The illusion of control: Sequential dependencies underlie contingent attentional capture

The degree to which humans have top-down control over which information they process remains a central debate within the attention literature. Most of the evidence supporting the top-down control of visuospatial attention has come from cueing paradigms in which target stimuli are preceded by cues that are similar or dissimilar from the target. These studies find that the cues similar to targets capture attention, but dissimilar cues do not, suggesting the top-down control of attention. Here, we used a modified cueing paradigm to investigate an alternative possibility that the cue type differences are due to sequential dependency effects occurring between cue and target processing rather than the top-down control of attention. When individuals searched for color targets, we replicated contingent capture effects in RTs, which are susceptible to sequential dependencies, but memory performance was always best at the cued locations, regardless of the cue’s identity. When individuals searched for onset targets, we observed contingent capture in both tasks. These results demonstrate the utility of the memory probe paradigm and suggest an asymmetry between how strongly onsets and color defined cues capture attention.     

Dimension-based working memory-driven capture of visual selection

We studied attentional capture by dimensional cueing of visual objects. Participants received two dimension cues, one relevant for a memory test and the other relevant for an attention test. Performance in the attention task was impaired on incongruent trials (i.e., when the relevant dimensions for memory and attention did not match) relative to congruent trials. Dimensional cueing effects were enhanced when the cued dimension was held “online” in working memory through the trial, compared to when the cued dimension did not have to be held in memory. The findings demonstrate that dimensional cueing of visual selection can occur in a largely automatic manner, with working memory exerting a strong modulatory influence. We discuss the implications of these findings for understanding the interaction between memory and attention.     

Resolving conflicting views: Gaze and arrow cues do not trigger rapid reflexive shifts of attention

It has become widely accepted that the direction of another individual's eye gaze induces rapid, automatic, attentional orienting, due to it being such a vital cue as to where in our environment we should attend. This automatic orienting has also been associated with the directional-arrow cues used in studies of spatial attention. Here, we present evidence that the response-time cueing effects reported for spatially nonpredictive gaze and arrow cues are not the result of rapid, automatic shifts of attention. For both cue types, response-time effects were observed only for long-duration cue and target stimuli that overlapped temporally, were largest when the cues were presented simultaneously with the response-relevant target, and were driven by a slowing of responses for invalidly cued targets rather than speeding for validly cued ones. These results argue against automatic attention-orienting accounts and support a novel spatial-incongruency explanation for a whole class of rapid behavioural cueing effects.     

A configural dominant account of contextual cueing: Configural cues are stronger than colour cues

Previous work has shown that reaction times to find a target in displays that have been repeated are faster than those for displays that have never been seen before. This learning effect, termed “contextual cueing” (CC), has been shown using contexts such as the configuration of the distractors in the display and the background colour. However, it is not clear how these two contexts interact to facilitate search. We investigated this here by comparing the strengths of these two cues when they appeared together. In Experiment 1, participants searched for a target that was cued by both colour and distractor configural cues, compared with when the target was only predicted by configural information. The results showed that the addition of a colour cue did not increase contextual cueing. In Experiment 2, participants searched for a target that was cued by both colour and distractor configuration compared with when the target was only cued by colour. The results showed that adding a predictive configural cue led to a stronger CC benefit. Experiments 3 and 4 tested the disruptive effects of removing either a learned colour cue or a learned configural cue and whether there was cue competition when colour and configural cues were presented together. Removing the configural cue was more disruptive to CC than removing colour, and configural learning was shown to overshadow the learning of colour cues. The data support a configural dominant account of CC, where configural cues act as the stronger cue in comparison to colour when they are presented together.     

Arrow-elicited cueing effects at short intervals: Rapid attentional orienting or cue-target stimulus conflict?

The observation of cueing effects (faster responses for cued than uncued targets) rapidly following centrally-presented arrows has led to the suggestion that arrows trigger rapid automatic shifts of spatial attention. However, these effects have primarily been observed during easy target-detection tasks when both cue and target remain on the screen until the behavioral response. We manipulated stimulus duration and task difficulty in an attention-cueing experiment to explore non-attentional explanations for rapid cueing effects. Contrary to attention-based predictions, short-interval cueing effects were observed only for long-duration cue and target stimuli, occurred even when the cue and target were presented simultaneously, and were driven by slowing of the uncued-target responses, rather than any facilitation for cued targets. We propose that, under these long-duration, short-interval conditions, the processing of the cue and target interact more extensively in the brain, and that when the cue and target convey incongruent spatial information (i.e., on invalidly cued trials) it leads to conflict-related slowing of responses.     

