Biomedical subjects

Wouter Hulstijn

Publications and source records attributed to Wouter Hulstijn.

At least 19 recordsLinked to original sources

PubMed2007

Psychomotor and memory effects of haloperidol, olanzapine, and paroxetine in healthy subjects after short-term administration.

RATIONALE: Impaired psychomotor function has been shown to be associated with clinical and functional outcome in schizophrenia. However, few studies have investigated the short-term effects of antipsychotics on the cognitive and psychomotor functions of this patient group. Because many confounding factors tend to influence the test results in patient research, this study investigates the drugs' effects in healthy volunteers. OBJECTIVES: The short-term effects of haloperidol (2.5 mg), olanzapine (10 mg), and paroxetine (20 mg) on psychomotor function in 15 healthy volunteers are compared with placebo and each other. METHODS: In a crossover design, the subjects completed a battery of psychomotor tasks assessing psychomotor speed, sensorimotor accuracy, visuospatial monitoring, and speed of information processing. In addition, peak velocity of saccadic eye movements and subscales of the visual analog scales were analyzed as the objective and subjective measures for sedation, respectively. Finally, the verbal memory test was used to assess the drugs' effects on memory. RESULTS: Apart from affecting the pursuit task where visuospatial monitoring, sensorimotor speed, and sensorimotor accuracy are measured simultaneously, haloperidol has been proven to be not associated with sedative nor with impairing effects on psychomotor function or verbal memory. In contrast, olanzapine had significant sedative effects. Moreover, the subjects displayed a significant impairment on all measures of psychomotor function and verbal memory, which was not attributable to the drug's sedative effects. After administration of paroxetine, no effects were found, with the exception of a single improvement in eye movement velocity. CONCLUSIONS: Short-term administration of olanzapine, and not of haloperidol, impedes several aspects of psychomotor function and verbal memory in healthy volunteers.

Adult↗

PubMed2006

Visual completion and complexity of visual shape in children with pervasive developmental disorder.

Much evidence has been gathered for differences in visual perceptual processing in individuals with Autistic Spectrum Disorder. The presence of the fundamental process of visual completion was tested in a group of children with Pervasive Developmental Disorder (PDD), as this requires perceptually integrating visual structure into wholes. In Experiment 1, it was investigated whether visual completion is present for simple partly occluded shapes in a group of children with PDD and a typically developing group. In Experiment 2, the presence of contextual influences in visual completion was investigated for the two groups. A total of 19 children with PDD and 28 controls who were matched for chronological age and IQ took part in two primed-matching tasks. For both groups, visual completion was present and for both groups, contextual influences were found to be dominant in this process. However, only for the group with PDD no priming effects (PEs) were found from less regular primes on congruent test pairs. The group with PDD did integrate visual information into wholes and did this in a contextually dependent way. However, for more complex shapes, visual completion is weaker for this group.

Autistic Disorder↗

PubMed2006

Acute effects of the ampakine farampator on memory and information processing in healthy elderly volunteers.

Ampakines act as positive allosteric modulators of AMPA-type glutamate receptors and facilitate hippocampal long-term potentiation (LTP), a mechanism associated with memory storage and consolidation. The present study investigated the acute effects of farampator, 1-(benzofurazan-5-ylcarbonyl) piperidine, on memory and information processes in healthy elderly volunteers. A double-blind, placebo-controlled, randomized, cross-over study was performed in 16 healthy, elderly volunteers (eight male, eight female; mean age 66.1, SD 4.5 years). All subjects received farampator (500 mg) and placebo. Testing took place 1 h after drug intake, which was around Tmax for farampator. Subjects performed tasks assessing episodic memory (wordlist learning and picture memory), working and short-term memory (N-back, symbol recall) and motor learning (maze task, pursuit rotor). Information processing was assessed with a tangled lines task, the symbol digit substitution test (SDST) and the continuous trail making test (CTMT). Farampator (500 mg) unequivocally improved short-term memory but appeared to impair episodic memory. Furthermore, it tended to decrease the number of switching errors in the CTMT. Drug-induced side effects (SEs) included headache, somnolence and nausea. Subjects with SEs had significantly higher plasma levels of farampator than subjects without SEs. Additional analyses revealed that in the farampator condition the group without SEs showed a significantly superior memory performance relative to the group with SEs. The positive results on short-term memory and the favorable trends in the trail making test (CTMT) are interesting in view of the development of ampakines in the treatment of Alzheimer's disease and schizophrenia.

Adult↗

PubMed2006

Psychomotor slowing in schizophrenia.

Psychomotor slowing (PS) is a cluster of symptoms that was already recognized in schizophrenia by its earliest investigators. Nevertheless, few studies have been dedicated to the clarification of the nature and the role of the phenomenon in this illness. Moreover, slowed psychomotor functioning is often not clearly delineated from reduced processing speed. The current, first review of all existing literature on the subject discusses the key findings. Firstly, PS is a clinically observable feature that is most frequently established by neuropsychological measures assessing speed of fine movements such as writing or tasks that require rapid fingertip manipulations or the maintenance of maximal speed over brief periods of time in manual activities. Moreover, the slowed performance on the various psychomotor measures has been demonstrated independent of medication and has also been found to be associated with negative symptoms and, to a lesser extent, with positive and depressive symptoms. Importantly, performance on the psychomotor tasks proved related to the patients' social, clinical, and functional outcomes. Several imaging studies showed slowed performance to coincide with dopaminergic striatal activity. Finally, conventional neuroleptics do not improve the patients' PS symptoms, in contrast to the atypical agents that do seem to produce modestly improving effects.

