Orienting of attention: Then and now

It is nearly 35 years since I gave the 7th Sir Frederick Bartlett lecture at Oxford University. This was published as a paper entitled “Orienting of attention in the quarterly journal”. The topic was then primarily in psychology, but now equally often in neuroscience. This paper summarizes the background of the reaction time methods used in the original paper and findings that emerged later on the sensory consequences of orienting, mainly in the visual system. It then discusses the brain network that is the source of the sensory amplification and other brain networks that are involved in attention. Next, it reviews studies of the development of attentional networks in early life. Finally, it indicates how the new tools available to explore the human brain can lead to further progress.     

Visual orienting in response to attentional cues: Spatial correspondence is critical,conscious awareness is not

Three experiments examined visual orienting in response to spatial precues. In Experiments 1 and 2, attentional effects of central letters were stimulus driven: Orienting was dependent on the spatial layout of the cue display. When there were no correspondences between spatial features of the cue display and target location, attentional effects were absent, despite a conscious intention to orient in response to the symbolic information carried by the cue letters. In Experiment 3 clear orienting effects were observed when target location corresponded with spatial features of the cue display, but the magnitude of these effects was unaffected by whether participants were aware or unaware of the cue–target relationship. These findings are consistent with the view that (1) spatial correspondences between cues and targets are a critical factor driving visual orienting in cueing paradigms, and (2) attentional effects of spatial precues are largely independent of participants’ conscious awareness of the cue–target relationship.     

Investigating hemispheric lateralization of reflexive attention to gaze and arrow cues

Recent studies have demonstrated that central cues, such as eyes and arrows, reflexively trigger attentional shifts. However, it is not clear whether the attentional mechanisms induced by these two cues are similar or rather differ in some important way. We investigated hemispheric lateralization of the orienting effects induced by the two cue types in a group of 48 healthy participants comparing arrows and eye gaze as central non-predictive cues in a discrimination task, in which a target stimulus was briefly presented in one of two peripheral positions (left or right of fixation). As predicted by neuropsychological data, reflexive orienting to gaze cues was only observed when the target was presented in the left visual field, whereas reflexive orienting to arrow cues occurred for targets presented in both left and right visual fields.     

Exogenous and endogenous spatial attention effects on visuospatial working memory

In this study, we investigate how exogenous and endogenous orienting of spatial attention affect visuospatial working memory (VSWM). Specifically, we focused on two attentional effects and their consequences on storage in VSWM, when exogenous (Experiment 1) or endogenous (Experiment 2) orienting cues were used. The first effect, known as the meridian effect, is given by a decrement in behavioural performance when spatial cues and targets are presented in locations separated by vertical and/or horizontal meridians. The second effect, known as the distance effect, is given by a decrement in the orienting effects as a function of the spatial distance between cues and targets. Our results revealed a dissociation between exogenous and endogenous orienting mechanisms in terms of both meridian and distance effects. We found that meridian crossing affects performance only when endogenous cues were used. Specifically, VSWM performance with endogenous cueing depended more on the number of meridian crossings than on distance between cue and target. By contrast, a U-shaped distance dependency was observed using exogenous cues. Our findings therefore suggest that exogenous and endogenous orienting mechanisms lead to different forms of attentional bias for storage in VSWM.     

Voluntary and involuntary attention have different consequences: The effect of perceptual difficulty

We propose that voluntary and involuntary attention affect different mechanisms and have different consequences for performance measured in reaction time. Voluntary attention enhances the perceptual representation whereas involuntary attention affects the tendency to respond to stimuli in one location or another. In a spatial-cueing paradigm, we manipulated perceptual difficulty and compared voluntary and involuntary attention. For the voluntary-attention condition, the spatial cue was predictive of the target location, whereas in the involuntary-attention condition it was not. Increasing perceptual difficulty increased the attention effect with voluntary attention, but decreased it with involuntary attention. Thus voluntary and involuntary attention have different consequences when perceptual difficulty is manipulated and hence are probably caused by different mechanisms.     