Attentional orientation induced by temporarily established self-referential cues

Self-referential stimuli such as self-face surpass other-referential stimuli in capture of attention, which has been attributed to attractive perceptual features of self-referential stimuli. We investigated whether temporarily established self-referential stimuli are different from other-referential cues in guiding voluntary visual attention. Temporarily established self-referential or friend-referential shapes served as central cues in Posner's endogenous cueing task. We found that, relative to friend-referential cues, self-referential cues induced smaller cueing effect (i.e., the difference in reaction times to targets at cued and uncued locations) when the interstimulus interval was short but larger cueing effect when the interstimulus interval was long. Our findings suggest that temporarily established self-referential cues are more efficient to capture reflexive attention at the early stage of perceptual processing and to shift voluntary attention at the later stage of perceptual processing.     

Differential time course of implicit and explicit cueing by colour and orientation in visual search

Using a cued conjunction search task, Anderson, Heinke, and Humphreys (2010) demonstrated larger effects from cueing target colour than from cueing target orientation. In this study, we separated the implicit (nonexpectation-dependent) and explicit (expectation-dependent) effects of orientation and colour visual cues. In Experiment 1, we replicated the original findings for short cue durations (100–200 ms), demonstrating that cues matching the physical property of the target on 80% of trials exert a rapid effect on search. These early cueing effects on reaction times were supported by evidence of guidance from cues on early eye movements. Experiment 2 introduced a feature to the cue that randomly matched the colour or orientation of the target. When cue orientation was predictive, there were strong implicit effects based on whether the colour of the cue and target matched. When cue colour was predictive, there were only weak effects from the cue's orientation. Implicit effects from cue colour remained when orientation-predictive cues were used and colour was unlikely to predict the target (Experiment 3). The data suggest that strong effects of colour cueing result from a combination of implicit and explicit processes, whereas effects from orientation cues are largely limited to the explicit guidance of visual search.     

The influence of visual short-term memory on size perception

We show that perceived size of visual stimuli can be altered by matches between the contents of visual short-term memory and stimuli in the scene. Observers were presented with a colour cue (to hold in working memory or to merely identify) and subsequently had to indicate which of the two different-coloured objects presented simultaneously on the screen appeared bigger (or smaller). One of the two objects for size judgements had the same colour as the cue (matching stimulus) and the other did not (mismatching stimulus). Perceived object size was decreased by the reappearance of the recently seen cue, as there were more size judgement errors on trials where the matching stimulus was physically bigger (relative to the mismatching stimulus) than on trials where the matching stimulus was physically smaller. The effect occurred regardless of whether the visual cue was actively maintained in working memory or was merely identified. The effect was unlikely generated by the allocation of attention, because shifting attention to a visual stimulus actually increased its perceived size. The findings suggest that visual short-term memory, whether explicit or implicit, can decrease the perceived size of subsequent visual stimuli.     

Cognitive control in cued task switching with transition cues: Cue processing,task processing,and cue–task transition congruency

We investigated the processes underlying performance during cued task switching with transition cues. To this end, transition cueing and explicit cueing were compared in a design controlling for sequential effects in the two preceding trials in order to further examine the contribution of cue processes, task processes, and cue–task transition congruency during transition cueing. The study confirmed that the task-switch cost in transition cueing is larger than the task-switch cost in explicit cueing and showed that this larger switch cost is mainly due to cue processing. We also successfully decomposed performance in transition cueing into cue processing, task processing, and cue–task transition congruency on both a theoretical (Experiment 1) and an empirical basis (Experiments 2–3). Our empirical dissociation also demonstrates that cue–task transition congruency affects performance during both cue processing and task processing. We discuss the importance of our findings in relation to the different theories on task switching.     

The bandwidth of consolidation into visual short-term memory depends on the visual feature

We investigated the nature of the bandwidth limit in the consolidation of visual information into visual short-term memory. In the first two experiments, we examined whether previous results showing differential consolidation bandwidth for colour and orientation resulted from methodological differences by testing the consolidation of colour information with methods used in prior orientation experiments. We briefly presented two colour patches with masks, either sequentially or simultaneously, followed by a location cue indicating the target. Participants identified the target colour via buttonpress (Experiment 1) or by clicking a location on a colour wheel (Experiment 2). Although these methods have previously demonstrated that two orientations are consolidated in a strictly serial fashion, here we found equivalent performance in the sequential and simultaneous conditions, suggesting that two colours can be consolidated in parallel. To investigate whether this difference resulted from different consolidation mechanisms or a common mechanism with different features consuming different amounts of bandwidth, Experiment 3 presented a colour patch and an oriented grating either sequentially or simultaneously. We found a lower performance in the simultaneous than the sequential condition, with orientation showing a larger impairment than colour. These results suggest that consolidation of both features share common mechanisms. However, it seems that colour requires less information to be encoded than orientation. As a result, two colours can be consolidated in parallel without exceeding the bandwidth limit, whereas two orientations or an orientation and a colour exceed the bandwidth and appear to be consolidated serially.     

