Non-phobic Participants Research Articles

A novel probe of attentional bias for threat in specific phobia: Application of the “MouseView.js” approach

Although attentional bias for threat has been implicated in anxiety disorders, traditional attentional bias measures have been criticized for lack of reliability and validity, and eye tracking technologies can be cost-prohibitive. MouseView.js was recently developed to mimic eye tracking online by using the computer cursor as a proxy for gaze, and although it is equally reliable, MouseView.js’ utility for capturing attentional bias for threat in anxiety-related disorders remains unclear. To fill this knowledge gap, snake phobic and non-phobic participants (N = 62) completed a behavioral avoidance task (BAT) and the MouseView.js task which consisted of 10-second exposures to blurred, side-by-side images of either pleasant-neutral or threat-neutral pairings and were instructed to freely move the mouse to reveal the images. Results demonstrated that snake phobic participants had significantly shorter average mouse dwell time on threat images than non-phobic individuals and showed a significant reduction in average dwell time on threat images following the first presentation of the threat-neutral pairing. Additionally, dwell time on threat images significantly mediated the group differences in steps completed on the BAT. Results highlight the utility of MouseView.js in capturing avoidant patterns of attentional bias for threat that may also partially drive avoidance in snake phobia. Implications for capturing attentional bias for threat in anxiety disorders more broadly are discussed.

Facing Your Fear in Immersive Virtual Reality: Avoidance Behavior in Specific Phobia.

Specific phobias are the most common anxiety disorder and are characterized by avoidance behavior. Avoidance behavior impacts daily function and is proposed to impair extinction learning. However, despite its prevalence, its objective assessment remains a challenge. To this end, we developed a fully automated experimental procedure using immersive virtual reality. The procedure contained a behavioral search, forced-choice, and an approach task with varying degrees of freedom and task relevance of the stimuli. In this study, we examined the sensitivity and feasibility of these tasks to assess avoidance behavior in patients with specific phobia. We adapted the tasks by replacing the originally conditioned stimuli with a spider and a neutral animal and investigated 31 female participants composed of 15 spider-phobic and 16 non-phobic participants. As the non-phobics were quite heterogeneous in terms of their Fear of Spiders Questionnaire (FSQ) scores, we subdivided them into six “fearfuls” that had elevated FSQ scores, and 10 “non-fearfuls” that had no fear of spiders. The phobics successfully managed to complete the procedure and showed consistent avoidance behavior across all behavioral tasks. Compared to the non-fearfuls, which did not show any avoidance behavior at all, the phobics looked at the spider much more often and clearly directed their body toward it in the search task. In the approach task, they hesitated most when they were close to the spider, and their difficulty to touch the spider was reflected in a strong increase in right hand acceleration changes. The fearfuls showed avoidance behavior depending on the tasks: strongest in the search task and weakest in the approach task. Additionally, we identified subjective valence ratings of the spider as the main influence on both objective avoidance behavior and subjective well-being after exposure, mediating the effect of the FSQ. In summary, the behavioral tasks are well suited to assess avoidance behavior in phobic participants and provide detailed insights into the process of avoidance.

Summary of: Oral health status of non-phobic and dentally phobic individuals; a secondary analysis of the 2009 Adult Dental Health Survey.

Introduction The aim of this study was to conduct an exploration of differences in oral health behaviour and outcome between dentally phobic and non-phobic participants in the UK Adult Dental Health Survey (ADHS, 2009). The null hypotheses for this study were that there are no differences in oral health status of non-phobic and dental phobic individuals. Methods The ADHS survey covered the adult population in England, Wales and Northern Ireland and was commissioned by the NHS Information Centre for Health and Social Care (NHS IC). Dental anxiety was defined using the Modified Dental Anxiety (MDAS) with the cut-off point set at 19 and above as indicating dental phobia. Descriptive statistics were calculated and the chi-square test was used to compare both groups in terms of their demographics, oral health, oral health-related behaviour and attitudes, and treatment. Results More women (16.8% [1,023]) than men (7% [344]) reported dental phobia. Generally, people with dental phobia were in routine occupations (648 [47.7%]), single (402 [29.4%]) and with lower educational attainment (858 [80.9%]). They were irregular attendees (798 [58.5%]), had a less restored dentition, increased numbers of one or more teeth with caries (292 [39.9%]), and were more likely to have PUFA (puss, ulceration, fistulae, abscess) scores of one or more (89 [12.2%]) in comparison to the non-phobic group (314 [5.6%]). However, people with and without dental phobia had similar numbers of sound and missing teeth (34.5% of the phobic group had 20 or more sound teeth in comparison to 31.7% of the non-phobic group). There were significant differences (p <0.001) between the phobic group's and non-phobic group's Oral Health Impact Profile-14 (OHIP) and Oral Impacts on Daily Performance (OIDP) scores with phobic participants having generally higher scores. Additionally, the phobic group responded negatively more commonly about their most recent dental treatment in terms of dentists' ability to listen to their concerns, explaining the reasons for their dental care while paying full attention to their needs by treating them with respect and dignity. The difference between the two groups was statistically significant (p <0.001). Conclusions Participants reporting dental phobia are mostly females, irregular attendees and have a greater treatment need with increased caries levels.

