A time-course analysis of attentional cueing by threatening scenes

Models of attention and emotion have assigned a special status to the processing of threatening information: Facilitated attentional capture by threat and its prioritized processing would allow for swift and adequate action to potentially dangerous stimuli. In four experiments, we examined the time-course of facilitated orienting of attention to threatening scenes in the exogenous cueing paradigm. Threat value and presentation duration of the cues were systematically varied. Facilitated attentional capture by threat was limited to highly threatening pictures presented for 100 ms. No attentional effects were observed with a 28 ms cue presentation duration. At slightly longer cue presentations, 200 ms and 500 ms, results indicated no and even reduced attentional capture by threat compared with neutral information. The present results provide support for the idea that threat facilitates fast attentional orienting to its location, followed by the inhibition of attention to threat.     

Attentional prioritisation of threatening information: Examining the role of the size of the attentional window

In line with most models of emotion, research has shown that threatening information receives attentional priority over neutral information. Recently, it has been suggested that the degree to which participants divide their attention across the visual field (the attentional window) may modulate the extent to which salient objects are attentionally prioritised. In the current study, participants were required to identify a target inside one of a variable number of coloured circles. One colour (Conditioned Stimulus, CS +) was fear-conditioned using an electrocutaneous stimulus at tolerance level. This search task was combined with a go/no-go task that required participants to either divide attention across the visual field to create a broad attentional window (global group), or focus their attention on the fixation point to create a narrow attentional window (local group). The results showed that only in the global group was the CS + colour prioritised over the neutral colours, indicating that a broader attentional window leads to enhanced attentional prioritisation of threat. Implications for research on attentional bias to threat are discussed.     

Distracted by danger: Temporal and spatial dynamics of visual selection in the presence of threat

Threatening stimuli are known to influence attentional and visual processes in order to prioritize selection. For example, previous research showed faster detection of threatening relative to nonthreatening stimuli. This has led to the proposal that threatening stimuli are prioritized automatically via a rapid subcortical route. However, in most studies, the threatening stimulus is always to some extent task relevant. Therefore, it is still unclear if threatening stimuli are automatically prioritized by the visual system. We used the additional singleton paradigm with task-irrelevant fear-conditioned distractors (CS+ and CS-) and indexed the time course of eye movement behavior. The results demonstrate automatic prioritization of threat. First, mean latency of saccades directed to the neutral target was increased in the presence of a threatening (CS+) relative to a nonthreatening distractor (CS-), indicating exogenous attentional capture and delayed disengagement of covert attention. Second, more error saccades were directed to the threatening than to the nonthreatening distractor, indicating a modulation of automatically driven saccades. Nevertheless, cumulative distributions of the saccade latencies showed no modulation of threat for the fastest goal-driven saccades, and threat did not affect the latency of the error saccades to the distractors. Together these results suggest that threatening stimuli are automatically prioritized in attentional and visual selection but not via faster processing. Rather, we suggest that prioritization results from an enhanced representation of the threatening stimulus in the oculomotor system, which drives attentional and visual selection. The current findings are interpreted in terms of a neurobiological model of saccade programming.     

Looking out for danger: An attentional bias towards spatially predictable threatening stimuli

Attentional bias to threat is well established, however, the influence of spatial predictability on this attentional bias has never been investigated. Here we investigated how threat affects attentional capture and disengagement when its spatial location is predictable. Using a visual search paradigm, participants were required to identify a target inside one of a variable number of colored circles. One color (Conditioned Stimulus, CS+) was fear-conditioned using an electrocutaneous stimulus at tolerance level. In the experimental group the CS+ was made spatially predictable (occurred more often at one location in the visual display), while this was not the case in the control group. Results showed no complete automatic capture of attention by the CS+, but the experimental group did show more prioritization of the CS+ and less difficulty to disengage from the CS+ than the control group. Of further importance was the finding that the experimental group also attended to the location that was predictive of the CS+, even when no CS+ was presented. Findings are discussed in terms the effects of predictability on anxiety.     

Eye movements reveal mechanisms underlying attentional biases towards threat

Mechanisms underlying attentional biases towards threat (ABTs), such as attentional avoidance and difficulty of disengagement, are still unclear. To address this issue, we recorded participants' eye movements during a dot detection task in which threatening or neutral stimuli served as peripheral cues. We evaluated response times (RTs) in trials where participants looked at the central fixation cross (not at the cues), as they were required, and number and duration of (unwanted) fixations towards threatening or neutral cues; in all analyses trait anxiety was treated as a covariate. Difficulty in attentional disengagement (longer RTs) was found when peripheral threatening stimuli were presented for 100?ms. Moreover, we observed significantly shorter (unwanted) fixations on threatening than on neutral peripheral stimuli, compatible with an avoidance bias, for longer presentation times. These findings demonstrate that, independent of trait anxiety levels, disengagement bias occurs without eye movements, whereas eye movements are implied in threat avoidance.     

