Lag-1 Sparing Research Articles

Total sleep deprivation effects on the attentional blink.

The Attentional Blink (AB) is a phenomenon that reflects difficulty in detecting or identifying the second of two successive targets (T1 and T2) that are presented in rapid succession, between 200-500ms apart. The AB involves indicators of attentional and temporal integration mechanisms related to the early stages of visual processing. The aim of this study was to identify the effects of 24-h of sleep deprivation (total sleep deprivation, TSD) on the attentional and temporal integration mechanisms of the AB. Twenty-two undergraduate students were recorded during five successive days, in these three conditions: baseline (two days), TSD (one day), and recovery (two days). Each day, at around 12:00h, participants responded to a Rapid Serial Visual Presentation task (RSVP) that presented two targets separated by random intervals from 100 to 1000ms. The attentional mechanisms were assessed by the AB presence, the AB magnitude, and the AB interval, while the temporal integration mechanisms were evaluated by lag-1 sparing and order reversal responses. TSD negatively affected the attentional mechanisms, which is expressed by an overall reduction in performance, an extended AB interval, and a reduced AB magnitude. TSD also negatively affected the temporal integration mechanisms, manifested by an absence of lag-1 sparing and an increase in order reversals. These results suggest that people are still able to respond to two successive stimuli after 24h without sleep. However, it becomes more difficult to respond to both stimuli because the attentional and temporal integration mechanisms of the AB are impaired.

The temporal cost of deploying attention limits accurate target identification in rapid serial visual presentation

Lag-1 sparing is a common exception to the attentional blink, where a target presented directly after T1 can be identified and reported accurately. Prior work has proposed potential mechanisms for lag 1 sparing, including the boost and bounce model and the attentional gating model. Here, we apply a rapid serial visual presentation task to investigate the temporal limitations of lag 1 sparing by testing three distinct hypotheses. We found that endogenous engagement of attention to T2 requires between 50 and 100 ms. Critically, faster presentation rates yielded lower T2 performance, whereas decreased image duration did not impair T2 detection and report. These observations were reinforced by subsequent experiments controlling for short-term learning and capacity-dependent visual processing effects. Thus, lag-1 sparing was limited by the intrinsic dynamics of attentional boost engagement rather than by earlier perceptual bottlenecks such as insufficient exposure to images in the stimulus stream or visual processing capacity limitations. Taken together, these findings support the boost and bounce theory over earlier models that focus only on attentional gating or visual short-term memory storage, informing our understanding of how the human visual system deploys attention under challenging temporal constraints.

Modelling the simultaneous encoding/serial experience theory of the perceptual moment: a blink of meta-experience.

One way to understand a system is to explore how its behaviour degrades when it is overloaded. This approach can be applied to understanding conscious perception by presenting stimuli in rapid succession in the ‘same’ perceptual event/moment. In previous work, we have identified a striking dissociation during the perceptual moment, between what is encoded into working memory [Lag-1 sparing in the attentional blink (AB)] and what is consciously perceived (Lag-1 impairing in the experiential blink). This paper links this dissociation to what, taking inspiration from the metacognition literature, could be called meta-experience; i.e. how the ability to track and comment on one’s visual experience with subjectivity ratings reflects objective performance. Specifically, we provide evidence that the information (in bits) associated with an encoding into working memory decouples from the experiential reflection upon that perceptual/encoding event and that this decoupling is largest when there is the greatest perceptual overload. This is the meta-experiential blink. Meta-experiential self-observation is common to many computational models, including connectionist interpretations of consciousness, Bayesian observers and the readout-enhanced simultaneous type/serial token (reSTST) model. We assess how our meta-experiential blink data could be modelled using the concept of self-observation, providing model fits to behavioural and electroencephalogram responses in the reSTST model. We discuss the implications of our computational modelling of parallel encoding but serial experience for theories of conscious perception. Specifically, we (i) inform theories of Lag-1 sparing during the AB and (ii) consider the implications for the global workspace theory of conscious perception and higher-order theories of consciousness.

The number of expected targets modulates access to working memory: A new unified account of lag-1 sparing and distractor intrusions.

