Target switch costs in visual search arise during the preparatory activation of target templates.

Prior research on task switching has shown that the reconfiguration of stimulus-response mappings across trials is associated with behavioral switch costs. Here, we investigated the effects of switching representations of target-defining features in visual search (attentional templates). Participants searched for one of two color-defined target objects that changed predictably every two trials (Experiment 1) or every four trials (Experiment 2).

A dissociation between the effects of expectations and attention in selective visual processing.

It is often claimed that probabilistic expectations affect visual perception directly, without mediation by selective attention. However, these claims have been disputed, as effects of expectation and attention are notoriously hard to dissociate experimentally. In this study, we used a new approach to separate expectations from attention.

Transient Attention Gates Access Consciousness: Coupling N2pc and P3 Latencies Using Dynamic Time Warping.

The N2pc and P3 event-related potentials (ERPs), used to index selective attention and access to working memory and conscious awareness, respectively, have been important tools in cognitive sciences. Although it is likely that these two components and the underlying cognitive processes are temporally and functionally linked, such links have not yet been convincingly demonstrated. Adopting a novel methodological approach based on dynamic time warping (DTW), we provide evidence that the N2pc and P3 ERP components are temporally linked.

A new method for tracking the preparatory activation of target templates for visual search with high temporal precision.

Efficiently selecting task-relevant objects during visual search depends on foreknowledge of their defining characteristics, which are represented within attentional templates. These templates bias attentional processing toward template-matching sensory signals and are assumed to become anticipatorily activated prior to search display onset. However, a direct neural signal for such preparatory template activation processes has so far remained elusive.

Attention and feature binding in the temporal domain.

Previous studies have shown that illusory conjunction can emerge for both spatially and temporally proximal objects. However, the mechanisms involved in binding in the temporal domain are not yet fully understood. In the current study, we investigated the role of attentional processes in correct and incorrect temporal binding, and specifically how feature binding is affected by the speed of attentional engagement.

The Preparatory Activation of Guidance Templates for Visual Search and of Target Templates in Non-Search Tasks.

Representations of task-relevant object attributes (attentional templates) control the adaptive selectivity of visual processing. Previous studies have demonstrated that templates involved in the guidance of attention during visual search are activated in a preparatory fashion prior to the arrival of visual search displays. The current study investigated whether such proactive mechanisms are also triggered in non-search tasks, where attentional templates do not mediate the guidance of attention towards targets amongst distractors but are still necessary for subsequent target recognition processes.

Do We Prepare for What We Predict? How Target Expectations Affect Preparatory Attentional Templates and Target Selection in Visual Search.

Visual search is guided by representations of target-defining features (attentional templates) that are activated in a preparatory fashion. Here, we investigated whether these template activation processes are modulated by probabilistic expectations about upcoming search targets. We tracked template activation while observers prepared to search for one or two possible color-defined targets by measuring N2pc components (markers of attentional capture) to task-irrelevant color probes flashed every 200 msec during the interval between search displays.

Proactive suppression can be applied to multiple salient distractors in visual search.

There is a growing body of research demonstrating that the capture of attention by a single salient distractor can be prevented via proactive suppression. In real-world contexts, there are often several distracting events that compete for attention, but it is entirely unknown whether multiple objects can be suppressed concurrently. We used behavioral and electrophysiological measures to investigate the existence and time course of multiple-item suppression.

The temporal dynamics of selective attention are reflected by distractor intrusions.

When observers have to identify an object embedded in a rapid serial visual presentation (RSVP) stream, they often erroneously report the identity of a distractor instead of the target (distractor intrusion). In two experiments, we examined whether these intrusion errors are associated with the speed of attentional engagement. Participants reported the identity of target digits indicated by shape selection cues.

Categorization templates modulate selective attention.

Many models of attention assume that categorization (the individuation of events based on the feature dimension relevant for response selection) occurs only after an object has been selected and encoded in working memory (WM). In contrast, we propose that the match between an item and the currently activated set of possible response features (categorization template) already modulates selective perceptual processing prior to WM encoding. To test this proposal, we measured electrophysiological markers of attentional engagement (N2pc components) and behavioral interference effects from posttarget distractors (PTDs) as a function of whether these distractors matched the categorization template.

Sensory experience modulates the reorganization of auditory regions for executive processing.

Crossmodal plasticity refers to the reorganization of sensory cortices in the absence of their typical main sensory input. Understanding this phenomenon provides insights into brain function and its potential for change and enhancement. Using functional MRI, we investigated how early deafness influences crossmodal plasticity and the organization of executive functions in the adult human brain.

Expectation-based blindness: Predictions about object categories gate awareness of focally attended objects.

Selective attention gates access to conscious awareness, resulting in surprising failures to notice clearly visible but unattended objects ('inattentional blindness'). Here, we demonstrate that expectations can have a similar effect, even for fully attended objects ('expectation-based blindness'). In three experiments, participants (N = 613) were presented with rapid serial visual presentation (RSVP) streams at fixation and had to identify a target object indicated by a cue.

