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Biomedical subjects

Walter Everaerd

Publications and source records attributed to Walter Everaerd.

At least 19 recordsLinked to original sources
PubMed2006

Psychological and cognitive functioning in children and adolescents with congenital heart disease: a meta-analysis.

OBJECTIVE: Findings in the literature are inconsistent on the impact of congenital heart disease (CHD) on the psychological and cognitive functioning of children and adolescents. The aim of the present study was to systematically review this empirical body of literature. METHODS: We conducted a meta-analysis to review studies on behavior problems and cognitive functioning in CHD. RESULTS: Only older children and adolescents with CHD displayed an increased risk of overall, internalizing, and to a lesser extent externalizing behavior problems. In addition, patients with severe CHD exhibited lower cognitive functioning than patients with less severe CHD, specifically with respect to performance intelligence. Moreover, decreased cognitive functioning remained relatively stable across different age groups. CONCLUSIONS: Children with severe heart disease may benefit from interventions specifically targeting perceptual organizational abilities, such as visual-spatial abilities. Moreover, older children and adolescents with CHD may benefit from psychological interventions reducing anxiety symptoms and depression.

Adolescent↗
PubMed2006

Stress-induced heart symptoms and perceptual biases in patients with congenital heart disease.

BACKGROUND: The aim of the present study is to clarify whether biased symptom perception towards heart symptoms may explain a reduced quality of life in patients with congenital heart disease (ConHD). The present study tested the hypothesis that the combination of ConHD and high trait anxiety increases the perception of heart symptoms during acute stress. METHODS: 25 patients and 24 healthy participants completed a stressful computer task. Participant's heart and non-heart symptoms were measured after stress and after relaxation. Heart rate, blood pressure, respiratory rate, and arterial partial pressure of CO2 were monitored continuously. RESULTS: In line with the prediction, a combination of high trait anxiety and ConHD resulted in an increased perception of specifically heart symptoms during stress. Moreover, the increased perception of heart symptoms could not be explained by acute heart dysfunction. CONCLUSIONS: Heart dysfunction is not the only cause of an increased perception of heart symptoms. A history of disease experience in combination with high trait anxiety may increase the perception of heart symptoms during stress and may eventually result in an increased risk of developing a reduced quality of life.

Analysis of Variance↗
PubMed2006

Endogenous cortisol level interacts with noradrenergic activation in the human amygdala.

Animal studies show that high cortisol levels exert their effect on stressful task performance via modulation of the amygdala. Availability of noradrenaline in this brain region appears to be a critical prerequisite for this effect. This relationship between noradrenaline and cortisol is explained by an animal model where the amygdala constitutes a crucial region for this interaction. In humans this model has not been extensively tested so far. In a previously reported study human subjects (aged 20.93+/-2.38) were scanned using fMRI when watching sets of emotional and neutral pictures after taking the beta-adrenergic antagonist propranolol or placebo. Stimulus sets consisted of 92 pictures, divided in four emotional categories that ranged from neutral scenes of domestic objects (CAT1) to extremely negative scenes of mutilation or accidents (CAT4). Confrontation with arousing emotional pictures, accompanied by increased noradrenaline levels, evoked increased amygdala activation under placebo but not under betablocker condition. This new and additional analysis of this data set was carried out to determine the effect of differential endogenous cortisol levels on amygdala activation. Cortisol levels during scanning were determined using salivary samples and subjects were post hoc divided in a High (n=14) and Low cortisol group (n=14). When subjects were watching emotional stimuli, presumably associated with enhanced noradrenaline (NA) levels, amygdala activation was contrasted between the two cortisol groups. We hypothesized that emotional stimuli would elicit more amygdala activation in the High than in the Low cortisol group. Here we demonstrate indeed a significant interaction effect of the endogenous cortisol level with increasing activation in the amygdala under placebo but not under betablocker condition, thereby extending the rodent based model of a synergistic effect of the two stress hormones to the human.

Adolescent↗
PubMed2005

Salivary alpha amylase as marker for adrenergic activity during stress: effect of betablockade.