In rapid serial visual presentation (RSVP) tasks, failures of attentional selectivity are frequently observed when a single target is followed by a potentially reportable distractor (distractor intrusions). However, in tasks with two targets, accuracy for both targets is typically high when they are presented in immediate succession (lag-1 sparing). To account for this apparent contradiction, we tested whether expectations about the number of targets affects the number of items encoded in working memory (WM). Colored target digits were embedded among gray letters and digits. The first target was followed either by a gray digit, or a second target (another colored digit). To manipulate expectations, the ratio of one-target and two-targets trials (75% to 25% or vice versa) was varied between blocks. Participants were much more likely to report seeing two targets when two targets were expected. Analogous results were obtained in an additional experiment where two successive colored digits appeared on all trials, and participants were instructed to either report both or only the first digit. ERP markers of attentional allocation (N2pc) and WM storage processes (contralateral delayed activity, CDA) were larger when two targets were expected, regardless of the actual number of targets. These results show that the number of expected targets modulates the activation of sensory representations during attentional episodes, which affects the probability that they are subsequently encoded in WM. These findings suggest that a single mechanism can account both for lag-1 sparing and distractor intrusions in RSVP tasks. They also provide new evidence for strategic top-down control over WM encoding. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

A Design of Global Workspace Model with Attention: Simulations of Attentional Blink and Lag-1 Sparing

There are many developed theories and implemented artificial systems in the area of machine consciousness, while none has achieved that. For a possible approach, we are interested in implementing a system by integrating different theories. Along this way, this paper proposes a model based on the global workspace theory and attention mechanism, and providing a fundamental framework for our future work. To examine this model, two experiments are conducted. The first one demonstrates the agent’s ability to shift attention over multiple stimuli, which accounts for the dynamics of conscious content. Another experiment of simulations of attentional blink and lag-1 sparing, which are two well-studied effects in psychology and neuroscience of attention and consciousness, aims to justify the agent’s compatibility with human brains. In summary, the main contributions of this paper are (1) Adaptation of the global workspace framework by separated workspace nodes, reducing unnecessary computation but retaining the potential of global availability; (2) Embedding attention mechanism into the global workspace framework as the competition mechanism for the consciousness access; (3) Proposing a synchronization mechanism in the global workspace for supporting lag-1 sparing effect, retaining the attentional blink effect.

What factors influence the switch from unitary to divided attention?

The focus of attention can be either unitary or divided and can transition from unitary to divided while performing a task. In Experiment 1, we investigated whether alerting hastens the transition from unitary to divided attention. To this end, we employed a dual-RSVP-stream Attentional Blink task (AB; impaired perception of the second of two rapidly sequential targets) with two pairs of letter targets (T1-pair and T2-pair). One component of the AB known as Lag-1 sparing (unimpaired perception of the T2-pair when it is presented directly after the T1-pair) occurs only when the T2-pair falls in an attended location. When the T2-pair falls in an unattended location, the converse pattern occurs (Lag-1 deficit). Accordingly, we used the incidence of Lag-1 sparing/deficit to index whether a location was attended or unattended. We found that presenting a brief brightening flash of the screen (alerting) just before the T1-pair hastened the transition from the initial unitary focus to a divided focus. In Experiment 2, we pitted the hastening account against an alternative hypothesis that the flash triggers phasic activation of the Locus Coeruleus-norepinephrine neuromodulatory system, thus resetting the underlying neural networks that mediate the distribution of attention, triggering a switch from unitary to divided attention. The results of Experiment 2 were incompatible with the hastening account, but consistent with the network-reset account.

