Parallel, independent attentional control settings for colors and shapes

Attentional capture can be contingent on attentional control settings (ACSs), such that peripheral cues influence processing for a subsequent target only when they share a critical feature with the target. Our previous demonstration that two ACSs from within the same feature category can be maintained simultaneously allows us to investigate the processing stage at which such ACSs are implemented. We compared the relative efficacy of ACSs from two different feature categories (shape and color) that are associated with different levels within the visual processing hierarchy. Participants were instructed to respond to one of two colors at one location and one of two shapes at another location, while ignoring the nontarget color and shape. We observed that spatial capture was modulated by whether the cues fit an ACS, with slightly greater contingent capture effects for ACSs defined by color than by shape. Thus, two ACSs from different feature sets (color and shape) can be maintained in parallel, although effectiveness of the control set varied with the type of feature.     

All set! Evidence of simultaneous attentional control settings for multiple target colors

Although models of visual search have often assumed that attention can only be set for a single feature or property at a time, recent studies have suggested that it may be possible to maintain more than one attentional control setting. The aim of the present study was to investigate whether spatial attention could be guided by multiple attentional control settings for color. In a standard spatial cueing task, participants searched for either of two colored targets accompanied by an irrelevantly colored distractor. Across five experiments, results consistently showed that nonpredictive cues matching either target color produced a significant spatial cueing effect, while irrelevantly colored cues did not. This was the case even when the target colors could not be linearly separated from irrelevantly cue colors in color space, suggesting that participants were not simply adopting one general color set that included both target colors. The results could not be explained by intertrial priming by previous targets, nor could they be explained by a single inhibitory set for the distractor color. Overall, the results are most consistent with the maintenance of multiple attentional control settings.     

Goal-driven attentional capture by invisible colors: Evidence from event-related potentials

We combined event-related brain potentials (ERPs) and behavioral measures to test whether subliminal visual stimuli can capture attention in a goal-dependent manner. Participants searched for visual targets defined by a specific color. Search displays served as metacontrast masks for preceding cue displays that contained one cue in the target color. Although this target-color cue was spatially uninformative, it produced behavioral spatial cuing effects and triggered an ERP correlate of attentional selection (i.e., the N2pc component). These results demonstrate that target-color cues captured attention, in spite of the fact that cue localization performance assessed in separate blocks was at chance level. We conclude that task-set contingent attentional capture is not restricted to supraliminal stimuli, but is also elicited by visual events that are not consciously perceived.     

Multiple attentional control settings at distinct locations without the confounding of repetition priming

An attentional control setting (ACS), which is based on the task goal, induces involuntary attentional capture by a stimulus possessing a target-defining feature. It is unclear whether ACSs are maintained for multiple targets defined as conjunctions of a color and location. In the present study we examined the possibility of local ACSs for dual targets defined as combinations of color and location, using different paradigms: visual search in Experiment 1, and spatial cueing in Experiment 2. In Experiment 1, a distractor captured attention only when its features matched the ACSs. Likewise, in Experiment 2, a significant attentional capture effect was found only with a matching cue, whose color and location were in line with the conjunction of the target definition. Importantly, the identical pattern of attentional capture was also obtained for a neutral-color target, which was unlikely to be primed by any color of the cue. Thus, these findings imply that the attentional bias depending on the match between the cue and target did not result from cue–target repetition priming. The present study highlights that top-down attentional control can be set flexibly to accomplish a complex task goal efficiently.     

Attentional capture by color without any relevant attentional set

The aim of the present study was to investigate mechanisms underlying attentional capture by color. Previous work has shown that a color singleton is able to summon attention only in the presence of a relevant attentional set, whereas when a color singleton is not useful for a task, evidence for purely stimulus-driven attentional capture is controversial. Three visual search experiments (T-L task) were conducted using a method different from that based on set sizes, consisting of monitoring target-singleton distance in a unique display size. In Experiment 1, we demonstrated that attention can be summoned in a real stimulus-driven manner by an irrelevant color singleton. Experiment 2A extended this observation, showing that the color singleton attracted attention even when capture was detrimental. However, Experiment 2B showed that such capture can be strategically prevented. Finally, in Experiment 3, we examined whether such a capture was due to a spatial shift or to a filtering cost, providing evidence supporting the shift hypothesis. Stimulus-driven capture was observed when color was neither the defining nor the reported target attribute (Yantis, 1993) and when subjects naive of visual search tasks were used. The present results give experimental support to many contemporary models of visual attention.     

