Spider-fearful Participants Research Articles

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.

The fear of spiders: perceptual features assessed in augmented reality.

Persons with specific phobias typically generalize the dangerousness of the phobic animal to all members of its species, possibly as a result of malfunctioning brain circuitry normally providing quick and dirty identification of evolutionary-relevant stimuli. An objective assessment of which perceptual features make an animal more or less scary to phobic and non-phobic people would help overcome the limitations of the few studies available so far, based on self-reports. To achieve this aim, we built an augmented reality setting where volunteers with different levels of fear of spiders were asked to make holographic spiders that look either dangerous or harmless. To reach this goal, a computerized interface allowed participants to modify the spider's perceptual features (hairiness, body/leg size, and locomotion) in real time. On average, the dangerous spiders were made hairy, thick, and moving according to spider-like locomotion; coherently, the harmless spiders were made hairless, slim, and moving according to a butterfly-like locomotion. However, these averaged preferences could not fully describe the complex relationship between perceptual preferences with each other and with arachnophobia symptoms. An example of a key finding revealed by cluster analysis is the similarity in perceptual preferences among participants with little or no fear of spiders, whereas participants with more arachnophobia symptoms expressed more varying preferences. Perceptual preferences toward the spider's features were behaviorally assessed through an observational study, objectively confirming a generalization effect characterizing spider-fearful participants. These results advance our knowledge of phobic preferences and could be used to improve the acceptability of exposure therapies.

Attentional, emotional, and behavioral response toward spiders, scorpions, crabs, and snakes provides no evidence for generalized fear between spiders and scorpions

Spiders are among the animals evoking the highest fear and disgust and such a complex response might have been formed throughout human evolution. Ironically, most spiders do not present a serious threat, so the evolutionary explanation remains questionable. We suggest that other chelicerates, such as scorpions, have been potentially important in the formation and fixation of the spider-like category. In this eye-tracking study, we focused on the attentional, behavioral, and emotional response to images of spiders, scorpions, snakes, and crabs used as task-irrelevant distractors. Results show that spider-fearful subjects were selectively distracted by images of spiders and crabs. Interestingly, these stimuli were not rated as eliciting high fear contrary to the other animals. We hypothesize that spider-fearful participants might have mistaken crabs for spiders based on their shared physical characteristics. In contrast, subjects with no fear of spiders were the most distracted by snakes and scorpions which supports the view that scorpions as well as snakes are prioritized evolutionary relevant stimuli. We also found that the reaction time increased systematically with increasing subjective fear of spiders only when using spiders (and crabs to some extent) but not snakes and scorpions as distractors. The maximal pupil response covered not only the attentional and cognitive response but was also tightly correlated with the fear ratings of the picture stimuli. However, participants’ fear of spiders did not affect individual reactions to scorpions measured by the maximal pupil response. We conclude that scorpions are evolutionary fear-relevant stimuli, however, the generalization between scorpions and spiders was not supported in spider-fearful participants. This result might be important for a better understanding of the evolution of spider phobia.

Is It Safe Now? Intolerance of Uncertainty as a Pre-treatment Predictor of Exposure Outcome

Safety learning is considered to be a key aspect in attaining symptom reduction for patients with anxiety disorders. While treatment based on safety learning principles is highly effective in general, individual differences exist in the speed and retention of fear reduction. An individual difference variable that has been demonstrated to be associated with difficulties in safety learning in laboratory paradigms is intolerance of uncertainty, or the incapacity to endure the absence of key information and the corresponding perception of uncertainty. In this study, we sought to determine if intolerance of uncertainty is associated with the course and outcome of an exposure intervention. Intolerance of uncertainty was assessed in 104 subclinical spider-fearful participants, prior to a 30-minute exposure session in virtual reality. While the exposure session was found to be successful in modifying spider fear and avoidance, we failed to find significant correlations between intolerance of uncertainty and any of the outcome measures. Exploratory analyses assessed if intolerance of uncertainty was associated with reductions in physiological arousal during the exposure session itself. No significant correlations were found between intolerance of uncertainty and arousal reduction within the exposure exercises or throughout the session. In conclusion, deviating from some of the findings in extinction research, we failed to find evidence for associations between intolerance of uncertainty and the outcome and course of exposure. Still, additional research is needed to assess the replicability of these findings.

