The time course of competition for attention: attention is initially labile

Competition for attention between 2 written words was investigated by presenting the words briefly in a single stream of distractors (Experiment 1) or in different streams (Experiment 2-6), using rapid serial visual presentation at 53 ms/item. Stimulus onset asynchrony (SOA) was varied from 0 to 213 ms. At all SOAs there was strong competition, but which word was more likely to be reported shifted markedly with SOA. At SOAs in the range of 13-53 ms the second word was more likely to be reported, but at 213 ms, the advantage switched to the first word, as in the attentional blink. A 2-stage competition model of attention is proposed in which attention to a detected target is labile in Stage 1. Stage 1 ends when one target is identified, initiating a serial Stage 2 process of consolidation of that target.     

Fast trial pacing in a lexical decision task reveals a decay of automatic semantic activation

We report an experiment showing that reducing attentional resources by presenting trials with a short, 400 ms intertrial interval (ITI) (a) did not affect semantic priming at a 160 ms prime-to-target stimulus-onset asynchrony (SOA), relative to a 2500 ms ITI, and (b) eliminated the priming that occurred at a 1200 ms SOA when the ITI was 2500 ms. However, the elimination of priming at the 1200 ms SOA occurred only when the relatedness proportion (RP, proportion of related primes and targets) was .25 and not when it was .75. We interpret these results as showing that attentional/strategic priming occurs with an RP as low as .25, but only when sufficient attentional resources are available. Equally important, this is the first direct evidence that automatic semantic activation decays within 1200 ms in the standard semantic-priming/lexical-decision paradigm when attentional resources are not being used to maintain the goal of sustaining prime activation. We further argue that the frequent occurrences of related primes and targets with a high RP serve as reminders to maintain that goal such that cognitive load does not reduce long-SOA priming when the RP is high.     

Early mechanism of negativity bias: An attentional blink study1

Abstract: The negativity bias is the perceptual phenomena whereby an emotionally negative stimulus is processed faster than a positive or neutral stimulus. We used the attentional blink paradigm to investigate whether attentional resources are required to obtain the negativity bias. Positive, negative or neutral words were used as a preceding target (T1) and/or a subsequent target (T2). Experiment 1 showed that the negativity bias occurred, because the attentional blink was reduced by a negative T2, but not by a positive or neutral T2. Experiment 2 indicated that a negative T1 grabbed attentional resources, interfering with the identification of a neutral T2. Experiment 3 demonstrated that the report of a negative T2 deteriorated when T1 was also negative. We conclude that attentional resources were required for the occurrence of the negativity bias.     

Evidence from the attentional blink for different sources of word repetition effects

T2 in an attentional blink paradigm served as a high- or low-frequency prime word for a subsequent repeated target. Consistent with research in visual word identification, only reported primes facilitated the identification of a target repeated approximately 8 s after RSVP. Priming was greater for low- than high-frequency words. Analogous with masked priming, a blinked T2 facilitated report of a repeated target occurring 318 ms after T2 in RSVP. The blinked repetition priming effect was additive with target frequency. These results indicate that: (1) the outcomes of processing prime words are a key factor in repetition priming effects, with blinked and reported T2s behaving like masked and unmasked primes, respectively, (2) there may be different sources of repetition effects, (3) there is a consistent cross-paradigm pattern of repetition effects that occurs as a function of prime–target interval and the ability to identify the word on its first and second presentation.     

注意瞬脱范式中的知觉负载对情绪面孔加工的影响

情绪性刺激的加工是否受注意影响目前尚存争论。基于许多操纵空间注意焦点的研究未能在注意资源的分配上进行精确的调节, 本实验将时间维度的注意瞬脱范式与负载理论相结合, 通过调节注意瞬脱中T1刺激物知觉负载水平的高低(箭头朝向相同与否), 观察被试在四种时间延迟条件下(延迟2, 延迟3, 延迟5, 延迟8)T2目标侦测任务恐惧和中性面孔的反应正确率, 从而对情绪性刺激的加工特征进行研究。实验发现：对恐惧面孔侦测的正确率在高知觉负载条件下显著降低, 而中性面孔则不受知觉负载水平影响, 并且这种高知觉负载对恐惧面孔加工的抑制作用仅发生在注意瞬脱中的短延迟条件下。说明在知觉加工资源和注意调节作用同时受限的情况下恐惧面孔的优势加工受到限制, 提示情绪性刺激的加工与中性刺激相比消耗的加工资源较少, 并依赖于注意的调控。     