Representational dynamics preceding conscious access

Our senses are continuously bombarded with more information than our brain can process up to the level of awareness. The present study aimed to enhance understanding on how attentional selection shapes conscious access under conditions of rapidly changing input. Using an attention task, EEG, and multivariate decoding of individual target- and distractor-defining features, we specifically examined dynamic changes in the representation of targets and distractors as a function of conscious access and the task-relevance (target or distractor) of the preceding item in the RSVP stream. At the behavioral level, replicating previous work and suggestive of a flexible gating mechanism, we found a significant impairment in conscious access to targets (T2) that were preceded by a target (T1) followed by one or two distractors (i.e., the attentional blink), but striking facilitation of conscious access to targets shown directly after another target (i.e., lag-1 sparing and blink reversal). At the neural level, conscious access to T2 was associated with enhanced early- and late-stage T1 representations and enhanced late-stage D1 representations, and interestingly, could be predicted based on the pattern of EEG activation well before T1 was presented. Yet, across task conditions, we did not find convincing evidence for the notion that conscious access is affected by rapid top-down selection-related modulations of the strength of early sensory representations induced by the preceding visual event. These results cannot easily be explained by existing accounts of how attentional selection shapes conscious access under rapidly changing input conditions, and have important implications for theories of the attentional blink and consciousness more generally.

Mindful non-reactivity is associated with improved accuracy in attentional blink testing: A randomized controlled trial

Practitioners with years of mindfulness training (MT) have a reduced attentional blink (AB), relative to novices and non-practitioners. There is still a lack of evidence regarding the impact of relatively short-term intensive traditional MT on AB. Moreover, it is unknown which component(s) of mindfulness underlie mindfulness-associated reductions in AB. Eighty-nine Chinese subjects were randomized into a MT group (N = 44) and a control (CON) group (N = 45). The participants in the CON group were waitlisted for the opportunity to participate in the training program during the 8 weeks that the MT group underwent training. Before (pretest) and after (posttest) the MT program, the subjects completed the Five-Facet Mindfulness Questionnaire (FFMQ), Peace-of-mind questionnaire (POM), and an AB task. Ultimately, 73 participants (MT group/CON group: 35/38) completed the study. From the pretest to the posttest, the MT group exhibited increases in FFMQ scores (total scores, observing subscores, and non-reactivity subscores) and POM scores, as well as improved accuracy in the AB task and a reduction in the lag-1 sparing effect. Increases in T2 accuracy in the AB correlated with improved non-reactivity. These findings broaden our understanding of the association between mindfulness and AB, and support the supposition that the skill of mindful non-reactivity plays an important role in reducing AB.

Supplemental Material for The Number of Expected Targets Modulates Access to Working Memory: A New Unified Account of Lag-1 Sparing and Distractor Intrusions

Supplemental Material for The Number of Expected Targets Modulates Access to Working Memory: A New Unified Account of Lag-1 Sparing and Distractor Intrusions

Two replications of Raymond, Shapiro, and Arnell (1992), The Attentional Blink

In order to improve the trustworthiness of our science, several new research practices have been suggested, including preregistration, large statistical power, availability of research data and materials, new statistical standards, and the replication of experiments. We conducted a replication project on an original phenomenon that was discovered more than 25 years ago, namely the attentional blink (Raymond, Shapiro, & Arnell, Human Perception and Performance, 18(3), 849–860, 1992), which has been conceptually replicated hundreds of times with major variations. Here, we ran two identical experiments, adopting the new practices and closely reproducing the original experiment. The two experiments were run by different research groups in different countries and laboratories with different participants. Experiment 1 shared remarkable similarities (in magnitude and duration of the effect) with the original study, but also some differences (the overall accuracy of participants, the timing of the effect, and lag-1 sparing). Experts interviewed to evaluate our results stressed the similarities rather than the differences. Experiment 2 replicated nearly identically the results observed in Experiment 1. These findings show that the adoption of new research practices improves the replicability of experimental research and opens the door for a quantitative and direct comparison of the results collected across different laboratories and countries.

Categorical similarity modulates temporal integration in the attentional blink.

Attentional blink (AB) speaks to a phenomenon that, when reporting two targets in a rapid serial visual presentation, the second target (T2) is often missed if it followed the first target (T1) within an interval of less than 500 ms. An interesting exception is the preserved performance of T2 at Lag 1 position (Lag-1 sparing), or even in an extended period, which recently has been termed temporal integration. Both T1 and T2 can be successfully reported but with a loss of their temporal order. The integration has been attributed to the temporal distance between the two targets. However, previous studies on temporal perception have revealed that similarity between two stimuli modulated their temporal order judgment, suggesting that temporal integration is affected by stimulus characteristics. In the present study, we investigated whether stimulus characteristics modulated temporal integration in the AB. We manipulated the categorical similarity between T1 and T2 targets and found that the order reversals were significantly higher in the same-category condition than that in the different-category condition. Our results thus provided clear evidence for the contribution of categorical similarity to the temporal integration in the AB.

