Attentional suppression is delayed for threatening distractors

Moving spiders do not boost visual search in spider fear

Previous research on attention to fear-relevant stimuli has largely focused on static pictures or drawings, and thus did not consider the potential effect of natural motion. Here, we aimed to investigate the effect of motion on attentional capture in spider-fearful and non-fearful participants by using point-light stimuli and naturalistic videos. Point-light stimuli consist of moving dots representing joints and thereby visualizing biological motion (e.g. of a walking human or cat) without needing a visible body. Spider-fearful (n = 30) and non-spider-fearful (n = 31) participants completed a visual search task with moving targets (point-light/naturalistic videos) and static distractors (images), static targets and moving distractors, or static targets and static distractors. Participants searched for a specified animal type (snakes, spiders, cats, or doves) as quickly as possible. We replicated previous findings with static stimuli: snakes were detected faster and increased distraction, while spiders just increased distraction. However, contrary to our hypotheses, spider targets did not speed up responses, neither in the group of control nor in the group of spider-fearful participants. Interestingly, stimuli-specific effects were toned down, abolished, or even changed direction when motion was introduced. Also, we demonstrated that point-light stimuli were of similar efficiency as naturalistic videos, indicating that for testing effects of motion in visual search, "pure" motion stimuli might be sufficient. As we do show a substantial modulation of visual search phenomena by biological motion, we advocate for future studies to use moving stimuli, equivalent to our dynamic environment, to increase ecological validity.

Queues, crowds, and angry mobs: Face identification under distraction in a virtual airport

In visual environments, selective attention must be employed to focus on task-relevant stimuli. A key question here concerns the extent to which other stimuli within the visual field influence target processing. In this study, we ask whether face identity matching is subject to similar effects from irrelevant stimuli in the visual field, specifically task-irrelevant people. Although most previous studies rely on highly controlled face and body stimuli presented in isolation, here we use a more realistic environment. Participants take the role of passport officers and must match a person's face to their photo-ID, while other people appear in the background, waiting to be processed. Presenting an interactive virtual environment on screen (Experiments 1 and 2) or in immersive VR (Experiment 3), we generally found no evidence for distraction from background people on face-matching accuracy. However, when immersed in VR, an angry crowd in the background delayed matching speed while not affecting accuracy. We discuss the theoretical implications of these results and their potential importance in practical settings.

The interference of negative emotional stimuli on semantic vigilance performance in a dual-task setting

A large body of previous research has shown that emotional stimuli have an advantage in a wide variety of cognitive processes. This was mainly observed in visual search and working memory tasks. Emotionally charged objects draw and hold attention, are remembered better, and interfere more with the completion of the primary task than neutral ones. Therefore, it seems reasonable to assume that emotional stimuli also greatly affect sustained attention and vigilance decrement. In the present research, we investigated whether emotional stimuli demand more attentional resources than neutral ones in a dual-task paradigm. We adopted the abbreviated semantic discrimination vigilance task and measured participants' (N = 49) performance in a single-task and two dual-task settings. In the dual-task conditions, the visual semantic vigilance paradigm was combined with an auditory word recall task (with neutral or emotional stimuli). We found reduced vigilance and improved word recall performance in the emotional dual-task condition compared to the neutral dual-task and single-task conditions. The reduced performance was apparent throughout the task, while in the neutral conditions, participants' performance first increased and then dropped as time progressed. To conclude, our results indicate that emotional stimuli not only have an advantage in cognitive processing but also demand more attentional resources continuously while it is present compared to neutral stimuli. These results are consistent with the emotionality effect theory and evolutionary accounts of the neural circuits underlying motivated behaviors associated with critical survival needs.

Can the processing of task-irrelevant threatening stimuli be inhibited? - The role of shape and valence in the saliency of threatening objects

Numerous studies have demonstrated that attention is quickly oriented towards threatening stimuli, and that this attentional bias is difficult to inhibit. The root cause(s) of this bias may be attributable to the affective (e.g., valence) or visual features (e.g., shape) of threats. In two experiments (behavioral, eye-tracking), we tested which features play a bigger role in the salience of threats. In both experiments, participants looked for a neutral target (butterfly, lock) among other neutral objects. In half of the trials a threatening (snake, gun) or nonthreatening (but visually similar; worm, hairdryer) task-irrelevant distractor was also present at a near or far distance from the target. Behavioral results indicate that both distractor types interfered with task performance. Rejecting nonthreatening distractors as nontargets was easier when they were presented further from the target but distance had no effect when the distractor was threatening. Eye-tracking results showed that participants fixated less often (and for less time) on threatening compared to nonthreatening distractors. They also viewed targets for less time when a threatening distractor was present (compared to nonthreatening). Results suggest that visual features of threats are easier to suppress than affective features, and the latter may have a stronger role in eliciting attentional biases.