Exogenous attention to angry faces in social anxiety: A perceptual accuracy approach

We investigated the interaction between endogenous and exogenous attention for the processing of emotional stimuli in individuals with high social anxiety using accuracy rates. Following the presentation of an endogenous cue at the centre, exogenous cues (i.e., angry and neutral faces) were presented at peripheral locations. Subsequently, non-emotional masked targets were presented, and the participants were instructed to discriminate between the targets. With respect to exogenous attention, high socially anxious people exhibited higher accuracy when the angry face and target appeared on the same side than when they appeared on different sides, whereas low socially anxious people did not exhibit such effects. On the other hand, different abilities of endogenous attention were not observed between high and low socially anxious people. These results suggest that exogenous attention is biased towards threat in high socially anxious people.     

Auditory orienting of attention: Effects of cues and verbal workload with children and adults

The use of tone cues has an improving effect on the auditory orienting of attention for children as for adults. Verbal cues, on the contrary, do not seem to orient attention as efficiently before the age of 9 years. However, several studies have reported inconsistent effects of orienting attention on ear asymmetries. Multiple factors are questioned, such as the role of verbal workload. Indeed, the semantic nature of the dichotic pairs and their load of processing may explain orienting of attention performance. Thus, by controlling for the role of verbal workload, the present experiment aimed to evaluate the development of capacities for the auditory orienting of attention. Right-handed, 6- to 12-year-olds and adults were recruited to complete either a tone cue or a verbal cue dichotic listening task in the identification of familiar words or nonsense words. A factorial design analysis of variance showed a significant right-ear advantage for all the participants and for all the types of stimuli. A major developmental effect was observed in which verbal cues played an important role: they allowed the 6- to 8-year-olds to improve their performance of identification in the left ear. These effects were taken as evidence of the implication of top-down processes in cognitive flexibility across development.     

Orienting of attention with eye and arrow cues and the effect of overtraining

In contrast to the classical distinction between a controlled orienting of attention induced by central cues and an automatic capture induced by peripheral cues, recent studies suggest that central cues, such as eyes and arrows, may trigger a reflexive-like attentional shift. Yet, it is not clear if the attention shifts induced by these two cues are similar or if they differ in some important aspect. To answer this question, in Experiment 1 we directly compared eye and arrow cues in a counter-predictive paradigm while in Experiment 2 we compared the above cues with a different symbolic cue. Finally, in Experiment 3 we tested the role of over-learned associations in cueing effects. The results provide evidence that eyes and arrows induce identical behavioural effects. Moreover, they show that over-learned associations between spatially neutral symbols and the cued location play an important role in yielding early attentional effects.     

Emotional attention: effects of emotion and gaze direction on overt orienting of visual attention

In the present study we considered the two factors that have been advocated for playing a role in emotional attention: perception of gaze direction and facial expression of emotions. Participants performed an oculomotor task in which they had to make a saccade towards one of the two lateral targets, depending on the colour of the fixation dot which appeared at the centre of the computer screen. At different time intervals (stimulus onset asynchronies, SOAs: 50,100,150 ms) following the onset of the dot, a picture of a human face (gazing either to the right or to the left) was presented at the centre of the screen. The gaze direction of the face could be congruent or incongruent with respect to the location of the target, and the expression could be neutral or angry. In Experiment 1 the facial expressions were presented randomly in a single block, whereas in Experiment 2 they were shown in separate blocks. Latencies for correct saccades and percentage of errors (saccade direction errors) were considered in the analyses. Results showed that incongruent trials determined a significantly higher percentage of saccade direction errors with respect to congruent trials, thus confirming that gaze direction, even when task-irrelevant, interferes with the accuracy of the observer’s oculomotor behaviour. The angry expression was found to hold attention for a longer time with respect to the neutral one, producing delayed saccade latencies. This was particularly evident at 100 ms SOA and for incongruent trials. Emotional faces may then exert a modulatory effect on overt attention mechanisms.     

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.     

