Biomedical subjects

A Mathews

Publications and source records attributed to A Mathews.

At least 19 recordsLinked to original sources

PubMed1995

Memory for actual and imagined events in OC checkers.

Information-processing theorists have suggested that obsessive-compulsive (OC) checking may be a function of either (1) an impaired memory of emotional events, (2) an attenuated ability to distinguish between real and imagined events or (3) a dissatisfaction with one's recall without actual memory impairment. These hypotheses were tested by having OC and control Ss engage in real and imagined actions. Some of the actions were designed to produce anxiety in the OC Ss while other events were designed to be emotionally neutral. No differences in reality-monitoring ability were found between OC and control Ss. Contrary to our prediction, OC Ss recall of their last actual behavior was superior to controls, but only for those actions that elicited anxiety. OC Ss, but not controls, reported that they desired higher levels of memory vividness than they were able to produce. The potential mechanism whereby dissatisfaction with memory vividness could contribute to repetitive checking is discussed.

Adult↗

PubMed1995

Effect of psychological treatment on cognitive bias in generalized anxiety disorder.

Measures of attention and implicit memory for threatening words were obtained from anxious patients before and after psychological treatment, and compared with data from non-anxious control Ss collected over the same period. Findings confirmed the expectation that the presence of threatening distractors would be associated with greater interference with the performance of anxious patients than with that of controls, in both color-naming and attentional search tasks, but failed to confirm the previous finding of related differences in priming on a word completion task. Treatment significantly reduced selective interference effects in anxious patients, and abolished evidence of differences between the treated patients and controls. It is suggested that cognitive bias effects in anxiety may either depend on state factors alone, or may represent a more enduring individual difference that becomes apparent only when vulnerable individuals are primed by mood state or stressful events.

Adult↗

PubMed1995

Effect of extracellular calcium on survival of human proximal tubular cells exposed to hypoxia.

Removal of extracellular calcium has been demonstrated to improve membrane integrity of rodent myocytes, astrocytes, and renal tubular cells injured by hypoxia. In this study, the effect of extracellular calcium on long-term survival of cultured human proximal tubular epithelial cells (PTEC) subjected to hypoxia was evaluated. In addition, the effect of extracellular calcium on release of arachidonic acid metabolites (AAM) was assessed during and after hypoxia. To induce hypoxic injury, PTEC were incubated in an anaerobic chamber in glucose-free buffer (combined oxygen/glucose deprivation, COGD). Long-term survival was assessed by measuring lactate dehydrogenase (LDH) efflux during COGD and after an additional 24-h "recovery" period (in routine culture medium in 95% air/5% CO2). To determine if extracellular calcium influenced AAM release from membrane phospholipids, cells were preincubated with [3H]arachidonic acid and the release of AAM was measured during COGD and recovery. With this model system, PTEC exhibited minimal LDH efflux during < or = 12 h COGD, but LDH efflux increased to 73.9 +/- 4.7% by 24 h COGD. With 12-18 h of COGD, the extent of LDH efflux was greater during recovery than during COGD, indicating that, for human PTEC, the extent of membrane damage does not become fully evident by LDH efflux for hours after hypoxia. PTEC exposed to 24 h of COGD in the absence of extracellular calcium exhibited strikingly less LDH efflux during COGD than cells incubated in the presence of extracellular calcium, suggesting that extracellular calcium contributes to membrane damage during COGD. However, upon reexposure of PTEC to extracellular calcium, LDH efflux rapidly increased to control levels. Furthermore, despite allowing cells to recover in oxygen or oxygen and glucose before exposure to calcium-containing medium, a rapid increase in LDH efflux could not be avoided. These results suggest that COGD induces an irreversible injury that ultimately leads to loss of membrane integrity whether or not extracellular calcium is present; however, extracellular calcium accelerates the loss of membrane integrity caused by hypoxia. Extracellular calcium did not alter AAM release, indicating that the effect of extracellular calcium on membrane damage (as indicated by LDH efflux) was not mediated by an increased activity of phospholipases (such as phospholipase A2) that are involved in the release of AAM.

