RESUMO
The current registered report focused on the temporal dynamics of the relationship between expectancy and attention toward threat, to better understand the mechanisms underlying the prioritization of threat detection over expectancy. In the current event-related potentials experiment, a-priori expectancy was manipulated, and attention bias was measured, using a well-validated paradigm. A visual search array was presented, with one of two targets: spiders (threatening) or birds (neutral). A verbal cue stating the likelihood of encountering a target preceded the array, creating congruent and incongruent trials. Following cue presentation, preparatory processes were examined using the contingent negative variation (CNV) component. Following target presentation, two components were measured: early posterior negativity (EPN) and late positive potential (LPP), reflecting early and late stages of natural selective attention toward emotional stimuli, respectively. Behaviorally, spiders were found faster than birds, and congruency effects emerged for both targets. For the CNV, a non-significant trend of more negative amplitudes following spider cues emerged. As expected, EPN and LPP amplitudes were larger for spider targets compared to bird targets. Data-driven, exploratory, topographical analyses revealed different patterns of activation for bird cues compared to spider cues. Furthermore, 400-500 ms post-target, a congruency effect was revealed only for bird targets. Together, these results demonstrate that while expectancy for spider appearance is evident in differential neural preparation, the actual appearance of spider target overrides this expectancy effect and only in later stages of processing does the cueing effect come again into play.
Assuntos
Antecipação Psicológica , Viés de Atenção , Eletroencefalografia , Potenciais Evocados , Aranhas , Humanos , Feminino , Animais , Aranhas/fisiologia , Potenciais Evocados/fisiologia , Masculino , Adulto Jovem , Adulto , Viés de Atenção/fisiologia , Antecipação Psicológica/fisiologia , Sinais (Psicologia) , Atenção/fisiologia , Aves/fisiologia , Medo/fisiologiaRESUMO
BACKGROUND AND OBJECTIVES: The relation between fear and interpretation bias has been widely studied in children. However, much less is known about its content-specificity and how interpretation biases predict variance in avoidance. The current study examined different interpretation bias tasks, the role of priming and the ability of the interpretation bias tasks to predict spider fear-related avoidance behaviour. METHODS: 169 children with varying levels of spider fear performed a behavioural avoidance task, two versions of the Ambiguous Scenarios Task (AST; with and without priming), and a size and distance estimation task. RESULTS: Both versions of the AST and the size-estimation were significantly related to self-reported spider fear and avoidance. These relations were content-specific: children with higher levels of spider fear had a more negative interpretation bias related to spider-related materials than to other materials, and a more negative bias than children with lower levels of spider fear. Furthermore, self-reported spider fear, the AST with priming, and the size-estimation predicted unique variance in avoidance behaviour. LIMITATIONS: Children varied in their level of spider fear, but clinical diagnoses of spider phobia were not assessed. The participants of this study were not randomly selected, they were children of parents with panic disorder or social anxiety disorder or no anxiety disorder and could therefore partly be seen as children at risk. CONCLUSIONS: The results support cognitive models of childhood anxiety and indicate that both controlled and automatic processes play an important role in fear-related behaviour.
Assuntos
Transtornos Fóbicos , Aranhas , Criança , Humanos , Animais , Transtornos Fóbicos/psicologia , Medo/psicologia , Transtornos de Ansiedade/psicologiaRESUMO
Most experimental avoidance paradigms lack either control over the experimental situation or simplify real-life avoidance behavior to a great extent, making it difficult to generalize the results to the complex approach-avoidance situations that anxious individuals face in daily life. The current study aimed to examine the usability of our recently developed free-exploratory avoidance paradigm in Virtual Reality (VR) that allows for the assessment of subjective as well as behavioral avoidance in participants with varying levels of spider fear. In a VR escape room, participants searched for cues to decipher a code-locked door. Opening a wooden box marked with a post-it note (conditioned stimulus, CS) resulted in exposure to a virtual crawling spider (unconditioned stimulus, US). Avoidance of the original CS and other objects marked with the CS (generalization stimuli, GSs; EXPgen condition) or non-marked (CONT condition) objects was measured via questionnaires and relative manipulation times in a novel room. We expected a positive linear relationship between US aversiveness (levels of spider fear) and (generalization of) fear and avoidance behaviors. Avoidance learning and generalization was demonstrated on both a subjective and behavioral level. Higher levels of spider fear were, overall, related to more negative emotions in response to the encounter with the spider, higher US expectancies for the GSs, and more self-reported and behavioral avoidance of the original CS and the GSs. Finally, we explored relationships between trait anxiety and intolerance of uncertainty and fear and avoidance (generalization), but no robust associations were observed. In conclusion, we confirmed the expected positive linear relationship between spider fear and (generalization of) fear and avoidance behaviors. Our results suggest that our free-exploratory VR avoidance paradigm is well-suited to investigate avoidance behaviors and the generalization of avoidance.
