Irrelevant auditory and visual events induce a visual attentional blink

Attention Limitations in the Detection and Identification of Alarms in Close Temporal Proximity

OBJECTIVE

The aim of this study was to establish the effects of simultaneous and asynchronous masking on the detection and identification of visual and auditory alarms in close temporal proximity.

BACKGROUND

In complex and highly coupled systems, malfunctions can trigger numerous alarms within a short period of time. During such alarm floods, operators may fail to detect and identify alarms due to asynchronous and simultaneous masking. To date, the effects of masking on detection and identification have been studied almost exclusively for two alarms during single-task performance. This research examines 1) how masking affects alarm detection and identification in multitask environments and 2) whether those effects increase as a function of the number of alarms.

METHOD

Two experiments were conducted using a simulation of a drone-based package delivery service. Participants were required to ensure package delivery and respond to visual and auditory alarms associated with eight drones. The alarms were presented at various stimulus onset asynchronies (SOAs). The dependent measures included alarm detection rate, identification accuracy, and response time.

RESULTS

Masking was observed intramodally and cross-modally for visual and auditory alarms. The SOAs at which asynchronous masking occurred were longer than reported in basic research on masking. The effects of asynchronous and, even more so, simultaneous masking became stronger as the number of alarms increased.

CONCLUSION

Masking can lead to breakdowns in the detection and identification of alarms in close temporal proximity in complex data-rich domains.

APPLICATION

The findings from this research provide guidance for the design of alarm systems.

The modulation of expectation violation on attention: Evidence from the spatial cueing effects

The study sought to investigate whether and how expectation violation can modulate attention using the exogenous spatial cueing paradigm, under the theoretical framework of the Memory Encoding Cost (MEC) model. The MEC proposes that exogenous spatial cueing effects are mainly driven by a combination of two distinct mechanisms: attentional facilitation triggered by the presence of an abrupt cue, and attentional suppression induced by memory encoding of the cue. In current experiments, participants needed to identify a target letter that was sometimes preceded by a peripheral onset cue. Various types of expectation violation were introduced by regulating the probability of cue presentation (Experiments 1 & 5), the probability of cue location (Experiments 2 & 4), and the probability of irrelevant sound presentation (Experiment 3). The results showed that expectation violation could enhance the cueing effect (valid vs. invalid cue) in some cases. More crucially, all experiments consistently observed asymmetrical modulation of expectation violation on the cost (invalid vs. neutral cue) and benefit (valid vs. neutral cue) effects: Expectation violation increased the cost effects while did not modulate or decreased (or even reversed) the benefit effects. Furthermore, Experiment 5 provided direct evidence that violation of expectations could enhance the memory encoding of a cue (e.g., color) and this memory advantage could manifest quickly in the early stages of the experiment. The MEC better explains these findings than some traditional models like the spotlight: Expectation violation can both enhance the attentional facilitation of the cue and memory encoding of irrelevant cue information. These findings suggest that expectation violation has a general adaptive function in modulating the attention selectivity.

An online browser-based attentional blink replication using visual objects

The complex relationship between attention and visual perception can be exemplified and investigated through the Attentional Blink. The attentional blink is characterised by impaired attention to the second of two target stimuli, when both occur within 200 - 500ms. The attentional blink has been well studied in experimental lab settings. However, despite the rise of online methods for behavioural research, their suitability for studying the attentional blink has not been fully addressed yet, the main concern being the lack of control and timing variability for stimulus presentation. Here, we investigated the suitability of online testing for studying the attentional blink with visual objects. Our results show a clear attentional blink effect between 200 to 400ms following the distractor including a Lag 1 sparing effect in line with previous research despite significant inter-subject and timing variability. This work demonstrates the suitability of online methods for studying the attentional blink with visual objects, opening new avenues to explore its underlying processes.