Arachidonic Acid↗

PubMed1992

Interpretation of bodily symptoms in hypochondriasis.

Although it has been suggested that hypochondriasis is caused by the misinterpretation of innocuous bodily sensations, support for this hypothesis rests largely upon uncontrolled self-report. We investigated the interpretation of ambiguous bodily sensations in three experiments using separate samples of non-clinical subjects differing in level of hypochondriacal concern. Results confirmed that subjects with high hypochondriacal concern endorse more thoughts about illness interpretations of bodily sensations, but reported thought content resembled 'catastrophic' rather than the 'non-emergency' thoughts suggested by Warwick and Salkovskis (Hypochondriasis. Behavior Research and Therapy, 28, 105-117, 1990). Presence of an interpretive bias was further supported in a study of recognition bias for disambiguated versions of ambiguously threatening sentences, although this applied as much to social as to illness threats. A final experiment failed to support the hypothesis of an automatic inference bias, but did show that subjects with high hypochondriacal concern were quicker to correctly identify previously exposed illness words. Thus, reported thoughts are consistent with catastrophic interpretations of common bodily sensations, but interpretive bias may not be limited to illness threat. However, high hypochondriacal subjects do show a more specific enhanced perceptual sensitivity to illness cues, which may play a role in maintaining their concern with bodily symptoms.

Adolescent↗

PubMed1992

Mood-congruent memory in depression: emotional priming or elaboration?

We investigated whether mood-congruent memory (MCM) bias in depression is a function of implicit or explicit memory. Implicit memory is taken as a measure of ease of activation, whereas explicit memory also taps elaboration. As expected, MCM bias was found in the explicit memory task but not in the implicit memory task. We believe this finding supports the involvement of elaborative mechanisms in MCM. In addition, memory bias was found with words related to depression but not with words denoting physical threat. Thus, the MCM bias in explicit memory was found to be specific to information that was congruent with depression rather than to all negative information.

Adult↗

PubMed1992

EASEing in the 90s.

Explore the source record for details and available documents.

Hospitals, County↗

PubMed1992

Urinary incontinence caused by prazosin.

Urinary incontinence is a common problem in elderly women. However, urinary incontinence secondary to the commonly used antihypertensive, prazosin, is a rare phenomenon. The possible mechanism of this drug in causing incontinence is described in this case report. The possibility of an exaggerated response to the drug by women suffering from borderline stress incontinence is highlighted.

Female↗

PubMed1991

Biased cognitive operations in anxiety: accessibility of information or assignment of processing priorities?

There is considerable evidence that anxiety is associated with a cognitive bias favouring the processing of threat-related information. Bower's (1981) network model attributes this bias to the enhanced availability of mood congruent information from memory. However, certain experimental tasks do not reveal such a bias, when this effect is strongly predicted by the model. We note that all tasks which have demonstrated such mood congruent processing effects in anxious subjects share the requirement that these subjects must assign priorities to simultaneously available, and differentially valenced, alternative processing options. This feature has been consistently lacking in those paradigms we have found insensitive to the influence of anxiety. It is therefore suggested that anxiety is associated with the assignment of high processing priorities to threat-related options, rather than with the facilitated availability of threat-related information from memory. This proposal was experimentally tested using a lexical decision task, which is sensitive to the accessibility of information from memory, under conditions which either do or do not introduce the requirement to assign priorities to alternative processing options. The results indicate that the facilitated processing of threat related stimulus words, shown by generalised anxiety patients, does indeed appear to reflect a bias in the assignment of processing priorities, rather than the enhanced availability of this information from memory.

Adult↗

PubMed1991

Biased cognitive operations in anxiety: artefact, processing priorities or attentional search?