The attentional blink: why does Lag-1 sparing occur when the dependent measure is accuracy, but Lag-1 deficit when it is RT?

Perception of the second of two targets (T1, T2) displayed in rapid sequence is impaired if it comes shortly after the first (attentional blink, AB). In an exception, known as Lag-1 sparing, T2 is virtually unimpaired if it is presented directly after T1. Three experiments examined the seemingly inconsistent findings that Lag-1 sparing occurs in accuracy but Lag-1 deficit occurs in RT. Experiment 1 pointed to masking of T2 as the critical factor. When T2 was not masked, the results replicated the conventional findings. The novel finding was that Lag-1 sparing occurred in RT, provided that T2 was masked. An account was provided by a psychological refractory period-based model in which processing was said to occur in two broadly sequential stages: stimulus selection and response planning. Experiments 2 and 3 tested predictions from the PRP-based model regarding Lag-1 sparing/Lag-1 deficit. In Experiment 2, we increased T2 salience, notionally reducing the duration of the T2 selection stage, with corresponding reduction in Lag-1 sparing. In Experiment 3, we manipulated the compatibility between the T1 stimulus and the response to notionally decrease/increase the duration of the T1 response-planning stage with corresponding increment/decrement in Lag-1 sparing. The results of both experiments confirmed predictions from the PRP-based model.

First unitary, then divided: the temporal dynamics of dividing attention.

Whether focused visual attention can be divided has been the topic of much investigation, and there is a compelling body of evidence showing that, at least under certain conditions, attention can be divided and deployed as two independent foci. Three experiments were conducted to examine whether attention can be deployed in divided form from the outset, or whether it is first deployed as a unitary focus before being divided. To test this, we adapted the methodology of Jefferies, Enns, and Di Lollo (Journal of Experimental Psychology: Human Perception and Performance 40: 465, 2014), who used a dual-stream Attentional Blink paradigm and two letter-pair targets. One aspect of the AB, Lag-1 sparing, has been shown to occur only if the second target pair appears within the focus of attention. By presenting the second target pair at various spatial locations and assessing the magnitude of Lag-1 sparing, we probed the spatial distribution of attention. By systematically manipulating the stimulus-onset-asynchrony between the targets, we also tracked changes to the spatial distribution of attention over time. The results showed that even under conditions which encourage the division of attention, the attentional focus is first deployed in unitary form before being divided. It is then maintained in divided form only briefly before settling on a single location.

The perceptual wink model of non-switching attentional blink tasks.

The attentional blink (AB) is a temporary deficit for a second target (T2) when that target appears after a first target (T1). Although sophisticated models have been developed to explain the substantial AB literature in isolation, the current study considers how the AB relates to perceptual dynamics more broadly. We show that the time-course of the AB is closely related to the time course of the transition from positive to negative repetition priming effects in perceptual identification. Many AB tasks involve a switch between a T1 defined in one manner and a T2 defined in a different manner. Other AB tasks are non-switching, with all targets belonging to the same well-known category (e.g., letter targets versus number distractors) or sharing the same perceptual feature. We propose that these non-switching AB tasks reflect perceptual habituation for the target-defining attribute; thus, a 'perceptual wink', with perception of one attribute (target identity) undisturbed while perception of another (target detection) is impaired. On this account, the immediate benefit following T1 (lag-1 sparing) reflects positive repetition priming and the subsequent deficit (the blink) reflects negative repetition priming for the realization that a target occurred. In developing the perceptual wink model, we extended the nROUSE model of perceptual priming to explain the results of two new experiments combining the AB and identity repetitions. This establishes important connections between non-switching AB tasks and perceptual dynamics.