The effect of emotional arousal on visual attentional performance: a systematic review

Although the arousal elicited by emotional stimuli, similarly to valence, is an integrative part of emotion theories, previous studies and reviews mostly focused on the valence of a stimulus and rarely investigated the role of arousal. Here, I systematically searched for articles that used visual attentional paradigms, manipulated emotional arousal by auditory or visual, task-relevant or task-irrelevant stimuli, measured behavioral responses, ocular behavior, or neural correlates. I found that task-relevant arousing stimuli draw and hold attention regardless of the modality. In contrast, task-irrelevant arousing stimuli impaired task performance. However, when the emotional content precedes the task or it is presented for a longer duration, arousal increased performance. Future directions on how research could address the remaining questions are discussed.

Attentional demand induced by visual crowding modulates the anger superiority effect

Previous research on emotional bias in face perception has shown inconsistent findings, proposing either angry or happy faces to be detected more efficiently. A recent study showed that the anger superiority effect (ASE), which showed in the high attentional demand condition, vanished in the low attentional demand condition. The authors thus proposed an attentional demands modulation hypothesis to interpret the inconsistent findings. The present study tested this hypothesis in a visual crowding task in which participants were instructed to determine whether the target face was happy or angry. Attentional demands were manipulated by changing the strength of crowding, including presenting stimuli in different configurations (Experiment 1), and setting different target-flanker separations and presenting stimuli in different eccentricities (Experiment 2). Experiment 1 showed an ASE when the stimulus configuration incurred a high attentional demand. Intriguingly, the ASE became weaker and then disappeared as the attentional demand became lower. Experiment 2 replicated this finding and showed that the ASE decreased as the target-flanker separation became larger. Together, these results suggest that the emergence and magnitude of ASE is modulated by attentional demands, which supports the attentional demands modulation hypothesis.

Recoiling from Threat: Anxiety is Related to Heightened Suppression of Threat, Not Increased Attention to Threat

Increased attention to threat is considered a core feature of anxiety. However, there are multiple mechanisms of attention and multiple types of threat, and the relationships among attention, threat, and anxiety are poorly understood. The present study used event-related potentials (ERPs) to separately isolate attentional selection (N2pc) and suppression (P_D) of pictorial threats (photos of weapons, snakes, etc.) and conditioned threats (colored shapes paired with electric shock). In a sample of 48 young adults, both threat types were initially selected for increased attention (an N2pc), but only conditioned threats elicited subsequent suppression (a P_D) and a reaction time (RT) bias. Levels of trait anxiety were unrelated to N2pc amplitude, but increased anxiety was associated with larger P_Ds (i.e., greater suppression) and reduced RT bias to conditioned threats. These results suggest that anxious individuals do not pay more attention to threats, but rather engage more attentional suppression to overcome threats.

Response of multiple demand network to visual search demands

Neuroimaging studies for human participants have shown that the activity in the multiple-demand (MD) network is associated with various kinds of cognitive demand. However, surprisingly, it remains unclear how this MD network is related to a core component of cognition, the process of searching for a target among distractors. This was because previous neuroimaging studies of visual search were confounded by task difficulty or time on task. To circumvent these limitations, we examined human brain activity while participants perform two different visual search tasks. The performance of a task was limited by increased attentional demand, while the other task was primarily limited by poor quality of input data or neural noise. Throughout the MD network, increased activity and strengthened functional connectivity among the MD regions were observed under the search task recruiting capacity-limited attentional resources. The present findings provide unequivocal evidence that the MD network mediates visual search, as well as other capacity-limited cognitive processes.

Task Demands Modulate Effects of Threatening Faces on Early Perceptual Encoding

The threat capture hypothesis states that threatening stimuli are automatically processed with higher priority than non-threatening stimuli, irrespective of observer intentions or focus of attention. We evaluated the threat capture hypothesis with respect to the early perceptual stages of face processing. We focused on an electrophysiological marker of face processing (the lateralized N170) in response to neutral, happy, and angry facial expressions displayed in competition with a non-face stimulus (a house). We evaluated how effects of facial expression on the lateralized N170 were modulated by task demands. In the pixel task, participants were required to identify the gender of the face, which made the face task-relevant and entailed structural encoding of the face stimulus. In the pixel task, participants identified the location of a missing pixel in the fixation cross, which made the face task-irrelevant and placed it outside the focus of attention. When faces were relevant, the lateralized N170 to angry faces was enhanced compared to happy and neutral faces. When faces were irrelevant, facial expression had no effect. These results reveal the critical role of task demands on the preference for threatening faces, indicating that top-down, voluntary processing modulates the prioritization of threat.