Some animal specific fears are more specific than others: Evidence from attention and emotion measures

Using a visual search methodology we investigated the effect of feared animal stimuli on attention. Our results confirmed the important role of emotion on attention. All participants detected fear-relevant stimuli (snakes and spiders) faster than neutral (mushrooms) ones against a background of fruits. In addition, spider fearful participants were sensitized specifically to detect their feared stimulus (spiders), compared to their fear-relevant but non-feared (snakes) and neutral stimuli. However, for participants fearful of snakes there was no significant difference in detection latencies between the feared (snakes) and the fear-relevant but non-feared animal stimuli (spiders). The results from the attention task were mirrored in the emotional ratings, which showed that spider fear was highly specific, whereas snake fear was associated with a more generalized enhanced evaluation of all negative stimuli.     

The influence of animal fear on attentional capture by fear-relevant animal stimuli in children

The present study demonstrated that pictures of fear-relevant animals, snakes and spiders, presented among backgrounds of other animal stimuli captured attention and interfered in the detection of a neutral target to the same extent in a large sample of unselected children (N=81). Moreover, detection of a neutral target animal was slowed more in the presence of a feared fear-relevant distracter, e.g., a snake for snake fearful children, than in the presence of a not feared fear-relevant distracter, e.g., a spider for snake fearful children. These results indicate attentional capture by phylogenetically fear-relevant animal stimuli in children and the selective enhancement of this effect by fear of these animals. These findings are consistent with current models of preferential processing of phylogenetically prepared threat stimuli and with cognitive models of anxiety that propose an enhancing effect of fear in the processing of fear-related stimuli.     

No attentional bias for pictoral stimuli in spider-fearful subjects

A number of experiments have shown that (spider) fearful subjects direct their attention to fear-relevant words, even when these words are irrelevant to the completion of a target task (e.g., color naming). The present study examined whether subjects with an intense fear of spiders also display such attentional bias for a fear-relevant pictoral stimulus. Female spider-fearful (n=13) and control subjects (n=13) saw neutral patterns (i.e., horizontal and vertical bars). One pattern served as target for a reaction time, while the other pattern served as nontarget. Targets and nontargets were accompanied by either fear-relevant or neutral pictoral material (i.e., a picture of a spider or a picture of a flower, respectively). The fear-relevant picture did not selectively delibate reaction time performance of spider-fearful subjects. Thus, no evidence was found for an attentional bias for fear-relevant pictoral material in subjects with an intense fear of spiders. Instead, fearful subjects exhibited a general inhibition of performance which became stronger over trials. This suggests that the fear-relevant picture induced a state of anxious arousal or defensive withdrawal that interfered with reaction time performance on both fear-relevant and neutral trials.     

Maternal Modeling and the Acquisition of Fear and Avoidance in Toddlers: Influence of Stimulus Preparedness and Child Temperament

The aim of the present study was to investigate the influence of maternal modeling on the acquisition of fear and avoidance towards fear-relevant and fear-irrelevant, novel stimuli in a sample of 71 toddlers. Children were shown a rubber snake or spider (fear-relevant objects) and a rubber mushroom or flower (fear-irrelevant objects), which were alternately paired with either negative or positive expression by their mothers. Both stimuli were presented again after a 1- and a 10-min delay, while mothers maintained a neutral expression. The toddlers showed increased fear and avoidance of the objects following negative reaction from their mothers than following positive maternal expression. This was similarly true for both fear-relevant and fear-irrelevant stimuli. In addition, no association was found between child temperament and behavioral responses and a weak association emerged between child temperament and emotional responses. The results demonstrate that young children can rapidly form conditioned emotional and behavioral responses via maternal reactions regardless of stimulus preparedness or child temperament. It is suggested that early maternal modeling may be relevant to a broad spectrum of fearful reactions.     

The preparedness theory of phobias and human safety-signal conditioning

Seligman's preparedness theory of phobias implies that fear-relevant stimuli are contraprepared for safety-signal conditioning. This means that it should be very difficult to establish a fear-relevant stimulus as a safety-signal in nonphobic subjects. This hypothesis was tested in an electrodermal conditioning experiment with a picture of a snake serving as the fear-relevant CS and a picture of a flower serving as the fear-irrelevant CS. College students received discrimination training designed to establish the snake and the flower as safety-signals by nonreinforcing each in compound with a fear-eliciting CS. Although both the snake and the flower became conditioned safety-signals, neither stimulus showed greater safety-signal properties than the other. The results are inconsistent with predictions from preparedness theory.     