Automatic,stimulus-driven attentional capture by objecthood

In three experiments, we investigated whether the mere organization of some elements in the visual field by Gestalt factors into a coherent unit (an object), with no abrupt onset or any other unique transient, could attract attention automatically. Participants viewed a display of nine red and green elements, one of which was the target, and had to identify the target’s color. On some trials, a subset of the elements was grouped by Gestalt factors (collinearity, closure, and symmetry) into an object. The object was task-irrelevant and unpredictive of the target. Performance on trials with an object present in the display was faster than performance on trials with no object for targets in the object area (a benefit) but slower for targets in a nonobject area (a cost). These findings demonstrate that an object by itself can capture attention automatically in a stimulus-driven manner, much as exogenous cues can.     

Anxiety-related attentional biases and their regulation by attentional control

This study examined the role of self-reported attentional control in regulating attentional biases related to trait anxiety. Simple detection targets were preceded by cues labeling potential target locations as threatening (likely to result in negative feedback) or safe (likely to result in positive feedback). Trait anxious participants showed an early attentional bias favoring the threatening location 250 ms after the cue and a late bias favoring the safe location 500 ms after the cue. The anxiety-related threat bias was moderated by attentional control at the 500-ms delay: Anxious participants with poor attentional control still showed the threat bias, whereas those with good control were better able to shift from the threatening location. Thus, skilled control of voluntary attention may allow anxious persons to limit the impact of threatening information.     

Automatic and attentional priming in young and older adults: reevaluation of the two-process model.

Three experiments addressed the distinction between automatic and attentional mechanisms underlying semantic priming effects by factorially crossing prime-target relatedness, expectancy, and SOA in a task (pronunciation) that minimized postlexical checking processes. Also, possible age-related (young vs. older adults) differences in the automatic and attentional mechanisms were addressed. Across all experiments there was evidence of a Relatedness x Expectancy x SOA interaction, which is inconsistent with the notion of independent automatic and attentional mechanisms in semantic priming and the notion of a self-encapsulated modular lexicon. The results also indicated age-related differences in the build-up of the expectancy effect across SOAs when the prime was visually available for only 200 ms, independently of the prime-target SOA (Experiments 1 and 3), but not when the prime was visually available throughout the SOA (Experiment 2).     

Bidirectional semantic priming in the attentional blink

The time course of semantic priming between two associated words was tracked using rapid serial visual presentation of two synchronized streams of stimuli appearing at about 20 items/sec, each stream including a target word. The two words were semantically related or unrelated and were separated by stimulus onset asynchronies (SOAs) of 0–213 msec. Accuracy in reporting the first target (T1) versus the second target (T2) has been shown to interact dramatically with SOA over this range. The materials were in English in Experiment1 and Italian in Experiment2. T1 was semantically primed only at short SOAs, whereas T2 was primed at all SOAs (Experiment 1) or at all SOAs except the shortest one (Experiment2). The results indicate a strong competition between target words early in processing, with T2 often becoming the first word identified at short SOAs, thus priming T1.     

Perceptual latency priming: A measure of attentional facilitation

The present paper reviews recent research on perceptual latency priming (PLP). PLP is the relative latency advantage-earlier perception-of a visual stimulus that is preceded by another, masked stimulus at its location. The first stimulus attracts attention which accelerates perception of the second stimulus. This facilitation arises even if the first stimulus is visually backward-masked by the second one. The paper summarises research on temporal and spatial properties of PLP and the question whether intentions mediate shifts of attention to external events. Possible sources of PLP besides visuo-spatial attention are discussed. Finally, I give a review of feedforward and reentrant models of PLP and compare them to the empirical evidence.     

Perceptual latency priming by masked and unmasked stimuli: evidence for an attentional interpretation

Four experiments investigated the influence of a metacontrast-masked prime on temporal order judgments. The main results were (1) that a masked prime reduced the latency of the mask's conscious perception (perceptual latency priming), (2) that this effect was independent of whether the prime suffered strong or weak masking, (3) that it was unaffected by the degree of visual similarity between the prime and the mask, and that (4) there was no difference between congruent and incongruent primes. Finding (1) suggests that location cueing affects not only response times but also the latency of conscious perception. (2) The finding that priming was unaffected by the prime's detectability argues against a response bias interpretation of this effect. (3) Since visual similarity had no effect on the prime's efficiency, it is unlikely that sensory priming was involved. (4) The lack of a divergence between the effects of congruent and incongruent primes implies a functional difference between the judgments in the temporal order judgment task and speeded responses that have demonstrated differential effects of congruent and incongruent primes (e.g., Klotz & Neumann, 1999). These results can best be interpreted by assuming that the prime affects perceptual latency by initiating a shift of attention, as suggested by the Asynchronous Updating Model (AUM; Neumann 1978, 1982).     

