Biomedical subjects

G C Davey

Publications and source records attributed to G C Davey.

At least 19 recordsLinked to original sources

PubMed2001

A survey of genes in the Atlantic salmon (Salmo salar) as identified by expressed sequence tags.

We describe the construction and quality analysis of six cDNA libraries from the liver, ovary, testis, brain, spleen and muscle tissues of adult Atlantic salmon. The cDNA libraries were then screened with total cDNA probes to catalogue clones representing the abundant and rare mRNA populations in each tissue. Subsequently, the 5'-terminal DNA sequences of 1152 cDNA clones, composed of 96 clones from each of the abundant and rare mRNA populations in the six tissues, were determined. Bioinformatic analysis revealed that 510 (50%) of the salmon expressed sequence tags (ESTs) of sufficient length showed significant homology to previously identified genes from salmonid and other species, while 517 (50%) of salmon ESTs were unidentified or novel. After accounting for multi-EST redundancy, the 510 identified ESTs provided DNA sequence markers for 178 salmon genes which are listed in terms of tissue of origin and mRNA abundance class.

Animals↗

PubMed2001

The effect of mood and arousal on UCS expectancy biases.

This paper reports two studies investigating the role of mood and arousal on the development of UCS expectancy biases to fear-relevant and fear-irrelevant stimuli. Experiment 1 found that, compared with a neutral control condition, individuals in both experimentally-induced positive and negative moods significantly overestimated the possibility of aversive outcomes following all types of stimuli in a hypothetical thought' conditioning experiment. Experiment 2 found that this UCS expectancy bias produced by both positive and negative mood could not be explained by the effect that these mood states might have on arousal independently of the valency of the mood. The findings appear to be explained best by emotional response categorisation theory (Psychol. Rev. 106 (1999) 337-361), which predicts that individuals would be more likely to view emotionally valenced stimuli as similar when in an emotional state. It is argued that, while negative mood may be a genuine vulnerability factor for the development of anxiety-relevant threat-outcome expectancies, the effects found with positive mood in the current studies may have less ecological relevance to real-world aetiologies.

Adult↗

PubMed2001

The use of stimulus dimensions in judgement making in spider fearful and nonfearful individuals.

This study uses a multidimensional scaling approach to investigate the hypothesis that spider fearful individuals give priority to a threat-safety dimension when making judgments. The results show that when making judgments about stimuli, spider fearful individuals (1) placed significantly greater comparative weighting on a threat-relevant dimension than on a non-emotive dimension (colour), and (2) tended to rate threatening pairs of stimuli and safe pairs of stimuli as more similar than did the nonfearful group. This prioritised dimensional processing suggests a mechanism by which phobics can exhibit what initially appear to be paradoxical tendencies to give priority to both threat and safety information.

Adult↗

PubMed2001

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.

Adult↗

PubMed2000

UCS expectancy biases in spider phobics: underestimation of aversive consequences following fear-irrelevant stimuli.

This paper reports the results of two studies investigating judgements made by spider phobics about the potential threatening consequences (unconditioned stimulus, UCS, expectancies) associated with their phobic stimulus, fear-relevant (FR) stimuli, and fear-irrelevant (FI) stimuli. Using a 'thought experiment' UCS expectancy paradigm, the studies reported found that (1) spider phobics reported significantly higher UCS expectancies to spider stimuli than nonphobics, (2) spider phobics consistently underestimated the probability of aversive consequences following FI stimuli and (3) this underestimation of UCS expectancies to FI stimuli in phobics was not the result of a contrast effect resulting from sequential FR and FI judgements. This differential effect may have important implications for the kind of mechanism which mediates judgements about phobic consequences. These findings suggest that the dimensions on which phobic stimuli are categorised may be 'stretched' in the case of phobics and that this gives rise to the comparative underestimation of threat associated with FI stimuli but also makes phobics more vulnerable to acquiring other phobias.

Adolescent↗

PubMed1999

Reevaluating evaluative conditioning: a nonassociative explanation of conditioning effects in the visual evaluative conditioning paradigm.

In 2 studies, the authors investigated whether evaluative conditioning (EC) is an associative phenomenon. Experiment 1 compared a standard EC paradigm with nonpaired and no-treatment control conditions. EC effects were obtained only when the conditioned stimulus (CS) and unconditioned stimulus (UCS) were rated as perceptually similar. However, similar EC effects were obtained in both control groups. An earlier failure to obtain EC effects was reanalyzed in Experiment 2. Conditioning-like effects were found when comparing a CS with the most perceptually similar UCSs used in the procedure but not when analyzing a CS rating with respect to the UCS with which it was paired during conditioning. The implications are that EC effects found in many studies are not due to associative learning and that the special characteristics of EC (conditioning without awareness and resistance to extinction) are probably nonassociative artifacts of the EC paradigm.

Adolescent↗

PubMed1998

Catastrophic worrying: personal inadequacy and a perseverative iterative style as features of the catastrophizing process.

