Search PubMed⌕ Search

Biomedical subjects

E de Haan

Publications and source records attributed to E de Haan.

At least 19 recordsLinked to original sources
PubMed2001

Abnormally increased semantic priming in children with symptomatic HIV-1 disease: evidence for impaired development of semantics?

Language deficits are a major characteristic of neurobehavioral dysfunction in pediatric HIV disease. An object decision task, which assessed reaction time facilitation following a semantic or identical prime in comparison to an unrelated prime, was used to investigate whether semantic processing abnormalities could be responsible, in part, for these deficits. Thirty children with vertically acquired HIV infection (M age 9.0 years; range 6-13) participated. Either a picture of the same object (repetition prime), a semantically related object (semantic prime), a semantically unrelated object, or a nonsense object preceded a target picture, which in 50% of the cases was a real object. Brain scans of children were rated and used together with neurobehavioral functioning to classify children as having HIV-related CNS abnormalities (n = 13) or not (n = 17). Increased semantic priming but not repetition priming was associated with a greater degree of cortical atrophy. Furthermore, CNS compromised children had significantly faster reaction times following a semantic prime compared to an unrelated prime than non-compromised patients. This facilitation following semantic priming for the CNS compromised patients (13.3%) almost equaled the facilitation following repetition priming (15.3%) while for the non-compromised patients facilitation following semantic priming (7.9%) was clearly smaller than following repetition priming (14.6%). These data suggest that HIV infection in children may result in a reduced neural network leading to impoverished semantic representations characterized by poor differentiation between closely related objects.

Acquired Immunodeficiency Syndrome↗
PubMed2000

Conscious and preconscious selective attention to social threat: different neuroendocrine response patterns.

This study was designed to investigate the relationship between selective attention to social threat and neuroendocrine activity. Selective attention to social threat was measured using a supraliminal (unmasked) and a subliminal (masked) version of a pictorial emotional Stroop task, comparing color-naming latencies of neutral and angry faces. Neuroendocrine activity was assessed as (pre-task to post-task) increases in salivary cortisol and testosterone. Forty subjects were randomly assigned to the unmasked or masked version of the task. Analyses for the unmasked task revealed that post-task cortisol levels were significantly increased in subjects showing selective attention to angry faces. Results for the masked task indicated that post-task cortisol and testosterone levels were significantly increased in subjects showing preconscious selective attention to angry faces. The difference in neuroendocrine activity between tasks is suggested to depend on cortical (i.e. prefrontal) control in the unmasked task. Thus, psychological affective regulatory processes were involved in the unmasked task, whereas the neuroendocrine response patterns in the masked task indicates a biologically prepared mechanism.

Adult↗
PubMed1999

Correlations among salivary testosterone, mood, and selective attention to threat in humans.

An experiment was designed to investigate the relation among salivary testosterone, mood, and selective attention to threat. The participant group consisted of 32 nonclinical subjects (16 men and 16 women). Individuals completed the Profile Of Mood States (POMS) and performed a pictorial emotional Stroop task measuring selective attention to angry faces. Anticipating a time lag between testosterone (as measured in saliva) and cognitive emotional behavior, multiple time-coursed saliva samples were taken preceding the assessment of questionnaire and task for every subject. In both sexes, salivary testosterone was significantly related to mood (i.e., anger and tension) and selective attention to angry faces when saliva samples were taken 6 h before questionnaire and task assessment. Research on the relation between testosterone and human behavior might benefit by taking into account time lags between the behavioral manifestations and the continuously changing levels of testosterone.

Adolescent↗
PubMed1999

Collaborative study to improve the quality control of rare earth element determinations in environmental matrices.

