The effects of self-report cognitive failures and cognitive load on antisaccade performance

Individuals reporting high levels of distractibility in everyday life show impaired performance in standard laboratory tasks measuring selective attention and inhibitory processes. Similarly, increasing cognitive load leads to more errors/distraction in a variety of cognitive tasks. How these two factors interact is currently unclear; highly distractible individuals may be affected more when their cognitive resources are taxed, or load may linearly affect performance for all individuals. We investigated the relationship between self-reported levels of cognitive failures (CF) in daily life and performance in the antisaccade task, a widely used tool examining attentional control. Levels of concurrent cognitive demand were manipulated using a secondary auditory discrimination task. We found that both levels of self-reported CF and task load increased antisaccade latencies while having no effect on prosaccade eye-movements. However individuals rating themselves as suffering few daily life distractions showed a comparable load cost to those who experience many. These findings suggest that the likelihood of distraction is governed by the addition of both internal susceptibility and the external current load placed on working memory

Rapid attentional biases to threat-associated visual features: the roles of anxiety and visual working memory access

Threat-related information strongly biases attention, particularly for high anxious individuals. It is less clear though what the consequences of attentional capture by threat are, and how this influences subsequent visual processing. This study examined how capture by threat influences visual search when attributes related to a threat reappear as task-irrelevant information. In Experiment 1, participants completed a search task preceded by task-irrelevant face cues on each trial expressing neutral, happy, or angry emotions. Faces were filtered to appear in different colors, where this color could match a non-emotional distractor object in the upcoming search display. While the color of neutral/happy face cues had no impact on performance, there was evidence that angry face colors delayed reaction times when this color reappeared, driven by a positive correlation between costs and individual differences in trait anxiety. Experiment 2 assessed whether this phenomenon would be more readily observed when designating face cues task-relevant. When participants attended to and memorized faces for occasional probe trials, color biases were now evident irrespective of the emotional valence of face cues and unaffected by trait anxiety levels. These results suggest that task-irrelevant threat stimuli are granted privileged depth of processing by high anxious individuals, triggering biased attention towards features related to this object. Such biases are not dependent on threat per se, occurring for other objects voluntarily processed to similar depth regardless of personality factors. This highlights that anxiety-related phenomena, such as delayed disengagement of spatial attention from threat, may stem from task-irrelevant visual working memory representation

The guidance of spatial attention during visual search for colour combinations and colour configurations

Representations of target-defining features (attentional templates) guide the selection of target objects in visual search. We used behavioural and electrophysiological measures to investigate how such search templates control the allocation of attention in search tasks where targets are defined by the combination of two colours or by a specific spatial configuration of these colours. Target displays were preceded by spatially uninformative cue displays that contained items in one or both target-defining colours. Experiments 1 and 2 demonstrated that, during search for colour combinations, attention is initially allocated independently and in parallel to all objects with target-matching colours, but is then rapidly withdrawn from objects that only have one of the two target colours. In Experiment 3, targets were defined by a particular spatial configuration of two colours, and could be accompanied by nontarget objects with a different configuration of the same colours. Attentional guidance processes were unable to distinguish between these two types of objects. Both attracted attention equally when they appeared in a cue display, and both received parallel focal-attentional processing and were encoded into working memory when they were presented in the same target display. Results demonstrate that attention can be guided simultaneously by multiple features from the same dimension, but that these guidance processes have no access to the spatial-configural properties of target objects. They suggest that attentional templates do not represent target objects in an integrated pictorial fashion, but contain separate representations of target-defining features

Object-based target templates guide attention during visual search

During visual search, attention is believed to be controlled in a strictly feature-based fashion, without any guidance by object-based target representations. To challenge this received view, we measured electrophysiological markers of attentional selection (N2pc component) and working memory (SPCN) in search tasks where two possible targets were defined by feature conjunctions (e.g., blue circles and green squares). Critically, some search displays also contained nontargets with two target features (incorrect conjunction objects, e.g., blue squares). Because feature-based guidance cannot distinguish these objects from targets, any selective bias for targets will reflect object-based attentional control. In Experiment 1, where search displays always contained only one object with target-matching features, targets and incorrect conjunction objects elicited identical N2pc and SPCN components, demonstrating that attentional guidance was entirely feature-based. In Experiment 2, where targets and incorrect conjunction objects could appear in the same display, clear evidence for object-based attentional control was found. The target N2pc became larger than the N2pc to incorrect conjunction objects from 250 ms post-stimulus, and only targets elicited SPCN components. This demonstrates that after an initial feature-based guidance phase, object-based templates are activated when they are required to distinguish target and nontarget objects. These templates modulate visual processing and control access to working memory, and their activation may coincide with the start of feature integration processes. Results also suggest that while multiple feature templates can be activated concurrently, only a single object-based target template can guide attention at any given time

Does contralateral delay activity reflect working memory storage or the current focus of spatial attention within visual working memory?

