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In contrast to the paradigms used in most laboratory experiments on interval timing, everyday tasks often involve tracking multiple, concurrent intervals without an explicit starting signal. As these characteristics are problematic for most existing clock-based models of interval timing, here we explore an alternative notion that suggests that time perception and working memory encoding might be closely connected. In this integrative model, the consolidation of a new item in working memory initiates cortical oscillations that also signal the onset of a time interval. The objective of this study was to test whether memory consolidation indeed acts as the starting signal of interval timing. Participants performed an attentional blink task in which they not only reported the targets, but also the estimated target onsets, allowing us to calculate estimated lag. In the attentional blink task, the second target (T2) in a rapid serial visual presentation is often not reported when it follows quickly after the first target (T1). However, if this fast T2 is reported, memory consolidation of T2 is presumably delayed. Consequently, if memory consolidation determines interval onset, we would expect a later estimated onset when consolidation is delayed. Furthermore, as the P3 ERP component is assumed to reflect memory consolidation, we expect that the estimated onsets and subjective lag are functions of the P3 latencies. The behavioral data show that the presumed delay in memory consolidation did not lead to later estimated onsets. In addition, the EEG results suggest that there was no relationship between P3 latency and subjective lag or estimated onset. Overall, our results suggest that there is no direct link between the encoding of items in working memory and sub-second interval timing of these items in the attentional blink task. [ABSTRACT FROM AUTHOR]

It remains unclear to date whether spatial attention towards emotional faces is contingent on, or independent of visual awareness. To investigate this question, a bilateral attentional blink paradigm was used in which lateralised fearful faces were presented at various levels of detectability. Twenty-six healthy participants were presented with two rapid serial streams of human faces, while they attempted to detect a pair of target faces (T2) displayed in close or distant succession of a first target pair (T1). Spatial attention shifting to the T2 fearful faces, indexed by the N2-posterior-contralateral component, was dependent on visual awareness and its magnitude covaried with the visual awareness negativity, a neural marker of awareness at the perceptual level. Additionally, information consolidation in working memory, indexed by the sustained posterior contralateral negativity, positively correlated with the level of visual awareness and spatial attention shifting. These findings demonstrate that spatial attention shifting to fearful faces depends on visual awareness, and these early processes are closely linked to information maintenance in working memory. • Spatial attention shifts to fearful faces depended on early perceptual awareness. • Working memory consolidation positively correlated with visual awareness. • Working memory consolidation positively correlated with spatial attention shifts. [ABSTRACT FROM AUTHOR]

Abstract: The attentional blink (AB), characterized as a failure to detect a second target following correct identification of a previous target in a rapid serial visual presentation (RSVP), has become a useful measure for investigation of the temporal dynamics of attention. In our previous work, we proposed a two-stage concurrent inhibition model that attributes AB not only to capacity limitations at the central, working memory but also to the lack of proper inhibitory processes, which depend in part on the integrity of white matter. To test the hypothesis that attentional blink can be influenced by the integrity of the white matter, we investigated AB in patients with multiple sclerosis (MS), where the dominant neuropathology is demyelination-related cortical white matter impairments. We tested 22 MS patients and 22 age-matched controls with RSVP task. MS patients were further examined with standard tests of motor functioning (9 Hole Peg Test—9HPT and 8m walking test) and 2 tests of working memory (Paced Auditory Serial Addition Test—PASAT and Digit Ordering test—DOT). On average, MS patients did not show working memory impairments, but greater and longer AB. Our results thus support the hypothesis that one potential mechanism of attentional impairments in MS could be unreliable inhibitory processes. We propose that in MS inhibitory processes depend on white matter integrity, i.e., functional connectivity between the perceptual and working memory modules. Future research should focus on concurrent measurements of neuroanatomical and attentional features of MS patients to further support our findings. [Copyright &y& Elsevier]