When pictures are not beneficial in multimedia learning: the case of threat-related pictures

According to the multimedia principle, adding relevant pictures to text is beneficial for learning. This beneficial effect is particularly true for text depicted in pictures (illustrated text information) but not for a text that is not illustrated in pictures (non-illustrated text information). The multimedia principle was examined for threat-related content: spider-fearful participants (SFs) learned about spiders. Since SFs typically inadequately process spider pictures, a beneficial effect of pictures concerning illustrated text information was not assumed for SFs but only for non-anxious control participants (NACs). Participants (N = 123) were randomly assigned to either a text-only condition or a text-picture condition and classified as SFs or NACs. In line with this assumption, adding pictures to text was not beneficial for SFs but only for NACs, particularly for illustrated text information. Thus, the perceived emotional content of pictures can serve as a boundary condition for the well-established multimedia principle.

Over the Edge: Extending the duration of a reconsolidation intervention for spider fear

Pharmacologically disrupting fear memory reconsolidation dramatically reduces fear behaviour. For example, 2–3 min of tarantula exposure followed by 40 mg of propranolol HCl (i.e., a reconsolidation intervention) abruptly decreased spider avoidance, an effect that persisted one year later. However, the success of reconsolidation interventions is not guaranteed: Pavlovian fear-conditioning research shows that the window to target memory reconsolidation is small and easy to miss. If exposure is too long to trigger reconsolidation, but too short for extinction learning, an inactive transitional limbo state occurs, rendering the fear memory unchanged and insensitive to amnesic agents. In this pre-registered study, we aimed to find this behaviourally-controlled boundary condition. Spider-fearful participants underwent a ~3 min (n = 23) or ~14 min (n = 20) exposure to a tarantula, intended to trigger reconsolidation or the limbo state respectively, followed by 40 mg of propranolol. We expected greater spider fear reduction after 3 than 14 min of exposure. Unexpectedly, there were no group differences on any outcome measures. In both groups, Bayesian analysis revealed a marked reduction in fear behaviour towards a generalisation stimulus (a house spider) accompanied by lower self-reported distress, with a sharp decline in spider fear scores two days after treatment that persisted one year later. Possible explanations include that the boundary conditions of reconsolidation are wider in older and stronger memories than experimentally-induced fears, or that alternative processes caused the treatment effects. Although the mechanism is unclear, these results carry a tentative promising message for the potential of brief reconsolidation-targeting interventions to mitigate irrational fears.

Placebo and Non-specific Effects in Reconsolidation-Based Treatment for Arachnophobia.

The idea that maladaptive memories may be rendered susceptible to interference after reactivation raises the possibility of reactivating and neutralizing clinically-relevant emotional memories. In this study, we sought to investigate the feasibility of such a “reconsolidation-based” intervention for arachnophobia, drawing upon previous research that successfully reduced fear of spiders in a subclinical sample. In Experiment 1, we piloted several reactivation procedures for conducting a reconsolidation-based treatment for arachnophobic individuals. All procedures involved some form of brief exposure to a fear-provoking spider, followed by the administration of 40 mg propranolol. In Experiment 2, we conducted a double-blind, placebo-controlled assessment of one procedure tested in Experiment 1. In Experiment 1, we found that most reactivation procedures produced drops in self-reported fear of spiders from pre- to post-treatment, including fear declines that were apparent up to 6- and even 14-months later. However, in Experiment 2, we found no evidence that the participants receiving propranolol were better off than those who received placebo. While our findings are limited by the small sample sizes used, they nevertheless show a different pattern of responses than was observed in a previous reconsolidation-based intervention for subclinical spider fearful participants. Alterations to the protocol made to accommodate the clinical participants may have led to greater opportunities for non-specific effects (e.g., exposure, placebo effects) to drive change in the participants. Our findings highlight both the challenges of translating reconsolidation-based procedures into clinical interventions, as well as the importance of controls for non-specific effects in reconsolidation-based research.

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

Background and objectivesPrevious 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. MethodsThe 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. ResultsAvoidance 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. LimitationsWe discuss potential reasons for this mixed pattern of results, including the low reliability of the dragging times. ConclusionsWe recommend the use of touchscreens for the assessment of approach-avoidance tendencies, and we suggest avenues for further research.