It has been shown that, under certain circumstances, anxiety is associated with a processing bias favouring threatening information. To explain why this bias is apparent only on certain cognitive tasks, it has recently been proposed that the bias operates only when there is competition for processing resources. The present study sought to replicate previous evidence for the 'competition' hypothesis, while taking into account a potential confounding factor of word categorization in the stimulus materials. Anxious patients and normal controls were compared on their lexical decision times for threatening, categorized neutral and uncategorized neutral words that were presented either alone or accompanied by irrelevant nonword stimuli (i.e. absence vs presence of competition). The results were only partially consistent with previous findings and highlighted the importance of considering separately the effects of word valence and word categorization. When the latter was taken into account, the results indicated that an anxiety-related bias was only evident when there was competition for processing resources and when the information was presented outside the focus of Ss' attention. A modified version of the competition hypothesis was proposed in the light of these results and previous research into attentional biases in anxiety.

Adult↗

PubMed1991

Bias in interpretation of ambiguous sentences related to threat in anxiety.

In the 1st of 2 experiments, currently clinically anxious, recovered clinically anxious, and normal control subjects were presented with a mixture of unambiguous and ambiguous sentences; both threatening and nonthreatening interpretations were possible for the latter. A subsequent recognition-memory test indicated that the currently anxious subjects were more likely than normal control and recovered anxious subjects to interpret the ambiguous sentences in a threatening fashion rather than in a nonthreatening fashion. This suggests that the biased interpretation of ambiguity found in currently anxious subjects reflected their anxious mood state. A 2nd experiment established that the difference in interpretative processes between currently anxious and control subjects was not due to response bias and that the interpretative bias was a reasonably general one.

Anxiety Disorders↗

PubMed1990

Is there a self-referent mood-congruent recall bias in anxiety?

Generally anxious patients and normal controls were compared on their recall of self- vs other-referenced adjectives that were either descriptive or non-descriptive of anxious mood. The results failed to confirm a self-referent mood-congruent recall bias in anxious patients. Anxious subjects tended to recall relatively more mood-congruent words overall, but this could be explained by response bias.

Adult↗

PubMed1990

Why worry? The cognitive function of anxiety.

The phenomenon of worry is considered to arise from cognitive processes involved in anxiety, that serve to maintain high levels of vigilance for personal danger. Rather than rely on self-report alone, the research described here draws on information processing methodology, to investigate this hypothesized cognitive function. Evidence is summarized to show that anxious subjects selectively attend to threatening information, and interpret ambiguous events in a relatively threatening way. However, the evidence on memory suggests that although such information may be easily activated, it is not necessarily more accessible. The allocation of attentional priority to threatening information is seen as a characteristic of anxious (rather than depressed) mood, while the ease with which this processing mode is adopted may underlie trait anxiety and vulnerability to anxiety disorders.

Anxiety↗

PubMed1990

Attentional bias in anxiety: selective search or defective filtering?

Two experimental tasks were used to investigate the nature of a previously documented bias in attention associated with anxiety. Results from the first task failed to reveal any differences between anxious and nonanxious subjects, either in attention focusing or selective search for letters. The second task, with words as targets and distractors, suggested that selective search was less efficient in anxious subjects when distractors were present. Currently anxious subjects were slower than controls when required to search for the target among distractors of any type, whereas both currently anxious and recovered subjects were slower when the distractors were threatening words. It was therefore suggested that a bias favoring threat cues during perceptual search is an enduring feature of individuals vulnerable to anxiety, rather than a transient consequence of current mood state alone.

Adult↗

PubMed1990

Effects of stress and anxiety on the processing of threat stimuli.

Two experiments extended the work of MacLeod and Mathews (1988) and examined whether a cognitive bias for threat information is a function of state or trait anxiety. Color-naming and attention deployment tasks were used to assess the effects of a stress manipulation procedure on attentional responses in high and low trait anxious subjects. Subjects under high stress selectively allocated processing resources toward threat stimuli, irrespective of their trait anxiety level. There was no consistent evidence of a cognitive bias associated with trait anxiety, and the effect of the stress manipulation did not appear to be mediated by state anxiety. It was suggested that trait factors do not modify attentional biases associated with acute stress, but may influence such biases when stress is prolonged.

