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.     

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).     

Matching cue size and task properties in exogenous attention

Exogenous attention is an involuntary, reflexive orienting response that results in enhanced processing at the attended location. The standard view is that this enhancement generalizes across visual properties of a stimulus. We test whether the size of an exogenous cue sets the attentional field and whether this leads to different effects on stimuli with different visual properties. In a dual task with a random-dot kinematogram (RDK) in each quadrant of the screen, participants discriminated the direction of moving dots in one RDK and localized one red dot. Precues were uninformative and consisted of either a large or a small luminance-change frame. The motion discrimination task showed attentional effects following both large and small exogenous cues. The red dot probe localization task showed attentional effects following a small cue, but not a large cue. Two additional experiments showed that the different effects on localization were not due to reduced spatial uncertainty or suppression of RDK dots in the surround. These results indicate that the effects of exogenous attention depend on the size of the cue and the properties of the task, suggesting the involvement of receptive fields with different sizes in different tasks. These attentional effects are likely to be driven by bottom-up mechanisms in early visual areas.     

工作记忆负荷对无意注意的影响

通过探讨工作记忆负荷对无意注意的影响,考察工作记忆的认知控制功能对选择性注意的作用机制。为了避免工作记忆和选择注意的目标或者干扰子之间的知觉注意资源的竞争,采用言语工作记忆任务和视觉空间位置辨别任务,同时视觉干扰刺激采用被试无法识别的韩语。结果发现,在高负荷条件下,干扰效应显著;而在低和中负荷条件下,没有观察到干扰效应。说明在高负荷条件下,被试没有额外的资源来抑制干扰加工,从而出现了显著的干扰效应。由此,本研究支持负荷理论的观点：工作记忆在选择性注意中执行认知控制功能。     

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.     

The role of spatial attention and other processes on the magnitude and time course of cueing effects

We are quite often exposed to multiple objects present in the visual scene, thus attentional selection is necessary in order to selectively respond to the relevant information. Objects can be selected on the basis of the location they occupy by orienting attention in space. In this paper, we review the evidence showing that attention can be oriented in space either endogenously, on the basis of central cues, predictive of the relevant location, or exogenously, automatically triggered by the salient properties of visual stimuli (peripheral cues). Several dissociations observed between orienting on the basis of the two types of cues have led to the conclusion that they do not represent just two modes of triggering the orienting of the very same attentional mechanism, but rather they modulate processing differently. We present a theoretical framework according to which endogenous predictive cues facilitate target processing by orienting attention, thus amplifying processing at the attended location. In contrast, apart from attentional orienting, peripherally presented discrepant cues might trigger additional cue-target event-integration and event-segregation processes, which modulate processing in a different way, thus leading to cueing effects that are exclusively triggered by peripheral cues.     

Spatial attention and feature-based attention are differentially sensitive to individual working memory capacity and perceptual load

ABSTRACT

A central and long-standing topic of interest to both psychologists and neuroscientists has been the capacity limited nature of perception, cognition and action. Most often, attention is the term invoked to label the mechanism by which a limited cognitive system can prioritize and select a subset of task-relevant sensory inputs and actions amongst a seemingly unbounded set of possible representations and behaviour. This selective mechanism is often modelled as a unitary and domain-general capacity-limited resource that is dynamically shifted to meet the processing demands invoked by the context. The present work offers a test of the unitary attention hypothesis using a variant of a classic validity manipulation [(Posner, M. I. (1980). Orienting of attention. Quarterly Journal of Experimental Psychology, 32, 3–25)] and the inferential logic of Sternberg (2001. Separate modifiability, mental modules, and the use of pure and composite measures to reveal them. Acta Psychologica, 106, 147–246). The results stand as evidence for at least two modular visual attention systems split according to a spatial and feature-based reference.     

The effect of induced sadness and moderate depression on attention networks

This study investigates how sadness and minor/moderate depression influences the three functions of attention: alerting, orienting, and executive control using the Attention Network Test. The aim of the study is to investigate whether minor-to-moderate depression is more similar to sadness or clinical depression with regard to attentional processing. It was predicted that both induced sadness and minor-to-moderate depression will influence executive control by narrowing spatial attention and in turn this will lead to less interference from the flanker items (i.e. less effects of congruency) due to a focused attentional state. No differences were predicted for alerting or orienting functions. The results from the two experiments, the first inducing sadness (Experiment 1) and the second measuring subclinical depression (Experiment 2), show that, as expected, participants who are sad or minor to moderately depressed showed less flanker interference compared to participants who were neither sad nor depressed. This study provides strong evidence, that irrespective of its aetiology, sadness and minor/moderate depression have similar effects on spatial attention.     