Automatic non-associative semantic priming: episodic affective priming of naming responses

Affective priming for associatively unrelated prime-target pairs was investigated using (a) the naming task, (b) a short stimulus onset asynchrony (250 ms), and (c) primes that had acquired their affective connotation during a differential evaluative conditioning procedure. Despite the fact that the primes and the targets were related on the affective dimension only, significant priming emerged. This finding indicates that mere affective overlap is sufficient to produce automatic priming. As such, our results are in line with theoretical accounts of automatic priming that are based on semantic relatedness.     

Long-term negative priming: Support for retrieval of prior attentional processes

Negative priming reveals that participants respond slowly to a probe target that was a task-irrelevant distractor in the preceding prime display (e.g., Tipper, 1985) and is thought to reflect processes mediating short-term behaviour. However, since the first surprising reports that negative priming is found with meaningless stimuli across delays of 30 days (e.g., DeSchepper & Treisman, 1996), researchers have questioned the existence of long-term negative priming effects. Because long-term negative priming could indicate that task-irrelevant information leaves a memory trace that impacts performance over time, such a finding is of immense theoretical importance. Indeed, the current research finds support for the existence of long-term negative priming as well as its generality across different stimuli and conditions. The authors propose that the initial processes that prevent response to irrelevant stimuli may be stored in memory, where retrieval of these processes can mediate behaviour over time.     

Ageing and attentional control

The research examines the structural bottleneck account and the resource account of the substantial dual-task deficits among older adults. Procedures from two common dual-task methodologies—the psychological refractory period and the relative-priority manipulation—were used to encourage maximization of the joint performance. Performance and time-sharing strategies from subjects between the ages of 20 and 70 years were examined. Age-related declines in time-sharing efficiency and in the precision of the executive control process were observed. The age-related effect was larger when two manual responses were required than when one manual and one vocal response were required, but no evidence for obligatory sequential processing was found. Except for the most demanding conditions, comparable practice effects were observed between the younger and older subjects, suggesting considerable cognitive plasticity in the older subjects. Implications for the two attentional accounts were discussed.     

Complex attentional control settings

One way that dis/likes are formed is through evaluative conditioning (EC). In two experiments we investigated the role of cognitive resources in flavour–flavour conditioning. Both experiments employed an EC procedure in which three novel flavoured conditioned stimuli (CSs) were consumed. One was consumed with a pleasant unconditioned stimulus (US; CS+ sugar), one with an aversive US (CS+ saline), and a third with plain water (CS–). Half of participants in each experiment performed a cognitive load task during conditioning. We measured EC using self-reported measures of liking (Experiments 1 and 2) and an indirect measure of liking: drink pick-up latency (Experiment 2). In both experiments, differential EC was observed in the no cognitive load condition but not in the cognitive load condition. This pattern of results was observed in self-reported measures of liking as well as in the drink pick-up latency data. Results from both experiments show that EC occurs only when there are sufficient cognitive resources available. The fact that this was observed using both self-reported and indirect measures suggests that insufficient cognitive resources affect learning itself rather than merely obstructing reporting.     

Exploring the modulation of attentional capture by attentional control settings using performance and illusory line motion

Modulation of attentional capture by attentional control settings was explored using performance and phenomenology. Trials began with four figure-8s presented above, below, left, and right of fixation. Any figure-8 (or none) brightened uninformatively (cue) before presentation of either a digit target (2 or 5 made from a figure-8 by deletion) calling for a speeded identification, or a line connecting adjacent figure-8s calling for a motion judgement. Such lines are seen drawn away from an adjacent cue. Digit targets appeared only on the horizontal or vertical axes, encouraging voluntary attention to two (target-relevant) of the four figure-8s. Whereas voluntary attention reduced attentional capture from cues at taskirrelevant locations (when lines were unlikely to be presented near the task-irrelevant locations), it had no effect on motion judgements, suggesting that cue-elicited exogenous attention affects perceptual arrival times while voluntary attention prioritizes locations for further processing without affecting arrival times.     

Automatic and attentional components in perception of shape-at-a-slant

In perceiving shape-at-a-slant it is assumed that a sequence of operations is executed. The aim of these experiments was to determine the extent to which execution of these operations requires allocation of attention. Three hypotheses were considered: zero automaticity--that all of the operations require attention; partial automaticity--that the operations culminating in a representation of projective shape and slant-in-depth are automatic while the combinatorial operations culminating in a distally correlated shape require attention; full automaticity--that the entire sequence of operations is automatic, proceeding without allocation of attention. To decide among these hypotheses, subjects performed forced-choice shape recognition tests under two conditions: In the shape-directed condition subjects were motivated to process shape. In the numerosity-directed condition subjects were motivated to direct attention to discrimination of numerosity, thereby causing attention to be diverted from processing of shape. Examination of the pattern of choices on the recognition test showed results that conformed best to the hypothesis of partial automaticity.