional target. These findings show that the root cause of the blink lies in the difficulty of engaging attention twice within a short period of time for 2 temporally discrete target events.
97 citations
TL;DR: Based on recent theoretical accounts of the AB effect, results indicate a phobia-related post-perceptual consolidation bias of threatening information in spider phobic subjects.
74 citations
TL;DR: The attentional blink as mentioned in this paper is a consequence of selection mechanisms that are not severely limited, but have an adaptive function: they enhance perception in response to relevant information but suppress perception when it is not relevant.
Abstract: What is the time course of attention? Research using rapid-stimulus streams has suggested that it is rather slow: Attention takes half a second to recover from processing one thing before it can process the next. This period is referred to as the attentional blink, and it is thought to reflect a fundamental bottleneck in conscious processing. If this period does exist, such a limitation would have severe consequences in real-life situations in which multiple events may rapidly succeed each other (e.g., in traffic). However, findings that support the attentional blink are at odds with other findings indicating that attention is not reduced, but enhanced, following potentially important occurrences. The article reviews evidence that these opposite effects are actually closely related. The attentional blink is a consequence of selection mechanisms that are not severely limited, but have an adaptive function: They enhance perception in response to relevant information but suppress perception in response to ir...
71 citations
TL;DR: Findings provide converging evidence in support of temporal attention models bridging behavior and electrophysiology that postulate a direct link between the cause of the AB effect and the sources of both amplitude and latency variations in the T2-locked P3 component.
TL;DR: The present work suggests that one factor contributing to this uncertainty is masking of the 1st target: When this mask is omitted, processing time and AB magnitude are reliably related.
Abstract: When observers are presented with 2 targets in rapid succession, identification of the 1st is highly accurate, whereas identification of the 2nd is impaired at brief intertarget intervals (i.e., 200-500 ms). This 2nd-target deficit is known as the attentional blink (AB). According to bottleneck models, the AB arises because attending to the 1st target delays allocation of attention to the 2nd target. Thus, these models predict that increasing 1st-target processing time will increase the magnitude of the AB. Previous tests of this prediction have yielded mixed results. The present work suggests that one factor contributing to this uncertainty is masking of the 1st target: When this mask is omitted, processing time and AB magnitude are reliably related. These findings clarify the role of 1st-target masking in the AB and support the validity of the bottleneck account.
TL;DR: Evidence is provided implicating the cerebellum as a critical node in the neuroanatomical network underlying visuotemporal attention and providing further evidence for the role of the Cerebellum in non-motor behaviors.
TL;DR: Findings indicate that socially anxious individuals are not characterized by a bias in the (explicit) detection of emotional expressions, and the present anger superiority effects are consistent with evolutionary models stressing the importance of being especially vigilant for signals of dominance.
TL;DR: The authors show that prior engagement of the attentional system may compromise the processing of items directed to the right visual field and explain the failures of previous attempts to demonstrate that parallel processing can improve item identification.
Abstract: Recent data have shown that parallel processing by the cerebral hemispheres can expand the capacity of visual working memory for spatial locations (J. F. Delvenne, 2005) and attentional tracking (G. A. Alvarez & P. Cavanagh, 2005). Evidence that parallel processing by the cerebral hemispheres can improve item identification has remained elusive. The authors used a novel variant of the attentional blink paradigm to show that the attentional blink is reduced if targets are divided between the hemispheres rather than directed to a single hemisphere. Parallel processing by the cerebral hemispheres can thus expand the capacity of processes involved in item identification. The authors also show that prior engagement of the attentional system may compromise the processing of items directed to the right visual field. This pseudoextinction may explain the failures of previous attempts to demonstrate that parallel processing can improve item identification (J. F. Delvenne, 2005; S. J. Luck, S. A. Hillyard, G. R. Mangun, & M. S. Gazzaniga, 1989).
TL;DR: The results were interpreted to suggest that adolescents with language impairments have an AB which differs from non-impaired individuals in both magnitude and duration.
TL;DR: The results support the Central Interference Theory of the attentional blink by showing that the time taken for central processing of T1 has a direct impact on performance in Task 2, even when the different levels of Task 1 difficulty are intermixed from trial to trial.
Abstract: Manipulations of Task 1 difficulty in the attentional blink paradigm can have minimal effects on performance of a subsequent visual encoding task, when Task 1 difficulty is thought of as a form of data limitation (e.g., by masking T1 more or less effectively) using mixed trials (e.g., McLaughlin, Shore, & Klein, 2001). In this work we show that a different form of Task 1 difficulty, namely the difficulty of organizing T1 as a representation in STM, has a large impact on accuracy in Task 2, even when the different levels of Task 1 difficulty are intermixed from trial to trial. The results support the Central Interference Theory of the attentional blink by showing that the time taken for central processing of T1 has a direct impact on performance in Task 2.
