Cross-task repetition amnesia: Impaired recall of RSVP targets held in memory for a secondary task

People often fail to select and encode the second of two targets presented within less than 500ms in rapid serial visual presentation (RSVP), an effect known as the attentional blink. We investigated how report of the two targets is affected when one of them is maintained in working memory for a secondary, memory-search task. The results showed that report of either target was impaired when it was a member of the memory set relative to when it was not. This effect was independent of both the temporal interval separating the RSVP target from the presentation of the memory set and the interval separating the targets. We propose that the deficit in recall occurs because the association between a target and the memory-search task interferes with the formation of a new association between that target and the following RSVP task, with the result that observers may be biased to ascribe the target only to the memory set.     

The costs and benefits of processing emotional stimuli during rapid serial visual presentation

Using a dual-target identification task during rapid serial visual presentation (RSVP), we examined facilitation and interference effects exerted by emotional stimuli. Emotionally arousing first targets (T1s) were encoded with higher accuracy than neutral T1s. At the same time, identification of a second neutral target (T2) was impaired reflecting a failure of disengaging attention from arousing T1s. Similar interference was triggered by arousing filler stimuli that were not voluntarily searched for in the RSVP stream (Experiment 2). In Experiment 3, we showed that interference is reduced (though facilitation for arousing T1s is maintained) when the second task itself involves variations in emotional arousal. Vice versa, when arousal associated with the T2 stimulus was predictable, interference recurred (Experiment 4). Our findings indicate that the perceived emotional intensity of a stimulus is a determinant of successful identification during RSVP: Encoding of arousing stimuli is reliably facilitated. Interference effects with subsequent processing arise independently and are strongly modulated by the overall task context and specific processing strategies.     

视觉工作记忆负载对听觉偏差干扰效应的调控：来自不同外周提示线索的证据

采用线索提示和视听Oddball结合的实验设计, 通过四个实验探讨了外周视线索下视觉工作记忆负载对听觉偏差干扰效应的调控作用。结果表明：(1)操作外周视线索有效性为50%的条件下, 视觉工作记忆负载的增加使得原本抑制无关声音的过程失败, 因此出现了显著的听觉偏差干扰效应; (2)操作外周视线索有效性为80%的条件下, 发现有策略性的注意定向消耗了注意资源, 无视觉工作记忆负载的情况下同样出现听觉偏差干扰, 并且随着工作记忆负载增加偏差干扰效应增强。研究说明视觉工作记忆负载对听觉偏差干扰的调控是有条件性的, 当来自不同感觉通道的无关刺激与目标的加工过程存在重叠时, 视觉工作记忆负载的增加使得听觉偏差干扰效应增强而不是减弱。     

What it costs to implement a plan: Plan-level and task-level contributions to switch costs

Four experiments were conducted to identify the costs of implementing a plan in the task span procedure, which requires subjects to retrieve the task to perform on the current target from a list of planned tasks in memory. Experiment 1 compared switch costs in the task span procedure with switch costs in the explicit task-cuing procedure, which presented cues indicating the task to perform on each target. Switch costs were greater in the task span procedure. Experiments 2-4 were designed to identify the sources of this difference. Experiment 2 showed that the requirement of establishing a correspondence between the list of task names and the list of targets contributed to switch costs. Experiment 3 showed that retaining lists of similar task names produced greater switch costs than did retaining lists of dissimilar task names. Experiment 4 showed that memory load had no effect on switch costs. The results are discussed in terms of the interaction between plan-level and task-level processing in the implementation of plans.     

Repetition blindness has a perceptual locus: evidence from online processing of targets in RSVP streams

Four experiments tested whether repetition blindness (RB; reduced accuracy reporting repetitions of briefly displayed items) is a perceptual or a memory-recall phenomenon. RB was measured in rapid serial visual presentation (RSVP) streams, with the task altered to reduce memory demands. In Experiment 1 only the number of targets (1 vs. 2) was reported, eliminating the need to remember target identities. Experiment 2 segregated repeated and nonrepeated targets into separate blocks to reduce bias against repeated targets. Experiments 3 and 4 required immediate "online" buttonpress responses to targets as they occurred. All 4 experiments showed very strong RB. Furthermore, the online response data showed clearly that the 2nd of the repeated targets is the one missed. The present results show that in the RSVP paradigm, RB occurs online during initial stimulus encoding and decision making. The authors argue that RB is indeed a perceptual phenomenon.     