Interpreting and responding to ambiguous natural images in spider phobia

Background and objectivesThe fast detection of and response to threatening stimuli is an important task of the human visual and motor systems, and is especially challenging when stimuli are ambiguous. This study investigates the perception, evaluation and fast response to ambiguous natural spider stimuli in spider-fearful and non-anxious participants. MethodsStimuli were created by gradually morphing natural images of spiders and non-spiders (a crab, a starfish, a bunch of keys, and a flower). In Study 1, participants rated the images on perceptual and emotional dimensions and responded to them in a response priming task to measure rapid information processing. In Study 2, results were validated and extended in a different paradigm by using a go/no-go task. ResultsAs expected, spider-fearful participants showed an interpretative bias for ambiguous stimuli (i.e., perceived them as more similar to spiders) and rated spider(-like) stimuli as more unpleasant, arousing, and disgusting. In Study 1, spider stimuli were preferentially processed in spider-fearful participants as observed in faster responses to spider targets–however, responses were not different to comparison participants for ambiguous stimuli. Study 2 suggests that this finding can be explained by differences in stimulus duration. LimitationsNo participants with positive attitudes towards spiders or a second fearful comparison group were included. ConclusionsWe suggest that these findings can be explained by the nature of the applied tasks that tap into early phases of visual processing, thereby relying on feedforward-mediated low-spatial-frequency information extracted via the fast, subcortical path to the amygdala.

High Spider-Fearful and Low Spider-Fearful Individuals Differentially Perceive the Speed of Approaching, but not Receding, Spider Stimuli

The looming vulnerability model of fear predicts that high fearful individuals, as compared to low fearful individuals, will display a heightened tendency to perceive feared stimuli as moving disproportionately quickly when such stimuli are approaching, but not when they are receding. Experiments testing this prediction have been compromised by methodological limitations that preclude their ability to determine its validity. The present study employed a novel methodology designed to overcome these limitations to examine whether individuals with heightened levels of spider-fear exhibit this predicted perceptual bias. Two groups of participants who differed in spider-fear completed a perceptual task that presented stimulus pairs comprising spider and butterfly images under two movement conditions. In one condition images displayed approaching movement, while in the other condition images displayed receding movement. Participants were required to indicate which stimulus they perceived to move fastest. As predicted, it was found that participants with heightened spider-fear demonstrated a significantly greater tendency than low spider-fearful participants to perceive the spider stimuli as moving fastest, only when stimuli displayed approaching movement. Implications and avenues for future research are discussed.

Cue conditioning using a virtual spider discriminates between high and low spider fearful individuals

The fear conditioning paradigm is one of the most commonly used procedures to examine the etiology and treatment of anxiety disorders in laboratories. However, findings with this procedure often do not generalize to clinical settings. Virtual reality (VR) is a promising tool for improving the ecological and predictive validity of fear conditioning. The current study explored whether a classical differential cue conditioning paradigm with spider-fearful participants can be conducted in a VR-environment. Specifically, 25 spider-fearful and 25 non-fearful female students participated in a fear-conditioning experiment with a virtual spider as an unconditioned stimulus (US). The experiment took place in a virtual office in which participants viewed an avatar of themselves sitting at a desk. Conditioned stimuli (CS) were a blue (CS+; 100% reinforcement) and a green (CS-) light emitted by a desk lamp. Fear reactions were measured by fear ratings, skin conductance responses (SCR), and fear potentiated startle responses (FPS). Our results indicated stronger differential fear conditioning for spider-fearful participants than for non-fearful participants. Furthermore, we demonstrate that these results relate specifically to spider-fear, and not to general trait anxiety. We conclude that fear conditioning in VR is a promising tool to improve the validity of classical fear conditioning procedures.

Threat vs. Threat: Attention to Fear-Related Animals and Threatening Faces.

It is generally thought to be adaptive that fear relevant stimuli in the environment can capture and hold our attention; and in psychopathology attentional allocation is thought to be cue-specific. Such hypervigilance toward threatening cues or difficulty to disengage attention from threat has been demonstrated for a variety of stimuli, for example, toward evolutionary prepared animals or toward socially relevant facial expressions. Usually, specific stimuli have been examined in individuals with particular fears (e.g., animals in animal fearful and faces in socially fearful participants). However, different kinds of stimuli are rarely examined in one study. Thus, it is unknown how different categories of threatening stimuli compete for attention and how specific kinds of fears modulate these attentional processes. In this study, we used a free viewing paradigm: pairs of pictures with threat-related content (spiders or angry faces) or neutral content (butterflies or neutral faces) were presented side by side (i.e., spiders and angry faces, angry and neutral faces, spiders and butterflies, butterflies and neutral faces). Eye-movements were recorded while spider fearful, socially anxious, or non-anxious participants viewed the picture pairs. Results generally replicate the finding that unpleasant pictures more effectively capture attention in the beginning of a trial compared to neutral pictures. This effect was more pronounced in spider fearful participants: the higher the fear the quicker they were in looking at spiders. This was not the case for high socially anxious participants and pictures of angry faces. Interestingly, when presented next to each other, there was no preference in initial orientation for either spiders or angry faces. However, neutral faces were looked at more quickly than butterflies. Regarding sustained attention, we found no general preference for unpleasant pictures compared to neutral pictures.

