Dental phobias and anxieties: evidence for conditioning processes in the acquisition and modulation of a learned fear

The present study investigated some of the factors which differentiate individuals with dental anxieties and phobias from those without such fears. In particular, two questions were addressed: (i) What differentiates subjects who have never been anxious about dental treatment from subjects who at some time have been anxious? and (ii) What factors lead to subjects changing their attitudes either from anxious to relaxed or from relaxed to anxious? The results suggest that the factors which influence the acquisition and modulation of dental anxieties are consistent with the associative and representational processes portrayed in contemporary models of human conditioning. Subjects who reported never having had anxieties about dental treatment were less likely to have had a painful dental treatment than subjects who did report an anxiety. Subjects who did report a painful dental experience but did not acquire anxiety reported a history of dental treatment favourable to the operation of latent inhibition. Subjects who reported that they were good at enduring pain were more likely to report a longer interval between their very first dental treatment and their first painful dental treatment. Under some conditions in which latent inhibition should have precluded the acquisition of a dental fear, an anxiety appeared to be acquired because a very painful experience had attenuated the latent inhibition process. Subjects whose dental anxiety did not remit reported significantly more painful and traumatic dental experiences than subjects whose anxiety did remit.     

Sensory preconditioning and UCS inflation in human 'fear' conditioning

This study describes a human electrodermal conditioning experiment involving processes of sensory preconditioning and UCS inflation. In stage 1 of the experiment Ss received six presentations of a CS+ paired with an innocuous 65 dB tone (UCS) and six presentations of an unpaired CS-. In stage 2, Ss in the experimental group had the aversiveness of the UCS inflated as the intensity of the 65 dB tone was increased to 115 dB. In stage 3, Ss were given test presentations of CS+ and CS-. A differential CR to CS+ was found only in stage 3 of the experiment and only in Ss who had experienced the UCS inflation procedure. These results suggest that (i) sensory preconditioning had occurred in stage 1 despite the failure to observe a differential CR in this stage, and (ii) the differential CR observed in stage 3 was mediated by an internal representation of the UCS whose aversiveness had been inflated in stage 2. As well as confirming that processes of sensory preconditioning and UCS inflation can be observed in human as well as animal Ss, these findings have important implications for contemporary conditioning models of clinical fears. In particular, they suggest that a contemporary conditioning model of acquired fears is not bound by the need to discover contiguous stimulus-trauma experiences in the histories of clinical phobias since, in humans at least, processes of stimulus association and UCS revaluation appear to be relatively independent.     

Food anticipation and lever-directed activities in rats

Three experiments are described which elaborate some of the conditions under which rats will contact and manipulate a periodically presented retractable lever. Experiment 1 demonstrated that (i) initial manipulative oral and manual contact with the lever was facilitated if the rat had previous experience of food delivery in the experimental chamber; (ii) persistence in contacting the lever on successive presentations was a function of whether food continued to be presented in the experimental environment; and (iii) food satiation significantly reduced the tendency of the rat to contact the lever even though an expectancy of food had previously been established under conditions of food deprivation. Experiment 2 suggested that the tendency to approach and contact the lever was in part a function of the local moment-to-moment conditional probability of food delivery. Experiment 3 found that the probability of contacting the lever was higher during presentation of an auditory CS signaling a high rate of food delivery than during stimuli signaling no food at all. These results are interpreted as suggesting that the food-signaling aspects of an appetitive CS and that CS's ability to generate signal-directed behaviors are experimentall separable properties.     

Autoshaping in the rat: The effects of localizable visual and auditory signals for food

Two experiments investigated autoshaping in rats to localizable visual and auditory conditioned stimuli predicting response-independent food. In Experiment 1 considerable conditioned-stimulus approach behavior was generated by a localizable visual conditioned stimulus that was situated approximately 35 cm from the food tray. Using the same apparatus in Experiment 2 we found that the conditioned-stimulus approach was generated only to a visual conditioned stimulus and not to a localizable auditory conditioned stimulus even though subjects (1) could discriminate presentations of the auditory conditioned stimulus, (2) had associated it with food, (3) could localize it, and (4) would approach the auditory stimulus if this behavior constituted an instrumental response to food. The predominant conditioned responses to the auditory stimuli were goal tracking (entering the food tray) and orienting towards the food-paired conditioned stimulus by head turning and rearing and turning. These results imply that rats do not invariably approach a localizable appetitive Pavlovian conditioned stimulus but that stimulus-approach responses depend on the nature and modality of the conditioned stimulus.     