Fear of Anxiety in Fearful Adults: An Analysis of Heterogeneity Among Phobia Types

Fear of anxiety, the fear of developing physiological symptoms associated with anxiety, is investigated in this study and the extent to which fear of anxiety is differentially present in the various subtypes of specific phobias. Participants were 260 undergraduate students divided into those having fears corresponding to one of the specific phobia types and those having no reported fears. Participants completed a variety of measures including the Agoraphobic Cognitions Questionnaire and the Body Sensations Questionnaire. Results indicated fearful participants had more fear of anxiety than non-fearful participants. In addition, non-fearful participants reported significantly less frequent catastrophic cognitions than fearful participants of the situational and other types. Non-fearful control participants also reported less fear of bodily sensations than fearful participants of the animal and other subtypes. This study provides supporting evidence that the phenomenon of fear of anxiety is present in fears similar to specific phobias.     

Dissociations between Covariation Bias and Expectancy Bias for Fear-relevant Stimuli

The illusory correlation paradigm of Tomarken, Mineka, and Cook (1989) was used to examine bias in threat appraisal for biological (snake, spider) and technological (gun, knife) fear-relevant stimuli. Subjects showed bias in terms of higher on-line shock expectancy ratings and skin conductance responses, and higher post-experimental judgements of shock covariation, for fear-relevant stimuli. However, there were multiple dissociations between the measures: (1) expectancy bias was observed for both biological and technological stimuli, whereas covariation bias was restricted to biological stimuli; (2) prior fear of the target stimulus had no effect on expectancy bias, but covariation bias was restricted to high fear subjects; and (3) covariation bias was observed at the end of the experiment, by which time expectancy bias had disappeared. These results suggest that covariation bias is not simply a continuation of a pre-experimental expectancy bias.     

When danger lurks in the background: attentional capture by animal fear-relevant distractors is specific and selectively enhanced by animal fear

Across 2 experiments, a new experimental procedure was used to investigate attentional capture by animal fear-relevant stimuli. In Experiment 1 (N=34), unselected participants were slower to detect a neutral target animal in the presence of a spider than a cockroach distractor and in the presence of a snake than a large lizard distractor. This result confirms that phylogenetically fear-relevant animals capture attention specifically and to a larger extent than do non-fear-relevant animals. In Experiment 2 (N=86), detection of a neutral target animal was slowed more in the presence of a feared fear-relevant distractor (e.g., a snake for snake-fearful participants) than in presence of a not-feared fear-relevant distractor (e.g., a spider for snake-fearful participants). These results indicate preferential attentional capture that is specific to phylogenetically fear-relevant stimuli and is selectively enhanced in individuals who fear these animals.     

Tracking fear in snake and spider fearful participants during visual search: A multi-response domain study

In visual search tasks snake or spider fearful participants showed shorter reaction times (RTs) to respond to their feared animal (e.g., snake) than to the nonfeared animal (i.e., spider) (Öhman, Flykt, & Esteves, 2001). Here, we used this paradigm with heart rate (HR), RTs, and event-related potential (ERP) measures, to investigate the nature of the responses to the feared animal, a nonfeared (but fear-relevant) animal, and fear-irrelevant target stimuli with snake fearful, spider fearful, and nonfearful participants. Fearful participants showed shorter RTs and evoked larger amplitudes on a late positive potential (LPP; 500–700 ms) for their feared compared to the nonfeared and the fear-irrelevant targets. No relevant significant differences were found on early ERP components and HR measures. These findings do not support an involvement of early information processing in the detection of the feared animal in fearful participants, they favour instead a more elaborated analysis of these complex stimuli to achieve the detection.     

Attentional bias to pictures of fear-relevant animals in a dot probe task

Attentional bias to fear-relevant animals was assessed in 69 participants not preselected on self-reported anxiety with the use of a dot probe task showing pictures of snakes, spiders, mushrooms, and flowers. Probes that replaced the fear-relevant stimuli (snakes and spiders) were found faster than probes that replaced the non-fear-relevant stimuli, indicating an attentional bias in the entire sample. The bias was not correlated with self-reported state or trait anxiety or with general fearfulness. Participants reporting higher levels of spider fear showed an enhanced bias to spiders, but the bias remained significant in low scorers. The bias to snake pictures was not related to snake fear and was significant in high and low scorers. These results indicate preferential processing of fear-relevant stimuli in an unselected sample.     