Oral health status of non-phobic and dentally phobic individuals; a secondary analysis of the 2009 Adult Dental Health Survey.

The aim of this study was to conduct an exploration of differences in oral health behaviour and outcome between dentally phobic and non-phobic participants in the UK Adult Dental Health Survey (ADHS, 2009). The null hypotheses for this study were that there are no differences in oral health status of non-phobic and dental phobic individuals. The ADHS survey covered the adult population in England, Wales and Northern Ireland and was commissioned by the NHS Information Centre for Health and Social Care (NHS IC). Dental anxiety was defined using the Modified Dental Anxiety (MDAS) with the cut-off point set at 19 and above as indicating dental phobia. Descriptive statistics were calculated and the chi-square test was used to compare both groups in terms of their demographics, oral health, oral health-related behaviour and attitudes, and treatment. More women (16.8% [1,023]) than men (7% [344]) reported dental phobia. Generally, people with dental phobia were in routine occupations (648 [47.7%]), single (402 [29.4%]) and with lower educational attainment (858 [80.9%]). They were irregular attendees (798 [58.5%]), had a less restored dentition, increased numbers of one or more teeth with caries (292 [39.9%]), and were more likely to have PUFA (puss, ulceration, fistulae, abscess) scores of one or more (89 [12.2%]) in comparison to the non-phobic group (314 [5.6%]). However, people with and without dental phobia had similar numbers of sound and missing teeth (34.5% of the phobic group had 20 or more sound teeth in comparison to 31.7% of the non-phobic group). There were significant differences (p<0.001) between the phobic group's and non-phobic group's Oral Health Impact Profile-14 (OHIP) and Oral Impacts on Daily Performance (OIDP) scores with phobic participants having generally higher scores. Additionally, the phobic group responded negatively more commonly about their most recent dental treatment in terms of dentists' ability to listen to their concerns, explaining the reasons for their dental care while paying full attention to their needs by treating them with respect and dignity. The difference between the two groups was statistically significant (p<0.001). Participants reporting dental phobia are mostly females, irregular attendees and have a greater treatment need with increased caries levels.

When Spiders Make Time Crawl

The current study used a temporal bisection task to investigate how fear influences the perception of short time durations. Spider phobic individuals (N=20) and non-phobic individuals (N=21) were asked to judge the duration of images containing spiders. Replicating previous research it was found that spider phobic participants more frequently overestimated the amount of time spent looking at images of spiders than non-phobic participants. Finally, spider phobic participants took longer to judge the duration of spider images (as measured by response time) than non-phobic participants. The findings are interpreted in terms of the operation of a switch mechanism within an internal clock.

A dissociation between detection and identification of phobic stimuli: Unconscious perception?

A psychophysical paradigm for investigating unconscious perception was used to test the hypothesis of dissociation between detection and identification of phobic stimuli. Spider-phobic and non-phobic participants were presented with masked images of spiders and flowers and an equal number of control stimuli in a random sequence. After each masked stimulus was flashed, participants first reported whether or not an object was presented. Then they identified each stimulus as either a spider or a flower, regardless of their prior detection response. Phobic participants identified both detected and undetected spiders better than chance, as assessed by two measures of response bias. They did not exhibit dissociation between detection and identification for flowers. Non-phobic participants did not exhibit detection–identification dissociation for either spiders or flowers. These results are consistent with the interpretation that phobic individuals unconsciously perceive their feared stimulus, and constitute the first direct demonstration of such for emotional stimuli.