This article describes 6 studies that have used a catastrophizing interview technique to investigate some of the characteristics of catastrophic worrying. The main findings were (a) worriers were willing to catastrophize both a positive aspect of their life and a new hypothetical worry significantly more than nonworriers, (b) worriers were more likely than nonworriers to rate catastrophizing steps for a new worry as containing information relevant to existing worries, (c) worriers displayed a general iterative style that was independent of the valency of the iterative task, and (d) worriers tended to couch their worries in terms of personal inadequacies, and personal inadequacy became a feature of their catastrophizing regardless of the worry topic. Worriers' tendency to couch worries and catastrophizing steps in terms of personal inadequacies and their perseverative iterative style are both important contributors to the unresolved catastrophic thought experienced by chronic worriers.

Adolescent↗

PubMed1997

Manipulation of dangerousness judgements to fear-relevant stimuli: effects on a priori UCS expectancy and a posteriori covariation assessment.

Using a covariation assessment procedure, the present study pre-experimentally manipulated subjects' assessments of the dangerousness of fear-relevant stimuli. The results demonstrated that this manipulation subsequently influenced both a priori expectancy that the stimulus will be followed by an aversive consequence (UCS), and inflated an a posteriori covariation bias indicating that subjects judged the stimulus to be followed more frequently by the aversive UCS than by a non-aversive stimulus. These findings support the view that judgments about such characteristics as the dangerousness of a stimulus causally contribute to a UCS expectancy bias and an a posteriori covariation bias, and thus contribute to the formation of selective associations.

Adolescent↗

PubMed1997

Height phobia and biases in the interpretation of bodily sensations: some links between acrophobia and agoraphobia.

The present study was designed to investigate some of the factors that might underlie the commonly found association between agoraphobia and fear of heights (acrophobia). The results showed that measures of acrophobia are highly associated with the tendency to interpret ambiguous bodily sensations as threatening, and with an increased tendency to report bodily sensations of anxiety. These features of acrophobia did not appear to be characteristics found in phobic states in general, nor did measures of acrophobia show any significant relationship to the tendency to interpret external and social stimuli as threatening. These findings suggest that the frequently found co-morbidity between agoraphobia and acrophobia may be linked to cognitive biases in the discrimination and interpretation of bodily sensations that agoraphobia and acrophobia share in common. In addition, the present findings also generate testable hypotheses about the aetiology of acrophobia.

Adolescent↗

PubMed1997

The psychological impact of negative TV news bulletins: the catastrophizing of personal worries.

This study investigated the effect of the emotional content of television news programmes on mood state and the catastrophizing of personal worries. Three groups were shown 14-min TV news bulletins that were edited to display either positive-, neutral- or negative-valenced material. Participants who watched the negatively valenced bulletin showed increases in both anxious and sad mood, and also showed a significant increase in the tendency to catastrophize a personal worry. The results are consistent with those theories of worry that implicate negative mood as a causal factor in facilitating worrisome thought. They also suggest that negatively valenced TV news programmes can exacerbate a range of personal concerns that are not specifically relevant to the content of the programme.

Adolescent↗

PubMed1996

The expectancy bias model of selective associations: the relationship of judgements of CS dangerousness, CS-UCS similarity and prior fear to a priori and a posteriori covariation assessments.

This paper describes three experiments examining predictions from the expectancy bias model of selective associations (Davey, 1995). In a simulated 'threat' conditioning procedure, Experiment 1 showed that UCS expectancy following both ontogenetic and phylogenetic CSs was significantly predicted by: (1) ratings of the dangerousness of the CS, perceptions of CS-UCS similarity, and level of prior fear to the CS; and (2) ratings of CS-UCS similarity on the dimensions of valence, arousal and anxiety. Experiment 2 used a covariation assessment procedure which confirmed the findings of Experiment 1, and also showed that both phylogenetic and ontogenetic fear-relevant CSs exhibited both a priori and a posteriori covariation biases. Experiment 3 found that Ss high and low in fear to a fear-relevant CS exhibited a significant a priori UCS expectancy bias, but this bias was significantly larger in high fear Ss. Only high fear Ss exhibited an a posteriori covariation bias. These results are consistent with predictions from the expectancy bias model.

Adolescent↗

PubMed1995

The effect of prior fear levels on UCS-expectancy ratings to a fear-relevant stimulus.

This study investigated the effect of levels of prior fear to a fear-relevant stimulus on UCS expectancy ratings in a threat conditioning procedure. The results suggested that UCS-expectancy ratings are independently influenced by both the nature of the stimulus (whether it is fear-relevant or fear-irrelevant) and the level of prior fear to the stimulus. Furthermore, significantly higher UCS-expectancy levels caused by prior fear and stimulus type were accompanied in some stages of the experiment by greater magnitudes of skin conductance responses during the stimulus.

Adolescent↗

PubMed1995

Coping strategies and phobias: the relationship between fears, phobias and methods of coping with stressors.