In order to control the quality of rare earth determinations in environmental matrices, the Standards, Measurements and Testing Programme (formerly Community Bureau of Reference, BCR) of the European Commission has started a project, the final aim of which is to certify four types of matrices (tuna muscle, mussel tissue, aquatic plant and estuarine sediment) for their contents of a range of rare earth elements (Sc, Y and the lanthanides: La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu). The elements U and Th were added to the study. The first part of this project consisted of an interlaboratory study which aimed to test the feasibility of preparation of environmental reference materials and to detect and remove most of the pitfalls observed in rare earth determinations. This paper presents the preparation of the four matrices for the intercomparison study and for the candidate reference material. The main results are presented of the interlaboratory study that was carried out prior to the certification campaign. This collaborative trial is the first attempt ever carried out at this scale to evaluate the state-of-the-art of rare earth determinations in the environment. Its impact on the improvement of chemical measurements will have positive effects on the comparability of data necessary for environmental monitoring.

Chemistry Techniques, Analytical↗
PubMed1998

Baseline salivary cortisol levels and preconscious selective attention for threat. A pilot study.

This study was conducted to examine the relationship between baseline salivary cortisol (CORT) levels and selective attention for displays of angry faces. Selective attention was investigated using a pictorial emotional Stroop task, comparing colournaming-speed of angry and neutral faces. The task was assessed in supraliminal (unmasked) and subliminal (masked) conditions to 28 non-clinical subjects (14 male and 14 female). Repeated measures analysis of variance revealed a significant interaction between median split CORT levels (low vs. high) and masked face valence (angry vs. neutral). The latter effect was mainly due to significant facilitation in the high CORT subject-group; these subjects seemed to allocate their attention away from the masked angry face. A relation between baseline CORT levels and fast withdrawal behavior is suggested.

Adult↗
PubMed1998

Behavior therapy versus clomipramine for the treatment of obsessive-compulsive disorder in children and adolescents.

OBJECTIVE: To compare, via a pilot study, the effectiveness of behavior therapy and of drug treatment in children and adolescents with obsessive-compulsive disorder. METHOD: Twenty-two children aged between 8 and 18 years were randomly assigned to behavior therapy (n = 12) or open clomipramine (n = 10) in a parallel design lasting 12 weeks. Behavior therapy included exposure and response prevention administered in weekly sessions. The mean dosage of clomipramine was 2.5 mg/kg (range = 1.4-3.3 mg/kg). The main outcome variables were the Children's Yale-Brown Obsessive Compulsive Scale (CY-BOCS) and the Leyton Obsessional Inventory-Child Version (LOI-CV). RESULTS: Significant improvement was obtained in both treatment conditions. Behavior therapy produced stronger therapeutic changes than clomipramine on the CY-BOCS (p < .05), whereas on the LOI-CV no significant differences between the results of the two treatments were found. Five of the nine initial nonresponders showed significant changes after extension of treatment for another 12 weeks. CONCLUSION: Behavior therapy is shown to be a good alternative for drug treatment and deserves further study in larger samples of children with obsessive-compulsive disorder.

Behavior Therapy↗
PubMed1998

Cognitive and behavioral therapies alone versus in combination with fluvoxamine in the treatment of obsessive compulsive disorder.

The purpose of this treatment package design study was to investigate the differential efficacy of cognitive therapy or exposure in vivo with response prevention for obsessive compulsive disorder (OCD) versus the sequential combination with fluvoxamine. Patients with OCD (N = 117) were randomized to one of the following five conditions: a) cognitive therapy for weeks 1 to 16, b) exposure in vivo with response prevention for weeks 1 to 16, c) fluvoxamine for weeks 1 to 16 plus cognitive therapy in weeks 9 to 16, d) fluvoxamine for weeks 1 to 16 plus exposure in vivo with response prevention in weeks 9 to 16, or e) waiting list control condition for weeks 1 to 8 only. Assessments took place before treatment (pretest) and after 8 (midtest), and 16 weeks (posttest). In the first 8 weeks, six treatment sessions were delivered. During weeks 9 to 16, another 10 sessions were given. Thirty-one patients dropped out. Outcome was assessed by patient-, therapist- and assessor-ratings of the Anxiety Discomfort Scale, the Yale-Brown Obsessive Compulsive Scale, and the Padua Inventory-Revised. In contrast with the four treatments, after 8 weeks the waiting list control condition did not result in a significant decrease of symptoms. After 16 weeks of treatment, all four treatment packages were effective on these OCD ratings, but they did not differ among each other in effectiveness. In OCD, the sequential combination of fluvoxamine with cognitive therapy or exposure in vivo with response prevention is not superior to either cognitive therapy or exposure in vivo alone.