Very brief exposure II: The effects of unreportable stimuli on reducing phobic behavior

This experiment compared the effects of exposure to masked phobic stimuli at a very brief stimulus-onset asynchrony on spider-phobic and non-phobic individuals. Participants were identified through a widely used questionnaire and a Behavioral Avoidance Test (BAT) with a live, caged tarantula to establish baseline levels of avoidance. One week later, they were individually administered one of two continuous series of masked images: spiders or flowers. Preliminary masking experiments showed that independent samples of participants from the same populations failed to recognize these stimuli. Participants in the main experiment reported ratings of subjective distress immediately before and after the exposure manipulation. Then they engaged in the BAT once again. Very brief exposure to images of spiders reduced phobic participants' avoidance of the tarantula. No effects were evidenced on subjective distress, or on non-phobic participants. Theoretical implications for the non-conscious basis of fear are discussed.

The role of presence in the level of anxiety experienced in clinical virtual environments

Recent reviews point towards that Virtual Reality Exposure Therapy (VRET) can be an effective medium to provide exposure therapy for anxiety disorders. The concept of presence, usually defined as the sense of being inside the virtual environment, has been considered the principal mechanism that leads to the experience of anxiety in clinical virtual environments. The present study sought to examine the relationship between sense of presence and in-session anxiety in a sample of 210 students showing high and low test anxiety when exposed to both clinical and non-stressful virtual environments. This is the largest study conducted to date with the aim of examining the relationship between presence and anxiety in clinical virtual environments, and the first to explore separately the relationship between presence and state-anxiety in phobic and non-phobic participants. The results suggest that presence was not related to anxiety in a non-stressful environment. It was also found that although presence is related to anxiety in both groups of students when exposed to clinical virtual environments, this relationship was clearly stronger for high test anxiety students. This line of research will broaden our understanding of the mechanisms that lead to the efficacy of VRET.

An fMRI Study Examining Effects of Acute D-Cycloserine During Symptom Provocation in Spider Phobia

Exposure-based therapy for anxiety disorders is believed to operate on the basis of fear extinction. Studies have shown acute administration of D-cycloserine (DCS) enhances fear extinction in animals and facilitates exposure therapy in humans, but the neural mechanisms are not completely understood. To date, no study has examined neural effects of acute DCS in anxiety-disordered populations. Two hours prior to functional magnetic resonance imaging scanning, 23 spider-phobic and 23 non-phobic participants were randomized to receive DCS 100 mg or placebo. During scanning, participants viewed spider, butterfly, and Gaussian-blurred baseline images in a block-design paradigm. Diagnostic and treatment groups were compared regarding differential activations to spider versus butterfly stimuli. In the phobic group, DCS enhanced prefrontal (PFC), dorsal anterior cingulate (ACC), and insula activations. For controls, DCS enhanced ventral ACC and caudate activations. There was a positive correlation between lateral PFC and amygdala activation for the placebo-phobic group. Reported distress during symptom provocation was correlated with amygdala activation in the placebo-phobic group and orbitofrontal cortex activation in the DCS-phobic group. Results suggest that during initial phobic symptom provocation DCS enhances activation in regions involved in cognitive control and interoceptive integration, including the PFC, ACC, and insular cortices for phobic participants.

Evaluative conditioning of fear and disgust in blood-injection-injury phobia: Specificity and impact of individual differences in disgust sensitivity

The present study examines whether the repeated pairing of neutral facial expressions with phobic-relevant stimuli differentially influences evaluative ratings of fear and disgust between analogue blood-injection-injury (BII) phobic ( n = 40) and non-phobic ( n = 40) participants. Consistent with prior research, BII phobics reported greater disgust sensitivity than non-phobic participants even after controlling for between group differences in anxiety symptoms. Results from the evaluative conditioning experiment indicated that pre- to posttest increases in fear ratings were only marginally greater for phobic compared to non-phobic participants. However, increases in disgust from pre- to posttest were greater for phobic compared to non-phobic participants and greater for neutral expressions that were paired with threat-relevant stimuli compared to stimuli not paired with threat-relevant stimuli. Subsequent analysis also indicated that pre- to posttest increases in disgust ratings of neutral expressions that were paired with threat-relevant stimuli was moderated by disgust sensitivity levels among phobic and non-phobic participants. Heightened fear and disgust ratings were subsequently reduced by an extinction procedure. Implications of present findings in understanding the role of fear and disgust in BII phobia are discussed.