Assuntos
Transtornos Fóbicos , Aranhas , Animais , Humanos , Medo/psicologia , Transtornos Fóbicos/psicologia , Ansiedade/psicologia , Aprendizagem da Esquiva/fisiologiaRESUMO
When responding to stimuli, response and stimulus' features are thought to be integrated into a short episodic memory trace, an event file. Repeating any of its components causes retrieval of the whole event file leading to benefits for full repetitions and changes but interference for partial repetitions. These binding effects are especially pronounced if attention is allocated to certain features. We used attentional biases caused by spider stimuli, aiming to modulate the impact of attention on retrieval. Participants discriminated the orientation of bars repeating or changing their location in prime-probe sequences. Crucially, shortly before probe target onset, an image of a spider and that of a cub appeared at one position each - one of which was spatially congruent with the following probe target. Participants were faster when responding to targets spatially congruent with a preceding spider, suggesting an attentional bias toward aversive information. Yet, neither overall binding effects differed between content of preceding spatially congruent images nor did this effect emerge when taking individual fear of spiders into account. We conclude that attentional biases toward spiders modulate overall behavior, but that this has no impact on retrieval.
Assuntos
Viés de Atenção , Transtornos Fóbicos , Aranhas , Animais , Humanos , Viés de Atenção/fisiologia , Medo , Atenção/fisiologiaRESUMO
RATIONALE: The administration of glucocorticoids (GC) as an adjunct to exposure represents a promising strategy to improve one-session exposure outcome in anxiety disorders. It remains to be determined whether similar effects can be induced with the use of acute stress. Furthermore, the possible modulation of exposure effects by hormonal factors (e.g., use of oral contraceptives (OCs)) was not explored so far. OBJECTIVES: We investigated whether acute stress prior to one-session exposure for spider fear affects its efficacy in women using oral contraceptives (OC) relative to free-cycling (FC) women. In addition, effects of stress on generalization of exposure therapy effects towards untreated stimuli were examined. METHODS: Women with fears of spiders and cockroaches were randomly assigned to a Stress (n = 24) or No-Stress (n = 24) condition prior to one-session exposure. Of these 48 participants, 19 women used OC (n = 9 in the Stress, and n = 10 in the No-Stress group). All FC women had a regular menstrual cycle and were tested only in the follicular phase of their menstrual cycle. Pre-exposure stress induction was realized with the socially evaluated cold-pressor test. Exposure-induced changes towards treated and untreated fear stimuli were tested with behavioral approach tests for spiders and cockroaches and subjective fear and self-report measures. RESULTS: Acute stress did not influence exposure-induced reduction in fear and avoidance of the treated stimuli (spiders). Similarly, stress had no effect on the generalization of exposure-therapy effects towards untreated stimuli (cockroaches). Exposure-induced reduction in subjective fear and self-report measures for treated stimuli was less evident in women using OC specifically after pre-exposure stress. Women using OC had higher levels of subjective fear and scored higher in self-report measures at post-treatment (24 h after exposure) and follow-up (4 weeks after exposure). CONCLUSIONS: OC intake may represent an important confounding factor in augmentation studies using stress or GC.
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Terapia Implosiva , Transtornos Fóbicos , Aranhas , Humanos , Animais , Feminino , Anticoncepcionais Orais/farmacologia , Transtornos Fóbicos/terapia , Medo , Transtornos de Ansiedade , Glucocorticoides/farmacologiaRESUMO
Spider fear is an excellent model to experimentally study processes in the maintenance and treatment of long-lasting fears. A valid, reliable, and practical tool to assess spider-related distress dimensionally, and to differentiate between spider-related fear and disgust in a time-sensitive manner, may help to better understand individual differences in these two emotions and to tailor treatments accordingly. We developed a concise self-report questionnaire, the Spider Distress Scale (SDS), that combines the strengths of established spider fear questionnaires and addresses their shortcomings. We explored (study 1 and 2) and confirmed (study 3) a two-factor structure of the SDS in samples from the general population (n = 370; n = 360; n = 423), recruited online via Prolific Academic from the United Kingdom, the Netherlands, and the United States. The fear and disgust factors of the SDS are highly internally consistent and the SDS has excellent test-retest reliability. We found good convergent and discriminant validity, based on self-report measures and spider behavioural approach tasks, and the SDS successfully differentiated between individuals with and without spider fear (study 4, n = 75). Our series of studies suggests that fear and disgust are functionally related, but that disgust towards spiders can be differentially assessed when focussing on unique elements of disgust-related information.