Stressing the mind: the effect of cognitive load and articulatory suppression on attentional guidance from working memory

Four experiments explored the effect of cognitive load on the time course of top-down guidance of attention from working memory (WM). Observers had to search for a target presented among several distractors, with the target and distractor stimuli embedded inside different objects. On half of the trials, one of the distractor objects was cued by a matching item held in WM. When a single item was maintained in memory, search performance was impaired relative to a neutral baseline, where the memory and search displays did not match. These effects of WM on subsequent search were reduced by including a verbal suppression task during the WM and search displays, and by varying the WM load. The degree of competition for resources in WM is a key factor in determining the time course and magnitude of the interaction between WM and visual selection.     

The time-course of threat processing in children: a temporal dissociation between selective attention and behavioral interference

Although selective attention to threatening information is an adaptive mechanism, exaggerated attention to threat may be related to anxiety disorders. However, studies examining threat processing in children have obtained mixed findings. In the present study, the time-course of attentional bias for threat and behavioral interference was analyzed in a community sample of 8-18-year-old children (N=33) using a pictorial dot probe task. Threatening and neutral stimuli were shown during 17 ms (masked), 500 ms, and 1250 ms. Results provide preliminary evidence of an automatic attentional bias for threat at 17 ms that persists during later, more controlled stages of information processing (500 and 1250 ms). Furthermore, participants showed a delayed response to threat-containing trials relative to neutral trials in the 500 and 1250 ms condition, which may indicate interference by threat. Together, these results suggest that an attentional bias for threat precedes behavioral interference in children. Furthermore, results indicate that performance in daily life can be temporarily interrupted by the processing of threatening information. In addition, results of earlier studies into selective attention in children using tasks based on behavioral responses may have been confounded by interference effects of threat. For future studies, we recommend to take behavioral interference into account.     

Is there a mutual relationship between opposite attentional biases underlying anxiety?

Current models that account for attentional processes in anxiety have proposed that high-trait anxious individuals are characterized by a hypervigilant-avoidant pattern of attentional biases to threat. We adopted a laboratory conditioning procedure to induce concomitant hypervigilance and avoidance to threat, emphasizing a putative relationship between lower-level reactive and upper-level controlled attentional mechanisms as the core account of attentional processes involved in the development and maintenance of anxiety. Eighty high- and low-trait anxious participants underwent Pavlovian conditioning to a human face. Eye tracking was used to monitor attentional changes to the conditioned stimulus (CS+) face and the neutral stimulus (CS-) face, presented at 200, 500, and 800 ms durations. The high-anxious participants developed the expected attentional bias toward the CS+ at 200 ms presentation time and attentional avoidance at 500 and 800 ms durations. Hypervigilance to aversive stimuli at 200 ms and later avoidance to the same stimuli at 500 and 800 ms were associated with higher levels of galvanic skin conductance to the CS+. The low-anxious individuals developed the opposite attentional pattern with an initial tendency to orient attention away from the aversive stimuli in the 200 ms condition and to orient attention toward aversive stimuli in the remaining time. The differential modulation between hypervigilance and avoidance elicited in the two groups by the conditioning procedure suggests that vulnerability to anxiety is characterized by a latent relationship between diverse attentional mechanisms. Within this relationship, hypervigilance and avoidance to threat operate at different stages of information processing suggesting fuzzy boundaries between early reactive and later-strategic processing of threat.     

Working memory, perceptual priming, and the perception of hierarchical forms: Opposite effects of priming and working memory without memory refreshing

Previous research has shown that stimuli held in working memory (WM) can influence spatial attention. Using Navon stimuli, we explored whether and how items in WM affect the perception of visual targets at local and global levels in compound letters. Participants looked for a target letter presented at a local or global level while holding a regular block letter as a memory item. An effect of holding the target’s identity in WM was found. When memory items and targets were the same, performance was better than in a neutral condition when the memory item did not appear in the hierarchical letter (a benefit from valid cuing). When the memory item matched the distractor in the hierarchical stimulus, performance was worse than in the neutral baseline (a cost on invalid trials). These effects were greatest when the WM cue matched the global level of the hierarchical stimulus, suggesting that WM biases attention to the global level of form. Interestingly, in a no-memory priming condition, target perception was faster in the invalid condition than in the neutral baseline, reversing the effect in the WM condition. A further control experiment ruled out the effects of WM being due to participants’ refreshing their memory from the hierarchical stimulus display. The data show that information in WM biases the selection of hierarchical forms, whereas priming does not. Priming alters the perceptual processing of repeated stimuli without biasing attention.     