Selective memory disrupted in intra-modal dual-task encoding conditions

Given natural memory limitations, people can generally attend to and remember high-value over low-value information even when cognitive resources are depleted in older age and under divided attention during encoding, representing an important form of cognitive control. In the current study, we examined whether tasks requiring overlapping processing resources may impair the ability to selectively encode information in dual-task conditions. Participants in the divided-attention conditions of Experiment 1 completed auditory tone-distractor tasks that required them to discriminate between tones of different pitches (audio-nonspatial) or auditory channels (audio-spatial), while studying items in different locations in a grid (visual-spatial) differing in reward value. Results indicated that, while reducing overall memory accuracy, neither cross-modal auditory distractor task influenced participants' ability to selectively encode high-value items relative to a full attention condition, suggesting maintained cognitive control. Participants in Experiment 2 studied the same important visual-spatial information while completing demanding color (visual-nonspatial) or pattern (visual-spatial) discrimination tasks during study. While the cross-modal visual-nonspatial task did not influence memory selectivity, the intra-modal visual-spatial secondary task eliminated participants' sensitivity to item value. These results add novel evidence of conditions of impaired cognitive control, suggesting that the effectiveness of top-down, selective encoding processes is attenuated when concurrent tasks rely on overlapping processing resources.

The Attentional Blink is Related to the Microsaccade Rate Signature

The reduced detectability of a target T2 following discrimination of a preceding target T1 in the attentional blink (AB) paradigm is classically interpreted as a consequence of reduced attention to T2 due to attentional allocation to T1. Here, we investigated whether AB was related to changes in microsaccade rate (MSR). We found a pronounced MSR signature following T1 onset, characterized by MSR suppression from 200 to 328 ms and enhancement from 380 to 568 ms. Across participants, the magnitude of the MSR suppression correlated with the AB effect such that low T2 detectability corresponded to reduced MSR. However, in the same task, T1 error trials coincided with the presence of microsaccades. We discuss this apparent paradox in terms of known neurophysiological correlates of MS whereby cortical excitability is suppressed both during the microsaccade and MSR suppression, in accordance to poor T1 performance with microsaccade occurrence and poor T2 performance with microsaccade absence. Our data suggest a novel low-level mechanism contributing to AB characterized by reduced MSR, thought to cause suppressed visual cortex excitability. This opens the question of whether attention mediates T2 performance suppression independently from MSR, and if not, how attention interacts with MSR to produce the T2 performance suppression.

Concurrent brain responses to separate auditory and visual targets

In the attentional blink, a target event (T1) strongly interferes with perception of a second target (T2) presented within a few hundred milliseconds. Concurrently, the brain's electromagnetic response to the second target is suppressed, especially a late negative-positive EEG complex including the traditional P3 wave. An influential theory proposes that conscious perception requires access to a distributed, frontoparietal global workspace, explaining the attentional blink by strong mutual inhibition between concurrent workspace representations. Often, however, the attentional blink is reduced or eliminated for targets in different sensory modalities, suggesting a limit to such global inhibition. Using functional magnetic resonance imaging, we confirm that visual and auditory targets produce similar, distributed patterns of frontoparietal activity. In an attentional blink EEG/MEG design, however, an auditory T1 and visual T2 are identified without mutual interference, with largely preserved electromagnetic responses to T2. The results suggest parallel brain responses to target events in different sensory modalities.

Early perceptual interactions shape the time course of cueing

Performance in spatial cueing tasks is characterized by a rapid attentional enhancement with increasing cue-target SOA. We recently found that this enhancement function also applies when the cue and the target are presented invariably at a single central location, suggesting a universal cueing time course [Wilschut et al., 2011, PLoS ONE, 6, e27661]. However, using a very similar cueing task, Nieuwenstein et al. [2009, JoV, 9, 1-14] have found a rather different pattern, namely a U-shaped deficit in performance after a cue-like stimulus. The present study varied the properties of the cue and the target in order to investigate the mechanisms underlying the different time functions. In four experiments, cueing was found to either improve or decrease performance with increasing SOA, depending on the type of target that was used. In addition, the level of performance at the shortest cue-target intervals (33-83ms) was dependent on the relative strength of the cue and the target, akin to what has been found in visual masking studies. The results suggest that cueing shapes performance via two mechanisms, one sensory-related and one attention-related, the combination of which results in either U-shaped or monotonic patterns.