Assuntos
Asco , Aranhas , Animais , Medo/psicologia , Humanos , Psicometria , Reprodutibilidade dos Testes , Inquéritos e QuestionáriosRESUMO
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.
Assuntos
Borboletas , Transtornos Fóbicos , Aranhas , Animais , Medo , Feminino , Humanos , Reprodutibilidade dos TestesRESUMO
We investigated the role of self-reports and behavioral measures of interpretation biases and their content-specificity in children with varying levels of spider fear and/or social anxiety. In total, 141 selected children from a community sample completed an interpretation bias task with scenarios that were related to either spider threat or social threat. Specific interpretation biases were found; only spider-related interpretation bias and self-reported spider fear predicted unique variance in avoidance behavior on the Behavior Avoidance Task for spiders. Likewise, only social-threat related interpretation bias and self-reported social anxiety predicted anxiety during the Social Speech Task. These findings support the hypothesis that fearful children display cognitive biases that are specific to particular fear-relevant stimuli. Clinically, this insight might be used to improve treatments for anxious children by targeting content-specific interpretation biases related to individual disorders.
Assuntos
Ansiedade/psicologia , Medo/psicologia , Fobia Social/psicologia , Transtornos Fóbicos/psicologia , Criança , Feminino , Humanos , Masculino , AutorrelatoRESUMO
Attentional bias towards threat can be demonstrated by enhanced processing of threat-related targets and/or greater interference when threat-related distractors are present. These effects are argued to reflect processing within the orienting and executive control networks of the brain respectively. This study investigated behavioural (RT) and electrophysiological correlates of early selective attention and top-down attentional control among females with high (n = 16) or low (n = 16) spider fear (Mean age = 22 years). Participants completed a novel flanker go/nogo task in which a central schematic flower or spider stimulus was flanked by either congruent or incongruent distractors. Participants responded to green stimuli (go trials) and withheld response to yellow stimuli (nogo trials). High fear participants demonstrated significantly shorter reaction times and greater P1 amplitude to spider targets, suggesting specific hypervigilance towards threat-relevant stimuli. In contrast to predictions, there was little evidence for behavioural interference effects or differences in N2 amplitude when distractor stimuli were threat-relevant.
Assuntos
Ansiedade/fisiopatologia , Viés de Atenção/fisiologia , Potenciais Evocados/fisiologia , Medo/fisiologia , Adolescente , Adulto , Animais , Feminino , Humanos , Tempo de Reação/fisiologia , Aranhas , Adulto JovemRESUMO
Memories can be modified when recalled. Experimental fear conditioning studies support that amygdala-localized fear memories are attenuated when reconsolidation is disrupted through extinction training immediately following memory activation. Recently, using functional brain imaging in individuals with lifelong spider fears, we demonstrated that fear memory activation followed by repeated exposure to feared cues after 10min, thereby disrupting reconsolidation, attenuated activity in the amygdala during later re-exposure, and also facilitated approach behavior to feared cues. In contrast, repeated exposure 6h after fear memory activation, allowing for reconsolidation, did not attenuate amygdala activity and resulted in less approach behavior as compared to the group that received disrupted reconsolidation. We here evaluated if these effects are stable after 6 months and found that amygdala activity was further reduced in both groups, with a tendency towards greater reductions in the 10min than the 6h group. Hence, disrupted reconsolidation results in long lasting attenuation of amygdala activity. The behavioral effect, with more approach towards previously feared cues, in the 10min than the 6h group also persisted. Thus, the brain effect of disrupted reconsolidation is stable over 6 months and the behavioral effect also remained. We therefore conclude that disrupted reconsolidation result in a long-lasting diminished fear memory representation in the amygdala which may have clinical importance.
