Self-report and physiological changes accompanying repeated imagining of a phobic scene.

Twenty female subjects were selected from a larger subject pool on the basis of their scores to the ‘snakes’ item on the Geer (1965) Fear Survey Schedule. Ten of the subjects were selected as phobic; the other ten were non-phobic controls. Heart rate, skin conductance and self-reports of fear and imagery vividness were continuously monitored while subjects repeatedly imagined a prescribed snake scene for a total of 15 trials. The phobic group reported more overall fear to the images. Further, while the nonphobic subjects reported progressively less fear over trials, the phobic subjects reported progressively more fear. The groups did not differ in rated imagery vividness. However, heart rate responses to the image differentiated the two groups. The non-phobic subjects showed a progression from cardiac acceleration in the early trials to a biphasic response pattern, deceleration preceding acceleration, in the later trials. In contrast, the phobic subjects demonstrated sustained acceleration in the later trials. The groups did not differ in skin conductance response amplitude.     

Trait Anxiety and Fear Responses to Safety Cues: Stimulus Generalization or Sensitization?

Abnormal fear responding to threat cues may contribute to the aetiology and maintenance of persistent fears and pathological anxiety. Chronic anxiety may also involve abnormal fear responding to ??safety?? cues, which do not signal danger. Yet investigations of fear responding to acquired safety cues are scarce and the basis of such responding remains unclear. Moreover, previous studies do not distinguish between stimulus generalization (an associative mechanism based on perceptual similarity between threat and safety cues) and sensitization (a non-associative mechanism whereby fear responses to any novel, intense, or fear-related stimulus are temporarily elevated). This study investigated responses to acquired safety cues in volunteers with varying trait anxiety, using a novel fear conditioning paradigm designed to distinguish between effects of trait anxiety on generalization and sensitization. The paradigm used three conditioned stimuli: a threat cue (CS+) and two safety cues (CS?), one perceptually similar to the CS+ and one perceptually dissimilar. Conditioned fear to these cues was indexed by fear potentiation of the startle blink reflex, skin conductance responses, and self-report. To examine how trait anxiety moderated responses to safety cues, participants were divided into high and low trait anxiety subgroups. Startle, skin conductance, and self-reported fear measures indicated that generalization of fear occurred for the safety cue which resembled the threat cue, but not for the perceptually dissimilar safety cue, consistent with the stimulus generalization hypothesis. There was some evidence that stimulus generalization was exaggerated in anxious individuals. The current study sheds light on the mechanism by which fear responses to safety cues arise in healthy individuals, and offers some insight into the influence of this mechanism in chronic anxiety.     

Animal phobias versus claustrophobias: Exteroceptive versus interoceptive cues

The overall purpose of this investigation was to examine heterogeneity among specific phobias. In particular, the goals were to compare features of fear responding between individuals fearful of claustrophobic situations and individuals fearful of spiders/snakes, and to compare their response to hyperventilation challenges. By so doing, specific predictions were tested in relation to a conceptual model of exteroceptive and interoceptive fear cues. Using a nonclinical sample, 19 subjects with spider/snake phobias, 18 nonphobies, and 9 subjects with claustrophobias were exposed on two separate occasions to a live tarantula or python, a small closet, and a hyperventilation challenge. Dependent measures included subjective anxiety, panic attacks, physical symptoms, cognitive symptoms (or, fear of symptoms) and heart rate. In addition, subjects completed a standardized self-report scale that measures fear of bodily symptoms of arousal. It was found that subjects with claustrophobia reported more physical symptoms and cognitive symptoms than did subjects with snake/spider phobias, in response to their fear-relevant stimulus. In addition, claustrophobic subjects were more fearful of hyperventilation challenges and reported more fear of bodily symptoms, than did snake/spider phobic subjects. Finally, subjects with claustrophobia were as fearful of hyperventilation as they were of their fear-relevant stimulus. Theoretical and empirical implications of these findings are discussed.     