Modulation of the neural network involved in the processing of anger prosody: The role of task-relevance and social phobia

Individuals with social phobia display neural hyperactivation towards angry facial expressions. However, it is uncertain whether they also show abnormal brain responses when processing angry voices. In an event-related functional magnetic resonance imaging study, we investigated brain responses to neutral and angry voices in 12 healthy control participants and 12 individuals with social phobia when emotional prosody was either task-relevant or task-irrelevant. Regardless of task, both phobic and non-phobic participants recruited a network comprising frontotemporal regions, the amygdala, the insula, and the striatum, when listening to angry compared to neutral prosody. Across participants, increased activation in orbitofrontal cortex during task-relevant as compared to task-irrelevant emotional prosody processing was found. Compared to healthy controls, individuals with social phobia displayed significantly stronger orbitofrontal activation in response to angry versus neutral voices under both task conditions. These results suggest a disorder-associated increased involvement of the orbitofrontal cortex in response to threatening voices in social phobia.

Symptom provocation and reduction in patients suffering from spider phobia

Neurofunctional mechanisms underlying cognitive behavior therapy (CBT) are still not clearly understood. This functional magnetic resonance imaging (fMRI) study focused on changes in brain activation as a result of one-session CBT in patients suffering from spider phobia. Twenty-six female spider phobics and 25 non-phobic subjects were presented with spider pictures, generally disgust-inducing, generally fear-inducing and affectively neutral scenes in an initial fMRI session. Afterwards, the patients were randomly assigned to either a therapy group (TG) or a waiting list group (WG). The scans were repeated one week after the treatment or after a one-week waiting period. Relative to the non-phobic participants, the patients displayed increased activation in the amygdala and the fusiform gyrus as well as decreased activation in the medial orbitofrontal cortex (OFC) during the first exposure. The therapy effect consisted of increased medial OFC activity in the TG relative to the WG. Further, therapy-related reductions in experienced somatic anxiety symptoms were positively correlated with activation decreases in the amygdala and the insula. We conclude that successful treatment of spider phobia is primarily accompanied by functional changes of the medial OFC. This brain region is crucial for the self-regulation of emotions and the relearning of stimulus-reinforcement associations.

Information processing biases in spider phobia: Application of the Stroop and “White Noise” Paradigm

The present study examines attentional and implicit memory biases in spider phobic and nonphobic participants. The results showed that spider phobics demonstrated increased interference for neutral, negative, and spider-relevant words on a computerized Stroop task. However, no group differences emerged when adjusting for differences in color-naming speed. Prior exposure to a dead spider did result in higher overall Stroop interference in spider phobics and this appeared to be mostly pronounced for spider-relevant words. Implicit memory bias for threat was examined with a noise judgment task. Participants first heard neutral and spider-relevant sentences and implicit memory for these sentences was evaluated by having participants rate the volume of noise accompanying the presentation of old sentences intermixed with new sentences. An implicit memory bias is indicated if participants rate noise accompanying old sentences as less loud than noise accompanying new sentences. No evidence was found for an implicit memory bias in spider phobics. These findings are discussed in relation to the role of information processing biases in spider phobia.

Beyond fear and disgust: The role of (automatic) contamination-related associations in spider phobia

This study explored the role of threat and contamination-related associations in spider phobia. Treatment-seeking ( n=60) and non-phobic ( n=30) individuals completed threat and disgust-related Implicit Association Tests (IATs). Phobic individuals were assessed before and after one session of 2.5 h in vivo exposure. To differentiate actual treatment effects from test–retest effects on the IAT, half of the phobic individuals completed the IAT twice before treatment. Results showed that: (1) threat and contamination associations similarly distinguished between phobic and non-phobic participants on self-reports and IATs; (2) only self-reported threat associations incrementally predicted participants’ overt avoidance behavior next to self-reported global affective associations; (3) self-reported associations were significantly reduced following treatment; (4) IAT-effects showed no significant reduction following treatment, and no evidence was found for an additional treatment-induced change over and above test–retest effects.

Analysis of physiological response to two virtual environments: driving and flying simulation.