Two studies are described which assessed the extent to which fears and phobias are associated with particular types of strategies for coping with stress. Study 1 compared scores on the Fear Survey Schedule (FSS) with scores on a modified version of the Health and Daily Living Form and the Miller Behavioural Style Scale (MBSS) in a normal population. A principal component analysis revealed that high scores on the social fears and miscellaneous phobias subscales of the FSS were directly associated with avoidance coping strategies, inversely associated with cognitive reappraisal strategies which devalue or deny the importance of the stressor, but unrelated to any of the measures on the MBSS. Study 2 compared the coping strategies of simple phobics, panic disorder patients and normal controls. Both simple phobics and panic disorder patients differed from normal control subjects by reporting greater use of avoidance coping strategies, and reduced use of cognitive threat devaluation. These findings are consistent with models of anxiety-based disorders which implicate avoidance or escape in the maintenance of such disorders, or which identify the evaluation of the precipitating trauma as important in the acquisition of such disorders.

Adaptation, Psychological↗

PubMed1994

Disease-avoidance model: factor analysis of common animal fears.

This paper reports the results of two studies investigating a disease-avoidance model of common animal fears. In Study 1, a factor analysis of a variety of self-rated animal fears revealed that these fears can be grouped into two theoretically meaningful categories which correspond to predatory animals and fear-relevant animals. Study 2 found a significant correlation between disgust sensitivity and fear to animals in the fear-relevant category, but not between disgust sensitivity and fear to animals in the predatory category. In addition, fear of animals in the fear-relevant category was significantly associated with scores on the obsessive washing sub-scale of the Maudsley Obsessive-Compulsive Inventory, but was not associated with obsessive behaviour in general.

Adolescent↗

PubMed1994

Is evaluative conditioning a qualitatively distinct form of classical conditioning?

This paper contains a critical review of the claim that evaluative conditioning (EC) represents a theoretically distinct form of classical conditioning. A review of the evidence suggests that: (i) while it is claimed that EC can occur without awareness, EC studies have either adopted inappropriate statistical comparisons to demonstrate this or have failed to use the control conditions necessary to indicate that what is being measured is associative conditioning; (ii) there is no theoretical reason why conditioning without awareness might be observed in any conditioning paradigm if a relatively complex covariation assessment procedure such as that adopted in EC studies is used; and (iii) there are a variety of possible explanations for the relative resistance to extinction reported with EC, some of which allude to failure to use appropriate control conditions and others which point to specific details unique to the EC extinction procedure. Until these appropriate procedural and statistical comparisons are made, it is concluded that it is premature to assume that EC represents a form of conditioning that is theoretically distinct from other types of classical conditioning.

Animals↗

PubMed1994

Worrying, social problem-solving abilities, and social problem-solving confidence.

This study investigated the relationship between worrying and two features of social problem solving: problem-solving ability and confidence. However, while levels of worrying were significantly related to both poor problem-solving confidence and poor perceived control over the problem-solving process, worrying was unrelated to problem-solving ability per se. The failure to find a relationship between worrying and social problem-solving skills was found separately at both low and high levels of worrying, and also when levels of trait anxiety had been controlled for. These results provide no support for the hypothesis that chronic worrying results from poor social problem-solving abilities, but the results are consistent with the belief that worrying is primarily an anxiety-related phenomenon with any problem-solving deficits occurring at the level of solution implementation rather than solution generation.

Adult↗

PubMed1994

Unconditioned stimulus rehearsal and the retention and enhancement of differential "fear" conditioning: effects of trait and state anxiety.

In 2 experiments, the effect of anxiety on the cued-unconditioned stimulus (UCS) rehearsal phenomenon was investigated (T. Jones & G. C. L. Davey, 1990). In Experiment 1, postconditioning rehearsal of the unconditioned stimulus (UCS) resulted in an increase in conditioned response (CR) strength during extinction, but only in subjects with high levels of trait anxiety. An induced mood procedure was used in Experiment 2, and a postrehearsal increase in CR strength was found in subjects who had undergone induced somatic anxiety but not in subjects who had undergone induced worrying or who underwent a neutral induction procedure. In both experiments, the increase in CR strength following UCS rehearsal was associated with inflated ratings of the aversiveness of rehearsing the UCS. These results are discussed in terms of the ways in which anxiety might influence UCS rehearsal and facilitate physiological CRs to the conditioned stimulus.

Adolescent↗

PubMed1994

Self-reported fears to common indigenous animals in an adult UK population: the role of disgust sensitivity.

Two studies are described which report on the prevalence and intensity of self-reported fears to common indigenous animals in an adult UK population. The results of Study 1 suggest that (i) around a third of the variance in fear of indigenous animals can be accounted for by two factors which represent the theoretically coherent categories of invertebrates (e.g. slug, worm, cockroach) and fear-relevant animals (e.g. rat, snake, bat); (ii) females tend to report significantly greater levels of fear than males to a large majority of prevalently feared animals; and (iii) there were no obviously consistent patterns of fear with age. Study 2 identifies individual disgust sensitivity levels as being an important and significant predictor of fear of animals in both the invertebrate and fear-relevant categories, and finds that females report significantly higher disgust sensitivity levels than males. Since most of the prevalently feared indigenous animals appear to be disgust-relevant, this latter finding helps to explain the generally higher fear ratings given by females.

Adult↗