Fear-relevant selective associations and covariation bias

Three experiments used an illusory correlation paradigm to assess the effects of fear on the perception of the covariation between fear-relevant stimuli and shock. In Experiment 1, high- and low-fear women were exposed to 72 trials during each of which a fear-relevant (snake or spider) or fear-irrelevant (mushroom and flower) slide was followed by a shock, a tone, or nothing. Although the relation between slide types and outcomes was random, high-fear subjects markedly overestimated the contingency between feared slides and shock. Experiment 2 showed that this bias was due to the aversive, rather than more generally salient, features of shock. Low-fear subjects demonstrated biases equivalent to those of high-fear subjects only when the base rate of shock was increased from 33% to 50% in Experiment 3. It is concluded that fear may be linked to biases that serve to confirm fear. The relevance of the present findings to preparedness theory is also discussed.     

In the grip of fear: Dissociations in attentional processing of animal fearful individuals

Using a modified attention paradigm we investigated specific attentional mechanisms in processing animal feared stimuli. In this paradigm arrays of four pictures were displayed and after its disappearance from view a probe (a letter, X or P) then followed unpredictably in the location of one of the four pictures. The results showed that discriminations of probes tended to be impeded by spider stimuli, compared to snake stimuli. This effect was potentiated by high anxiety but only for those individuals fearful of spiders, since no such effect was observed for snake fearful individuals. Moreover, the discrimination of the probes was not facilitated when presented after the feared stimuli. The implications of these findings are discussed as a function of the cognitive bias involved in specific fear.     

To look or not to look: an eye movement study of hypervigilance during change detection in high and low spider fearful students

Previous eye movement studies of attentional bias in spider fear reported inconsistent results with respect to early attentional capture, suggesting that overt attentional capture only reliably occurs under specific circumstances. In addition, none of these studies explored covert attention. The present study examined attentional bias in spider phobia using a change detection paradigm that was expected to provide good conditions for documenting attentional capture. In contrast to our expectations, eye movement data showed that all participants' first fixations were fastest on general negative targets, whereas participants' first fixations on spider targets were slower in the spider fearful than in the nonfearful group. In addition, spider fearful participants made more nontarget fixations before fixating on a spider target than did nonfearful participants. Thus, we found that participants' overt attention was more quickly focused on general negative targets, whereas covert attentional processes enabled initial avoidance of fear-relevant (i.e. spider) stimuli. The present findings have important implications for research on attention and fear as they indicate that fearful individuals are not characterized by static attentional orienting toward threat but, under certain conditions, may avert attention from threat automatically.     

The relationship between self-reported animal fear and ERP modulation: Evidence for enhanced processing and fear of harmless invertebrates in snake- and spider-fearful individuals

The present study used ERPs to compare processing of fear-relevant (FR) animals (snakes and spiders) and non-fear-relevant (NFR) animals similar in appearance (worms and beetles). EEG was recorded from 18 undergraduate participants (10 females) as they completed two animal-viewing tasks that required simple categorization decisions. Participants were divided on a post hoc basis into low snake/spider fear and high snake/spider fear groups. Overall, FR animals were rated higher on fear and elicited a larger LPC. However, individual differences qualified these effects. Participants in the low fear group showed clear differentiation between FR and NFR animals on subjective ratings of fear and LPC modulation. In contrast, participants in the high fear group did not show such differentiation between FR and NFR animals. These findings suggest that the salience of feared-FR animals may generalize on both a behavioural and electro-cortical level to other animals of similar appearance but of a non-harmful nature.     

Observational conditioning of fear to fear-relevant versus fear-irrelevant stimuli in rhesus monkeys

Two experiments examined whether superior observational conditioning of fear occurs in observer rhesus monkeys that watch model monkeys exhibit an intense fear of fear-relevant, as compared with fear-irrelevant, stimuli. In both experiments, videotapes of model monkeys behaving fearfully were spliced so that it appeared that the models were reacting fearfully either to fear-relevant stimuli (toy snakes or a toy crocodile), or to fear-irrelevant stimuli (flowers or a toy rabbit). Observer groups watched one of four kinds of videotapes for 12 sessions. Results indicated that observers acquired a fear of fear-relevant stimuli (toy snakes and toy crocodile), but not of fear-irrelevant stimuli (flowers and toy rabbit). Implications of the present results for the preparedness theory of phobias are discussed.     