Adult↗
PubMed1997

Prediction of outcome and early vs. late improvement in OCD patients treated with cognitive behaviour therapy and pharmacotherapy.

In this study, follow-up results of cognitive-behaviour therapy and of a combination of cognitive-behaviour therapy with a serotonergic antidepressant were determined. The study also examined factors that can predict this treatment effect, both in the long term and in the short term. In addition, it investigated whether differential prediction is possible for cognitive-behaviour therapy vs. a combination of cognitive-behaviour therapy with a serotonergic antidepressant. A total of 99 patients were included in the study. Treatment lasted 16 weeks, and a naturalistic follow-up measurement was made 6 months later. Of the 70 patients who completed the treatment, follow-up information was available for 61 subjects. Significant time effects were found on all outcome measures at both post-treatment measurement and follow-up. No differences in efficacy were found between the treatment conditions. Effectiveness at post-treatment measurement appears to predict success at follow-up. However, 17 of the 45 non-responders at the post-treatment measurement had become responders by the follow-up. The severity of symptoms, motivation for treatment and the dimensional score on the PDQ-R for cluster A personality disorder appear to predict treatment outcome. No predictors were found that related specifically to cognitive-behaviour therapy or combined treatment. These results indicate that the effectiveness of cognitive-behaviour therapy or a combination of cognitive-behaviour therapy and fluvoxamine at the post-treatment measurement is maintained at follow-up. However, non-response at post-treatment does not always imply non-response at follow-up. Patients with more severe symptoms need a longer period of therapy to become responders. Although predictors for treatment success were found, no evidence was found to determine the choice of one of the treatment modalities.

Adult↗
PubMed1996

Nonspatial visual attention explained by spatial attention plus limited storage.

The use of nonspatial attentional mechanisms in search tasks was investigated by presenting observers with stimuli that contained 4-12 elements located on a circle around the fixation point. The elements differed in one of six nonspatial 'dimensions', namely orientation, contrast, scale, number of cycles, 'shape', and place in the alphabet. The target element of the search task differed from trial to trial but was always presented to the observer as a nonspatial, visual cue. This cue was displayed either before the stimulus (precue) or after the stimulus (postcue). Whereas a precue creates optimal conditions for the use of nonspatial attentional mechanisms, a postcue precludes benefits from their use. The fact that performance was better in the case of precued stimuli than in the case of postcued stimuli indicates that observers employed nonspatial attentional mechanisms. In the final analysis, however, the effect of nonspatial attention reduces to spatial attention in combination with limited storage capacity.

Attention↗
PubMed1996

Dissociating face processing skills: decision about lip-read speech, expression, and identity.

The separability of different subcomponents of face processing has been regularly affirmed, but not always so clearly demonstrated. In particular, the ability to extract speech from faces (lip-reading) has been shown to dissociate doubly from face identification in neurological but not in other populations. In this series of experiments with undergraduates, the classification of speech sound (lip-reading) from personally familiar and unfamiliar face photographs was explored using speeded manual responses. The independence of lip-reading from identity-based processing was confirmed. Furthermore, the established pattern of independence of expression-matching from, and dependence of identity-matching on, face familiarity was extended to personally familiar faces and "difficult"-emotion decisions. The implications of these findings are discussed.

Adolescent↗
PubMed1995

Cognitive therapy and exposure in vivo in the treatment of obsessive compulsive disorder.

