Involuntary listening aids seeing: evidence from human electrophysiology

It is well known that sensory events of one modality can influence judgments of sensory events in other modalities. For example, people respond more quickly to a target appearing at the location of a previous cue than to a target appearing at another location, even when the two stimuli are from different modalities. Such cross-modal interactions suggest that involuntary spatial attention mechanisms are not entirely modality-specific. In the present study, event-related brain potentials (ERPs) were recorded to elucidate the neural basis and timing of involuntary, cross-modal spatial attention effects. We found that orienting spatial attention to an irrelevant sound modulates the ERP to a subsequent visual target over modality-specific, extrastriate visual cortex, but only after the initial stages of sensory processing are completed. These findings are consistent with the proposal that involuntary spatial attention orienting to auditory and visual stimuli involves shared, or at least linked, brain mechanisms.     

Top-down control over involuntary attention switching in the auditory modality

We tested the effects of predictability on involuntary attention switching to task-irrelevant sound changes (distraction). Behavioral and neurophysiological evidence are provided, showing that the predictability of task-irrelevant sound changes eliminates effects of distraction even though the automatic auditory change detection system remains responsive. Two indices of distraction, slower task performance and cortical brain responses associated with attention switching, were seen only in the unpredictable condition, in which the irrelevant acoustic changes were unexpected. Attention was not involuntarily drawn away from the primary task when the subjects had foreknowledge of when the irrelevant changes would occur. These results demonstrate attentional control over orienting to sound changes and suggest that involuntary attention switching occurs mainly when an irrelevant stimulus change is unexpected. The present data allowed observation of the temporal dynamics of attention switching in the human brain.     

ERPs reveal similar effects of social gaze orienting and voluntary attention, and distinguish each from reflexive attention

Spatial attention can be reflexively captured by a physically salient stimulus, effortfully directed toward a relevant location, or involuntarily oriented in the direction of another person's gaze (i.e., social gaze orienting). Here, we used event-related potentials to compare the effects of these three types of orienting on multiple stages of subsequent target processing. Although gaze orienting has been associated more strongly with reflexive capture than with voluntary attention, the present data provide new evidence that the neural effects of social gaze orienting are markedly different from the effects of reflexive attentional capture by physically salient stimuli. Specifically, despite their similar behavioral effects, social gaze orienting and reflexive capture produce different effects on both early sensory processing (~120 ms; P1/N1 components) and later, higher-order processing (~300 ms; P3 component). In contrast, the effects of social gaze orienting were highly similar to those of voluntary orienting at these stages of target processing.     

Active suppression after involuntary capture of attention

After attention has been involuntarily captured by a distractor, how is it reoriented toward a target? One possibility is that attention to the distractor passively fades over time, allowing the target to become attended. Another possibility is that the captured location is actively suppressed so that attention can be directed toward the target location. The present study investigated this issue with event-related potentials (ERPs), focusing on the N2pc component (a neural measure of attentional deployment) and the Pd component (a neural measure of attentional suppression). Observers identified a color-defined target in a search array, which was preceded by a task-irrelevant cue array. When the cue array contained an item that matched the target color, this item captured attention (as measured both behaviorally and with the N2pc component). This capture of attention was followed by active suppression (indexed by the Pd component), and this was then followed by a reorienting of attention toward the target in the search array (indexed by the N2pc component). These findings indicate that the involuntary capture of attention by a distractor is followed by an active suppression process that presumably facilitates the subsequent voluntary orienting of attention to the target.     

Contingent attentional capture or delayed allocation of attention?