Free salivary cortisol is an established non-invasive marker of hypothalamus pituitary adrenal (HPA) axis activity. In contrast, such a well-characterized salivary marker for activity of the sympatho-adrenal medullar (SAM) system is still missing. As one potential candidate salivary alpha amylase (sAA) has been suggested. In humans increases in sAA levels have been observed in response to physiological and psychological stress. The present study aimed at exploring the effects of a pharmacological manipulation (betablockade) on sAA in the context of a stressful fMRI experiment on emotional information processing. Thirty young healthy subjects participated in a double blind group comparison study and received 80 mg of the betablocker (BB) propranolol or a placebo (PL). Salivary samples were obtained before and 90 min (pre-scan) and 135 min (post-scan) after drug application. In addition heart rate and blood pressure were assessed. During rest a significant drug by time interaction was observed, lowering sAA levels as well as heart rate and systolic blood pressure in the betablocker treatment group. During the scanning procedure, in which participants were confronted with highly negative emotional pictures, the significant increase in sAA levels in the PL group compared to the BB group persisted. No additional change was noticed in heart rate or blood pressure during scanning in the PL or BB group. The current pharmacological study in the human provides direct evidence for the sensitivity of sAA to changes in adrenergic activation, specifically in reaction to psychological stress.

Adolescent↗
PubMed2005

Noradrenaline mediates amygdala activation in men and women during encoding of emotional material.

The amygdala is a pivotal structure in humans for encoding of emotional information, as shown by recent imaging studies. It is unknown which neurotransmitters are specifically involved in the human amygdala, although in animal studies noradrenaline was shown to be essential. In our study, participants received the betablocker propranolol (which blocks the noradrenergic response) or placebo when watching neutral to highly negative arousing pictures. Amygdala activation, monitored with functional magnetic resonance imaging (fMRI), increased with emotional intensity of the pictures under placebo condition. Betablockade selectively decreased amygdala activation for emotional pictures of the second highest category, but not for the highest or lower (neutral) category pictures. Two findings add to the existing knowledge in this area. First, the activation pattern in the amygdala under placebo condition shows a nonlinearity related to the emotional categories of the pictures. Second, propranolol disturbs this activation pattern in the amygdala. Explorations with respect to gender show a similar effect of betablockade on amygdala activation in both men and women, but a difference in its effect on long-term memory for emotional pictures. This study supports the hypothesis that the neurotransmitter noradrenaline also mediates amygdala activity in humans when processing emotional stimuli and that betablockers can disrupt the normal activation pattern in the amygdala.

Adolescent↗
PubMed2005

Effect of a single dose of levodopa on sexual response in men and women.

From animal research, there is ample evidence for a facilitating effect of dopamine on sexual behavior. In humans, little experimental research has been conducted on the inter-relation between dopamine and sexual response, even less so in women than in men. We investigated the effect of levodopa (100 mg) on sexual response in men and women following a double-blind, placebo-controlled crossover design. Genital and subjective sexual responses were measured as well as somatic motor system activity by means of Achilles tendon (T) reflex modulation. Genital and subjective sexual arousal were not affected by levodopa. However, the drug increased T reflex magnitude in response to sexual stimulation in men, but not in women. These results support the view that dopamine is involved in the energetic aspects of appetitive sexual behavior in men. The observed gender difference in the effect of levodopa is discussed in the perspective of possible dopamine-steroid interaction.

Adolescent↗
PubMed2005

Modulation of spinal reflexes by sexual films of increasing intensity.

Sexual arousal can be viewed as an emotional state generating sex-specific autonomic and general somatic motor system responses that prepare for sexual action. In the present study modulation of spinal tendious (T) reflexes by sexual films of varying intensity was investigated. T reflexes were expected to increase as a function of increased film intensity. Through use of a between-subjects design, participants were exposed to three erotic films of low, moderate, and high intensity or to three films of moderate intensity. Self-report and genital data confirmed the induction of increasing versus stable levels of sexual arousal. Exposure to the films of increasing intensity resulted in increasing T reflexes. The results indicate that T reflex modulation is sensitive to varying levels of sexual arousal and may be of use in research on behavioral mechanisms underlying appetitive motivation.