The present study is the first controlled study that evaluates the effects of cognitive therapy along the lines of Beck (1976) [Cognitive therapy and the emotional disorder. New York: International University Press] and Salkovskis (1985) [Behaviour Research and Therapy, 23, 571-583] in obsessive compulsive disorder (OCD) and compares these effects with those of self-controlled exposure in vivo with response prevention. Seventy-one patients were randomly assigned to either cognitive therapy or exposure in vivo. In each treatment condition seven patients dropped out. Both treatments consisted of 16 sessions. Cognitive therapy as well as exposure in vivo led to statistically significant improvement. Multivariate significant differences suggesting a superior efficacy of cognitive therapy in comparison to exposure in vivo on the obsessive compulsive measures and on the measures for associated psychopathology. However, no univariate differences were found. Further, in both treatment conditions a considerable percentage of the patients was rated as "recovered". Significantly more patients were rated as "recovered" in the cognitive therapy. The results show that this form of cognitive therapy is an effective treatment for OCD and suggest that cognitive therapy may be even more effective than exposure in vivo.

Adult↗
PubMed1993

Do patients suffering from obsessions alone differ from other obsessive-compulsives?

The aim of this study was to determine whether a group of 48 patients with obsessions and compulsions differed from a group of 26 patients with obsessions alone, on the basis of demographic variables, variables relating to obsessive-compulsive neurosis, psychological variables and treatment outcome. It was found that they differed significantly in the following areas: marital status, level of education, age at onset of complaints, psychoactive medication taken when admitted for treatment, severity of obsessive-compulsive complaints, depression and intelligence. No difference was found as far as treatment outcome was concerned. Patients suffering from obsessions alone, would appear to form a distinct sub-group within the group of obsessive-compulsive patients as a whole.

Adult↗
PubMed1992

Do drop-outs differ from successfully treated obsessive-compulsives?

The most common reasons given by patients for dropping out of treatment are: environmental constraints, dissatisfaction with services and that they no longer need help. In this study two groups of patients suffering from obsessive-compulsive disorders are compared. The drop-outs' reasons for terminating treatment are compared with the comments of patients who completed the therapy successfully. Drop-outs differ from successfully treated OCD's in five respects: they appear to be less obsessive-compulsive; they have more discongruent treatment expectations; they are more critical of the therapist; they experience less anxiety in carrying out homework assignments; they less frequently come under pressure from people close to them.

Adaptation, Psychological↗
PubMed1992

The treatment of children with obsessive-compulsive disorder.

Very little is known about the treatment of children with an obsessive-compulsive disorder (OCD). No controlled studies have been conducted into the effects of behaviour therapy or other kinds of psychotherapy. There have only been three studies into the effects of antidepressants. After providing some general information on OCD, this article discusses the possibilities, effects and some of the difficulties of treatment.

Adolescent↗
PubMed1990

Marital adjustment and obsessive-compulsive disorder.

Fifty obsessive-compulsives were treated by behavioural therapy (self-exposure in vivo and response prevention) either with their partner directly involved in all aspects of treatment or without their partner. The two treatment formats were equally effective. Although a substantial number of obsessive-compulsives were found to have marital problems, behavioural treatment directed at the obsessive-compulsive disorder resulted in improvement irrespective of marital quality and partner involvement in the therapy. The effects of treatment led neither to a deterioration of the marriage nor to adjustment problems in the partner.

Adaptation, Psychological↗
PubMed1989

The significance of the patient-therapist relationship in the treatment of obsessive-compulsive neurosis.

Results are presented of two studies into the predictive value of the therapeutic relationship in the treatment of 60 and 25 obsessive-compulsive patients. A relationship was found between the therapist's score on the Barret-Lennard Relationship Inventory, assessed after the second and 10th sessions. As far as the patients' scores were concerned, however, a significant correlation with outcome was found only after the 10th session.

Follow-Up Studies↗