Combined expectancy effects are modulated by the relation between expectancy cues

Studies of combined expectancies have shown that spatial cueing effects are reduced on trials on which participants have to respond with an unexpected motor response. In the first two experiments the range of reduced expectancy effects is examined. Advance knowledge of the likely response was combined in a trial-by-trial procedure with modality cueing, object cueing, and task cueing. Effects of modality cueing were reduced on trials on which the target requested an unexpected response. However, effects of object cueing as well as effects of task cueing were unaffected by response cueing. Comparing experiments revealed that different types of cues were used in different experiments. To test the effect of type of cue on the interaction of expectancies the third experiment combined spatial cueing with response cueing. When integrated cues were used that cued the likely target location by an arrow and the likely response by an arrow too, spatial cueing effects were reduced on trials with unexpected responses. However, spatial cueing effects remained unaffected by response cueing when separated cues were used consisting in a word cueing the response and an arrow cueing target location. An account for the modulation of combined expectancies by the relation between cues is suggested in terms of the adjusted expectancy model.     

Textures shape the attentional focus: Evidence from exogenous and endogenous cueing

The spatial cueing paradigm (Posner Quarterly Journal of Experimental Psychology 32:3–25, 1980) has often been used to investigate the time course of the deployment of visual attention in space. In a series of eight experiments we investigated whether spatial cues would not only enhance processing of stimuli presented at cued locations, but also enhance processing of the entire texture in which the stimuli were presented. Results showed highest accuracy for responses to stimuli presented at cued locations, a replication of the traditional cueing effect (Posner 1980). Additionally, stimuli presented at uncued locations were responded to with higher accuracy when they were presented inside the same texture as the cued location, as compared with stimuli presented outside the texture with the cued location. To investigate this texture advantage for both automatic and voluntary attention deployment, exogenous and endogenous cues were used. The texture advantage was observed for short interstimulus intervals (ISIs) of 50 and 100 ms for exogenous cues and for a longer ISI of 200 ms for endogenous cues. These findings indicate that the arrangement of task-irrelevant visual stimuli also can have a large impact on the cueing effect. This suggests that visual spatial attention spreads texture-wise across the visual field. Control experiments revealed that the homogeneity within texture elements contributes most to the effect but that the texture advantage is a function of both orientation contrast at the texture border and homogeneity within texture elements.     

Detection costs and contingent attentional capture

Peripheral cues reduce reaction times (RTs) to targets at the cued location with short cue-target SOAs (cueing benefits) but increase RTs at long SOAs (cueing costs or inhibition of return). In detection tasks, cueing costs occur at shorter SOAs and are larger compared with identification tasks. To account for effects of task, detection cost theory claims that the integration of cue and target into an object file makes it more difficult to detect the target as a new event, which is the principal task-requirement in detection tasks. The integration of cue and target is expected to increase when cue and target are similar. We provided evidence for detection cost theory in the modified spatial cueing paradigm. Two types of cues (onset, color) were paired with two types of targets (onset, color) in separate blocks of trials. In the identification task, we found cueing benefits with matching (i.e., similar) cue-target pairs (onset-onset, color-color) and no cueing effects with nonmatching cue-target pairs (onset-color, color-onset), which replicates previous work. In the detection task, cueing effects with matching cues were reduced and even turned into cueing costs for onset cues with onset targets, suggesting that cue-target integration made it more difficult to detect targets at the cued location as new events. In contrast, the results for nonmatching cue-target pairs were not affected by task. Furthermore, the pattern of false alarms in the detection task provides a measure of similarity that may explain the size of cueing benefits and costs.     

A biased-competition approach to spatial cueing: Combining empirical studies and computational modelling

We examined the effects of cue luminance on visual orienting. Experiment 1 established that the commonly-found early facilitation and late inhibition of return (IOR) effects were independent of cue luminance with single cues in terms of their amplitude, although IOR was delayed in the low compared to the high luminance cue condition. In contrast, Experiment 2 revealed that, with dual cues of mixed luminance, both facilitation and IOR effects were found only with bright cues. When cues had equal luminance, however, there were cueing effects for two cued locations but only when the cues were bright. The data were accommodated in a neural network model of biased competition in which cueing effects emerge at more than one location provided input activation is sufficient to overcome competitive damping of the selection system.     

Effects of varying target luminance and cue luminance on attentional effects of spatial cues

Attentional effects of letter cues on target processing were investigated in a bilateral spatial cueing paradigm. Luminance contrast of the cue stimuli and of the target stimuli were both manipulated. Consistent with predictions derived from theoretical models of visual attention, manipulating cue luminance and target luminance had very different effects on performance. In agreement with the dorsal stream attention hypothesis (Marrett et al., 2011) orienting effects were unaffected by changes in cue luminance; but in agreement with the work of Reynolds, Pasternak, and Desimone (2000) and Carrasco, Ling, and Read (2004) orienting effects were strongly modulated by changes in the luminance and perceptual quality of the target. Theoretical implications of the results are considered and the data are explained in terms of a sensory enhancement effect, whereby attention amplifies the neuronal responses for attended stimuli.     