Assuntos
Tonsila do Cerebelo/fisiologia , Medo/fisiologia , Consolidação da Memória/fisiologia , Memória de Longo Prazo/fisiologia , Mapeamento Encefálico , Condicionamento Clássico/fisiologia , Extinção Psicológica/fisiologia , Humanos , Imageamento por Ressonância MagnéticaRESUMO
BACKGROUND AND OBJECTIVES: Cognitive theories suggest that cognitive biases may be related and together influence the anxiety response. However, little is known about the interrelations of cognitive bias tasks and whether they allow for an improved prediction of fear-related behavior in addition to self-reports. This study simultaneously addressed several types of cognitive biases in children, to investigate attention bias, interpretation bias, memory bias and fear-related associations, their interrelations and the prediction of behavior. METHODS: Eighty-one children varying in their levels of spider fear completed the Spider Anxiety and Disgust Screening for Children and performed two Emotional Stroop tasks, a Free Recall task, an interpretation task including size and distance indication, an Affective Priming Task, and a Behavioral Assessment Test. RESULTS: We found an attention bias, interpretation bias, and fear-related associations, but no evidence for a memory bias. The biases showed little overlap. Attention bias, interpretation bias, and fear-related associations predicted unique variance in avoidance of spiders. Interpretation bias and fear-related associations remained significant predictors, even when self-reported fear was included as a predictor. LIMITATIONS: Children were not seeking help for their spider fear and were not tested on clinical levels of spider phobia. CONCLUSIONS: This is the first study to find evidence that different cognitive biases each predict unique variance in avoidance behavior. Furthermore, it is also the first study in which we found evidence for a relation between fear of spiders and size and distance indication. We showed that this bias is distinct from other cognitive biases.
Assuntos
Associação , Viés de Atenção/fisiologia , Disfunção Cognitiva/etiologia , Medo/psicologia , Memória/fisiologia , Transtornos Fóbicos/complicações , Adolescente , Animais , Aprendizagem da Esquiva/fisiologia , Criança , Feminino , Humanos , Masculino , Rememoração Mental , Testes Neuropsicológicos , Transtornos Fóbicos/psicologia , Escalas de Graduação Psiquiátrica , Análise de Regressão , Aranhas , Teste de StroopRESUMO
BACKGROUND AND OBJECTIVES: The aim of the study was to examine habituation of subjective anxiety and electrophysiological correlates of cortical hyper-vigilance during exposure to spider images among high (n = 12) and low (n = 11) spider fear groups. METHODS: Participants viewed a six-stage hierarchy of spider images. The images used at stage 1 and stage 6 were the same. Subjective anxiety was rated at four intervals during each three-minute exposure stage (0, 60, 120, and 180 s) and event-related potentials (ERPs) were averaged across these epochs (0-60, 60-120, 120-180). RESULTS: High spider fearfuls demonstrated greater habituation of self-reported anxiety within and between exposure stages compared to low fearfuls. Consistent with attentional hyper-vigilance, the high-fear group also demonstrated greater P1 amplitude in response to spider images. In both groups, habituation of P1 amplitude was found at later relative to earlier stages, but increased at stage six when the stage 1 image was re-presented, despite low subjective anxiety. LIMITATIONS: While the passive viewing paradigm mirrored image-based exposure, it was not possible to determine whether participants engaged in avoidance strategies. In addition, further research is needed to assess the relevance of habituation and reinstatement of P1 amplitude to therapeutic outcome. CONCLUSIONS: Habituation of subjective anxiety during image-based exposure is not necessarily accompanied by a reduction in measures of cortical hyper-vigilance. The reinstatement of the P1 response may indicate either re-activation of previous associations, less avoidance, or a more generalised dishabituation mechanism.
Assuntos
Ansiedade , Nível de Alerta/fisiologia , Habituação Psicofisiológica/fisiologia , Imagens, Psicoterapia/métodos , Transtornos Fóbicos , Autorrelato , Adolescente , Adulto , Análise de Variância , Animais , Ansiedade/fisiopatologia , Ansiedade/psicologia , Ansiedade/reabilitação , Eletroencefalografia , Potenciais Evocados/fisiologia , Feminino , Humanos , Masculino , Transtornos Fóbicos/fisiopatologia , Transtornos Fóbicos/psicologia , Transtornos Fóbicos/reabilitação , Escalas de Graduação Psiquiátrica , Aranhas , Inquéritos e Questionários , Adulto JovemRESUMO
Research has demonstrated large differences in the degree to which direct and indirect measures predict each other and variables including behavioural approach and attentional bias. We investigated whether individual differences in the co-variance of "implicit" and "explicit" spider fear exist, and whether this covariation exerts an effect on spider fear-related outcomes. One hundred and thirty-two undergraduate students completed direct and indirect measures of spider fear/avoidance, self-report questionnaires of psychopathology, an attentional bias task, and a proxy Behavioural Approach Task. TwoStep cluster analysis using implicit and explicit spider fear as criterion variables resulted in three clusters: (1) low explicit/low implicit; (2) average explicit/high implicit; and (3) high explicit/low implicit. Clusters with higher explicit fear demonstrated greater disgust propensity and sensitivity and less willingness to approach a spider. No differences between clusters emerged on anticipatory approach anxiety or attentional bias. We discuss results in terms of dual-systems and cognitive-behavioural models of fear.