During the retention of visual information in working memory, event-related brain potentials show a sustained negativity over posterior visual regions contralateral to the side where memorised stimuli were presented. This contralateral delay activity (CDA) is generally believed to be a neural marker of working memory storage. In two experiments, we contrasted this storage account of the CDA with the alternative hypothesis that the CDA reflects the current focus of spatial attention on a subset of memorized items set up during the most recent encoding episode. We employed a sequential loading procedure where participants memorised four task-relevant items that were presented in two successive memory displays (M1 and M2). In both experiments, CDA components were initially elicited contralateral to task-relevant items in M1. Critically, the CDA switched polarity when M2 displays appeared on the opposite side. In line with the attentional activation account, these reversed CDA components exclusively reflected the number of items that were encoded from M2 displays, irrespective of how many M1 items were already held in working memory. On trials where M1 and M2 displays were presented on the same side, and on trials where M2 displays appeared non-laterally, CDA components elicited in the interval after M2 remained sensitive to a residual trace of M1 items, indicating that some activation of previously stored items was maintained across encoding episodes. These results challenge the hypothesis that CDA amplitudes directly reflect the total number of stored objects, and suggest that the CDA is primarily sensitive to the activation of a subset of working memory representations within the current focus of spatial attention

The guidance of visual search by shape features and shape configurations

Representations of target features (attentional templates) guide attentional object selection during visual search. In many search tasks, targets objects are defined not by a single feature but by the spatial configuration of their component shapes. We used electrophysiological markers of attentional selection processes to determine whether the guidance of shape configuration search is entirely part-based or sensitive to the spatial relationship between shape features. Participants searched for targets defined by the spatial arrangement of two shape components (e.g., hourglass above circle). N2pc components were triggered not only by targets but also by partially matching distractors with one target shape (e.g., hourglass above hexagon) and by distractors that contained both target shapes in the reverse arrangement (e.g., circle above hourglass), in line with part-based attentional control. Target N2pc components were delayed when a reverse distractor was present on the opposite side of the same display, suggesting that early shape-specific attentional guidance processes could not distinguish between targets and reverse distractors. The control of attention then became sensitive to spatial configuration, which resulted in a stronger attentional bias for target objects relative to reverse and partially matching distractors. Results demonstrate that search for target objects defined by the spatial arrangement of their component shapes is initially controlled in a feature-based fashion but can later be guided by templates for spatial configurations

Testing a goal-driven account of involuntary attentional capture by threat

Attention has long been characterised within prominent models as reflecting a competition between goal-driven and stimulus-driven processes. It remains unclear, however, how involuntary attentional capture by affective stimuli, such as threat-laden content, fits into such models. While such effects were traditionally held to reflect stimulus-driven processes, recent research has increasingly implicated a critical role of goal-driven processes. Here we test an alternative goal-driven account of involuntary attentional capture by threat, using an experimental manipulation of goal-driven attention. To this end we combined the classic ‘contingent capture’ and ‘emotion-induced blink’ (EIB) paradigms in an RSVP task with both positive or threatening target search goals. Across six experiments, positive and threat distractors were presented in peripheral, parafoveal, and central locations. Across all distractor locations, we found that involuntary attentional capture by irrelevant threatening distractors could be induced via the adoption of a search goal for a threatening category; adopting a goal for a positive category conversely led to capture only by positive stimuli. Our findings provide direct experimental evidence for a causal role of voluntary goals in involuntary capture by irrelevant threat stimuli, and hence demonstrate the plausibility of a top-down account of this phenomenon. We discuss the implications of these findings in relation to current cognitive models of attention and clinical disorders

Electrophysiological correlates of active suppression and attentional selection in preview visual search

Advance preview of a subset of distractor objects improves the efficiency of visual search performance, but the causes and mechanisms of such preview benefits remain unclear. Here, we employed event-related potential (ERP) markers of the selective processing of preview displays and full search displays in lateralised preview search tasks where only one side of the search displays was task-relevant. Preview displays elicited a sustained positivity contralateral to the relevant side (PD component), indicative of the active suppression of distractor objects on this side. Lateralised ERP components to full search displays revealed qualitative differences between attentional selection processes on preview as compared to no-preview trials. When search displays were preceded by preview displays, attention was directly allocated to target objects, while distractors remained unattended. When all search display objects were presented simultaneously (no-preview), attention was directed non-selectively to objects on the task-relevant side, even when no target was present. These results suggest that behavioural preview effects in visual search can be accounted for by the inhibition of previewed distractors, and the subsequent rapid attentional selection of target objects on preview trials

Visual working memory load disrupts template-guided attentional selection during visual search

Mental representations of target features (attentional templates) control the selection of candidate target objects in visual search. The question where templates are maintained remains controversial. We employed the N2pc component as an electrophysiological marker of template-guided target selection to investigate whether and under which conditions templates are held in visual working memory (vWM). In two experiments, participants memorized one or four shapes (low versus high vWM load) before either being tested on their memory or performing a visual search task. When targets were defined by one of two possible colours (e.g., red or green), target N2pcs were delayed with high vWM load. This suggests that the maintenance of multiple shapes in vWM interfered with the activation of colour-specific search templates, supporting the hypothesis that these templates are held in vWM. This was the case despite participants always searching for the same two target colours. In contrast, the speed of target selection in a task where a single target colour remained relevant throughout was unaffected by concurrent load, indicating that a constant search template for a single feature may be maintained outside vWM in a different store. Additionally, early visual N1 components to search and memory test displays were attenuated under high load, suggesting a competition between external and internal attention. The size of this attenuation predicted individual vWM performance. These results provide new electrophysiological evidence for impairment of top-down attentional control mechanisms by high vWM load, demonstrating that vWM is involved in the guidance of attentional target selection during search