Adult↗
PubMed2004

Conscious processing of sexual information: mechanisms of appraisal.

To elucidate some of the activational mechanisms of sexual response, this study investigated the effects of conscious appraisal of sexual and neutral stimuli on a categorization task and on ratings of sexual arousal. Conscious appraisal is dependent on memory, regulatory, and attentional processes, interacting with one another. It is proposed that regulation is activated by attention, furnished by representations from implicit and explicit memory. Participants (26 men and 25 women) were asked to respond to "target" stimuli that were preceded by supraliminal "prime" stimuli. Primes and targets were operationalized by slides with sexual (i.e., romantic vs. explicit) and neutral content. In a cognitive task, participants had to group randomly presented targets as quickly as possible into sexual and nonsexual categories. Categorization of sexual targets was delayed when they were preceded by sexual primes compared to neutral primes. This was interpreted as an inhibitory process and compared with the Sexual Content-Induced Delay phenomenon (J. H. Geer & H. S. Bellard, 1996; J. H. Geer & J. S. Melton, 1997). No gender difference was found. In a subsequent affective task, participants provided an assessment of sexual arousal, followed by an evaluation of the target. This task was hypothesized to result in differential access to memory, where assessments of sexual arousal are influenced mainly by implicit memory, and where evaluations are influenced mainly by explicit memory. Gender differences were most prominent in the evaluation aspect of this task. It was concluded that cognitive processing of sexual information is similar for both genders, but that gender differences are present in affective processing of sexual information.

Adult↗
PubMed2004

Sexual behavior and responsiveness to sexual stimuli following laboratory-induced sexual arousal.

Sexual excitement can be seen as an action disposition. In this study sexual arousal was expected to generate sexual action and to increase interest and responsiveness to sexual stimuli. In two experiments, male and female participants were exposed to a neutral or a sexual film. We measured genital and subjective responses to the film, and sexual behavior following the laboratory visit. In Experiment 2, film exposure was followed by a task in which participants rated the sexual arousability of neutral and sexual pictures. Rating time of the sexual pictures served as an index for sexual interest. Responsiveness to the sexual pictures was measured by modulation of spinal tendinous (T) reflexes. Sexual activity, but not sexual desire, was higher for participants in the sexual film condition than for participants in the neutral condition. Sexual interest and responsiveness to still pictures were not higher for participants in the sexual film condition than for those in the neutral film condition. In addition, men who saw the neutral film showed a greater responsiveness to still pictures than men who saw the sexual film. The results support the view of sexual arousal as an emotional state generating action tendencies and actual sexual behavior.

Adult↗
PubMed2003

Interpretation of change and longitudinal validity of the quality of life for respiratory illness questionnaire (QoLRIQ) in inpatient pulmonary rehabilitation.

The quality of life for respiratory illness questionnaire (QoLRIQ) is an outcome measure for patients with asthma or chronic obstructive pulmonary disease (COPD). This study assessed the longitudinal validity, reliability of the change score and the interpretation of changes on the QoLRIQ in inpatient pulmonary rehabilitation, completed by 108 patients with moderate to severe asthma (39) or COPD (69). Domains and total score of the QoLRIQ changed significant (all p < 0.0002) with standardized response means from 0.46 to 0.90. All QoLRIQ-change scores were significantly correlated with self-rated change in health and in disease symptoms and with change in self-assessed health status (r from 0.2 to 0.61). There were several significant correlations between QoLRIQ-change scores and change in experienced invalidity, emotional well-being, anxiety, depressive symptoms and Rand-36-domains (r from 0.2 to 0.68). The intraclass correlation coefficient of change was 0.90. The size of a minimal important difference (MID), computed from a retrospective global rating of change by the patients and with the standard error of measurement, was 0.5 points on a 7-point response scale. Computation of the MID from retrospective assessment of change may not be valid because this change was significantly correlated to post-treatment health status and significantly higher than serial assessment of change. We conclude that the QoLRIQ is sensitive to change, longitudinally valid and reliable, with a MID of 0.5 points. These results enable the use of the QoLRIQ as an outcome measure in clinical trials with patients with moderate to severe asthma or COPD. The longitudinal measurement properties in less severe patients still need to be studied.