A pictorial version of the Extrinsic Affective Simon Task: sensitivity to generally affective and phobia-relevant stimuli in high and low spider fearful individuals

This study assessed whether a pictorial, rather than a verbal, Extrinsic Affective Simon Task (EAST: De Houwer, 2003) is, 1) sensitive to the affective valence of normatively positive, neutral, and negative pictures, 2) sensitive to interindividual differences pertaining to fear-relevant affective associations, and 3) a valid predictor for strategic and/or reflexive fear responses. High (n = 35) and low (n = 35) spider fearful individuals completed an EAST comprising of universal positive, negative, neutral, and spider pictures. The pictorial EAST was sensitive to normatively valenced stimuli, tended to differentiate between high and low fearful individuals with respect to spider pictures, and showed independent predictive validity for avoidance behavior.     

The Set of Fear Inducing Pictures (SFIP): Development and validation in fearful and nonfearful individuals

Emotionally charged pictorial materials are frequently used in phobia research, but no existing standardized picture database is dedicated to the study of different phobias. The present work describes the results of two independent studies through which we sought to develop and validate this type of database—a Set of Fear Inducing Pictures (SFIP). In Study 1, 270 fear-relevant and 130 neutral stimuli were rated for fear, arousal, and valence by four groups of participants; small-animal (N = 34), blood/injection (N = 26), social-fearful (N = 35), and nonfearful participants (N = 22). The results from Study 1 were employed to develop the final version of the SFIP, which includes fear-relevant images of social exposure (N = 40), blood/injection (N = 80), spiders/bugs (N = 80), and angry faces (N = 30), as well as 726 neutral photographs. In Study 2, we aimed to validate the SFIP in a sample of spider, blood/injection, social-fearful, and control individuals (N = 66). The fear-relevant images were rated as being more unpleasant and led to greater fear and arousal in fearful than in nonfearful individuals. The fear images differentiated between the three fear groups in the expected directions. Overall, the present findings provide evidence for the high validity of the SFIP and confirm that the set may be successfully used in phobia research.     

Time course of attentional bias for fear-relevant pictures in spider-fearful individuals

The time course of attentional biases for spider stimuli was assessed in two groups of individuals with high or low levels of spider fear. Pairs of photographs of spiders and cats were presented in a visual probe task with three exposure durations: 200, 500 and 2000 ms. Results indicated greater attentional bias for spider stimuli in high fear, than in low fear, individuals in the 200 ms condition. The attentional bias in the high fear group significantly reduced as stimulus exposure duration increased, with no significant biases found in the longer exposure conditions. Results support the view that high fear is associated with an enhanced initial attentional bias for fear-relevant stimuli, but that this attentional bias is not maintained over time.     

The emotional body and time perception

We examined the effects of emotional bodily expressions on the perception of time. Participants were shown bodily expressions of fear, happiness and sadness in a temporal bisection task featuring different stimulus duration ranges. Stimulus durations were judged to be longer for bodily expressions of fear than for those of sadness, whereas no significant difference was observed between sad and happy postures. In addition, the magnitude of the lengthening effect of fearful versus sad postures increased with duration range. These results suggest that the perception of fearful bodily expressions increases the level of arousal which, in turn, speeds up the internal clock system underlying the representation of time. The effect of bodily expressions on time perception is thus consistent with findings for other highly arousing emotional stimuli, such as emotional facial expressions.     

Fear of fear,trait anxiety and aerobic fitness in relation to state anxiety during adrenalin provocation

Abstract

Psychological explanations of both spontaneous and experimentally induced panic anxiety stress the role of fear of fear, especially fear of bodily symptoms of arousal. Fear of fear is conceptually different from trait anxiety but may be associated with repeated experience of arousal symptoms in fearful situations, while frequent physical exercise may lead to habituation to these symptoms. To test this hypothesis, 44 healthy male volunteers, classified as having high or low trait anxiety and high or low aerobic fitness, underwent a single-dose adrenalin infusion (80 nanogram/kilogram bodyweight/minute). In both groups, during the experiment a significant rise in state anxiety was found; compared to the group with low trait anxiety, subjects with high trait anxiety reported higher levels of state anxiety, which could be attributed to differences in aerobic fitness. In the high-anxious group, subjects showed a greater decrease in state anxiety during the recovery phase. State anxiety during adrenalin was strongly associated with fear of bodily symptoms only in the high-anxious group. Correlations between trait anxiety and somatic anxiety were not significant; state anxiety scores tended to correlate negatively with physical fitness. It is concluded that these results lend support to a fear of fear-model of panic anxiety.