Learning to avoid spiders: fear predicts performance, not competence

ABSTRACTWe used an immersive virtual environment to examine avoidance learning in spider-fearful participants. In 3 experiments, participants were asked to repeatedly lift one of 3 virtual boxes, under which either a toy car or a spider appeared and then approached the participant. Participants were not told that the probability of encountering a spider differed across boxes. When the difference was large (Exps. 1 and 2), spider-fearfuls learned to avoid spiders by lifting the few-spiders-box more often and the many-spiders-box less often than non-fearful controls did. However, they hardly managed to do so when the probability differences were small (Exp. 3), and they did not escape from threat more quickly (Exp. 2). In contrast to the observed performance differences, spider-fearfuls and non-fearfuls showed equal competence, that is comparable post-experimental knowledge about the probability to encounter spiders under the 3 boxes. The limitations and implications of the present study are discussed.

Relating experimentally-induced fear to pre-existing phobic fear in the human brain.

While prior work has demonstrated that fear-conditioning changes the neural representation of previously neutral stimuli, it remains unknown to what extent this new representation abstracts away from specific fears and which brain areas are involved therein. To investigate this question, we sought commonalities between experimentally-induced fear via electric shocks and pre-existing phobia. Using functional MRI, we tested the effect of fear-conditioning pictures of dogs in 21 spider-fearful participants across three phases: baseline, post-conditioning, and extinction. Considering phobic stimuli as a reference point for the state of fear allowed us to examine whether fear-conditioning renders information patterns of previously neutral stimuli more similar to those of phobic stimuli. We trained a classification algorithm to discriminate information patterns of neutral stimuli (rats) and phobic stimuli and then tested the algorithm on information patterns from the conditioned stimuli (dogs). Performing this cross-decoding analysis at each experimental phase revealed brain regions in which dogs were classified as rats during baseline, as spiders following conditioning, and again as rats after extinction. A follow-up analysis showed that changes in visual perception information cannot explain the changing classification performance. These results demonstrate a common neural representation for processing fear-eliciting information, either pre-existing or acquired by classical conditioning.

We prefer what we fear: A response preference bias mimics attentional capture in spider fear

The extent to which emotionally significant stimuli capture visual attention remains elusive because a preference for reporting or choosing emotionally significant stimuli could mimic attentional capture by these stimuli. We conducted two prior-entry experiments to disentangle whether phobic and fear-relevant stimuli capture attention or merely produce a response bias in spider-fearful participants. Prior entry denotes the effect that attended stimuli are perceived earlier than unattended stimuli as indicated by temporal order judgments. We presented phobic (spiders), fear-relevant (snakes) and neutral stimuli in pairs with varying temporal onset. The participants’ task was to indicate which stimulus was presented first (Experiment 1) or second (Experiment 2). In the first experiment, spider-fearful but not control participants indicated that they had perceived spiders as occurring earlier in time, suggesting a prior-entry effect for spiders in this group. But surprisingly, in the second experiment, spider-fearful participants indicated more frequently that they had seen spiders as being presented second. This finding rules out a genuine prior-entry effect and instead suggests a strong preference for the response option associated with the feared animal. This response bias may result from a hypervigilance toward the feared stimulus and contribute to maintaining avoidance behavior in individuals with specific phobias.

Toward an implicit measure of emotions: ratings of abstract images reveal distinct emotional states

ABSTRACTAlthough implicit tests of positive and negative affect exist, implicit measures of distinct emotional states are scarce. Three experiments examined whether a novel implicit emotion-assessment task, the rating of emotion expressed in abstract images, would reveal distinct emotional states. In Experiment 1, participants exposed to a sadness-inducing story inferred more sadness, and less happiness, in abstract images. In Experiment 2, an anger-provoking interaction increased anger ratings. In Experiment 3, compared to neutral images, spider images increased fear ratings in spider-fearful participants but not in controls. In each experiment, the implicit task indicated elevated levels of the target emotion and did not indicate elevated levels of non-target negative emotions; the task thus differentiated among emotional states of the same valence. Correlations also supported the convergent and discriminant validity of the implicit task. Supporting the possibility that heuristic processes underlie the ratings, group differences were stronger among those who responded relatively quickly.