Adult↗

PubMed1990

Aerobic fitness, physical activity, and psychophysiological reactions to mental tasks.

The association between aerobic fitness, exercise, and psychophysiological reactivity was assessed in cross-sectional and prospective analyses. Seventy-five healthy but sedentary adults carried out a sub-maximal exercise test and easy and difficult problem solving tasks. Blood pressure, heart rate, skin conductance level, respiration rate, tidal volume, and oxygen consumption were monitored and additional heart rate was also computed. Differences between relatively fit and unfit individuals were found in respiration rate during tasks and in skin conductance level during post-task recovery periods, with a tendency toward diminished heart rate reactivity in fitter people. Subjects were subsequently allocated to four conditions: high intensity aerobic training, moderate intensity aerobic training, an undemanding strength and flexibility program (designed as an attention-placebo condition), and waiting list control. Training programs were conducted over a 10-week period, and were followed by a second laboratory session. Appropriate changes in aerobic performance over the training period were observed in the 12-min run/walk test. There were no important modifications in psychophysiological stress reactions associated with the different experimental conditions. These results are discussed in relation to the literature concerning the effects of fitness and physical activity on physiological response patterns.

Adult↗

PubMed1989

Selective processing of threat cues in anxiety states: a replication.

A replication of Mathews and MacLeod's (Behav. Res. Ther. 23, 563-569, 1985) study, using a modified Stroop task, confirmed that threat words selectively interfere with the colour-naming performance of generally anxious patients, compared with normal controls. Clearer evidence was obtained of a highly specific interference effect of threat words that were congruent with the predominant worries reported by anxious patients. However, there was no evidence of a subsequent recognition memory bias for the threat words in anxious Ss. These results are discussed in relation to findings from other recent experiments investigating attentional and memory biases for threat-related information in anxiety states, and their implications for cognitive theories of anxiety are considered.

Adult↗

PubMed1989

The effects of exercise training on mood and perceived coping ability in anxious adults from the general population.

A comparison was carried out of the psychological effects of a moderate aerobic training programme (n = 24) and an attention-placebo strength and flexibility training programme (n = 23) in previously inactive anxious adults from the general population. Training consisted of one supervised and three unsupervised sessions per week for 10 weeks. Effects were assessed with the Profile of Mood States, the State-Trait Anxiety Inventory and questionnaires indexing perceived coping ability. Seven participants dropped out of each condition during the training period. Expectations of benefit assessed pre-training, and satisfaction assessed post-training, did not differ between conditions. The moderate exercise programme led to significant improvements in aerobic fitness, and was associated with significantly greater reductions in tension-anxiety, depression and other moods than the attention-placebo condition, together with increases in perceived ability to cope with stress. Psychological responses were not correlated with changes in fitness assessed with bicycle ergometry or the 12 min walk/run test. These effects were maintained on 3 month follow up.

Adaptation, Psychological↗

PubMed1989

The effects of exercise training on mental well-being in the normal population: a controlled trial.

This study was designed to compare the effects of two aerobic training programmes of differing intensities on mood and mental well-being with those of a credible attention-placebo condition. One hundred and nine sedentary adult volunteers from the local population were assigned to four conditions: high intensity aerobic training, moderate intensity aerobic training, attention-placebo and waiting list. Training was carried out over a 10 week period. Subjects were assessed before and after training with psychological measures and the 12 min walk-run test, and follow-up evaluations were undertaken after 3 months. Ninety-four subjects began the programme and the adherence rate averaged 80%, with no significant differences in number of drop-outs between conditions. Appropriate changes in estimated maximum oxygen consumption were observed in the three active conditions with the 12 min walk-run test. Psychological benefits were seen with the moderate exercise condition but not in the high exercise or attention-placebo conditions. These effects were manifest immediately after training on measures of tension/anxiety and confusion, and at follow-up on measures of perceived coping ability. The mechanisms underlying this pattern of results are discussed and the relative importance for health of vigorous activity and physical fitness is considered.

Adaptation, Psychological↗