Endogenous shifts of attention cause distortions in the perception of space: Reviewing and examining the attentional repulsion effect

ABSTRACT

The functioning of spatial attention and its effects on visual processing are typically studied using chronometric and accuracy measures of behaviour. However, a growing body of literature has studied the attentional repulsion effect (ARE). Simply put, when attention is focused on one location in the visual field, stimuli appearing nearby the attended location are perceived as being located further away from the attended location than they physically are. The ARE is particularly compelling, as it is best explained by considering the receptive field properties of visual cells, thus allowing for more direct comparisons between behaviour and neural functioning. Nonetheless, most research testing the ARE has manipulated spatial attention exogenously. Furthermore, for studies that have explored endogenous attention and the ARE, empirical evidence is conflicting. Therefore, the aim of the current study was to address this inconsistency by testing the effect of voluntary attention on spatial repulsion using an optimal operationalization of endogenous attention. Centrally presented, highly informative double-cues were used to shift attention, and placeholders were included in the display to help anchor attention. Overall, we observed strong spatial repulsion effects when attention was shifted endogenously, providing compelling evidence that voluntary deployments of attention can cause perceptual distortions of space.     

Processing spatial relations with different apertures of attention

Neuropsychological studies suggest the existence of lateralized networks that represent categorical and coordinate types of spatial information. In addition, studies with neural networks have shown that they encode more effectively categorical spatial judgments or coordinate spatial judgments, if their input is based, respectively, on units with relatively small, nonoverlapping receptive fields, as opposed to units with relatively large, overlapping receptive fields. These findings leave open the question of whether interactive processes between spatial detectors and types of spatial relations can be modulated by spatial attention. We hypothesized that spreading the attention window to encompass an area that includes two objects promotes coordinate spatial relations, based on coarse coding by large, overlapping, receptive fields. In contrast, narrowing attention to encompass an area that includes only one of the objects benefits categorical spatial relations, by effectively parsing space. By use of a cueing procedure, the spatial attention window was manipulated to select regions of differing areas. As predicted, when the attention window was large, coordinate spatial transformations were noticed faster than categorical transformations; in contrast, when the attention window was relatively smaller, categorical spatial transformations were noticed faster than coordinate transformations. Another novel finding was that coordinate changes were noticed faster when cueing an area that included both objects as well as the empty space between them than when simultaneously cueing both areas including the objects while leaving the gap between them uncued.     

Interoceptive and exteroceptive attention have opposite effects on subsequent somatosensory perceptual decision making

Evidence suggests that interoceptive and exteroceptive attention might have different perceptual effects. However, the effects of these different types of body-focused attention have never been directly compared. The current research investigated how interoceptive and exteroceptive attention affect subsequent performance on the somatic signal detection task (SSDT). In Experiment 1, 37 participants completed the SSDT under usual testing conditions and after performing an interoceptive heartbeat perception task. This task led to a more liberal response criterion, leading to increased touch reports in the presence and absence of a target vibration. This finding is consistent with suggestions that attending internally contributes to physical symptom reporting in patients with medically unexplained symptoms (MUS). In Experiment 2, 40 participants completed the SSDT before and after an exteroceptive grating orientation task. This task led to a more stringent response criterion, leading to decreased touch reports in the presence and absence of the target, possibly via a reduction in sensory noise. This work demonstrates that internal and external body-focused attention can have opposite effects on subsequent somatic perceptual decision making and suggests that attentional training could be useful for patients reporting MUS.     

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 and attention deficits in 5- and 10-month-old preterm infants

Cognitive outcomes for children born prematurely are well characterized, including increased risk for deficits in memory, attention, processing speed, and executive function. However, little is known about deficits that appear within the first 12 months, and how these early deficits contribute to later outcomes. To probe for functional deficits in visual attention, preterm and full-term infants were tested at 5 and 10 months with the Infant Orienting With Attention task (IOWA; Ross-Sheehy, Schneegans and Spencer, 2015). 5-month-old preterm infants showed significant deficits in orienting speed and task related error. However, 10-month-old preterm infants showed only selective deficits in spatial attention, particularly reflexive orienting responses, and responses that required some inhibition. These emergent deficits in spatial attention suggest preterm differences may be related to altered postnatal developmental trajectories. Moreover, we found no evidence of a dose-response relation between increased gestational risk and spatial attention. These results highlight the critical role of postnatal visual experience, and suggest that visual orienting may be a sensitive measure of attentional delay. Results reported here both inform current theoretical models of early perceptual/cognitive development, and future intervention efforts.     