Abstract: The failure to correctly report two targets (“T1”, “T2”) that follow each other in close temporal proximity has been called the “attentional blink” (AB). The AB has, so far, mainly been studied using experimental approaches. The present studies investigated individual differences in AB performance, revealing (among further findings) a high positive correlation between the accuracies of detecting the two targets correctly (r=0.69); and between T2∣T1 accuracy and psychometric intelligence (0.41≤r≤0.43) and RT variability in short-term and working memory (−0.38≤r≤−0.45). Together, these results support important aspects of major theoretical accounts of the AB from an individual differences perspective and introduce intelligence and intra-subject stability as contributing factors in AB performance. [ABSTRACT FROM AUTHOR]

Abstract: The Attentional Blink (AB) – a deficit in reporting the second of two target stimuli presented in close succession in a rapid sequence of distracters – has been related to individual processing limitations of working memory. Given the known role of dopamine (DA) in working memory processes, the present experiment tested the hypothesis that DA, and in particular the DA/D1 subsystem, plays a role in the AB. We present evidence that the spontaneous eyeblink rate (EBR), a functional marker of central dopaminergic function, reliably predicts the size of AB. Thus, in line with our hypothesis, these data point to a modulatory role for DA in the AB. [Copyright &y& Elsevier]

Primary cognitive processes, such as spatial attention, are essential to our higher cognitive abilities and develop dramatically in the first year of life. The spatial aspect of infants' working memory is equivalent to that of adults. However, it is unclear whether this is true for the temporal domain. Thus, we investigated the temporal aspect of infants' working memory using an attentionally demanding task by focusing on the attentional blink effect, in which the identification of the second of the two brief targets is impaired when inter-target lags are short. We argue that finding a similar pattern of the attentional blink in preverbal infants and adults indicates that infants can complete the consolidation of the first target into working memory at a similar temporal scale as adults. In this experiment, we presented 7- to 8-month-old infants with rapid serial visual streams at a rate of 100 ms/item, including two female faces as targets, and examined whether they could identify the targets by measuring their preference to novel faces compared to targets. The temporal separation between the two targets was 200 or 800 ms. We found that the infants could identify both targets under the longer lag, but they failed to identify the second target under the shorter lag. The adult experiment using the same temporal separation as in the infant experiment revealed the attentional blink effect. These results suggest that 7- to 8-month-old infants can consolidate two items into working memory by 800 ms but not by 200 ms. [ABSTRACT FROM AUTHOR]

Abstract: Temporal visual working memory (VWM) biases in spider anxiety were studied with an Attentional Blink paradigm. In Experiment 1, participants viewed pictures sequentially presented at rates of 80ms and were instructed to memorize two target pictures. We varied time between targets and valence of the second target (neutral: mushroom, positive: blossom, negative: spider). In Experiment 2, spider fearfuls and non-anxious controls (both without snake anxiety) participated. Here we tested two negative targets: disorder-related spiders and disorder-irrelevant snakes. Both positive and negative items were memorized more successfully than neutral targets. Spiders were preferentially recalled by spider fearfuls compared to non-anxious controls, implying temporal VWM biases in spider anxiety. This advantage for threat was not related to a disruption of the encoding of non-threatening targets presented before the threat item. [Copyright &y& Elsevier]

Abstract: In order to investigate the interplay between visuo-spatial attention and central attention, we varied the relative probability (25% vs. 75%) of the responses to lateralized targets in an attentional blink paradigm. When the first target was associated with a less probable response, we observed a larger attentional blink, that is, a general reduction in accuracy for the second target. The efficiency of deployment of spatial attention to the second target was also reduced as a function of the response frequency for the first target. Both the N2pc, an event-related potential (ERP) associated with the deployment of attention in visual space, and the SPCN (sustained posterior contralateral negativity), an ERP associated with the maintenance of information in visual short-term memory, time-locked to T2 were significantly reduced when the first target was associated with a less frequent response. Furthermore, the P3 ERP to T2 was abolished when the response to T1 was rare but not when it was frequent. 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. [Copyright &y& Elsevier]