Assuntos
Transtornos Fóbicos/psicologia , Pensamento , Adulto , Animais , Ansiedade/etiologia , Ansiedade/psicologia , Atenção , Medo , Feminino , Humanos , Individualidade , Masculino , Aranhas , Inquéritos e Questionários , Adulto JovemRESUMO
BACKGROUND AND OBJECTIVES: The 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. METHODS: 40 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. RESULTS: Results 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. LIMITATIONS: The 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. CONCLUSIONS: This 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.
Assuntos
Sinais (Psicologia) , Medo/psicologia , Inibição Psicológica , Transtornos Fóbicos/fisiopatologia , Transtornos Fóbicos/psicologia , Adolescente , Adulto , Nível de Alerta , Viés , Feminino , Humanos , Masculino , Estimulação Luminosa , Tempo de Reação/fisiologia , Fatores de Tempo , Adulto JovemRESUMO
Snakes were probably one of the earliest predators of primates, and snake images produce specific behavioral and electrophysiological reactions in humans. Pictures of snakes evoke enhanced activity over the occipital cortex, indexed by the "early posterior negativity" (EPN), as compared with pictures of other dangerous or non-dangerous animals. The present study investigated the possibility that the response to snake images is independent from visual awareness. The observers watched images of threatening and non-threatening animals presented in random order during rapid serial visual presentation. Four different masking conditions were used to manipulate awareness of the images. Electrophysiological results showed that the EPN was larger for snake images than for the other images employed in the unmasked condition. However, the difference disappeared when awareness of the stimuli decreased. Behavioral results on the effects of awareness did not show any advantage for snake images.
Assuntos
Conscientização/fisiologia , Medo/fisiologia , Lobo Occipital/fisiologia , Estimulação Luminosa/métodos , Percepção Visual/fisiologia , Adulto , Animais , Encéfalo/fisiologia , Feminino , Humanos , Masculino , Mascaramento Perceptivo/fisiologia , Transtornos Fóbicos/fisiopatologia , Serpentes , Estudantes/psicologia , Adulto JovemRESUMO
A large group one-session exposure treatment (LG-OST) based on indirect modeled exposure strategies was carried out to investigate its feasibility and effectiveness in a sample of highly spider fearful individuals (N = 78). The stability of LG-OST-effects was assessed at 8-month follow-up (FU). Furthermore, a second sample (N = 30) of highly spider fearful individuals was treated in a standard, single-person one-session treatment (SP-OST) design to compare LG-OST-effects to a standard spider fear treatment. Participants' fear of spider was assessed by multiple questionnaires and by a behavioral approach test. The fear assessment took place before and after the respective intervention, and at 8-month FU in LG-OST. Regarding subjective spider fear measures, LG-OST mainly showed medium to large effect sizes, ranging from Cohen's d = 0.69 to d = 1.21, except for one small effect of d = 0.25. After LG-OST, participants approached the spider closer at post-treatment measures (d = 1.18). LG-OST-effects remained stable during the 8-month FU-interval. However, SP-OST-effects proved superior in most measures. An LG-OST-protocol provided evidence for feasibility and efficiency. The effects of LG-OST were equal to those of indirect modeled exposure strategies, carried out in single-settings. LG-OST may represent a useful tool in future phobia-treatment, especially if it can match the effects of single-setting OST, e.g., by including more direct exposure elements in future large group attempts.
RESUMO
We demonstrate that feature-specific attention allocation influences the way in which repeated exposure modulates implicit and explicit evaluations toward fear-related stimuli. During an exposure procedure, participants were encouraged to assign selective attention either to the evaluative meaning (i.e., Evaluative Condition) or a non-evaluative, semantic feature (i.e., Semantic Condition) of fear-related stimuli. The influence of the exposure procedure was captured by means of a measure of implicit evaluation, explicit evaluative ratings, and a measure of automatic approach/avoidance tendencies. As predicted, the implicit measure of evaluation revealed a reduced expression of evaluations in the Semantic Condition as compared to the Evaluative Condition. Moreover, this effect generalized toward novel objects that were never presented during the exposure procedure. The explicit measure of evaluation mimicked this effect, although it failed to reach conventional levels of statistical significance. No effects were found in terms of automatic approach/avoidance tendencies. Potential implications for the treatment of anxiety disorders are discussed.