Attentional capture by signals of threat

Attention can be captured automatically by events that are physically salient. Similarly, emotional stimuli are known to be prioritised by the visual system because of their behavioural significance. The present study investigated whether a neutral stimulus which became associated with fear captured attention in visual search. Using a fear-conditioning procedure, one stimulus was repeatedly combined with an electrical shock (CS+), whereas another stimulus with identical physical features was never combined with a shock (CS?). Following conditioning, participants had to search for a target; while on some trials, either an irrelevant CS+ or CS? stimulus was present. The results show that the presence of an irrelevant distractor that was previously associated with fear slowed a search more than a distractor without fear association. The current results indicate that learned fear associations have the ability to capture our attention even if we try to ignore them.     

Attentional bias to angry faces using the dot-probe task? It depends when you look for it

A number of studies using the dot-probe task now report the existence of an attentional bias to angry faces in participants who rate highly on scales of anxiety; however, no equivalent bias has been observed in non-anxious populations, despite evidence to the contrary from studies using other tasks. One reason for this discrepancy may be that researchers using the dot-probe task have rarely investigated any effects which might emerge earlier than 500 ms following presentation of the threat-related faces. Accordingly, in the current study we presented pairs of face stimuli with emotional and neutral expressions and probed the allocation of attention to these stimuli for presentation times of 100 and 500 ms. Results showed that at 100 ms there was an attentional bias towards the location of the relatively threatening stimulus (the angry face in angry/neutral pairs and the neutral face in neutral/happy pairs) and this pattern reversed by 500 ms. Comparisons of reaction time (RT) scores with an appropriate baseline suggested that the early bias toward threatening faces may actually arise through inhibition of the relatively least threatening member of a face pair rather than through facilitation of, or vigilance towards, the more threatening stimulus. However the mechanisms governing the observed biases are interpreted, these data provide evidence that probing for the location of spatial attention at 500 ms is not necessarily indicative of the initial allocation of attention between competing emotional facial stimuli.     

Angry faces hold the eyes

Efficient processing of complex social and biological stimuli associated with threat is crucial for survival. Previous studies have suggested that threatening stimuli such as angry faces not only capture visual attention, but also delay the disengagement of attention from their location. However, in the previous studies disengagement of attention was measured indirectly and was inferred on the basis of delayed manual responses. The present study employed a novel paradigm that allows direct examination of the delayed disengagement hypothesis by measuring the time it takes to disengage the eyes from threatening stimuli. The results showed that participants were indeed slower to make an eye movement away from an angry face presented at fixation than from either a neutral or a happy face. This finding provides converging support that the delay in disengagement of attention is an important component of processing threatening information.     

基于记忆的注意捕获和注意抑制效应：ERP证据

采用工作记忆与视觉搜索双任务范式, 通过操作匹配试次出现概率来诱发不同水平的认知控制动机, 考察了基于记忆的注意引导过程的时程特点。结果：记忆匹配刺激首先诱发了N2pc成分, 随后诱发了与抑制过程相关的差异正波。并且, 认知控制动机水平越高, N2pc波幅越小、潜伏期越短; 抑制性差异正波波幅越大。结论：基于记忆的注意引导过程包括早期的注意捕获和后期的注意抑制两个阶段; 其效应量和时程受到认知控制动机水平的调节。     

Do threatening stimuli draw or hold visual attention in subclinical anxiety?

Biases in information processing undoubtedly play an important role in the maintenance of emotion and emotional disorders. In an attentional cueing paradigm, threat words and angry faces had no advantage over positive or neutral words (or faces) in attracting attention to their own location, even for people who were highly state-anxious. In contrast, the presence of threatening cues (words and faces) had a strong impact on the disengagement of attention. When a threat cue was presented and a target subsequently presented in another location, high state-anxious individuals took longer to detect the target relative to when either a positive or a neutral cue was presented. It is concluded that threat-related stimuli affect attentional dwell time and the disengage component of attention, leaving the question of whether threat stimuli affect the shift component of attention open to debate.     

自动情绪调节对负性情绪面孔注意偏向的影响

本研究通过成语匹配任务启动情绪调节目标,在情绪flanker任务中考察了自动情绪调节启动对注意偏向的影响。结果表明,中性启动条件下,被试表现出对负性情绪面孔的注意偏向,而情绪调节启动条件下,被试对正性、负性情绪面孔的注意分配不存在显著差异。这一结果说明自动情绪调节可以有效地减弱被试的负性情绪面孔注意偏向。     