Temporal selection is suppressed, delayed, and diffused during the attentional blink

How does temporal selection work, and along what dimensions does it vary from one instance to the next? We explored these questions using a phenomenon in which temporal selection goes awry. In the attentional blink, subjects fail to report the second of a pair of targets (T1 and T2) when they are presented at stimulus onset asynchronies (SOAs) of roughly 200 to 500 ms. We directly tested the properties of temporal selection during the blink by analyzing distractor intrusions at a fast rate of item presentation. Our analysis shows that attentional selection is (a) suppressed, (b) delayed, and (c) diffused in time during the attentional blink. These effects are dissociated by their time course: The measure of each effect returns to the baseline value at a different SOA. Our results constrain theories of the attentional blink and indicate that temporal selection varies along at least three dissociable dimensions: efficacy, latency, and precision.     

Identification facilitation for emotionally arousing verbs during the attentional blink

The present study aimed to examine affective modulation of the "attentional blink" effect during rapid serial visual presentation (RSVP). Pleasant, neutral, and unpleasant written verbs were used as a 2nd target (T2) in an 8.6-Hz RSVP paradigm. Pronounced effects of 1st target (T1)-T2 stimulus onset asynchrony (SOA) were found, showing reduced report accuracy for 232- and 464-ms SOAs. Affectively arousing (pleasant and unpleasant) T2s were associated with enhanced accuracy compared with neutral T2s specifically during short (232 ms) SOAs. In contrast, pleasant and unpleasant T2s rated low in terms of emotional arousal did not show this enhancement. These results suggest that affectively arousing information is selected preferentially from a temporal stream, facilitating processes such as working memory consolidation and action.     

Attention blinks for selection, not perception or memory: reading sentences and reporting targets

In whole report, a sentence presented sequentially at the rate of about 10 words/s can be recalled accurately, whereas if the task is to report only two target words (e.g., red words), the second target suffers an attentional blink if it appears shortly after the first target. If these two tasks are carried out simultaneously, is there an attentional blink, and does it affect both tasks? Here, sentence report was combined with report of two target words (Experiments 1 and 2) or two inserted target digits, Arabic numerals or word digits (Experiments 3 and 4). When participants reported only the targets an attentional blink was always observed. When they reported both the sentence and targets, sentence report was quite accurate but there was an attentional blink in picking out the targets when they were part of the sentence. When targets were extra digits inserted in the sentence there was no blink when viewers also reported the sentence. These results challenge some theories of the attentional blink: Blinks result from online selection, not perception or memory.     

The attentional blink reflects retrieval competition among multiple rapid serial visual presentation items: tests of an interference model

When people respond to a target (T1) in a rapid serial visual presentation stream, their perception of a subsequent target (T2) is impaired if the intertarget stimulus onset asynchrony is between about 100 and 500 ms. Three experiments supported the interference model's (K. L. Shapiro, J. E. Raymond, & K. M. Arnell, 1994) claim that this attentional blink reflects competition for retrieval among multiple items in visual short-term memory. Experiments 1 and 2 revealed that items appearing during the blink are named as T2 on an above-chance proportion of trials when T2 must be identified. Experiment 3 demonstrated that both the size of the blink and sensitivity to T2 reflected the number of items competing for retrieval as T2; such competition, moreover, occurred at a conceptual or categorical level rather than at a purely visual one. The relationship between the interference and alternative models of the attentional blink is discussed.     

Does failure to mask T1 cause lag-1 sparing in the attentional blink?

The attentional blink (AB) effect demonstrates that when participants are instructed to report two targets presented in a rapid visual stimuli stream, the second target (T2) is often unable to be reported correctly if presented 200-500 msec after the onset of the first target (T1). However, if T2 is presented immediately after T1, in the conventional lag-1 position (100-msec stimulus onset asynchrony; SOA), little or no performance deficit occurs. The present experiments add to the growing literature relating the "lag-1 sparing" effect to T1 masking. Using a canonical AB paradigm, our results demonstrate that T2 performance at lag 1 is significantly reduced in the presence of T1 masking. The implications of this outcome are discussed in relation to theories of the AB.     