Under certain circumstances, external stimuli will elicit an involuntary shift of spatial attention, referred to as attentional capture. According to the contingent involuntary orienting account (Folk, Remington, & Johnston, 1992), capture is conditioned by top-down factors that set attention to respond involuntarily to stimulus properties relevant to one's behavioral goals. Evidence for this comes from spatial cuing studies showing that a spatial cuing effect is observed only when cues have goal-relevant properties. Here, we examine alternative, decision-level explanations of the spatial cuing effect that attribute evidence of capture to postpresentation delays in the voluntary allocation of attention, rather than to on-line involuntary shifts in direct response to the cue. In three spatial cuing experiments, delayed-allocation accounts were tested by examining whether items at the cued location were preferentially processed. The experiments provide evidence that costs and benefits in spatial cuing experiments do reflect the on-line capture of attention. The implications of these results for models of attentional control are discussed.     

When cross-modal spatial attention fails

There is now convincing evidence that an involuntary shift of spatial attention to a stimulus in one modality can affect the processing of stimuli in other modalities, but inconsistent findings across different paradigms have led to controversy. Such inconsistencies have important implications for theories of cross-modal attention. The authors investigated why orienting attention to a visual event sometimes influences responses to subsequent sounds and why it sometimes fails to do so. They examined visual-cue-on-auditory-target effects in two paradigms--implicit spatial discrimination (ISD) and orthogonal cuing (OC)--that have yielded conflicting findings in the past. Consistent with previous research, visual cues facilitated responses to same-side auditory targets in the ISD paradigm but not in the OC paradigm. Furthermore, in the ISD paradigm, visual cues facilitated responses to auditory targets only when the targets were presented directly at the cued location, not when they appeared above or below the cued location. This pattern of results confirms recent claims that visual cues fail to influence responses to auditory targets in the OC paradigm because the targets fall outside the focus of attention. (PsycINFO Database Record (c) 2008 APA, all rights reserved).     

The time course of attentional zooming: A comparison of voluntary and involuntary allocation of attention to the levels of compound stimuli

Summary The time course of attentional zooming between the levels of hierarchically structured compound stimuli (level-specific covert orienting of attention) is explored experimentally. The experiment compares the RTSOA functions of voluntarily and involuntarily initiated level-specific reorienting within a cost-benefit experiment using level-specific cues. With respect to the two modes of initiation, the results reveal no functional differences between attention shift and attentional zooming. Both can be initiated either voluntarily or involuntarily, the latter mode dominating the former; for both, involuntary initiation produces faster reorienting of attention than does voluntary initiation, and for both, involuntary initiation is more effective than voluntary initiation. However, the time needed to complete attentional orienting is about twice as long for zooming than for shifts. This quantitative difference suggests that there is a functional difference between level-specific and horizontal covert orienting. The difference is explained by postulating that zooming and attention shifts differ in the number of parameter sets that have to be adjusted in the reorienting of attention. The experiment also reveals that attentional zooming to the local level needs more time than does zooming to the global level. This result gives some support to the hypothesis that the RT difference between global and local identifications (Navon's global-dominance phenomenon) is due to an additional step in the course of reorienting attention away from the global level (which is usually attended to first) to the local level, when this level is to be identified.     

Attention and ageing: Measuring effects of involuntary and voluntary orienting in isolation and in combination

The cueing paradigm provides an established method for eliciting involuntary and voluntary attention shifts. Involuntary orienting is traditionally measured with non‐predictive peripheral cues and voluntary orienting with predictive central arrows. Recent studies with young adults have established that predictive central arrows trigger a combination of involuntary and voluntary orienting, raising the possibility that previous studies – including those with older adults – misinterpreted their findings with central arrow cues as isolating the effects of voluntary attention. The present experiment applied different cueing conditions that measured involuntary orienting, voluntary orienting, and involuntary and voluntary orienting in combination in older adults. The results show that past studies of voluntary orienting in older adults confound involuntary and voluntary orienting. Cueing effects in a condition that for the first time isolated voluntary orienting (predictive number cues) with older adults were significant, and comparable to effects for younger adults, demonstrating that older adults successfully utilize cues to direct their spatial attention strategically. A similar normal pattern of orienting was observed for involuntary orienting. Our study provides a methodology that can be applied effectively to isolate and investigate the effects of age on voluntary and involuntary attention.     