The diachronic account of attentional selectivity.

Many models of attention assume that attentional selection takes place at a specific moment in time that demarcates the critical transition from pre-attentive to attentive processing of sensory input. We argue that this intuitively appealing standard account of attentional selectivity is not only inaccurate, but has led to substantial conceptual confusion. As an alternative, we offer a 'diachronic' framework that describes attentional selectivity as a process that unfolds over time.

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).

P components and distractor inhibition in visual search: New evidence for the signal suppression hypothesis.

The hypothesis that salient distractors in visual search are actively suppressed is supported by the fact that these objects elicit P components believed to be associated with inhibition. This account was challenged by researchers who found that a P to lateral color singleton distractors was followed by a contralateral negativity, which they interpreted as an N2pc indicative of attentional capture. As this would be at odds with successful distractor suppression, they proposed an alternative lateral-first serial scanning hypothesis, which assumes that the P might actually be an N2pc elicited when a lateral context item is selected.

Tuning in to anxiety-related differences in attentional control: Apprehension of threat improves template switching during visual search.

Anxiety is believed to disrupt selective attention, supported by evidence that both individual differences in trait anxious personality and induced apprehensive mood can increase distractibility during visual search. While much research has focused on the role of anxiety-related emotion in affecting the ability to "tune out" irrelevant information, there is a scarcity of research on its possible role in affecting the "tuning in" of attention to relevant information. Here, we examined the role of both trait anxiety and induced apprehension on the efficiency to maintain one or more target templates to guide attentional selection during visual search and the switch between search templates.

The role of trait anxiety in attention and memory-related biases to threat: An event-related potential study.

Threat-related information strongly competes for attentional selection, and can subsequently be more strongly represented within visual working memory. This is particularly the case for individuals reporting high trait anxious personality. The present study examined the role of anxiety in both attention and memory-related interactions with threat.

Action biases perceptual decisions toward expected outcomes.

We predict how our actions will influence the world around us. Prevailing models in the action control literature propose that we use these predictions to suppress or "cancel" perception of expected action outcomes, to highlight more informative surprising events. However, contrasting normative Bayesian models in sensory cognition suggest that we are more, not less, likely to perceive what we expect-given that what we expect is more likely to occur.

The guidance of attention by templates for rejection during visual search.

The hypothesis that foreknowledge of nontarget features in visual search is represented by negative search templates ("templates for rejection") that facilitate attentional guidance remains disputed. In five experiments, we investigated this proposal by measuring search performance and electrophysiological markers of target selection (N2pc components) and nontarget suppression (P components). We compared search tasks where positive or negative cues signaled the color of targets or nontargets, respectively, and tasks with neutral non-informative cues.

Neural responses in a fast periodic visual stimulation paradigm reveal domain-general visual discrimination deficits in developmental prosopagnosia.

We investigated selective impairments of visual identity discrimination in developmental prosopagnosia (DP), using a fast periodic identity oddball stimulation paradigm with electroencephalography (EEG). In Experiment 1, neural responses to unfamiliar face identity changes were strongly attenuated for individuals with DP as compared to Control participants, to the same extent for upright and inverted faces. This reduction of face identity discrimination responses, which was confirmed in Experiment 2, provides direct evidence for deficits in the visual processing of unfamiliar facial identity in DP.

Perceptual competition between targets and distractors determines working memory access and produces intrusion errors in rapid serial visual presentation (RSVP) tasks.

When a target and a distractor that share the same response dimension appear in rapid succession, participants often erroneously report the distractor instead of the target. Using behavioral and electrophysiological measures, we examined whether these intrusion errors occur because the target is often not encoded in working memory (WM) or are generated at later postencoding stages. In 4 experiments, participants either provided two guesses about the target's identity, or had to select the target among items that did not include the potential intruder.

Distractor intrusions are the result of delayed attentional engagement: A new temporal variability account of attentional selectivity in dynamic visual tasks.

When observers must identify targets among distractors in a rapid serial visual presentation (RSVP) stream, distractor intrusion errors are frequent, demonstrating the difficulty of allocating attention to the right object at the right moment in time. However, the mechanisms responsible for such intrusion errors remain disputed. We propose a new attentional engagement account of selective visual processing in RSVP tasks.

Preparatory Template Activation during Search for Alternating Targets.

Visual search is guided by representations of target-defining features (attentional templates). We tracked the time course of template activation processes during the preparation for search in a task where the identity of color-defined search targets switched across successive trials (ABAB). Task-irrelevant color probes that matched either the upcoming relevant target color or the previous now-irrelevant target color were presented every 200 msec during the interval between search displays.

Attentional repulsion effects produced by feature-guided shifts of attention.

Attention shifts to particular objects in the visual field can distort perceptual location judgments. Visual stimuli are perceived to be shifted away from the current focus of attention (the attentional repulsion effect [ARE]). Although links between repulsion effects and stimulus-driven exogenous attentional capture have been demonstrated conclusively, it remains disputed whether AREs can also be elicited as a result of feature-guided attention shifts that are controlled by endogenous task sets.