Capturing and holding attention: The impact of emotional words in rapid serial visual presentation

When two masked, to-be-attended targets are presented within approximately 500 msec of each other, accurate report of the second target (T2) suffers more than when targets are presented farther apart in time--an attentional blink (AB). In the present study, the AB was found to be larger when taboo words were presented as a first target (T1), as compared with the AB found when emotionally neutral, negative, or positive words were presented as T1, suggesting that taboo words received preferential attentional processing. Comparable results were also obtained when taboo words were presented as to-be-ignored distractors in single-target rapid serial visual presentation (RSVP). Arousal, but not valence, ratings of the emotional words predicted accuracy on subsequent targets in both dual- and single-task RSVP. Recognition memory for taboo words accounted fully for the negative relationships between arousal ratings and accuracy on subsequent targets, suggesting that arousal-triggered changes in attentional allocation influenced encoding of taboo words at the time they were encountered.     

A dissociation between selective attention and conscious awareness in the representation of temporal order information

Previous electrophysiological studies have shown that attentional selection processes are highly sensitive to the temporal order of task-relevant visual events. When two successively presented colour-defined target stimuli are separated by a stimulus onset asynchrony (SOA) of only 10 ms, the onset latencies of N2pc components to these stimuli (which reflect their attentional selection) precisely match their objective temporal separation. We tested whether such small onset differences are accessible to conscious awareness by instructing participants to report the category (letter or digit) of the first of two target-colour items that were separated by an SOA of 10, 20, or 30 ms. Performance was at chance level for the 10 ms SOA, demonstrating that temporal order information which is available to attentional control processes cannot be utilized for conscious temporal order judgments. These results provide new evidence that selective attention and conscious awareness are functionally separable, and support the hypothesis that attention and awareness operate at different stages of cognitive processing.     

The locus of semantic priming in RSVP target search

At what stage does semantic priming affect accuracy in target search? In two experiments, participants viewed two streams of stimuli, each including a target word among distractors. Stimulus onset asynchronies (SOAs) between the targets (T1 and T2) ranged from 53 to 213 msec. A word semantically related to one or neither of the targets preceded each trial. In Experiment 1, participants were instructed to report both targets. Although more primed than unprimed targets were reported, there was no cost for unprimed words. A strong interaction between SOA and T1 versus T2 was found, but priming did not interact with either variable. In Experiment 2, only related targets were reported. Performance was similar to that for primed targets in Experiment 1. Semantic priming does not seem to modulate how attentional resources are initially allocated between targets, but instead affects a later stage of processing, the point at which a target word reaches lexical identification.     

Delayed working memory consolidation during the attentional blink

After the detection of a target (T1) in a rapid stream of visual stimuli, there is a period of 400–600 msec during which a subsequent target (T2) is missed. This impairment in performance has been labeled the attentional blink. Recent theories propose that the attentional blink reflects a bottleneck in working memory consolidation such that T2 cannot be consolidated until after T1 is consolidated, and T2 is therefore masked by subsequent stimuli if it is presented while T1 is being consolidated. In support of this explanation, Giesbrecht & Di Lollo (1998) found that when T2 is the final item in the stimulus stream, no attentional blink is observed, because there are no subsequent stimuli that might mask T2. To provide a direct test of this explanation of the attentional blink, in the present study we used the P3 component of the event-related potential waveform to track the processing of T2. When T2 was followed by a masking item, we found that the P3 wave was completely suppressed during the attentional blink period, indicating that T2 was not consolidated in working memory. When T2 was the last item in the stimulus stream, however, we found that the P3 wave was delayed but not suppressed, indicating that T2 consolidation was not eliminated but simply delayed. These results are consistent with a fundamental limit on the consolidation of information in working memory.     