RESUMO
A core symptom of anxiety disorders is the tendency to interpret ambiguous information as threatening. Using electroencephalography and blood oxygenation level dependent magnetic resonance imaging (BOLD-MRI), several studies have begun to elucidate brain processes involved in fear-related perceptual biases, but thus far mainly found evidence for general hypervigilance in high fearful individuals. Recently, multi-voxel pattern analysis (MVPA) has become popular for decoding cognitive states from distributed patterns of neural activation. Here, we used this technique to assess whether biased fear generalization, characteristic of clinical fear, is already present during the initial perception and categorization of a stimulus, or emerges during the subsequent interpretation of a stimulus. Individuals with low spider fear (n = 20) and high spider fear (n = 18) underwent functional MRI scanning while viewing series of schematic flowers morphing to spiders. In line with previous studies, individuals with high fear of spiders were behaviorally more likely to classify ambiguous morphs as spiders than individuals with low fear of spiders. Univariate analyses of BOLD-MRI data revealed stronger activation toward spider pictures in high fearful individuals compared to low fearful individuals in numerous areas. Yet, neither average activation, nor support vector machine classification (i.e., a form of MVPA) matched the behavioral results - i.e., a biased response toward ambiguous stimuli - in any of the regions of interest. This may point to limitations of the current design, and to challenges associated with classifying emotional and neutral stimuli in groups that differ in their judgment of emotionality. Improvements for future research are suggested.
RESUMO
Consistent with the snake detection hypothesis, previous ERP studies have established a larger early posterior negativity (EPN) in response to pictures depicting snakes than to pictures depicting other creatures. Here, we examined to what extent the curvilinear shape of the snake's body drives the larger EPN. To this end, we employed pictures of threatening and nonthreatening species with or without typical curvature. Participants watched a random rapid serial visual presentation of snake, worm, spider, and beetle pictures. The EPN was scored as the mean activity (225-300 ms after picture onset) at occipital and parieto-occipital electrodes. Across electrodes, the EPN was significantly larger for snake pictures than for spider, worm, and beetle pictures, and for spider and worm pictures than for beetle pictures. The results suggest that curvilinear body shapes may partly drive the enhanced EPN. However, the unique cortical response to snakes is not fully explained by this mechanism, and is most probably also determined by other threat-relevant cues.
Assuntos
Encéfalo/fisiologia , Potenciais Evocados Visuais/fisiologia , Reconhecimento Visual de Modelos/fisiologia , Adolescente , Adulto , Animais , Atenção/fisiologia , Sinais (Psicologia) , Eletroencefalografia , Medo/fisiologia , Feminino , Humanos , Masculino , Estimulação Luminosa , Serpentes , Aranhas , Adulto JovemRESUMO
BACKGROUND AND OBJECTIVES: Attention Bias Modification (ABM) targets attention bias (AB) towards threat and is a potential therapeutic intervention for anxiety. The current study investigated whether initial AB (towards or away from spider images) influenced the effectiveness of ABM in spider fear. METHODS: AB was assessed with an attentional probe task consisting of spider and neutral images presented simultaneously followed by a probe in spider congruent or spider incongruent locations. Response time (RT) differences between spider and neutral trials > 25 ms was considered 'Bias Toward' threat. RT difference < - 25 ms was considered 'Bias Away' from threat, and a difference between -25 ms and +25 ms was considered 'No Bias'. Participants were categorized into Initial Bias groups using pre-ABM AB scores calculated at the end of the study. 66 participants' (Bias Toward n = 27, Bias Away n = 18, No Bias n = 21) were randomly assigned to ABM-active training designed to reduce or eliminate a bias toward threat and 61 (Bias Toward n = 17, Bias Away n = 18, No Bias n = 26) to ABM-control. RESULTS: ABM-active had the largest impact on those demonstrating an initial Bias Towards spider images in terms of changing AB and reducing Spider Fear Vulnerability, with the Bias Away group experiencing least benefit from ABM. However, all Initial Bias groups benefited equally from active ABM in a Stress Task. LIMITATIONS: Participants were high spider fearful but not formally diagnosed with a specific phobia. Therefore, results should be confirmed within a clinical population. CONCLUSIONS: Individual differences in Initial Bias may be an important determinant of ABM efficacy.