The role of temporal synchrony in perceptual object formation and updating

The appearance and disappearance of an object in the visual field is accompanied by changes to multiple visual features at the object's location. When features at a location change asynchronously, the cue of common onset and offset becomes unreliable, with observers tending to report the most recent pairing of features. Here, we use these last feature reports to study the conditions that lead to a new object representation rather than an update to an existing representation. Experiments 1 and 2 establish that last feature reports predominate in asynchronous displays when feature durations are brief. Experiments 3 and 4 demonstrate that these reports also are critically influenced by whether features can be grouped using nontemporal cues such as common shape or location. The results are interpreted within the object-updating framework (Enns, Lleras, & Moore, 2010), which proposes that human vision is biased to represent a rapid image sequence as one or more objects changing over time.     

Measuring effects of voluntary attention: A comparison among predictive arrow,colour, and number cues

The Posner cueing paradigm is one of the most widely used paradigms in attention research. Importantly, when employing it, it is critical to understand which type of orienting a cue triggers. It has been suggested that large effects elicited by predictive arrow cues reflect an interaction of involuntary and voluntary orienting. This conclusion is based on comparisons of cueing effects of predictive arrows, nonpredictive arrows (involuntary orienting), and predictive numbers (voluntary orienting). Experiment 1 investigated whether this conclusion is restricted to comparisons with number cues and showed similar results to those of previous studies, but now for comparisons to predictive colour cues, indicating that the earlier conclusion can be generalized. Experiment 2 assessed whether the size of a cueing effect is related to the ease of deriving direction information from a cue, based on the rationale that effects for arrows may be larger, because it may be easier to process direction information given by symbols such as arrows than that given by other cues. Indeed, direction information is derived faster and more accurately from arrows than from colour and number cues in a direction judgement task, and cueing effects are larger for arrows than for the other cues. Importantly though, performance in the two tasks is not correlated. Hence, the large cueing effects of arrows are not a result of the ease of information processing, but of the types of orienting that the arrows elicit.     

On the role of attention in generating explicit awareness of contingent relations: evidence from spatial priming

In a series of four experiments, we examine the hypothesis that selective attention is crucial for the generation of conscious knowledge of contingency information. We investigated this question using a spatial priming task in which participants were required to localize a target letter in a probe display. In Experiment 1, participants kept track of the frequency with which the predictive letter in the prime appeared in various locations. This manipulation had a negligible impact on contingency awareness. Subsequent experiments requiring participants to attend to features (color, location) of the predictive letter increased contingency awareness somewhat, but there remained a large proportion of individuals who remained unaware of the strong contingency. Together the results of our experiments suggest that the construct of attention does not fully capture the processes that lead to contingency awareness, and suggest a critical role for bottom-up feature integration in explicit contingency learning.     

Duration of attention: The perceptual deprivation effect

College students viewed 18-sided randomly generated polygons. They were told to attend to each form until they “finished looking at it.” Before each stimulus presentation, 2, 16, 30, or 44 sec of perceptual deprivation was administered. The results indicated that there was a direct relationship between the duration of perceptual deprivation and the duration of attention. The results were interpreted in terms of the deprivation establishing a need for stimulation that is satisfied by attending.     

Differential effect of one versus two hands on visual processing

Hand position in the visual field influences performance in several visual tasks. Recent theoretical accounts have proposed that hand position either (a) influences the allocation of spatial attention, or (b) biases processing toward the magnocellular visual pathway. Comparing these accounts is difficult as some studies manipulate the distance of one hand in the visual field while others vary the distance of both hands, and it is unclear whether single and dual hand manipulations have the same impact on perception. We ask if hand position affects the spatial distribution of attention, with a broader distribution of attention when both hands are near a visual display and a narrower distribution when one hand is near a display. We examined the effects of four hand positions near the screen (left hand, right hand, both hands, no hands) on both temporal and spatial discrimination tasks. Placing two hands near the display compared to two hands distant resulted in improved sensitivity for the temporal task and reduced sensitivity in the spatial task, replicating previous results. However, the single hand manipulations showed the opposite pattern of results. Together these results suggest that visual attention is focused on the graspable space for a single hand, and expanded when two hands frame an area of the visual field.     

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.