Disentangling the facilitating and hindering effects of threat-related stimuli - A visual search study

Snake phobia among the general population of Tamil Nadu, India

BACKGROUND

A specific phobia is an anxiety disorder that is characterised by persistent and excessive fear in the presence of the object of the phobia. Animal phobias are the most prevalent forms of specific phobia among humans. Fear of snakes (snake phobia) is present in non-human primates which suggests its evolutionary origins as the ability to detect the threat of snakes was critical for survival. Snake phobia is a critical factor in protecting snakes and mitigating snakebite burden. To date, only one standardised psychometric test [the Snake Questionnaire (SNAQ) developed in 1974] has been used to quantify snake phobia although this was not performed in snakebite-endemic countries. In this study, we aimed to determine snake phobia in India, where snakebites and resulting deaths, disabilities and socioeconomic impacts are high.

METHODOLOGY/PRINCIPAL FINDINGS

A modified version of the SNAQ (i.e. SNAQ12), which has previously demonstrated internal consistency, excellent reliability, and good discrimination between phobics and non-phobics in Europe was used in this study. SNAQ12 was developed both in English and Tamil and validated by testing on several individuals. Then, the final questionnaire was disseminated to members of the public through various methods including social media and in person through academic and clinical organisations. We received a total of 2032 responses, comprising 1086 [53.4%] males and 946 [46.6%] females, and these data were analysed to determine various aspects of snake phobia in the study population.

CONCLUSIONS/SIGNIFICANCE

The results demonstrated good internal consistency in using SNAQ12 to determine the phobia amongst the tested population. The data suggests that males are more snake-phobic in all age groups than females in India, in contrast to previous research that suggested that females are usually more snake-phobic. No other critical factors contribute to snake phobia in this study population. The use of the SNAQ12 allowed us to easily discriminate between individuals with phobia and non-clinical controls. This tool can be used as part of the One Health approach to better understand the relationships between snake phobia and snakebites and their impact on the mental health and well-being of vulnerable populations.

Threat priming diminishes the gaze cueing effect

Gaze cueing effect (GCE) refers to attention orienting towards the gazed-at location, characterised by faster responses to gazed-at than non-gazed-at stimuli. A previous study investigated the effects of affective priming on GCE and reported that threatening primes enhanced GCE. However, it remains unknown whether the threat or heightened arousal potentiated GCE. We investigated how highly arousing threatening and positive primes, compared to low arousing neutral primes modulate GCE. After a brief exposure to an affective prime (pictures of threat or erotica) or a neutral prime, participants detected an asterisk validly or invalidly cued by the gaze direction of a neutral face. The results showed that the threatening primes diminished the magnitude of GCE. The highly arousing positive primes did not have an effect on GCE. Further analyses showed that, as compared to neutral priming, the reaction times after threatening primes were shortened on invalid trials. This finding was interpreted to suggest that the threatening primes enhanced goal-directed target detection and attenuated attention orienting by irrelevant gaze cues via improving executive control. In sum, the present findings indicate that threat priming modulates GCE, not because of heightened arousal but because of the threat.

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.

An ethologically based view into human fear

The quality of the defensive response to a threat depends on the elements that trigger the fear response. The current classification system of phobias does not account for this. Here, we analyze the fear-eliciting elements and discern the different types of fears that originate from them. We propose Pain, Disgust, Vasovagal response, Visual-vestibular and postural interactions, Movement and Speed, Distance and Size, Low and mid-level visual features, Smell, and Territory and social status. We subdivide phobias according to the fear-eliciting elements most frequently triggered by them and their impact on behavior. We discuss the implications of a clinical conceptualization of phobias in humans by reconsidering the current nosology. This conceptualization will facilitate finding etiological factors in defensive behavior expression, fine-tuning exposure techniques, and challenging preconceived notions of preparedness. This approach to phobias leads to surprising discoveries and shows how specific responses bear little relation to the interpretation we might later give to them. Dividing fears into their potentially fear-eliciting elements can also help in applying the research principles formulated by the Research Domain Criteria initiative.

The effects of task-irrelevant threatening stimuli on orienting- and executive attentional processes under cognitive load

Human visual attention is biased to rapidly detect threats in the environment so that our nervous system can initiate quick reactions. The processes underlying threat detection (and how they operate under cognitive load), however, are still poorly understood. Thus, we sought to test the impact of task-irrelevant threatening stimuli on the salience network and executive control of attention during low and high cognitive load. Participants were exposed to neutral or threatening pictures (with moderate and high arousal levels) as task-irrelevant distractors in near (parafoveal) and far (peripheral) positions while searching for numbers in ascending order in a matrix array. We measured reaction times and recorded eye-movements. Our results showed that task-irrelevant distractors primarily influenced behavioural measures during high cognitive load. The distracting effect of threatening images with moderate arousal level slowed reaction times for finding the first number. However, this slowing was offset by high arousal threatening stimuli, leading to overall shorter search times. Eye-tracking measures showed that participants fixated threatening pictures more later and for shorter durations compared to neutral images. Together, our results indicate a complex relationship between threats and attention that results not in a unitary bias but in a sequence of effects that unfold over time.