The involuntary capture of attention by novel feature pairings: A study of voice—location integration in auditory sensory memory

Past researchers of the integration of information in memory have typically required participants to attend to and/or commit to memory the stimuli conveying distinct features, rendering difficult the examination of whether the maintenance of the feature pairings can occur involuntarily. To address this issue, the integration of voice and location information in auditory sensory memory was measured using a cross-modal oddball task, in which task-irrelevant auditory deviants are known to capture attention in an involuntary fashion. Participants categorized visual digits presented shortly after to-be-ignored sounds. These sounds consisted in the same phoneme played simultaneously in both ears but in different voices (female in one ear, male in the other). On most trials, the pairing of voice to location was constant (standard sound). On rare and unpredictable trials, the voices swapped locations (deviant sound). In line with past work on attention capture by auditory novelty, the participants were significantly slower to judge the visual digits following the deviant sound, indicating the involuntary encoding of the links between voice and location in auditory memory. These results suggest that voices and locations are integrated in memory and that this binding occurs in conditions in which participants do not intend to commit any information to memory.     

A static color discontinuity can capture spatial attention when the target is an abrupt-onset singleton

C. L. Folk, R. W. Remington, and J. C. Johnston's (1992) contingent involuntary orienting hypothesis states that a salient visual feature will involuntarily capture attention only when the observer's attentional set includes similar features. In four experiments, when the target's relevant feature was its being an abruptly onset singleton, attentional capture occurred for a static discontinuity cue that was the boundary between a group of red Xs contiguously joined to a group of green Os within a single row. Such an attentional capture effect is novel and contrary to Folk et al.'s (1992) hypothesis, because the attentional set for the target should have included abrupt onset but not color discontinuity, which was the feature that captured attention. These capture effects were involuntary because they occurred even when the target never appeared in the same location as the cue, and color could not have been used as a cue to signal the appearance of the target array (cf. B. S. Gibson & E. M. Kelsey, 1998).     

An effective attentional set for a specific colour does not prevent capture by infrequently presented motion distractors

An organism's survival depends on the ability to rapidly orient attention to unanticipated events in the world. Yet, the conditions needed to elicit such involuntary capture remain in doubt. Especially puzzling are spatial cueing experiments, which have consistently shown that involuntary shifts of attention to highly salient distractors are not determined by stimulus properties, but instead are contingent on attentional control settings induced by task demands. Do we always need to be set for an event to be captured by it, or is there a class of events that draw attention involuntarily even when unconnected to task goals? Recent results suggest that a task-irrelevant event will capture attention on first presentation, suggesting that salient stimuli that violate contextual expectations might automatically capture attention. Here, we investigated the role of contextual expectation by examining whether an irrelevant motion cue that was presented only rarely (～3–6% of trials) would capture attention when observers had an active set for a specific target colour. The motion cue had no effect when presented frequently, but when rare produced a pattern of interference consistent with attentional capture. The critical dependence on the frequency with which the irrelevant motion singleton was presented is consistent with early theories of involuntary orienting to novel stimuli. We suggest that attention will be captured by salient stimuli that violate expectations, whereas top-down goals appear to modulate capture by stimuli that broadly conform to contextual expectations.     

How does reward compete with goal-directed and stimulus-driven shifts of attention?

In order to behave adaptively, attention can be directed in space either voluntarily (i.e. endogenously) according to strategic goals, or involuntarily (i.e. exogenously) through reflexive capture by salient or novel events. The emotional or motivational values of stimuli can also influence attentional orienting. However, little is known about how reward-related effects compete or interact with endogenous and exogenous attention mechanisms. Here we designed a visual search paradigm in which goal-driven and stimulus-driven shifts of attention were manipulated by classic spatial cueing procedures, while an irrelevant, but previously rewarded stimulus also appeared as a distractor and hence competed with both types of spatial attention during search. Our results demonstrated that stimuli previously associated with a high monetary reward received higher attentional priority in the subsequent visual search task, even though these stimuli and reward were no longer task-relevant, mitigating the attentional orienting induced by both endogenous and exogenous cues.     