自我姓名加工的相对独特性：来自RSVP的证据

研究采用注意瞬脱的双任务RSVP范式通过操纵T1任务知觉负载水平的高低及T1-T2间的延迟长短,检验不同负载和延迟条件被试对陌生姓名、明星姓名和自我姓名的识别正确率。研究发现,自我姓名加工具有明显的注意瞬脱对抗效应,体现出加工的独特性,但其独特性受负载及延迟条件的影响,且明星姓名在一定条件下也出现了与之相近注意瞬脱的对抗效应,证明自我姓名加工具有相对的独特性。     

Delayed attentional engagement in the attentional blink

Observers often miss the 2nd of 2 visual targets (first target [T1] and second target [T2]) when these targets are presented closely in time; the attentional blink (AB). The authors hypothesized that the AB occurs because the attentional response to T2 is delayed by T1 processing, causing T2 to lose a competition for attention to the item that follows it. The authors investigated this hypothesis by determining whether the AB is attenuated when T2 is precued. The results from 4 experiments showed that the duration and magnitude of the AB were substantially reduced when T2 was precued. The observed improvement in T2 report did not occur at the expense of T1 report, suggesting that processing of T1 was already completed or was at least protected when the cue was presented. The authors conclude that, during the AB, there is a delay between detection and the selection of target candidates for consolidation in short-term memory.     

Age Differences in the Magnitude of the Attentional Blink

When people attend to a target in a rapid sequence of items, their perception of a subsequent target is impaired for about 500 ms. This is termed the attentional blink. In the present experiment, a dual task rapid serial presentation task (Raymond, Shapiro & Arnell, 1992) was used as a measure of inhibitory function of younger and older adults. We found that the attentional blink was larger among older adults as compared to younger adults, supporting Hasher and Zacks' (1988) inhibitory deficit hypothesis and current models of the attentional blink.     

A conceptual and methodological framework for measuring and modulating the attentional blink

The attentional blink (AB) is a transient attention cost that is shown when report accuracy for a second target (T2) is reduced when T2 is presented within approximately 500?ms of a first target (T1). Thus, by definition an AB is only observed when T2 accuracy is reduced at short relative to long T1?CT2 separations, and the magnitude of the AB is reflected in the change in T2 performance across target separations. However, the designs, analyses, and interpretations of several studies of the AB have suggested a lack of clear definitions about what constitutes a demonstration of the AB, what constitutes a modulation of the AB across participant groups or manipulations, and how AB magnitude might best be represented accurately as a single value for a given individual. In this article, we discuss the important conceptual and methodological issues that should be considered when obtaining, analyzing, and interpreting AB data, and we discuss the pros and cons of various approaches while providing suggestions as to how best to validly represent the AB and its modulations.     

Electrophysiological difference between the representations of causal judgment and associative judgment in semantic memory

Causally related concepts like “virus” and “epidemic” and general associatively related concepts like “ring” and “emerald” are represented and accessed separately. The Evoked Response Potential (ERP) procedure was used to examine the representations of causal judgment and associative judgment in semantic memory. Participants were required to remember a task cue (causal or associative) presented at the beginning of each trial, and assess whether the relationship between subsequently presented words matched the initial task cue. The ERP data showed that an N400 effect (250–450 ms) was more negative for unrelated words than for all related words. Furthermore, the N400 effect elicited by causal relations was more positive than for associative relations in causal cue condition, whereas no significant difference was found in the associative cue condition. The centrally distributed late ERP component (650–750 ms) elicited by the causal cue condition was more positive than for the associative cue condition. These results suggested that the processing of causal judgment and associative judgment in semantic memory recruited different degrees of attentional and executive resources.     

Suppression of EEG gamma activity may cause the attentional blink

The attentional blink (AB) is an impairment of attention, which occurs when subjects have to report a target stimulus (T2) following a previous target (T1) with a short delay (up to 600 ms). Theories explaining the AB assume that processing of T2 is more vulnerable to decay or substitution, as long as attention is allocated to T1. Existing models of the AB, however, do not account for the fact that T2 detection accuracy reaches the minimum when T2 is presented after about 300 ms and not immediately following T1. Therefore, a new model is suggested, which is based on chronometrical considerations together with recent neurophysiological findings concerning the relation between the P3 event-related potential and the AB, the interaction between P3 and gamma oscillations, and the significance of the early evoked gamma band response. We hypothesize that suppression of the early gamma response to T2, accompanying the P3 related to T1, causes the AB.