Repetition blindness: out of sight or out of mind?

Does repetition blindness represent a failure of perception or of memory? In Experiment 1, participants viewed rapid serial visual presentation (RSVP) sentences. When critical words (C1 and C2) were orthographically similar, C2 was frequently omitted from serial report; however, repetition priming for C2 on a postsentence lexical decision task was equivalent whether or not C1 was similar to C2. In Experiment 2, participants monitored RSVP sentences for a predetermined target. Participants frequently failed to detect the target when it was preceded by an orthographically similar word. In Experiment 3, the authors investigated the role of the attentional blink in this effect. These experiments suggest that repetition blindness is a failure of conscious perception, consistent with predictions of the token-individuation hypothesis.     

Stage 2 processing and the divided-attention effect

In two experiments subjects performed a choice-reaction-time (CRT) task and a second task concurrently. The second task was a simple reaction-time task in Experiment 1 and sentence generation and recall tasks in Experiment 2. Both studies yielded two main findings: Performance of the second task was not affected by CRT memory load (one, two, or four items), and the requirement to perform the second task did not affect the rate of increase of CRT with memory load. The first finding indicates that the effect of memory load on CRT is attributable to memory scanning, or Stage 2 processing, and is not an artifact of the rehearsal demands of the CRT memory set. The second finding indicates that Stage 2 processing is not sensitive to division of attention between the CRT and a second task.     

视觉工作记忆负载类型对注意选择的影响

通过操纵Flanker任务相对于视觉工作记忆任务的呈现位置, 探讨在视觉工作记忆编码和保持阶段, 精度负载和容量负载对注意选择的影响。行为结果发现, Flanker任务呈现位置和视觉工作记忆负载类型影响注意选择; ERP结果发现, 在保持阶段, 当搜索目标和干扰项不一致时, 负载类型影响N2成分。研究表明, 在编码阶段, 视觉工作记忆负载主要通过占用更多知觉资源降低干扰效应, 支持知觉负载理论; 而在保持阶段, 当Flanker任务位于记忆项内部时, 两类负载在工作记忆表征过程中不同的神经活动导致投入到注意选择的认知控制资源不同, 可能是两类负载影响保持阶段注意选择的机制。     

Priming effects in attentional gating

Three experiments were conducted to determine the effects of amount of prior target information (Experiment 1) and semantic priming (Experiment 2) in an attentional gating task. The goal was to determine some causes of the processing deficits commonly observed in perceiving successive visual stimuli. Items in a rapid serial visual presentation (RSVP) stream are subject to processing deficits before they are processed to the level of recognition (early selection) and after they have been recognized (late selection). Deficits in the former case presumably are due to an early filter that prevents complete recognition and semantic analysis, whereas deficits in the latter case arise from interference or response competition, producing forgetting among a set of recognized items. The semantic-priming effects found between a cue and a target (Experiment 2) and between two successive targets (Experiment 3) indicate that top-down processes can increase the subjective availability of related items. The results are consistent with the idea that most processing deficits observed in search through an RSVP sequence are due to limited capacity in our ability to form episodic representations of all the items in the sequence.     

Attentional blink for acronyms: Effects of familiarity and pre‐exposure

Seventy‐two university students participated in one of two experiments in the rapid serial visual presentation (RSVP) task. Distractors were four‐letter non‐words, the first target (T1) was a four‐letter word, and the second target (T2) was a two‐four‐letter acronym that followed T1 at lags of 2, 3 and 5 items (Experiment 1) or lags of 3 and 5 items (Experiment 2). Familiar acronyms were identified better than unfamiliar acronyms. One pre‐exposure of acronyms in a rating task improved RSVP accuracy for familiar acronyms only (Experiments 1 and 2), whereas three pre‐exposures produced a benefit for unfamiliar acronyms and no significant additional benefit for familiar acronyms (Experiment 2). Thus a pre‐existing unitised memory representation, and a relatively recent access of this representation, enhanced target identification. The effects of pre‐exposure were more consistent with resource depletion than attentional filtering accounts of the attentional blink.     

