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Biomedical subjects

G C Davey

Publications and source records attributed to G C Davey.

At least 37 records · Page 2Linked to original sources
PubMed1993

Familial resemblances in disgust sensitivity and animal phobias.

This paper reports the results of two studies, both of which suggest there are close intrafamilial resemblances between parental disgust sensitivity and various measures of offspring animal phobia. In Study 1, a multiple regression analysis identified parental disgust sensitivity as a primary predictor of offspring animal fear in general (as measured by the animal phobia sub-scale of the Fear Survey Schedule), and offspring spider fear in particular. Study 2 indicated that parental disgust sensitivity was only related to offsprings' fear of animals known to be associated with the disgust reaction. These intrafamilial resemblances are discussed in relation to genetic and cultural transmission of the disgust reaction.

Adolescent↗
PubMed1993

A comparison of three worry questionnaires.

This paper describes a study comparing three worry questionnaires; The Worry Domains Questionnaire (WDQ), The Penn State Worry Questionnaire (PSWQ), and The Student Worry Scale (SWS). The results suggested that (i) scores on two out of the three questionnaires exhibited sources of variance that were independent of trait anxiety, (ii) content-based questionnaires (the WDQ and SWS) appeared to capture features of task-oriented constructive worrying, whereas the PSWQ did not, and (iii) all three questionnaires indicated that worriers were characterized by an information-seeking, monitoring cognitive style and a tendency to indulge in avoidance coping behaviours. The implications of these findings for the development of a clinically useful diagnostic instrument are discussed.

Adaptation, Psychological↗
PubMed1993

UCS inflation in the aetiology of a variety of anxiety disorders: some case histories.

This paper reports a number of case histories which illustrate the involvement of UCS inflation processes in the aetiology of a variety of anxiety disorders including agoraphobia, simple phobia, PTSD, obsessive-compulsive disorder and panic disorder. These cases are discussed in the context of: (i) renewed interest in cognitive features of conditioning models of anxiety disorders; and (ii) the implications that such models might have for an understanding of the aetiology and treatment of anxiety-based disorders.

Adult↗
PubMed1993

The relationship between information-seeking and information-avoiding coping styles and the reporting of psychological and physical symptoms.

The present paper describes a prospective study of the relationship between information-seeking and information-avoiding coping styles ('monitoring' and 'blunting') and the reporting of both psychological and physical symptoms. The results suggested that blunting was directly associated with the reporting of both psychological symptoms and symptoms associated with opportunistic infections (such as colds, 'flu etc.). Furthermore, this association between blunting and symptom report was independent of initial symptom levels and of some other factors which have been shown to influence health status (i.e. the frequency of negative life experiences, the frequency of daily hassles and levels of trait anxiety). No significant relationships were found between monitoring and symptom report. It is argued that the most likely explanation of these results is that high blunters report more illness symptoms as a result of failing to respond to initial illness cues or seeking remedial treatment only at a later stage in the development of a disorder.

Adaptation, Psychological↗
PubMed1991

The effects of false response feedback on human 'fear' conditioning.

This study describes a human electrodermal conditioning experiment in which subjects were given false skin conductance feedback during CS presentation. In comparison with appropriate attentional control groups, subjects who believed they were exhibiting a strong CR did actually emit a greater magnitude CR, while subjects who believed they were exhibiting only a weak CR emitted a significantly lower magnitude CR. When both self-report and behavioural measures of UCS revaluation were taken after conditioning, the evidence suggested that response feedback had not differentially affected subjects evaluation of the aversiveness of the UCS. The results suggest that the response modulating effects of response feedback observed in this and other studies are not caused by response feedback influencing evaluation of the UCS, but they are consistent with the hypothesis that beliefs about the nature of response feedback influence the strength of the UCS representation itself.

Adult↗
PubMed1991

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.

Adolescent↗
PubMed1990

The effects of cued UCS rehearsal on the retention of differential 'fear' conditioning: an experimental analogue of the 'worry' process.

This study describes a human electrodermal conditioning experiment in which subjects were asked to mentally rehearse the UCS in a period following initial fear conditioning and prior to a test period involving nonreinforced presentations of the CS. Subjects who were asked to rehearse the UCS retained a differential fear CR during subsequent unreinforced presentations of the CS, but control subjects who were asked to rehearse either a nonaversive event or an aversive event unrelated to the UCS failed to retain the differential CR they had acquired during conditioning. These results suggest that rehearsal of the UCS during periods when CS and UCS are absent can aid the persistence of a fear CR in the absence of further pairings of the CS and UCS. It is argued that these effects can be explained in terms of the effect of UCS rehearsal on the strength and evaluation of the UCS representation. It is also suggested that cued UCS rehearsal might provide a useful procedure for understanding clinical incubation effects and for understanding how the 'worry' process contributes to the maintenance and incubation of fear.

Adolescent↗
PubMed1990

Performance on two fixed-interval schedules in the absence of neocortex in rats.

Rats with complete surgical removal of the neocortex (neodecorticates) were trained, with milk as the reinforcer, on a 40-s fixed-interval (FI-40) schedule, then on an FI-120, and finally reexposed to the FI-40. Like controls, neodecorticates developed and appropriately adjusted their postreinforcement pauses and response distributions and showed scallop-type responding on the FI-120 and a positive correlation between running rate and the preceding postreinforcement pause on both FI-40 schedules but not on the FI-120. On some variables neodecorticates reached asymptotic levels of performance more slowly than controls. Extended training on the first FI-40 did not differentially affect neodecorticates' performance. The results suggest that neodecorticates retain a functional timing mechanism.