Attentional shifts to emotionally charged cues: Behavioural and erp data

Abstract

When information activated in memory involves emotional associations, the ability to shift attention away from an emotional cue is impaired compared to an emotionally neutral cue. The purpose of the present study was to investigate how emotional stimuli modulate attentional processes, and how this is reflected in localised brain electrical activity. Eight emotion and eight neutral words served as cues in a covert attention spatial orienting task. The cues were either valid or invalid indicators of which hemifield the target would be presented to. In the remaining trials, no cue was presented prior to the target. Twenty subjects were instructed to manually respond to the target as fast as possible. Event-related potentials (ERPs) showed an enhanced P3 component to the emotion words. The ERPs to the target showed enhanced P1 and P3 components on invalid trials, with emotional cues. There were faster reaction times (RTs) to validly cued targets, but only when the emotion words served as cues. The results demonstrated that the emotional cues elicited sustained focused attention, facilitating an engage mechanism of spatial orienting.     

Inhibition of return in response to gaze cues: The roles of time course and fixation cue

Recent studies have demonstrated that orienting of attention in response to nonpredictive gaze cues arises rapidly and automatically, in a similar fashion to peripheral sudden onset cueing. However, while peripheral cues consistently elicit inhibition of return (IOR) at about 300 ms following cue onset, very little is known about inhibition effects in response to gaze cues. The present experiments systematically examined the conditions under which IOR arises with such cues. Reliable inhibition effects were obtained. Importantly, IOR emerged only at long cue-target intervals and only when a second cue actively triggered attention away from the cued location. This suggests that compared to sudden onset cueing, gaze cueing results in both prolonged facilitation and a delayed onset of inhibition processes. Thus, although both types of cues elicit very similar orienting effects in terms of their basic behavioural outcomes, there are more subtle differences between gaze and peripheral cues with respect to the maintenance and quality of those cueing effects across time.     

Sequence effects by non-predictive arrow cues

Previous studies have found that attention orienting is influenced by the orienting processes of previous trials in a spatial cueing paradigm. This study mainly investigated whether this sequence effect could happen for a non-predictive arrow cue and whether it was influenced by the cue-target SOAs in previous and current trials. A significant sequence effect was observed for arrow cues even when voluntary control was not required, and it was significantly influenced by the SOAs of previous trials. The present results support the automatic memory check hypothesis and may reflect some temporal characteristics of the memory mechanism in sequential processes. In addition, contrary to the previous findings, we found an overall response facilitation following a catch trial, suggesting that the influence of preceding catch trials may be sensitive to experimental contexts.     

Viewers prefer predictive cues

Devaluation-by-inhibition hypothesis demonstrated that previously ignored items are judged more negatively than previously attended and novel items. Based on this view, the present study investigated the evaluation of preceding stimuli that presumably elicit attentional processes to task-relevant stimuli. Accordingly, we employed a Posner-type cueing task followed by evaluation of the preceding cues indicating left and right directions. The important manipulation is predictability of two different preceding cues which predict the target location with high or with low probability. In Experiment 1 with two different arrows, a low predictive arrow was judged more negatively than a high predictive cue. Experiment 2 using gaze cues of two persons instead of two different arrows supported the findings of Experiment 1. These findings are consistent with devaluation-by-inhibition, suggesting that cue items triggering attention to the target are devaluated when they have less predictability.     

A severe capacity limit in the consolidation of orientation information into visual short-term memory

Previous research has suggested that two color patches can be consolidated into visual short-term memory (VSTM) via an unlimited parallel process. Here we examined whether the same unlimited-capacity parallel process occurs for two oriented grating patches. Participants viewed two gratings that were presented briefly and masked. In blocks of trials, the gratings were presented either simultaneously or sequentially. In Experiments 1 and 2, the presentation of the stimuli was followed by a location cue that indicated the grating on which to base one’s response. In Experiment 1, participants responded whether the target grating was oriented clockwise or counterclockwise with respect to vertical. In Experiment 2, participants indicated whether the target grating was oriented along one of the cardinal directions (vertical or horizontal) or was obliquely oriented. Finally, in Experiment 3, the location cue was replaced with a third grating that appeared at fixation, and participants indicated whether either of the two test gratings matched this probe. Despite the fact that these responses required fairly coarse coding of the orientation information, across all methods of responding we found superior performance for sequential over simultaneous presentations. These findings suggest that the consolidation of oriented gratings into VSTM is severely limited in capacity and differs from the consolidation of color information.