The contribution of relaxation and expectancy to fear reduction via graded, imaginal exposure to feared stimuli

Speech phobic subjects received five treatment sessions under either positive or neutral expectancy set. Therapy conditions included hierarchy exposure with contiguous relaxation (desensitization), exposure with noncontiguous relaxation, exposure only, and no-treatment. Expectancy had virtually no outcome effects. Desensitization was superior to the other conditions on subjective outcome measures. In contrast to the two exposure conditions without contiguous relaxation, desensitization resulted in increased imagery vividness, greater cardiovascular response to the first visualization of the initial hierarchy scene, and greater declines in cardiovascular response within repetitious visualizations of scenes and across initial visualizations of increasingly anxiety-provoking scenes. Expectancy significantly influenced both fear ratings and cardiovascular response to scenes during the first session, the latter effect disappearing after the first session. The results are discussed in terms of recent theorizing regarding the role of relaxation and expectancy in desensitization.     

The effects of instructional set on physiological response to stressful imagery

Centrally mediated or cognitive variables have received considerable attention in clinical research. With the establishment of the effectiveness of such specific treatment techniques as systematic desensitization (Paul. 1969a. 1969b). a question arises as to the influence of cognitions on process and outcome variables in such learning based treatments (Lang. 1971). Research investigating the influence of demand characteristics and subject expectancies has demonstrated such centrally mediated variables can significantly influence overt, behavioral and self-report measures of fear, stress, or anxiety (cf. Borkovec. 1972: Marcia. Rubin and Efran. 1969; McGlynn. Maelia and Nawas. 1969: McGlynn. Reynolds and Linder. 1971: Oliveau. Agras. Leitenberg and Wright. 1969; Rappaport. 1972: Rosen. 1974).However. Borkovec (1972) and Rappaport (1972) failed to obtain expectancy effects on physiological measures of anxiety. Neither investigation provided for an independent assessment of subjects' actual expectancies, or belief in the instructions, as recommended by Davison and Wilson (1973). Borkovec administered clinical procedures over four sessions and varied the information communicated about the ‘purpose’ of the treatments (physiological versus therapeutic instructions). Differential rationales for differential expectancies of physiological reactivity were not provided. After each session, subjects reviewed the same false physiological records depicting reductions in fear responses. Although these changes were explained either physiologically or therapeutically. the fact that such reductions were emphasized should have attenuated differences between groups. Rappaport (1972) exposed subjects to a fearful stimulus and varied the suggestion and rationale for the pseudotreatment: no expectancy (stress research): therapeutic expectancy (fear reduction); and negative expectancy (fear increase). The lack of an independent assessment of the expectancy manipulation, as well as the exclusion of a specific therapeutic procedure, make it impossible to interpret the results in relation to expectancy effects on physiological fear responses during the administration of therapeutic procedures. There is other evidence, however, that suggestion and instructional set can significantly influence somatic and autonomic response systems (Barber. 1961. 1965; Sternbach. 1964. 1965).The primary purpose of this study was to evaluate the effects of instructional set on physiological responses to stressful imagery. This was an early step in a research program investigating the effects of instructional and informational variables on physiological responses of clinical interest. One half of the subjects received abbreviated live relaxation training (R) as described m a manual by Bernstein and Borkovec (1972) and based upon the original work of Jacobson (1938). The other half received an inert placebo pill and undertook a target detection task (P). The latter procedure was similar to that used by Paul (1966). Although both procedures had previously been shown to have relaxing effects, the P task was included as an additional control for any potential effects specific to the tension-release procedure of R. In order to evaluate the effects of instructional set, one half of each of the above two groups received instructions designed to lead to an expectancy of response inhibition to stressful imagery by the respective procedure (Decrease Stress Response. DSR). while the other half received instructions designed to lead to an expectancy of an increased response to stressful imagery by the respective procedure (Increase Stress Response. ISR). Each subject visualized three individually specified items that were the most frightening scenes imaginable prior to training and four times after training visualized the scene producing the largest response. Considerable effort was devoted to eliciting from each subject the most frightening items possible for her. and it was clear from subject comments that the items did elicit negative emotional responses.Since previous research (Barber. 1961. 1965; Sternbach. 1964. 1965) indicated that instructional set can influence physiological reactivity, it was hypothesized the DSR) subjects should exhibit a greater reduction in emotional response from pre- to posttraining than ISR subjects.     