The development of and interaction among alerting,orienting, and executive attention in children

A sex-balanced sample (N = 96) of children from age 6.5 to age 12.5 completed a modified Attention Network Test. Across these ages, we found evidence for developmental changes to alerting and executive control but stable orienting. Additionally, we found that the youngest members of our sample manifested an interaction between alerting and executive control that is opposite to that typically found in adults; a reversal that diminishes with age to achieve the adult pattern by the older end of the age range of our sample.     

When endogenous spatial attention improves conscious perception: Effects of alerting and bottom-up activation

Recent studies have consistently demonstrated that conscious perception interacts with exogenous attentional orienting, but it can be dissociated from endogenous attentional orienting (Chica, Lasaponara, et al., 2011, Wyart and Tallon-Baudry, 2008). It has been hypothesized that enhanced conscious processing at exogenously attended locations results from a synergistic action of spatial orienting, bottom-up activation, and phasic alerting induced by the abrupt onset of the exogenous cue (Chica, Lasaponara, et al., 2011). Instead, as endogenous cues need more time to be interpreted, the phasic alerting they produce may have dissipated when the target appears. Furthermore, endogenous cues presumably elicit a weak bottom-up activation at the cued location. Consistent with these hypotheses, we observed that endogenous attention modulated conscious perception, but only when phasic alerting or bottom-up activation was increased. Results are discussed in the context of recent theoretical models of consciousness (Dehaene, Changeux, Naccache, Sackur, & Sergent, 2006).     

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.     

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.     

Modulation of auditory spatial attention by visual emotional cues: differential effects of attentional engagement and disengagement for pleasant and unpleasant cues

Previous research has demonstrated that threatening, compared to neutral pictures, can bias attention towards non-emotional auditory targets. Here we investigated which subcomponents of attention contributed to the influence of emotional visual stimuli on auditory spatial attention. Participants indicated the location of an auditory target, after brief (250 ms) presentation of a spatially non-predictive peripheral visual cue. Responses to targets were faster at the location of the preceding visual cue, compared to at the opposite location (cue validity effect). The cue validity effect was larger for targets following pleasant and unpleasant cues compared to neutral cues, for right-sided targets. For unpleasant cues, the crossmodal cue validity effect was driven by delayed attentional disengagement, and for pleasant cues, it was driven by enhanced engagement. We conclude that both pleasant and unpleasant visual cues influence the distribution of attention across modalities and that the associated attentional mechanisms depend on the valence of the visual cue.     

Sitting on the word “chair”: Behavioral support, contextual cues, and the literal use of symbols

Recent work from an embodied-cognition perspective suggests that symbolic understanding involves bodily actions. Indeed, laboratory evidence and cultural phenomena such as magic rituals and symbolic aggression show that the behaviors evoked by a word and its referent can be quite similar to each other. In other circumstances, however, words and objects fail to display the expected degree of functional equivalence: Although we regularly sit on chairs, for example, we normally do not sit on the word “chair.” In two experiments we evaluated whether functional equivalence between word and object depended on behavioral support and contextual stimuli, as suggested by some Pavlovian views of symbolic performance. Children spent more or less time seated on a token of the word “chair,” depending on supports for sitting and background stimuli. This study may help to understand the determinants of response frequency in symbolic understanding.     

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 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.     

Two types of behavioral inhibition: Relations to effortful control and attention in school children

This study aimed to examine the relationship of two types of behavioral inhibition, social inhibition and nonsocial inhibition, to effortful control and attention in 7–9-year olds. Social and nonsocial inhibition and effortful control were assessed by questionnaires. The child version of the Attention Network Task was used to measure attention including alerting, orienting and executive attention. Results indicated that in girls, social inhibition was negatively related to effortful control and alerting, while nonsocial inhibition was positively related to orienting; there was an interaction between social and nonsocial inhibition in predicting executive attention in boys. Thus, it is of great significance to differentiate social and nonsocial inhibition when examining the association between behavioral inhibition and effortful control and attention in school-age children.