As virtual reality technology continues to attract significant attention in clinical psychology, especially in the treatment of phobias, physiological monitoring is increasingly considered as an objective measurement tool for studying participants. There are few studies, however, of the normal physiological response to virtual environments or reactions to different virtual environments. The goal of this study is to analyze nonphobic participants' physiological reactions to two virtual environments: driving and flying. Eleven nonphobic participants were exposed to each virtual environment for 15 min. Heart rate, skin resistance, and skin temperature were measured during physiological monitoring, and the Presence and Simulator Sickness Questionnaire scores were obtained after each exposure. This study found that skin resistance and heart rate variability can be used to show arousal of participants exposed to the virtual environment experience and that such measures generally returned to normal over time. The data suggest that skin resistance and heart rate can be used as objective measures in monitoring the reaction of non-phobic participants to virtual environments. We also noted that heart rate variability could be useful for assessing the emotional states of participants.

Physiological Monitoring as an Objective Tool in Virtual Reality Therapy

The goals of this study were twofold: (1) to investigate nonphobics' and phobics' physiological response in virtual environments, and (2) to analyze the trend of phobics' physiology during virtual reality (VR) treatment. As a measure of physiology, heart rate, skin resistance, and skin temperature were acquired. The data for two groups of participants were analyzed: 22 nonphobic participants (mean = 32 +/- 9.4 years) and 36 subjects with fear of flying (mean = 40 +/- 12.1 years) who met the DSM-IV criteria for fear of flying. As a result, skin resistance showed significant differences between nonphobics and phobics, T(56) = 2.978 and p < 0.01, respectively. The physiological response of 33 phobic participants, who were able to fly without medicine after VR treatment, showed a gradual trend toward the nonphobics' physiological responses as therapy sessions progressed. In this study, physiological monitoring, in particular skin resistance, appeared to be useful both in understanding the physiological state of phobic individuals and in evaluating the results of treatment in VR psychotherapy.

An investigation of immersiveness in virtual reality exposure using physiological data.

As virtual reality technology is increasingly attracting significant attention in clinical psychology, especially in the treatment of phobias, physiological monitoring is increasingly considered as an objective measuring tool for studying participants. However, there are few studies of the normal individual's physiological response to virtual environments, or their reactions to different virtual environments. The goal of this study is to analyze non-phobic participants' physiological reaction to two virtual environments: driving and flying and to investigate the usefulness of heart rate variability. Eleven non-phobic participants were exposed to each virtual environment for 15 minutes. Heart rate, skin resistance, and skin temperature measurements were taken for physiological monitoring and Presence and Simulator Sickness Questionnaires were obtained after each exposure. This study found that skin resistance and heart rate variability can be used to show arousal of participant exposed to virtual environments experience and that such measures generally returned to normal as time went by. The Study showed that skin resistance and heart rate can be used as objective measures in monitoring the reaction of non-phobic participants to virtual environments. Significantly, heart rate variability analysis in virtual environments showed that it could be useful for assessing the emotional states of participants.

Exposure to disgust-evoking imagery and information processing biases in blood-injection-injury phobia

Biased processing of threat-relevant information is a central construct among contemporary theories of anxiety. However, biases in attentional and memory processes have not been systematically investigated in blood-injection-injury (BII) phobia. Theory has suggested that disgust rather than fear characterizes BII phobia and may mediate processing biases differently. We investigated the effects of a disgust mood induction on attention and memory in BII phobic and nonphobic participants. The Stroop task failed to demonstrate an attentional bias toward medical and disgust words, even under conditions of disgust provocation. However, an implicit memory task showed that BII phobics completed more medical and disgust word stems than nonphobics. These results suggest that BII phobia may be characterized by a similar implicit memory, but not an attentional, bias found in other anxiety disorders. As such, information processing in BII phobia may be qualitatively different from other anxiety disorders. Implications for further research regarding information processing biases in BII phobia are discussed.

Visual avoidance in specific phobia

Cognitive models of anxiety postulate that fear and anxiety serve as programs for avoidance of threat-relevant stimuli. We hypothesized that exposure to phobia-relevant stimuli would lead to visual avoidance in specific phobics. Spider phobic, blood-injection-injury phobic, and nonphobic participants were asked to view spider, injection, and neutral photographs through a three-channel tachistoscope that measured viewing time for each picture. Despite experimenter instructions to study the pictures carefully for a subsequent recognition test, phobic subjects showed decreased viewing times for threat-relevant pictures as compared to neutral pictures. Results are discussed in terms of cognitive models of anxiety disorders and implications for exposure-based therapies.