Perceptual Processing is Not Spared During the Attentional Blink

It's time for attentional control: Temporal expectation in the attentional blink

The attentional blink (AB) reveals a limitation in conscious processing of sequential targets. Although it is widely held that the AB derives from a structural bottleneck of central capacity, how the central processing is constrained is still unclear. As the AB reflects the dilemma of deploying attentional resources in the time dimension, research on temporal allocation provides an important avenue for understanding the mechanism. Here we reviewed studies regarding the role of temporal expectation in modulating the AB performance primarily based on two temporal processing strategies: interval-based and rhythm-based timings. We showed that both temporal expectations can help to organize limited resources among multiple attentional episodes, thereby mitigating the AB effect. As it turns out, scrutinizing on the AB from a temporal perspective is a promising way to comprehend the mechanisms behind the AB and conscious cognition. We also highlighted some unresolved issues and discussed potential directions for future research.

Electrophysiological Chronometry of Graded Consciousness during the Attentional Blink

One of the ongoing debates about visual consciousness is whether it can be considered as an all-or-none or a graded phenomenon. While there is increasing evidence for the existence of graded states of conscious awareness based on paradigms such as visual masking, only little and mixed evidence is available for the attentional blink paradigm, specifically in regard to electrophysiological measures. Thereby, the all-or-none pattern reported in some attentional blink studies might have originated from specifics of the experimental design, suggesting the need to examine the generalizability of results. In the present event-related potential (ERP) study (N = 32), visual awareness of T2 face targets was assessed via subjective visibility ratings on a perceptual awareness scale in combination with ERPs time-locked to T2 onset (components P1, N1, N2, and P3). Furthermore, a classification task preceding visibility ratings allowed to track task performance. The behavioral results indicate a graded rather than an all-or-none pattern of visual awareness. Corresponding graded differences in the N1, N2, and P3 components were observed for the comparison of visibility levels. These findings suggest that conscious perception during the attentional blink can occur in a graded fashion.

What processes are disrupted during the attentional blink? An integrative review of event-related potential research

Reporting the second of two targets is impaired when these appear in close succession, a phenomenon known as the attentional blink (AB). Despite decades of research, what factors limit our ability to process multiple sequentially presented events remains unclear. Specifically, two central issues remain open: does failure to report the second target (T2) reflect a structural limitation in working memory (WM) encoding or a disruption to attentional processes? And is perceptual processing of the stimulus that we fail to report impaired, or only processes that occur after this stimulus is identified? We address these questions by reviewing event-related potential (ERP) studies of the AB, after providing a brief overview of the theoretical landscape relevant to these debates and clarifying key concepts essential for interpreting ERP studies. We show that failure to report the second target is most often associated with disrupted attentional engagement (associated with a smaller and delayed N2pc component). This disruption occurs after early processing of T2 (associated with an intact P1 component), weakens its semantic processing (typically associated with a smaller N400 component), and prevents its encoding into WM (associated with absent P3b). However, failure to encode T2 in WM can occur despite intact attentional engagement and semantic processing. We conclude that the AB phenomenon, which reflects our limited ability to process sequential events, emerges from the disruption of both attentional engagement and WM encoding.

Searching for emotional salience

In the emotion induced blindness (EIB) paradigm, participants search for a single target picture embedded in a rapidly presented sequence of "background" pictures. When the sequence also contains a task-irrelevant, emotional distractor appearing shortly before the target, awareness for the target is severely impaired (Most, Chun, Widders, & Zald, 2005). This temporary "blindness" for the target is thought to reflect attention capture by the emotionally salient distractor which blocks the target's access to the attention system. However, there are also reasons to suspect that physical salience may play an important role in the initial attention capture process. The emotional pictures consist of close-ups of people and animals while the background pictures are wide-angle views of landscapes and cityscapes. These physical differences might result in pop-out of the distractor picture that is at least partially based on physical and not emotional salience. We investigated the role of physical salience in emotional capture by comparing the typical EIB paradigm, which uses dissimilar distractors, with one in which the background pictures consist of people and animals in non-emotional settings (similar distractors). If emotional salience is the basis of attention capture in EIB, we should see similar amounts of target suppression in both conditions. Instead, we found that the EIB effect was reduced and possibly eliminated in the similar background condition. A control experiment revealed that emotional information was still available in the similar background condition because the blink was restored when the emotional picture was designated for report by a salient cue. These findings are clearly inconsistent with current theories of EIB (e.g., McHugo, Olatunji, & Zald, 2013) which assume that initial attention capture is driven by emotional not physical salience.