TL;DR: Here, rapid sequences of complex stimuli are presented and observers are asked to detect and remember items of a specific category (either faces, watches, or both) but the duration of the AB depended on the target category.
TL;DR: This study presents a specific examination of the link between working memory and attention by engaging active rather than passive memory operations and provides evidence for the involvement of working memory in the attentional blink (AB) phenomenon.
Abstract: Theories of selective attention often have a central memory component, which is commonly thought to be limited in some way and is thereby a potential bottleneck in the attentional process. There have been only a few attempts to validate this assertion, and they have produced mixed results. This study presents a specific examination of the link between working memory and attention by engaging active rather than passive memory operations. Two experiments are reported that provide evidence for the involvement of working memory in the attentional blink (AB) phenomenon. Memory loads of increasing size had a detrimental effect on attentional performance within the blink-sensitive interval, but not beyond. Speeded response requirements proved to modulate the AB, but were independent from the memory load effect. Theoretical implications for current models of selective attention are discussed.
TL;DR: It is suggested that attention can be guided by global expectations of presentation speed within tens of milliseconds, as shown in the example of the attentional blink task.
Abstract: We investigated whether it is possible to control the temporal window of attention used to rapidly integrate visual information. To study the underlying neural mechanisms, we recorded ERPs in an attentional blink task, known to elicit Lag-1 sparing. Lag-1 sparing fosters joint integration of the two targets, evidenced by increased order errors. Short versus long integration windows were induced by showing participants mostly fast or slow stimuli. Participants expecting slow speed used a longer integration window, increasing joint integration. Difference waves showed an early (200 ms post-T2) negative and a late positive modulation (390 ms) in the fast group, but not in the slow group. The modulations suggest the creation of a separate event for T2, which is not needed in the slow group, where targets were often jointly integrated. This suggests that attention can be guided by global expectations of presentation speed within tens of milliseconds.
TL;DR: The results suggest that semantic and repetition priming effects, under rapid serial visual presentation conditions, are modulated by at least partially overlapping neural mechanisms.
TL;DR: The results of both experiments demonstrate that word meanings are not always accessed during the AB and are consistent with studies that suggest that attention can act to select information at multiple stages of processing depending on concurrent task demands.
Abstract: When two masked targets are presented in rapid succession, correct identification of the first target (T1) leads to a dramatic impairment in identification of the second target (T2). Several studies of this so-called attentional blink (AB) phenomenon have provided behavioral and physiological evidence that T2 is processed to the semantic level, despite the profound impairment in T2 report. These findings have been interpreted as an example of perception without awareness and have been explained by models that assume that T2 is processed extensively even though it does not gain access into consciousness. The present study reports two experiments that test this assumption. In Experiment 1, the perceptual load of the T1 task was manipulated and T2 was a word that was either related or unrelated to a context word presented at the beginning of each trial. The event-related potential (ERP) technique was used to isolate the context-sensitive N400 component evoked by the T2 word. The ERP data revealed that there was a complete suppression of the N400 during the AB when the perceptual load was high, but not when perceptual load was low. Experiment 2 replicated the high-load condition of Experiment 1 while ruling out two alternative explanations for the reduction of the N400 during the AB. The results of both experiments demonstrate that word meanings are not always accessed during the AB and are consistent with studies that suggest that attention can act to select information at multiple stages of processing depending on concurrent task demands.
TL;DR: Results suggest that AB performance depends on task requirements, and the attentional system is compromised in dyslexia, however, examination of individual case performance suggests that prolonged attentional dwell time is not a core deficit in Dyslexia.
TL;DR: Results suggests that dopamine plays a significant role in biasing memory toward emotionally salient information and that dopamine antagonists may act by attenuating this bias.
Abstract: OBJECTIVE:
Cognitive models suggest that biased processing of emotional information may play a role in the genesis and maintenance of psychotic symptoms. The role of dopamine and dopamine antagonists in the processing of such information remains unclear. The authors investigated the effect of a dopamine antagonist on perception of, and memory for, emotional information in healthy volunteers.
METHOD:
Thirty-three healthy male volunteers were randomly assigned to a single-blind intervention of either a single dose of the dopamine D(2)/D(3) antagonist amisulpride or placebo. An attentional blink task and an emotional memory task were then administered to assess the affective modulation of attention and memory, respectively.
RESULTS:
A significant interaction was observed between stimulus valence and drug on recognition memory accuracy; further contrasts revealed enhanced memory for aversive-arousing compared with neutral stimuli in the placebo but not the amisulpride group. No effect of amisulpride was observed on the perception of emotional stimuli.