Animals↗
PubMed1989

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.

Adolescent↗
PubMed1989

UCS revaluation and conditioning models of acquired fears.

Recent developments in the study of Pavlovian conditioning in humans have suggested that the strength of a conditioned response (CR) is affected not only by associative processes that link the conditioned stimulus (CS) with the unconditioned stimulus (UCS), but also by processes which lead the individual to revalue the UCS itself. These latter processes can frequently lead to dramatic changes in CR strength independently of any experience with the CS-UCS contingency. This paper discusses a number of ways in which UCS revaluation can be effected in human subjects, and discusses their implications for conditioning models of acquired fears.

Arousal↗
PubMed1989

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.

Adult↗
PubMed1989

Food hoarding behaviour in the golden hamster (Mesocricetus auratus): effects of body weight loss and hoard-size discrimination.

Two experiments investigated some of the factors that influence food hoarding behaviour in the golden hamster (Mesocricetus auratus). In Experiment 1, hamsters given limited access to food failed to increase the amount of food they consumed at each meal. Instead, they exhibited a significant increase in the amount of food taken to hoard during the limited access period, and this permitted hamsters who were allowed to retain their hoard to maintain body weight at levels comparable to free-feeding controls. Hamsters that were not allowed to retain hoarded food rapidly lost body weight. There was also an inverse correlation between body weight and amount of food taken to hoard in all hamsters given limited access to food, suggesting that body weight loss was one factor directly related to increased hoarding during periods of limited food accessibility. Experiment 2 investigated the effect of hoard-size discrimination on food hoarding in hamsters by artificially manipulating hoard size. The results suggested that hoarding behaviour could be influenced by artificially depleting and repleting the hoard, and this factor appears to influence hoarding in the absence of any significant changes in body weight. These results are discussed in relation to the kinds of adaptive feeding strategies that hamsters may utilize in their natural environment.

Animals↗
PubMed1988

Tail-pinch elicited eating in rats (Rattus norvegicus) and hamsters (Mesocricetus auratus).

Noninjurious tail-pinch (TP) elicited a normal hyperphagic reaction to a milk solution in sated rats but did not increase the amount of milk solution consumed by sated hamsters. In both rats and hamsters, TP did increase the rate of eating, but did not change the amount of time spent contacting the drinking spout in rats and actually decreased the amount of time spent contacting the spout in hamsters. These results suggest that (1) the failure of hamsters to increase meal size in response to food deprivation is also generalizable to TP-induced eating, and (2) TP-induced hyperphagia may be caused by the generalized energizing effect that TP has on ongoing behavior rather than by TP stimulation enhancing the releasing properties of environmental stimuli such as the drinking spout.

Animals↗
PubMed1984

The effect of early feeding experience on signal-directed response topography in the rat.

Ten Hooded Lister rats were divided from weaning into two groups of five. One group was fed exclusively on a liquid diet in the home cage (Complan-fed subjects), the other group was given normal laboratory chow (Chow-fed subjects). At approximately 60 days of age both groups were reduced to 80% of their ad lib body-weight and given pairings of a retractable lever (conditioned stimulus, CS) and response-independent food (unconditioned stimulus, UCS). In the first experimental condition a liquid UCS was used (condensed milk solution) and in later conditions this was substituted with a solid UCS (45 mg food pellet). Analysis of CS-directed behavior in the two groups suggested that (1) only very early in autoshaping training did feeding experience in the home cage influence the topography of signal-directed behavior, and subsequently (2) both Complan-fed and chow-fed subjects bit rather than licked the CS paired with a solid UCS and licked rather than bit the CS when it was paired with a liquid UCS. These results suggest that, in the long-term, the topography of signal-centered behavior in rats is more likely to be influenced by the nature of the reinforcer signalled by the CS than by the subject's feeding experiences during early development.

Animals↗
PubMed1983

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.

Journal Article↗
PubMed1982

Topography of signal-centered behavior in the rat: Effects of deprivation state and reinforcer type.

In a series of three experiments, groups of food-deprived and water-deprived rats were given pairings of a retractable lever (CS(+)) with response-independent deliveries of either solid or liquid reinforcers. In Experiment 1 food-deprived rats given a solid-pellet reinforcer differentially tended to sniff, paw, mouth, and bite the CS(+) lever more often than a lever that was not paired with food (CS(-)), whereas food-deprived rats given a liquid reinforcer tended to differentially sniff, paw, and lick the CS(+) lever. 23(1/2)-hour water-deprived rats given liquid reinforcers showed very little CS(+) contact. In Experiment 2 increasing the severity of water deprivation from 23(1/2) to 47(1/2) hours significantly increased CS(+) contact. In Experiment 3, subjects that were simultaneously food and water deprived and given a water reinforcer failed to exhibit differential CS(+) contact, but subjects that were simultaneously food and water deprived and given a food reinforcer did acquire differential CS(+)-contact behavior. These results suggest that (a) even under a single motivational state the nature of signal-centered behavior can be determined by type of reinforcer, (b) although water reinforcement produces less signal contact than food reinforcement, this can be facilitated with more severe water-deprivation levels, and (c) high CS-contact rates using food reinforcement are not simply a product of reductions in body weight with food deprivation.

Journal Article↗