Enhanced orienting effects: Evidence for an interaction principle

Predictive arrow cues, as used in the classic “Posner paradigm”, that were long thought to engage and isolate voluntary attention, may in fact trigger a strong interaction between voluntary and involuntary attention (Ristic & Kingstone, 2006). This interaction produces an orienting effect that exceeds both the effects of involuntary and voluntary attention alone, and the additive combination of involuntary and voluntary orienting. The present study shows that nonpredictive peripheral cues—understood to engage and isolate involuntary attention—if made predictive, result in enhanced orienting effects similar to predictive arrows. The important contribution of these data is that they suggest an “interaction principle”: If attention cues can elicit reliable involuntary orienting, then when they are made spatially predictive, the resulting attention effect will be greater than the sum of involuntary and voluntary orienting alone.     

When attention is intact in adults with ADHD

Is covert visuospatial attention—selective processing of information in the absence of eye movements—preserved in adults with attention-deficit/hyperactivity disorder (ADHD)? Previous findings are inconclusive due to inconsistent terminology and suboptimal methodology. To settle this question, we used well-established spatial cueing protocols to investigate the perceptual effects of voluntary and involuntary attention on an orientation discrimination task for a group of adults with ADHD and their neurotypical age-matched and gender-matched controls. In both groups, voluntary attention significantly improved accuracy and decreased reaction times at the relevant location, but impaired accuracy and slowed reaction times at irrelevant locations, relative to a distributed attention condition. Likewise, involuntary attention improved accuracy and speeded responses. Critically, the magnitudes of all these orienting and reorienting attention effects were indistinguishable between groups. Thus, these counterintuitive findings indicate that spatial covert attention remains functionally intact in adults with ADHD.     

儿童外显视空间注意转移

采用提示范式探讨了三、六年级儿童的外显视空间注意转移。实验结果表明：内源性提示下儿童表现出显著的提示效度效应,其效度效应量在年龄组间没有显著差异;较短SOAs的外源性提示下,儿童表现出显著的提示效度效应;较长SOAs的外源性提示下儿童没有表现出返回抑制效应。用注意的过滤器理论和对象文件模型讨论了本研究的结果     

Are eyes special? It depends on how you look at it

Recent behavioral data have shown that central nonpredictive gaze direction triggers reflexive shifts of attention toward the gazed-at location (e.g., Friesen & Kingstone, 1998). Friesen and Kingstone suggested that this reflexive orienting effect is unique to biologically relevant stimuli. Three experiments were conducted to test this proposal by comparing the attentional orienting produced by nonpredictive gaze cues (biologically relevant) with the attentional orienting produced by nonpredictive arrow cues (biologically irrelevant). Both types of cues produced reflexive orienting in adults (Experiment 1) and preschoolers (Experiment 2), suggesting that gaze cues are not special. However, Experiment 3 showed that nonpredictive arrows produced reflexive orienting in both hemispheres of a split-brain patient. This contrasts with Kingstone, Friesen, and Gazzaniga's (2000) finding that nonpredictive gaze cues produce reflexive orienting only in the face-processing hemisphere of split-brain patients. Therefore, although nonpredictive eyes and arrows may produce similar behavioral effects, they are not subserved by the same brain systems. Together, these data provide important insight into the nature of the representations of directional stimuli involved in reflexive attentional orienting.     