CONCLUSIONS:
Amisulpride abolished the enhanced memory for emotionally arousing stimuli seen in the placebo group but had no effect on the perception of such stimuli. These results suggests that dopamine plays a significant role in biasing memory toward emotionally salient information and that dopamine antagonists may act by attenuating this bias.
TL;DR: Findings from three experiments show that the attentional blink is significantly reduced when observers are set to achieve one single goal (reporting combinations of the two targets) instead of separate goals (reporting the two target).
Abstract: . Humans are fundamentally limited in processing information from the outside world. This is particularly evident in the attentional blink (AB), the impaired ability to identify the second of two targets presented in close succession. We report findings from three experiments showing that the AB is significantly reduced when observers are set to achieve one single goal (reporting combinations of the two targets) instead of separate goals (reporting the two targets). This finding raises questions about the nature of AB, and suggests that processes involved in goal-switching must be taken into account by theories of the AB phenomenon.
TL;DR: The results showed that the participants were able to detect the second target significantly more accurately in the AB stream when the Mozart sonata was played normally than in either of the other two conditions.
TL;DR: The results show that the association of T1 to either a rare or frequent response causes significant interference with the deployment of visual spatial attention to T2, and with the short-term consolidation of T2 into visual short- term memory.
TL;DR: Progressive changes in the magnitude of the attentional blink associated with aging was found to be significantly associated with the ability to detect the second target, whereby older age was correlated with the production of a longer and more pronounced AB; this supports the proposition that aging is associated with reduced inhibitory processes and selective attention.
Abstract: Previous studies on aging and attention typically examine group differences between younger and older adults, rather than seeing aging as a continuous process. Using correlational analyses, this study examined progressive changes in the magnitude of the attentional blink (AB) associated with aging. Increased age was found to be significantly associated with the ability to detect the second target (T2), whereby older age was correlated with the production of a longer and more pronounced AB; this supports the proposition that aging is associated with reduced inhibitory processes and selective attention. It was also found that AB performance somewhat improves between ages 18-39 years, but tends to decline from 40 years of age onward, providing an interesting and novel finding that AB effects may become more sensitive at this point in time. The AB task may prove useful in the assessment of selective attention in normal healthy adults, as well as changes associated with pathological aging.
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TL;DR: The authors examined the relationship between attentional blink (AB) and psychological refractory period (PRP) using a conventional AB procedure combined with a requirement of speeded responses to the second target (T2).
Abstract: This study examined the relationship between attentional blink (AB) and psychological refractory period (PRP) using a conventional AB procedure combined with a requirement of speeded responses to the second target (T2). Experiments 1 and 2 showed that, as with PRP, memory retrieval of targets is not a necessary condition for the occurence of AB in terms of accuracy and that AB occured in the speed data. Experiment 3 further indicated that the PRP-like speed data were not due to the first target serving as a warning signal that triggered preparation of responses to T2. Experiment 4 manipulated T2 stimulus intensity to be normal or low. Results showed an underadditive interaction between stimulus intensity and lag position in the speed data, whereas an overadditive interaction was found in the accuracy data, suggesting 2 sources of interference leading to AB: the single-channel bottleneck and resource-limited visual-processing capacity.
TL;DR: The visual search results suggest that the noradrenergic system is not directly involved in spatial attention processes but instead can modulate these processes in an indirect fashion, and are inconsistent with recent theories about the role of the noradsine system in temporal filtering and in mediating the attentional blink.
Abstract: Recent theories posit an important role for the noradrenergic system in attentional selection in the temporal domain. In contrast, the spatially diffuse topographical projections of the noradrenergic system are inconsistent with a direct role in spatial selection. To test the hypotheses that pharmacological attenuation of central noradrenergic activity should (1) impair performance on the attentional blink task, a task requiring the selection of targets in a rapid serial visual stream of stimuli; and (2) leave intact the efficiency of the search for a target in a two-dimensional visuospatial stimulus array. Thirty-two healthy adult human subjects performed an attentional blink task and a visual search task in a double-blind, placebo-controlled, between-subject study investigating the effects of the α2 adrenoceptor agonist clonidine (150 μg, oral dose). No differential effects of clonidine vs placebo were found on the attentional blink performance. Clonidine slowed overall reaction times in the visual search task but did not impair the efficiency of the visual search. The attentional blink results are inconsistent with recent theories about the role of the noradrenergic system in temporal filtering and in mediating the attentional blink. This discrepancy between theory and data is discussed in detail. The visual search results, in combination with previous findings, suggest that the noradrenergic system is not directly involved in spatial attention processes but instead can modulate these processes in an indirect fashion.