First unitary, then divided: The temporal dynamics of dividing attention

Whether focused visual attention can be divided has been the topic of much investigation, and there is a compelling body of evidence showing that, at least under certain conditions, attention can be divided and deployed as two independent foci. Three experiments were conducted to examine whether attention can be deployed in divided form from the outset, or whether it is first deployed as a unitary focus before being divided. To test this, we adapted the methodology of Jefferies, Enns, and Di Lollo (Journal of Experimental Psychology: Human Perception and Performance 40: 465, 2014), who used a dual-stream Attentional Blink paradigm and two letter-pair targets. One aspect of the AB, Lag-1 sparing, has been shown to occur only if the second target pair appears within the focus of attention. By presenting the second target pair at various spatial locations and assessing the magnitude of Lag-1 sparing, we probed the spatial distribution of attention. By systematically manipulating the stimulus-onset-asynchrony between the targets, we also tracked changes to the spatial distribution of attention over time. The results showed that even under conditions which encourage the division of attention, the attentional focus is first deployed in unitary form before being divided. It is then maintained in divided form only briefly before settling on a single location.

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

Lag-1 sparing in accuracy and reaction time: The importance of masking

Lag-1 sparing in accuracy and reaction time: The importance of masking

Reconsidering Temporal Selection in the Attentional Blink

Two episodes of attentional selection cannot occur very close in time. This is the traditional account of the attentional blink, whereby observers fail to report the second of two temporally proximal targets. Recent analyses have challenged this simple account, suggesting that attentional selection during the attentional blink is not only (a) suppressed, but also (b) temporally advanced then delayed, and (c) temporally diffused. Here, we reanalyzed six data sets using mixture modeling of report errors, and revealed much simpler dynamics. Exposing a problem inherent in previous analyses, we found evidence of a second attentional episode only when the second target (T2) follows the first (T1) by more than 100 to 250 ms. When a second episode occurs, suppression and delay reduce steadily as lag increases and temporal precision is stable. At shorter lags, both targets are reported from a single episode, which explains why T2 can escape the attentional blink when it immediately follows T1 (Lag-1 sparing).

Expectancy-based modulations of lag-1 sparing and extended sparing during the attentional blink.

Over 20 years of research has shown that impairments in the identification of sequential targets—known as the attentional blink—are often eliminated when 2 or more targets are presented in direct succession. Such instances of lag-1 sparing and, more recently, extended sparing are widely attributed to the fact that directly successive visual inputs that possess common characteristics can be processed during an extended attentional window. Critically, this explanation implies that direct temporal succession and shared characteristics are sufficient to result in sparing. Here, I test this proposition directly by varying the probability of successive targets appearing during an experimental session. Across 5 experiments, I show that probability manipulations significantly affect the magnitude of sparing, with less sparing when the probability of a target appearing is relatively low. This outcome cannot be explained by resource shifts between targets, errors in perception of target order, or practice effects. Instead, the results suggest that sparing is determined not only by temporal contiguity and shared target characteristics but also by endogenous control processes that directly affect the duration of the attentional window.

On the costs of lag-1 sparing.

The attentional blink (AB) is a dual-target, rapid serial visual presentation (RSVP) deficit thought to represent a failure of perceptual awareness that reflects the dynamics of temporal attention. However, second target (T2) report is typically unimpaired when the targets appear within 150 ms of one another (i.e., lag-1 sparing). In addition, this sparing can be extended if more targets appear sequentially. It is thought that sequential targets are processed in the same attentional window. Here, we investigated the fate of targets processed in these windows and, specifically, the consequence for subsequent targets when an item at lag-1 is reported versus missed. The results demonstrated that target encoding in attentional windows has an all-or-none influence on subsequent item report: When comparing two- and three-target (T1 and T2 not separated by distractors) RSVP streams, there was no difference in AB magnitude for the final target when either T2 or T1 was missed in the three-target condition, but both of these conditions had significantly smaller blinks than those observed when T1 and T2 were accurately reported. A comparison of our results to a computational model of temporal attention demonstrates how structural limitations on the rate of encoding affect perception, even during sparing.