Capturing attention is not that simple: Different mechanisms for stimulus-driven and contingent capture

Attentional orienting can be involuntarily directed to task-irrelevant stimuli, but it remains unsolved whether such attentional capture is contingent on top-down settings or could be purely stimulus-driven. We propose that attentional capture depends on the stimulus property because transient and static features are processed differently; thus, they might be modulated differently by top-down controls. To test this hybrid account, we adopted a spatial cuing paradigm in which a noninformative onset or color cue preceded an onset or color target with various stimulus onset asynchronies (SOAs). Results showed that the onset cue captured attention regardless of target type at short—but not long—SOAs. In contrast, the color cue captured attention at short and long SOAs, but only with a color target. The overall pattern of results corroborates our hypothesis, suggesting that different mechanisms are at work for stimulus-driven capture (by onset) and contingent capture (by color). Stimulus-driven capture elicits reflexive involuntary orienting, and contingent capture elicits voluntary feature-based enhancement.     

Is “Inhibition of Return” due to the inhibition of the return of attention?

Inhibition of Return (IOR) is usually explained in terms of orienting–reorienting of attention, emphasizing an underlying mechanism that inhibits the return of attention to previously selected locations. Recent data challenge this explanation to the extent that the IOR effect is observed at the location where attention is oriented to, where no reorienting of attention is needed. To date, these studies have involved endogenous attentional selection of attention and thus indicate a dissociation between the voluntary attention of spatial attention and the IOR effect. The present work demonstrates a dissociation between the involuntary orienting of spatial attention and the IOR effect. We combined nonpredictive peripheral cues with nonpredictive central orienting cues (either arrows or gaze). The IOR effect was observed to operate independent of involuntary spatial orienting. These data speak against the “reorienting hypothesis” of IOR. We suggest an alternative explanation whereby the IOR effect reflects a cost in detecting a new event (the target) at the location where another event (a cue) was coded before.     

The cognitive determinants of behavioral distraction by deviant auditory stimuli: a review

Numerous studies have demonstrated that rare and unexpected changes in an otherwise repetitive or structured sound sequence ineluctably break through selective attention and impact negatively on performance in an unrelated task. While the electrophysiological responses to unexpected sounds have been extensively studied, behavioral distraction has received relatively less attention until recently. In this paper, I review work examining the cognitive underpinnings of behavioral distraction by deviant sounds and highlight some of its key determinants. Evidence indicates that deviance distraction (1) derives from the time penalty associated with the involuntary orientation of attention to and away from the deviant sound and from resulting effects such as the reactivation of the relevant task set upon the presentation of the target stimulus; and (2) is mediated by a number of factors (some increasing distraction, such as aging or induced emotions; some decreasing it, such as a memory load or cognitive control). Contrary to the received view that deviants ineluctably elicit distraction, recent work demonstrates that it is contingent upon auditory distractors acting as unspecific warning signals in the service of goal-oriented behavior, and that deviants do not elicit distraction because they are rare but because they violate the cognitive system’s predictions (which can be manipulated through implicit rule learning or explicit cueing). Evidence is also presented indicating that the capture of attention by spoken deviant sounds is followed by an involuntary evaluation of their semantic properties, the outcome of which can be robust enough to linger in working memory and interfere with subsequent behavior. Finally, I review studies suggesting that behavioral deviance distraction is not the mere byproduct of the mismatch negativity, P3a and re-orientation negativity electrophysiological responses and highlight a number of outstanding questions for future research.     

Orienting to counterpredictive gaze and arrow cues

In separate experiments, counterpredictive arrow, eye gaze, or abrupt-onset cues were used to test the hypothesis that individual differences in voluntary control influence involuntary orienting. In contrast with previous findings (Friesen, Ristic, & Kingstone, 2004), involuntary orienting effects were found for arrow cues.Furthermore, for both eye gaze and arrow cues, individual differences in voluntarycontrol were associatedwith involuntary orienting: Involuntary orienting effects were larger for participants who were more effective at using the cue to reorient attention, and also for participants who reported greater ability to control attention. Orienting to abrupt-onset cues was not correlated to individual differences in self-reported attentional control. The findings show that eye gaze and arrow cues instigate similar involuntary and voluntary effects and that involuntary orienting to symbolic cues is linked to individual differences in voluntary control.