Adult↗
PubMed2003

Priming the sexual system: implicit versus explicit activation.

We investigated implicit versus explicit activation of the sexual system using a priming paradigm in which sexual slides were preceded by either sexual or neutral primes. In the first experiment, primes were made inaccessible to conscious cognitive elaboration. Identification of sexual targets was facilitated by sexual primes, indicating that sexual representations in memory can be activated automatically. In the second experiment, in which primes were presented at a conscious level, identification of sexual targets was decelerated by sexual primes. Primes elicited subjective sexual arousal in Experiment 2 only, demonstrating that the activation of subjective experience requires conscious cognitive elaboration. With the addition of a sexually specific physiological measure, to be constructed to measure initial genital responses, this paradigm may help elucidate activational mechanisms of sexual response.

Adult↗
PubMed2003

Modulation of spinal reflexes by aversive and sexually appetitive stimuli.

In this study, modulation of spinal tendinous (T) reflexes by sexual stimulation was investigated. T reflexes are augmented in states of appetitive and defensive action and modified by differences in arousal intensity. Reflexes were expected to be facilitated by both pleasant (sexual) and unpleasant (anxiety) stimuli. Subjects were exposed to a sexual, an anxiety-inducing, a sexually threatening, and a neutral film excerpt. Genital arousal, emotional experience, subjective action tendencies, and T reflexes were monitored. Self-report and genital data confirmed the affective states as intended. T reflex amplitude significantly increased during viewing of emotionally arousing film excerpts as compared with a neutral film excerpt. T reflexes were facilitated by the sex stimulus to the same extent as by the anxiety and sexual threat stimuli. The results support the view of sexual arousal as an emotional state, generating sex-specific autonomic and general somatic motor system responses, which prepare the organism for action.

Adult↗
PubMed2002

The effect of beta-adrenergic blockade after encoding on memory of an emotional event.

RATIONALE: Animal and human studies lend support to the hypothesis that enhanced memory associated with emotional experiences involves activation of the beta-adrenergic system. Evidence for the role of noradrenaline in emotional memory in humans has been gathered from experimental studies where blockade of the beta-adrenergic system with a beta-blocker selectively impaired long-term memory for an emotionally arousing story (a slide show), when the beta-blocker was given before subjects were confronted with the emotional stimuli. OBJECTIVE: The purpose of this study was to test whether effective beta-adrenergic blockade occurring only after the stage of encoding has a similar impairing effect on memory. METHODS: In a double blind experimental design, 60 healthy adult subjects received randomly one tablet of either propranolol (Inderal, 40 mg) or placebo. Drugs were administered just before the slide show begun and (in view of its pharmacokinetics) propranolol reaches peak levels 1 h after drug intake. Physiological arousal was monitored by heart rate and blood pressure. Half of the beta-blocker and placebo groups watched either a neutral or an arousal version of an 11-slide presentation. Memory performance was tested with a surprise free recall and recognition test 1 week later. RESULTS: Memory performance, specifically for the second phase in which emotional elements were introduced, was better in subjects who viewed the arousal version than subjects who saw the neutral version of the slide show. However, no effect of the beta-blocker condition was found. CONCLUSION: This experiment does not support a role for noradrenaline in the post-encoding phase and on the later processes of consolidation and retrieval. Although it remains possible that with a different dosage or timing protocol a post-treatment effect of noradrenaline in humans can be found, this experiment could not find support for it.

Adrenergic beta-Antagonists↗
PubMed2002

Modest contribution of psychosocial variables to hypoglycaemic awareness in Type 1 diabetes.