A comprehensive look at phobic fear in inhibition of return: Phobia-related spiders as cues and targets

Background and objectivesThe so called inhibition of return (IOR) effect refers to a bias against returning attention to a location which was previously investigated. Because emotionally salient material has the capacity to capture and hold attention it has been suggested that this material may disrupt this otherwise impressively stable phenomenon. Methods40 students participated in the experiment. Black and white schematic drawings of a spider, a butterfly or a cross were used as cues. A black dot, a spider, a butterfly or a cross were used as targets. Participants were required to press a key whenever the target picture appeared. Subsequently, they rated the pictures on valence and arousal. ResultsResults showed that the IOR effect remained stable and did not diminish with either fear-related cues or fear-related targets. This data adds strong arguments for the stability of IOR. LimitationsThe spider fearful participants were not diagnosed patients. They still meet the criteria for spider fear but follow-up studies should pursue the same question with a specific focus on participants’ levels of anxiety. ConclusionsThis study is a contribution to the debate on how emotions affect or do not affect attentional processes such as the IOR. IOR appears to be a robust phenomenon and the emotional valence of neither the cue nor the emotional valence of the target can override it.

An Abrupt Transformation of Phobic Behavior After a Post-Retrieval Amnesic Agent

BackgroundAlthough disrupting the process of memory reconsolidation has a great potential for clinical practice, the fear-amnesic effects are typically demonstrated through Pavlovian conditioning. Given that older and stronger memories are generally more resistant to change, we tested whether disrupting reconsolidation would also diminish fear in individuals who had developed a persistent spider fear outside the laboratory. MethodsSpider-fearful participants received a single dose of 40 mg of the noradrenergic β-blocker propranolol (n = 15), double-blind and placebo-controlled (n = 15), after a short 2-min exposure to a tarantula. To test whether memory reactivation was necessary to observe a fear-reducing effect, one additional group of spider-fearful participants (n = 15) received a single dose of 40 mg propranolol without memory reactivation. ResultsDisrupting reconsolidation of fear memory transformed avoidance behavior into approach behavior in a virtual binary fashion—an effect that persisted at least 1 year after treatment. Interestingly the β-adrenergic drug did initially not affect the self-declared fear of spiders but instead these reports followed the instant behavioral transformation several months later. ConclusionsOur findings are in sharp contrast with the currently pharmacological and cognitive behavioral treatments for anxiety and related disorders. The β-adrenergic blocker was only effective when the drug was administered upon memory reactivation, and a modification in cognitive representations was not necessary to observe a change in fear behavior. A new wave of treatments that pharmacologically target the synaptic plasticity underlying learning and memory seems to be within reach.

Temporal dynamics in the relation between presence and fear in virtual reality

Virtual reality (VR) is increasingly investigated as a new medium for exposure therapy, but process variables are not well understood. In particular, presence and fear during VR exposure correlate strongly, but the causal relationship between them remains unclear. We assigned 22 female spider-fearful participants randomly to either a stereoscopic (high presence) or a monoscopic (low presence) condition and exposed them repeatedly to a large virtual spider presented on a Powerwall. Presence and fear were assessed on subjective, physiological, and behavioral levels. Fear reactions were stronger and presence ratings were higher in the stereoscopic than the monoscopic condition. Presence in the first exposure trial correlated significantly with fear in the second exposure trial, while fear in the first exposure trial did not correlate significantly with presence in the second exposure trial. For the following exposure trials, correlations between presence and fear were significant in both directions. Limitations of our study include the small sample and the fact that we did not check diagnostic criteria of specific phobia. This is the first study to show temporal dynamics of the relationship between presence and fear. Initially, presence in VR seems to directly influence fear, while over time, presence and fear appear mutually dependent.

Exposure treatment in multiple contexts attenuates return of fear via renewal in high spider fearful individuals

Background and objectivesResearch has demonstrated that after exposure treatment, re-exposure to a previously feared stimulus outside of the treatment context can result in renewal of fear. The current study investigated whether conducting exposure treatment in multiple real-life contexts can attenuate renewal of fear. MethodsForty-six moderate to high spider fearful individuals were randomly allocated to groups that received exposure treatment in either one context or three contexts. Follow-up testing was conducted one week and four weeks after exposure in the treatment context or a novel context. ResultsRenewal of fear was found for the single extinction context group when exposed to the feared object in a novel context with self-report of fear, heart rate, and behavioural avoidance. However, renewal of fear was attenuated for the multiple extinction context group. LimitationsThe sample included moderate to high spider fearful participants rather than clients with spider phobia, potentially limiting the generalisability of the findings to clinical populations. ConclusionsUsing multiple extinction contexts in combination with other methods of attenuating renewal (e.g., context similarity) may provide a means to reduce the risk of renewal of fear.