The anxiety disorder spectrum: Fear imagery,physiological reactivity,and differential diagnosis∗

Abstract

This review considers recent research assessing psychophysiological reactivity to fear imagery in anxiety disorder patients. As in animal subjects, fear cues prompt in humans a state of defensive motivation in which autonomic and somatic survival reflexes are markedly enhanced. Thus, a startle stimulus presented in a fear context yields a stronger (potentiated) reflex, providing a quantitative measure of fearful arousal. This fear potentiation is further exaggerated in specific or social phobia individuals when viewing pictures or imagining the phobic object. Paradoxically, fear imagery studies with more severe anxiety disorder patients – panic disorder with agoraphobia, generalized anxiety disorder, or anxious patients with comorbid depression – show a blunted, less robust fear potentiated response. Furthermore, this reflex blunting appears to systematically be more pronounced over the anxiety disorder spectrum, coincident with lengthier chronicity, worsening clinician-based judgments of severity and prognosis, and increased questionnaire-based indices of negative affectivity, suggesting that normal defensive reactivity may be compromised by an experience of long-term stress.     

Lang's theory of emotional imagery

Abstract

An appraisal is presented of Lang's theoretical and experimental work on emotional imagery. Lang has adopted a “propositionalist” theory of imagery which emphasises the role of the activation of cognitive structures associated with imagery. Questions are raised about the exact properties of these structures and the relation between their activation and the experiential image. Lang's experimental work has provided a generally convincing demonstration of the prediction that response training enhances the subjective vividness of imagery and the level of emotional responsiveness associated with it, although questions remain about the explanation of this effect. hg's predictions regarding the modification of emotional responsiveness associated with imagery have so far received little support from habituation studies, and the available data is considered in the context of the dual-process habituation theory of desensitisation.     

In vitro flooding in the treatment of a 6-yr-old boy''s posttraumatic stress disorder

In vitro flooding was used to treat a 6-yr-old boy's war-related posttraumatic stress disorder. Traumatic scenes were identified and stimulus response imagery cues were presented according to a multiple-baseline regimen. The results revealed that the boy's affective, behavioral and cognitive parameters were positively influenced by the treatment.     

Posed and spontaneous communication of emotion via facial and vocal cues1

Subjects' facial expressions were videotaped without their knowledge while they watched two pleasant and two unpleasant videotaped scenes (spontaneous facial encoding). Later, subjects' voices were audiotaped while describing their reactions to the scenes (vocal encoding). Finally, subjects were videotaped with their knowledge while they posed appropriate facial expressions to the scenes (posed facial encoding). The videotaped expressions were presented for decoding to the same subjects. The vocal material, both the original version and an electronically filtered version, was rated by judges other than the original senders. Results were as follows: (a) accuracy of vocal encoding (measured by ratings of both the filtered and unfiltered versions) was positively related to accuracy of facial encoding; (b) posing increased the accuracy of facial communication, particularly for more pleasant affects and less intense affects; (c) encoding of posed cues was correlated with encoding of spontaneous cues and decoding of posed cues was correlated with decoding of spontaneous cues; (d) correlations, within encoding and decoding, of similar scenes were positive while those among dissimilar scenes were low or negative; (e) while correlations between total encoding and total decoding were positive and low, correlations between encoding and decoding of the same scene were negative; (f) there were sex differences in decoding ability and in the relationships of personality variables with encoding and decoding of facial cues.     

Measurement of fear of the conditioned stimulus and of situational cues at several stages of two-way avoidance learning

In Experiment 1, subjects were trained in a signaled two-way avoidance task to a criterion of either 2, 10, or 20 consecutive avoidance responses. Subsequently, they were allowed to escape, in the absence of shock, from one compartment of the avoidance apparatus to an adjacent safe box. For one group at each criterion level, the conditioned stimulus (CS) was presented during these trials; for another group, it was not (NCS). The rate and level of learning of the escape response were taken to reflect the amount of fear of the CS and situational cues present at the end of avoidance training for the CS groups and the amount of fear of the situational cues alone for the NCS groups. Under the CS condition, all groups learned equally well; under the NCS condition, learning occurred only in the two-criterion group. This pattern of results suggests that, as avoidance training continued, differential reinforcement led to the formation of a discrimination so that a substantial amount of fear was elicited by the CS plus situational cues but only a minimal amount by the situational cues alone. Such a loss of fear of situational cues would, according to effective reinforcement theory, serve to maintain or even increase reinforcement as avoidance training progressed. The results of Experiment 2, by ruling out some alternative explanations, supported the interpretation that the learning of the instrumental escape response in the first experiment was based on prior fear conditioning.     