Processing resource capacity and the comprehension of garden path sentences

Three experiments explored the relationship between verbal working memory capacity and the comprehension of garden path sentences. In Experiment 1, subjects with high, medium, and low working memory spans made acceptability judgments about garden path and control sentences under whole sentence and rapid serial visual presentation (RSVP) conditions. There were no significant differences between subjects with different working memory spans in the comprehension of garden path sentences in either condition. In Experiments 2A and 2B, subjects with high and low working memory spans were tested on the same materials at three RSVP rates. There were no significant differences between subjects with different working memory spans in the magnitude of the effect of garden path sentences at any presentation rate. The results suggest that working memory capacity, as measured by the Daneman and Carpenter (1980) reading span task, is not a major determinant of individual differences in the processing of garden path sentences.     

加工焦点性和任务负荷对不同认知方式大学生前瞻记忆的影响

采用双任务范式,探讨了加工焦点性和进行中任务负荷对不同认知方式大学生前瞻记忆的影响。包括两个实验:实验一探讨进行中任务与前瞻记忆任务加工的焦点性和加工类型的一致性对不同认知方式大学生前瞻记忆的影响;实验二探讨进行中任务负荷对不同认知方式大学生在在焦点加工和非焦点加工条件下前瞻记忆的影响。结果显示:焦点加工条件下的前瞻记忆成绩高于非焦点加工,且不受进行中任务负荷的影响;不管进行中任务与前瞻记忆任务的加工类型是否一致,在进行中任务负荷较高且非焦点加工条件下,场独立大学生的前瞻记忆成绩高于场依存大学生。本研究结果支持多重加工理论。     

Prospective Memory and Divided Attention

In three experiments, we manipulated the processing demands of a concurrent task to test the hypothesis that an event-based prospective memory task satisfies a criterion of automaticity proposed by Hasher and Zacks (1979). As in the previous studies, a prospective memory task (pressing a key whenever a target word was presented) was embedded within a short-term memory task (remembering seven words). In addition, participants performed a concurrent memory task which varied in difficulty. Participants repeated either 0 to 6 randomly generated digits or a single word. In all three experiments, short-term memory performance was influenced by the concurrent memory load. Prospective performance, in contrast, was not affected by the memory load even though an attempt was made to increase the difficulty of the prospective task by manipulating the specificity of the target instructions (Experiment 2) and the number of target words (Experiments 2 and 3). The results are discussed within the framework of automatic processing.     

Short-term memory and the attentional blink: Capacity versus content

When people monitor the rapid serial visual presentation (RSVP) of stimuli for two targets (T1 and T2), they often miss T2 if it falls into a time window of about half a second after T1 onset, a phenomenon known as the attentional blink (AB). We found that overall performance in an RSVP task was impaired by a concurrent short-term memory (STM) task and, furthermore, that this effect increased when STM load was higher and when its content was more task relevant. Loading visually defined stimuli and adding articulatory suppression further impaired performance on the RSVP task, but the size of the AB over time (i.e., T1-T2 lag) remained unaffected by load or content. This suggested that at least part of the performance in an RSVP task reflects interference between competing codes within STM, as interference models have held, whereas the AB proper reflects capacity limitations in the transfer to STM, as consolidation models have claimed.     

Is the interference between memory processing and timing specific to the use of verbal material?

Increasing load in a memory task performed simultaneously with a timing task shortens perceived time, an effect that has been observed previously with memory tasks using verbal material. The present experiments examine whether two similar memory tasks, one in which verbal material is used and another one in which nonverbal material is used, would produce similar interference effects on concurrent time reproduction. In Experiment 1, the number of nonverbal stimuli (pseudo‐random dot patterns) was manipulated in a memory task performed while a temporal interval to be reproduced was encoded. Reproductions shortened proportionally to the duration of memory processing executed during time estimation. Verbal stimuli (consonants) were used in Experiment 2 in otherwise identical experimental conditions. Effects observed in Experiment 2 were comparable to those obtained in Experiment 1. Taken together, these results support the notion that interference from memory tasks on concurrent time estimation is not determined by the specific type of material processed in memory, but instead by the duration of memory processing.     

Is the interference between memory processing and timing specific to the use of verbal material?

Increasing load in a memory task performed simultaneously with a timing task shortens perceived time, an effect that has been observed previously with memory tasks using verbal material. The present experiments examine whether two similar memory tasks, one in which verbal material is used and another one in which nonverbal material is used, would produce similar interference effects on concurrent time reproduction. In Experiment 1, the number of nonverbal stimuli (pseudo-random dot patterns) was manipulated in a memory task performed while a temporal interval to be reproduced was encoded. Reproductions shortened proportionally to the duration of memory processing executed during time estimation. Verbal stimuli (consonants) were used in Experiment 2 in otherwise identical experimental conditions. Effects observed in Experiment 2 were comparable to those obtained in Experiment 1. Taken together, these results support the notion that interference from memory tasks on concurrent time estimation is not determined by the specific type of material processed in memory, but instead by the duration of memory processing.     