Abstract: In the attentional blink [], the second of two targets in a Rapid Serial Visual Presentation (RSVP) stream is difficult to detect and identify when it is presented soon but not immediately after the first target. We varied the Stimulus Onset Asynchrony (SOA) of the items in the stream and the color of the targets (red from gray or vice versa), and looked at the responses to the second target. Exact responses to the second target (zero positional error) showed a typical attentional blink profile, with a drop in performance for an interval of 200–500ms after the first target. Approximate responses (positional error no greater than 3 frames) showed no such drop in performance, although results were still dependent on color (better for red) and increased with increasing SOA. These findings are consistent with a two-stage model of visual working memory, where encoding of the first target disrupts attention to (and temporal binding of) the second target. We suggest that this disruption occurs within a certain time (≈0.5s) after the first target, during which period salient distractors are as likely as the second target to enter working memory. [Copyright &y& Elsevier]

Abstract: Two experiments were conducted to investigate the relation between the attentional blink (AB), a deficit in reporting the second of two targets when it occurs 200–500ms after the first, and the P3 component of the event-related potential. Consistent with the view that the AB reflects a limited ability to consolidate information in working memory and that the P3 reflects working memory updating, increasing the amplitude of the P3 elicited by a first target (T1) by varying T1 probability (Experiment 1) or T1 cue validity (Experiment 2) led to an increase of the AB. Overall, the P3 elicited by T1 was greater when T2 was not identified than when it was. However, the correlation between P3 and AB magnitude across participants was not significant, leaving open the question of how direct the relationship between the P3 and the AB is. [Copyright &y& Elsevier]

Abstract: Schizophrenia patients exhibit numerous deficits on visual processing tasks, ranging from very early stages of visual processing (e.g., backward masking) to the later working memory stages (e.g., delayed match-to-sample, N-back). However, little is known about deficits in an intermediate stage of visual information processing, namely short term visual memory (STVM). The attentional blink (AB) paradigm is considered to be a valid way to assess the STVM, and recent studies have reported AB deficits in schizophrenia. However, it is not clear whether the reported AB deficit in schizophrenia patients is due to their increased susceptibility to backward masking or increased vulnerability in the STVM. In this study we first found poorer performance in the AB task in 37 schizophrenia patients compared to 26 normal controls. To examine the effects of increasing and decreasing mask strength on AB performance in patients and controls, we next systematically varied the masking effect by varying the length of the distracters immediately following the targets. The manipulation had relatively little effect on the patient – control differences and patients continued to show an enhanced AB effect across conditions. The findings suggest that the enhanced AB effect in schizophrenia reflects an abnormality in their short term visual memory, as opposed to their enhanced susceptibility to visual masking. [Copyright &y& Elsevier]

Abstract: The present report reviews behavioural, electroencephalographic, and especially magnetoencephalographic findings on the cortical mechanisms underlying attentional processes that separate targets from distractors and that ensure durable target representations for goal-directed action. A common way of investigation is to observe the system’s overt and covert behaviour when capacity limitations are reached. Here we focus on the aspect of temporally enhanced processing load, namely on performance deficits occurring under rapid-serial-visual-presentation (RSVP) conditions. The most prominent of these deficits is the so-called “attentional blink” (AB) effect. We first report MEG findings with respect to the time course of activation that shows modulations around 300ms after target onset which reflect demands and success of target consolidation. Then, findings regarding long-range inter-area phase synchronization are reported that are hypothesized to mediate communication within the attentional network. Changes in synchronization reflect changes in the attentional demands of the task and are directly related to behavioural performance. Furthermore, enhanced vigilance of the system elicits systematically increased synchronization indices. A hypothetical framework is sketched out that aims at explaining limitations in multiple target consolidation under RSVP conditions. [Copyright &y& Elsevier]