Auditory specific fear conditioning results in increased levels of synaptophysin in the basolateral amygdala

Auditory fear conditioning is one of the most well characterized models used in studies of learning and memory. In order to ensure the animals have been conditioned to fear the auditory stimulus, animals are generally tested for their response to this stimulus in a different context to that used for training. For this reason it is often unclear how much contextual fear conditioning the animals also acquire when they are trained. In this study, we have established a protocol for fear conditioning in mice which is explicit for auditory cues; mice trained using this protocol, show a very low fear response to contextual cues encountered during training. We have undertaken analysis to look for potential brain changes associated with this model by measuring levels of the synaptic vesicle protein, synaptophysin, in the basolateral nuclei of the amygdala following auditory fear conditioning. Our results show levels of synaptophysin were significantly higher in mice which learnt to associate the auditory stimulus with fear, in comparison to all non-learning control animals. These findings support the idea that synaptic plasticity associated with formation of fear conditioning to a single specific conditioned stimulus occurs within the basolateral nuclei of the amygdala. Furthermore, our results demonstrate the usefulness of this model in looking for changes in the brain specific for a defined learning event.     

Heart rate and self-report changes accompanying different types of relaxing imagery

Two groups of 10 subjects were instructed, following appropriate training, to evoke different types of relaxing imagery for a total of five 30 s trials. For one group the instruction stressed response elements in the image, for the other stimulus elements. A third, control group of 10 were invited to relax by any means they considered appropriate. No specific imagery instructions were given here. Heart rate was recorded throughout and ratings of sleepiness were made by subjects at the end of each trial. Analogue mood scales were completed pre- and post-experimentally. While the self-report measures intimated an increase in feelings of relaxation and sleepiness over the course of the experiment, no group differences were observed. For heart rate, however, group differences were apparent. Overall, heart rate change during trials took the form of cardiac acceleration. However, while the two imagery groups demonstrated more or less sustained acceleration throughout trial periods, the acceleration observed initially in the control group showed a pronounced linear decline with a net deceleration being recorded toward the end of each trial. The imagining of response or stimulus elements did not differentially affect heart rate. These data imply that the process of imagining constitutes a more important influence on heart rate in these circumstances than image type or affective content.     

Vividness of positive mental imagery predicts positive emotional response to visually presented Project Soothe pictures

Lang's bioinformational theory of mental imagery proposes that mental imagery and external stimuli engage emotional information-processing systems in similar ways. However, the positive and negative systems are thought to be distinct, so this similarity is likely to show a valence-specific effect. Therefore, we hypothesized that an individual's ability to construct vivid positive, but not negative, mental imagery would predict positive emotional responding to positive visual stimuli, independently of depressive symptoms. Our stimuli were pictures collected through Project Soothe for possible use in psychotherapy ( www.projectsoothe.com ); as these pictures were intended to induce soothing emotion, we hypothesized that theoretically linked variables Self-compassion and Self-criticism would also predict positive responding to the stimuli. A total of 214 participants completed an online study including validated questionnaire measures, mental imagery tasks, and a picture-rating exercise. Only Positive Imagery Vividness and Self-compassion were significant predictors of positive responding to the soothing pictures, even controlling for depressive symptoms, and Negative and General Imagery Vividness. These findings support Lang's theory and provide evidence for individual differences in a positive processing tendency shared across mental imagery-based and perceptual representations. As this relationship is distinct from depressive symptoms, future imagery-based psychotherapies might aim to influence this positive processing tendency.     