Target enhancement and distractor inhibition affect transitory surround suppression in dual tasks using multiple rapid serial visual presentation streams

Few studies have investigated the interaction between temporal and spatial dimensions on selective attention using dual tasks in the multiple rapid serial visual presentation (RSVP) paradigm. A phenomenon that the surround suppression in space changes over time (termed transitory surround suppression, TSS, in the present study) has been observed, suggesting the existence of this time–space interaction. However, it is still unclear whether target enhancement or distractor inhibition modulates TSS. Four behavioural experiments were conducted to investigate the mechanism of TSS by manipulating the temporal lag and spatial distance factors between two targets embedded in six RSVP streams. The TSS effect was replicated in a study that eliminated confounds of perceptual effects and attentional switch (Experiment 1). However, the TSS disappeared when two targets shared the same colour in a between-subjects design (Experiment 2a) and a within-subject design (Experiment 2b), suggesting the impact of target enhancement on TSS. Moreover, the TSS was larger for within-category than for between-category distractors (Experiment 3), indicating the impact of distractor inhibition on TSS. These two influences on TSS under different processing demands of target and distractor processing were further confirmed in a skeletal design (Experiment 4). Overall, combinative effects of target enhancement and distractor suppression contribute to the mechanisms of time–space interaction in selective attention during visual search.     

On the nature of the span of apprehension

Summary Typically, people can only report about four or five items from a briefly presented array of alphanumeric items. A new span task was used to explore the basis of this limitation. In Experiment l, performance suffered when very brief display durations were combined with a verbal-load task, but no significant effects of display duration were found when there was no verbal load. In Experiment 2, a similar interaction was observed between verbal load and the presence of a visual suffix; performance was worse in the verbal-load condition with a visual suffix, but no such effect was observed without verbal load. In both experiments, poorer performance was associated with enhanced serial-position effects. The results can be explained on the assumption that the verbal-load task required some processing resources, and that the quality of information in visual working memory depends on available resources. Thus, both brief-array presentation and the visual suffix degrade the information in visual working memory, but span performance is impaired only when processing resources are relatively scarce.     

Short-term consolidation of individual identities leads to Lag-1 sparing

A rapid serial visual presentation (RSVP) technique was used to investigate the role of the nature of processing carried out on targets in the Lag-1 sparing phenomenon. Lag-1 sparing refers to a higher accuracy in the task associated with the 2nd target when the 2 targets are immediately successive in the RSVP stream relative to when there are 1 or 2 intervening items between the targets. In 5 experiments, 0, 1, or 2 digits were embedded with equal probability in RSVP streams of letter distractors. In 4 of the experiments, subjects identified the digits in some blocks of trials, and they counted the number of presented digits in other blocks. In a 5th experiment, the counting task was replaced with a digit-sum task. The most interesting results were those from trials with 2 digits. Lag-1 sparing was always evident when the task involved the explicit identification of the digits. In addition, Lag-1 sparing was evident when subjects were required to sum 2 digits or to count digits of a prespecified parity subclass (e.g., count only even digits). In striking contrast, Lag-1 sparing was absent when subjects were required to count the digits independent of their parity subclass. These results suggest that the occurrence of Lag-1 sparing depends on the type of mental representation that must be generated on the basis of target information.     

Functional visual field in a rapid serial visual presentation task

Dynamic temporal change in the size of functional visual field was measured using a dual task: a peripheral task in which one square in a background pattern of squares was changed in shape to a dot; and a central task involving the rapid serial visual presentation of a sequence of letters (RSVP task). The temporal lag between the occurrences of the dot and the RSVP target was manipulated. University students were asked to detect the dot and to depress a mouse button as quickly as possible while searching for the RSVP target among a sequence of distracter letters. The abrupt change in the shape of a background square in the peripheral task caused a processing deficit in the RSVP task at relative lags from –3 to –1 (255 ms to 85 ms before presentation of the RSVP target), but the encoding and retaining processes involved in identifying the RSVP target did not impair the detection of the peripheral dot. The functional visual field was found to expand while participants were performing the dual task, suggesting that preattentive detection is affected by general attentional activity.