A test of a disease-avoidance model of animal phobias

This study examined the relationship between disgust/contamination sensitivity and fear of animals. The results suggested that sensitivity to disgust and contamination was directly related to scores on the animal phobia and fear of illness and death sub-scales of the Fear Survey Schedule (FSS). Further analysis suggested that disgust/contamination sensitivity was related only to fear of certain groups of animals: namely those animals that are not considered to attack and harm human beings but are considered fear-evoking (e.g. rat, spider, cockroach), and those animals that are normally considered to evoke revulsion (e.g. maggot, snail, slug). Disgust/contamination sensitivity was not related to fear of animals that are considered highly likely to attack and harm human beings (e.g. tiger, lion, shark). These results are discussed as support for a disease-avoidance model of common animal fears.     

Second-order ‘fear’ conditioning in humans: Persistence of CR2 following extinction of CR1

Two groups of subjects were given pairings of a slide of a triangle (CS₁) with an aversive loud noise (US). After first-order conditioning a different figure (CS₂⁺) was paired with CS₁, whilst a third figure acted as a non-paired control (CS₂⁰). Conditioned second-order skin conductance responses (SCRs) were established to CS₂⁺ for all subjects who had undergone first-order conditioning. Following second-order conditioning, SCRs to CS₁ were extinguished and CS₂⁺ was subsequently tested for retention of its SCR evoking properties. For the group of subjects who believed they had an avoidance response available during the second-order conditioning phase, CR₂ failed to survive extinction of CR₁. However, for the group of subjects who had no perceived control over US presentation, extinction of cr₁ did not eliminate CR₂. This latter finding is consistent with associative analyses of second-order conditioning in animals and has clinical implications for the treatment of fear-related problems.     

Mood as input and catastrophic worrying

The authors describe 3 experiments investigating a "mood-as-input" approach to understanding catastrophic worrying. Experiment 1 found that induced negative mood increased the number of steps emitted in both a catastrophizing interview procedure and a positive iteration task. Experiment 2 found that the number of items that worriers emitted in an iterative item generation task was dependent on the stop rules specified by the procedure. Experiment 3 found that manipulating the stop rules for catastrophizing had differential effects on worriers and nonworriers, depending on the nature of the stop rules specified. These results suggest that mood provides information about continuing or terminating the catastrophizing process that is interpreted in the context of the stop rules for the task. It is argued that the mood-as-input hypothesis accounts for the facts of exacerbated catastrophizing in worriers better than explanations couched in terms of either mood congruency effects or worriers possessing a generalized perseverative iterative style.     

Investigating the effect of intolerance of uncertainty on catastrophic worrying and mood

Intolerance of uncertainty (IU) is a construct known to influence catastrophic worry and is often observed in Generalized Anxiety Disorder (GAD). Research into the psychological manifestations of GAD suggests IU is associated with worry, but has not confirmed a causal link. The current study investigated the relationship between catastrophic worry and IU in a non-clinical undergraduate and postgraduate population (n = 46), with a mean age of 26.8 (SD = 5.52 years), where 71.74% were women. Participants received either a high or low IU manipulation, mood was measured throughout the study on 100 point visual analogue scales (VAS), and worry was measured using the catastrophising interview (CI). The high IU group generated significantly more catastrophising steps than the low IU group. Increased levels of sadness and anxiety were observed in the high as compared to the low IU group post IU manipulation, and this difference was maintained throughout the CI interview. A mediation analysis revealed that sadness and anxiety did not significantly mediate the relationship between IU and number of CI steps. These findings have implications for GAD treatment, as they suggest that manipulating IU affects measures of worry and its associated emotional and behavioural symptoms.