The effects of single-component extinction of a three-component serial CS on resistance to extinction of the conditioned avoidance response

Central to a fear interpretation of how avoidance responses are maintained in the absence of further CS-UCS pairings is the underlying assumption of an existing gradient of fear across the CS-UCS interval. Extrapolations based on this gradient lead to a number of differential predictions concerning the topography of avoidance responding during extinction. The present research was concerned with the differential effects of extinguishing separate components of the CS complex upon responding to the complete CS complex during extinction. In Phase 1 of the study, rats were classically conditioned to a three-component serial CS (S₁/S₂/S₃) followed by shock. Each subject was then given avoidance training in a one-way apparatus to a criterion of one successful avoidance. In Phase 2, subjects were divided into four groups, with three of the groups receiving nonreinforced exposure for 25 trials to one of the components of the serial CS (S₁, S₂, or S₃). The fourth group (S₀) was exposed for the same period of time to the apparatus cues. In Phase 3, the total stimulus complex was reintroduced in its original order, and animals were tested until extinction of the instrumental response was reached. The results are consistent with the hypothesis that a fear gradient exists in extinction and decreases in magnitude as the distance from the point of UCS onset increases.     

Emotional responding following experimental manipulation of facial electromyographic activity

Increases in zygomatic electromyographic (EMG) responding have been reported during the imagination of positive affective scenes, and increases in corrugator EMG have been reported during negative affective scenes. Thirty female subjects were instructed to imagine three positive affective scenes and three negative affective scenes. During the initial imagination of each scene, the subject was told simply to imagine the situation. The subject then imagined the situation again and was instructed to enhance the muscle tension in one of two muscle groups (the zygomatic muscles for positive scenes and the corrugator muscle for negative scenes). The subject then imagined the scence a third time and was instructed to suppress the muscle tension in the same muscle group. The order of administration of enhancement and suppression trials was randomized for each scene. Subjects were given several trials to practice controlling both zygomatic and corrugator EMG. Feedback was available during the practice trials and during the enhancement and suppression trials of the experiment. Continuous monitoring of both zygomatic and corrugator EMG during the study indicated that subjects were successful in altering muscle tension in accord with the experimental instructions, and videotapes of subjects' faces indicated no overt changes in facial responding during imagination of the scenes. Subjects' ratings of emotional responding during each scene indicated that subjects experienced less enjoyment and more distress during positive affective trials in which they suppressed zygomatic EMG activity. The results are discussed in terms of the facial feedback hypothesis.     

Diagnostic colours contribute to the early stages of scene categorization: Behavioural and neurophysiological evidence

We examined the effects of colour cues on the express categorization of natural scenes. Using a go/no-go paradigm sensitive to fast recognition processes, we measured early event-related potential (ERP) correlates of scene categorization to elucidate the processing stage at which colour contributes to scene recognition. Observers were presented with scenes belonging to four colour-diagnostic categories (desert, forest, canyon and coastline). Scenes were presented in one of three forms: Diagnostically coloured, nondiagnostically coloured, or greyscale images. In a verification task, observers were instructed to respond whenever the presented stimulus matched a previously presented category name. Reaction times and accuracy were optimal when the stimuli were presented as their original diagnostically coloured version, followed by their greyscale version, and lastly by their nondiagostically coloured version. These effects were mirrored in the early (i.e., 150 ms following stimulus onset) ERP frontal correlates. Their onset was delayed for greyscale scenes compared to diagnostically coloured scenes, and for nondiagnostically coloured scenes compared to the other two conditions. Frontal ERP amplitudes also decreased for greyscale and nondiagnostically coloured scenes. Together, the results suggest that diagnostic colours are part of the scene gist responsible for express scene categorization.     

Effect of worrisome and relaxing thinking on fearful emotional processing

This study replicated and extended previous data suggesting that worry inhibits emotional processing of fearful imagery. Female participants categorized as either victimization-fearful (N = 24) or victimization and speech-fearful (N = 27) completed trials of worrisome or relaxing thinking and tone-cued imagery. For each trial, participants engaged in 30 s of relaxing or worrisome (speech or victimization) thinking and then imagined speech or victimization fear scenes for 15 s. Heart rate and facial electromyography activity at the corrugator supercilii region were measured during the think and imagery periods to estimate degree of emotional processing of the fear imagery. Consistent with earlier findings, there was greater heart rate suppression during fearful imagery after a period of worry as opposed to relaxation. This finding, however, may have been the result of physiological differences between worrisome and relaxation thinking. Corrugator activation during thinking showed a similar pattern as the heart rate data while corrugator activation during fearful imagery was dependent on the baseline employed. These data, in combination with the imagery ratings data, suggest that worry may be an unsuccessful strategy for avoiding the physiological activation associated with emotional processing.