Grab it or not? Measuring avoidance of spiders with touchscreen-based hand movements

BACKGROUND AND OBJECTIVES

Previous studies have shown that humans, particularly those with high levels of spider fear, show automatic avoidance of spiders. However, most tasks used in these studies employ symbolic approach-avoidance movements instead of naturalistic movements.

METHODS

The current study employed a touchscreen-based approach-avoidance task in which 86 female participants made hand and arm movements that mimic the real-life touching, grasping, and moving of spiders. Using a large touchscreen, they had to reach for pictures of spiders and neutral objects (leaves), touch them, and drag them either away from themselves or towards themselves. To draw attention to stimulus content, pictures of butterflies were used in additional NoGo trials, they required participants to not move their hand.

RESULTS

Avoidance of spiders was observed in both the pre-movement times (time to lift the hand from a starting position) and the grabbing times (time to reach the picture), and this avoidance was larger for more spider-fearful participants. The dragging times (time to swipe the picture), however, revealed a relative spider-approach tendency: Compared to leaves, participants were faster to drag spiders closer than to swipe them away.

LIMITATIONS

We discuss potential reasons for this mixed pattern of results, including the low reliability of the dragging times.

CONCLUSIONS

We recommend the use of touchscreens for the assessment of approach-avoidance tendencies, and we suggest avenues for further research.

"Finding an Emotional Face" Revisited: Differences in Own-Age Bias and the Happiness Superiority Effect in Children and Young Adults

People seem to differ in their visual search performance involving emotionally expressive faces when these expressions are seen on faces of others close to their age (peers) compared to faces of non-peers, known as the own-age bias (OAB). This study sought to compare search advantages in angry and happy faces detected on faces of adults and children on a pool of children (N = 77, mean age = 5.57) and adults (N = 68, mean age = 21.48). The goals of this study were to (1) examine the developmental trajectory of expression recognition and (2) examine the development of an OAB. Participants were asked to find a target face displaying an emotional expression among eight neutral faces. Results showed that children and adults found happy faces significantly faster than angry and fearful faces regardless of it being present on the faces of peers or non-peers. Adults responded faster to the faces of peers regardless of the expression. Furthermore, while children detected angry faces significantly faster compared to fearful ones, we found no such difference in adults. In contrast, adults detected all expressions significantly faster when they appeared on the faces of other adults compared to the faces of children. In sum, we found evidence for development in detecting facial expressions and also an age-dependent increase in OAB. We suggest that the happy face could have an advantage in visual processing due to its importance in social situations and its overall higher frequency compared to other emotional expressions. Although we only found some evidence on the OAB, using peer or non-peer faces should be a theoretical consideration of future research because the same emotion displayed on non-peers' compared to peers' faces may have different implications and meanings to the perceiver.

Arousal modulates the motor interference effect stimulated by pictures of threatening animals

Previous research related to the motor interference effect from dangerous objects indicated that delayed responses to dangerous objects were associated with more positive parietal P3 amplitudes, suggesting that great attentional resources were allocated to evaluate the level of danger (i.e., negative valence). However, arousal covaried with valence in this research. Together with previous studies in which the P3 amplitude was found to be increased along with a higher arousal level in the parietal lobe, we raised the issue that more positive parietal P3 amplitudes might also be affected by a high arousal level. To clarify whether valence or arousal impacted the motor interference effect, this study used a motor priming paradigm mixed with a Go/NoGo task and manipulated the valence (negative, neutral and positive) and arousal (medium and high) of target stimuli. Analysis of the behavioral results identified a significant motor interference effect (longer reaction times (RTs) in the negative valence condition than in the neutral valence condition) at the medium arousal level and an increased effect size (increment of RT difference) at the high arousal level. The results indicated that negative valence stimuli may interfere with the prime elicited motor preparation more strongly at the high arousal level than at the medium arousal level. The ERP results identified larger centroparietal P3 amplitudes for the negative valence condition than for the neutral valence condition at a high arousal level. However, the inverse result, i.e., lower centroparietal P3 amplitudes for the negative valence condition than for the neutral valence condition, was observed at a medium arousal level. The ERP results further indicated that the effect size of the behavioral motor interference effect increased because subjects are more sensitive to the negative valence stimuli at the high arousal level than at the medium arousal level. Furthermore, the motor interference effect is related to the negative valence rather than emotionality of the target stimuli because different result patterns emerged between the positive and negative valence conditions. Detailed processes underlying the interaction between valence and arousal effects are discussed.