OBJECTIVE: To assess relationships between hypoglycaemic awareness and diabetes-related, psychosocial and demographic characteristics. METHOD: Ninety-eight type 1 diabetic patients completed questionnaires on somatic awareness (Somatic Awareness Questionnaire, SAQ), negative affectivity (Positive And Negative Affectivity Schedule, PANAS), symptom beliefs, bustle and variety of daily life. They then performed up to 70 measurements on a hand-held computer, during 4 to 6 weeks, at home. During every measurement, they rated the presence of 20 symptoms on a 0-6 scale, and estimated and measured their blood glucose level. The percentage of recognised hypoglycaemic episodes was calculated from these data, and used as a measure of hypoglycaemic awareness. RESULTS: Hypoglycaemic awareness was negatively associated with disease duration and antecedent hypoglycaemia, and positively associated with the use of an insulin pump instead of injections, variety in the daily life, somatic awareness, sensitivity of the symptom beliefs and female gender. However, only 17% of the variance in hypoglycaemic awareness was explained. CONCLUSIONS: Psychosocial variables contribute to hypoglycaemic awareness, to a moderate but statistically significant extent.

Activities of Daily Living↗
PubMed2002

Conscious processing of sexual information: interference caused by sexual primes.

The concept Sexual Content-Induced Delay (SCID) refers to a hesitancy in decision making related to erotic material (Geer & Bellard, 1996; Geer & Melton, 1997). Empirical evidence about SCID stems from lexical decision tasks. Our previous studies also showed SCID effects in sex versus neutral categorization tasks in which pictures were used. In these tasks, recognition of sexual pictures is delayed when preceded by consciously presented sexual primes. In the current study, 2 manipulations were added to the categorization task to investigate underlying information processing mechanisms of SCID. Firstly, the appraisal process was influenced by varying the instructions. Secondly, primes with nonsexual emotional content were added to test the specificity of the SCID effect. Thirty-seven undergraduates were asked to categorize sexual and neutral pictures that were primed by sexual, threatening, and neutral primes. Participants ignored or focussed prime content dependent on 2 different instructions. Results showed that the SCID effect only emerged when sexual primes were ignored; however, threatening primes also decelerated recognition of sexual pictures after the ignore instruction. Results of the focus instruction were qualitatively different, that is, participants recognized sexual pictures faster when primed sexually. It was suggested that SCID can be interpreted as the activation of regulatory modules by emotional stimuli in the stage of elicitation of emotional response. In contrast, when the sexual system is already activated, it appears that decisions regarding sexual information are facilitated.

Adult↗
PubMed2002

The enhancement of vaginal vasocongestion by sildenafil in healthy premenopausal women.

OBJECTIVE: This study examined the effect of a single oral dose of sildenafil citrate (Viagra, Pfizer, Inc., New York, NY) on vaginal vasocongestion and subjective sexual arousal in healthy premenopausal women. METHODS: Twelve women without sexual dysfunction were randomly assigned to receive either a single oral 50 mg dose of sildenafil or matching placebo in a first session and the alternate medication in a second session. Subjective measures of sexual arousal were assessed after participants had been exposed to erotic stimulus conditions. Vaginal vasocongestion was recorded continuously during baseline, neutral, and erotic stimulus conditions. At the end of each session, subjects were also asked to specify which treatment they suspected they had received. RESULTS: Significant increases in vaginal vasocongestion were found with sildenafil treatment compared with placebo. There were no differences between treatments on subjective sexual arousal experience. Analyses by suspected treatment received found that significantly stronger sexual arousal and vaginal wetness were reported for the treatment that was believed to be sildenafil vs. the treatment that was believed to be placebo. The suspected treatment sequence was incorrect for half of the women. Sildenafil was well tolerated, with no evidence of significant adverse events. CONCLUSIONS: Sildenafil was found to be effective in enhancing vaginal engorgement during erotic stimulus conditions in healthy women without sexual dysfunction but was not associated with an effect on subjective sexual arousal.

Administration, Oral↗