Searching for threat

In a series of experiments, a visual search task was used to test the idea that biologically relevant threatening stimuli might be recognized very quickly or capture visuo-spatial attention. In Experiment 1, there was evidence for both faster detection and faster search rates for threatening animals than for plants. However, examination of the basis of this effect in Experiment 2 showed that it was not due to threat per se, as detection and search rate advantages were found for pleasant rather than threatening animals compared to plants. In Experiment 3, participants searched for the plants and pleasant and threatening animals used in Experiments 1 and 2, among a fixed heterogeneous selection of non-target items. There was no search rate or detection advantage for threatening animals compared to pleasant animals or plants. The same targets and non-targets as those used in Experiment 3 were also used in Experiment 4. In Experiment 4, participants searched for targets that were presented either close to or distant from an initial fixation point. There was no evidence for a "threat" detection advantage either close to or distant from the cross. Finally, an experiment was conducted in which target categories (fruit, flowers, and animals) were not pre-specified prior to each trial block. There were no differences in reaction times to detect pleasant animals, threatening animals, or fruit. We conclude that the visual search paradigm does not readily reveal any biases that might exist for threatening stimuli in the general population.     

Foveal vs. parafoveal attention-grabbing power of threat-related information

We investigated whether threat words presented in attended (foveal) and in unattended (parafoveal) locations of the visual field are attention grabbing. Neutral (nonemotional) words were presented at fixation as probes in a lexical decision task. Each probe word was preceded by 2 simultaneous prime words (1 foveal, 1 parafoveal), either threatening or neutral, for 150 ms. The stimulus onset asynchrony (SOA) between the primes and the probe was either 300 or 1,000 ms. Results revealed slowed lexical decision times on the probe when primed by an unrelated foveal threat word at the short (300-ms) delay. In contrast, parafoveal threat words did not affect processing of the neutral probe at either delay. Nevertheless, both neutral and threat parafoveal words facilitated lexical decisions for identical probe words at 300-ms SOA. This suggests that threat words appearing outside the focus of attention do not draw or engage cognitive resources to such an extent as to produce interference in the processing of concurrent or subsequent neutral stimuli. An explanation of the lack of parafoveal interference is that semantic content is not extracted in the parafovea.     

非目标工作记忆表征下颜色关联和抽象关联的注意捕获和抑制

采用工作记忆—视觉搜索双任务范式,探讨在非目标工作记忆表征下,颜色关联和抽象关联干扰子的注意捕获和抑制现象。实验1结果发现,颜色关联干扰子在快速反应阶段捕获注意,随后被成功抑制;抽象关联干扰子仍能捕获注意。实验2消除知觉凸显后,结果发现颜色关联条件的抑制消失,干扰子重新捕获注意。结果表明,有效抑制策略受不同关联干扰子加工先后顺序的影响,选择性抑制颜色关联干扰子,而颜色特征的凸显有助于抑制策略形成。     

Differential impact of emotional task relevance on three indices of prioritised processing for fearful and angry facial expressions

It is commonly assumed that threatening expressions are perceptually prioritised, possessing the ability to automatically capture and hold attention. Recent evidence suggests that this prioritisation depends on the task relevance of emotion in the case of attention holding and for fearful expressions. Using a hybrid attentional blink (AB) and repetition blindness (RB) paradigm we investigated whether task relevance also impacts on prioritisation through attention capture and perceptual salience, and if these effects generalise to angry expressions. Participants judged either the emotion (relevant condition) or gender (irrelevant condition) of two target facial stimuli (fearful, angry or neutral) imbedded in a stream of distractors. Attention holding and capturing was operationalised as modulation of AB deficits by first target (T1) and second target (T2) expression. Perceptual salience was operationalised as RB modulation. When emotion was task-relevant (Experiment 1; N?=?29) fearful expressions captured and held attention, and were more perceptually salient than neutral expressions. Angry expressions captured attention, but were less perceptually salient and capable of holding attention than fearful and neutral expressions. When emotion was task-irrelevant (Experiment 2; N?=?30), only fearful attention capture and perceptual salience effects remained significant. Our findings highlight the importance for threat-prioritisation research to heed both the type of threat and prioritisation investigated.     

Components of attentional bias to threat in high trait anxiety: Facilitated engagement, impaired disengagement, and attentional avoidance

There is a wealth of evidence demonstrating enhanced attention to threat in high trait anxious individuals (HTA) compared with low trait anxious individuals (LTA). In two experiments, we investigated whether this attentional bias is related to facilitated attentional engagement to threat or difficulties disengaging attention from threat. HTA and LTA undergraduates performed a modified exogenous cueing task, in which the location of a target was correctly or incorrectly cued by neutral, highly and mildly threatening pictures. Results indicate that at 100 ms picture presentation, HTA individuals more strongly engaged their attention with and showed impaired disengagement from highly threatening pictures than LTA individuals. In addition, HTA individuals showed a stronger tendency to attentional avoidance of threat at the 200 and 500 ms picture presentation. These data provide evidence for differential patterns of anxiety-related biases in attentive processing of threat at early versus later stages of information processing.