Antipsychotic Agents↗

PubMed2006

Action monitoring and perfectionism in anorexia nervosa.

To study action monitoring in anorexia nervosa, behavioral and EEG measures were obtained in underweight anorexia nervosa patients (n=17) and matched healthy controls (n=19) while performing a speeded choice-reaction task. Our main measures of interest were questionnaire outcomes, reaction times, error rates, and the error-related negativity ERP component. Questionnaire and behavioral results indicated increased perfectionism in patients with anorexia nervosa. In line with their perfectionism and controlled response style patients made significantly less errors than controls. However, when controlling for this difference in error rates, the EEG results demonstrated a reduced error-related negativity in the patient group. These seemingly contradictory outcomes of improved performance and reduced error monitoring are discussed in relation with indications of anterior cingulate cortex hypoactivity in anorexia nervosa patients.

Adolescent↗

PubMed2006

Combined dexamethasone/CRF test in remitted outpatients with recurrent major depressive disorder.

BACKGROUND: Hyperactivity of the hypothalamic-pituitary-adrenal (HPA) axis is a prominent neurobiological finding during a major depressive episode, reflecting a state dependent factor. An issue under investigation is whether the dysfunction of the HPA axis has also a role to play as a state-independent or trait factor for major depressive disorder (MDD). In relation to this, it is important to examine HPA axis function in patients who are clinically remitted from depression. METHODS: Twenty-three remitted outpatients with recurrent MDD and 23 age- and gender-matched control individuals without a history of MDD participated in the sensitive combined dexamethasone/corticotropin-releasing factor (DEX/CRF) test. RESULTS: Free salivary cortisol responses were not significantly different between the two groups, although three patients (13%) displayed extremely elevated cortisol responses after CRF. LIMITATIONS: Limited sample size. All but one patient were under treatment with an antidepressant. CONCLUSIONS: This study shows no evidence for a disturbed DEX/CRF test as a state-independent factor in recurrent MDD on a group level. However, MDD is a complex and heterogenic disorder. Probably, there is a subgroup of patients who show a disturbed DEX/CRF test due to an inherited and/or acquired predisposition or as a biological scar after previous depressive episodes.

Adult↗

PubMed2006

Behavioural aspects of impulsivity in alcoholics with and without a cluster-B personality disorder.

AIMS: Studies have shown that alcoholics with a cluster-B personality disorder (cluster-B PD) are characterized by high levels of impulsivity. However, impulsivity has mainly been studied as a broad concept without its different aspects being considered. The present study compared abstinent alcoholic inpatients without any personality disorder (PD) and abstinent alcoholics with cluster-B PD on different aspects of impulsivity, i.e. self-reported impulsivity and neuropsychological indicators such as behavioural control and delay of gratification. METHODS: Forty alcohol-dependent inpatients without PD and 22 alcohol-dependent inpatients with a cluster-B PD were compared on two self-report impulsivity questionnaires (Barratt impulsiveness scale; sensation-seeking scales) and three behavioural impulsivity tasks [Go/No-Go task; delay discounting task (DDT); Stroop colour word test]. Tests were administered after stable abstinence of at least 3 weeks. RESULTS: Self-report measures of impulsivity were higher in cluster-B alcoholics than in alcoholics without PD. Behavioural tasks revealed a more differentiated pattern of impairments. On the Go/No-Go task, cluster-B alcoholics were impaired in inhibitory control but not in reaction time compared with alcoholics without PD. In contrast, no significant differences on the DDT and the Stroop were observed. CONCLUSION: Alcohol-dependent patients with and without a cluster-B PD differ in terms of behavioural inhibition but not in terms of activation or the ability to delay gratification. This finding may partly account for their impulsive and (self-) destructive behaviours. Treatment planning should pay specific attention to these impairments in behavioural control.

Adult↗

PubMed2006

Stereotypy in schizophrenia.

OBJECTIVES: In schizophrenia, stereotypy is observed, a symptom characterized by repetitive, functionless motor behaviour. Whereas cognitive dysfunctioning is known to remain stable throughout the illness, less is known about the course of the motor symptoms. The Zeigeversuch [Mittenecker, E., 1953. Perseveration und Persönlichkeit: 1. Teil: experimentelle Untersuchungen. Z. Exp. Angew. Psychol. 1, 5-31], which entails the generation of a random sequence of button presses, was claimed to capture stereotypy. We used a newly designed computerized version of the Zeigeversuch, the Stereotypy Test Apparatus (STA) to evaluate the evolution of STA performance through the course of the illness. METHODS: To assess stereotyped and perseverative behaviour, 58 schizophrenic inpatients and 48 healthy controls performed the STA and the Wisconsin Card Sorting Test (WCST), respectively, as well as several other traditional neuropsychological tests and the Symbol Digit Substitution Test (SDST) on a writing digitizer. RESULTS: The STA correlated only weakly with the WCST and SDST measures but not with the cognitive or motor slowing on the SDST, nor with the other cognitive measures. Stereotyped and perseverative idiosyncrasies both seem to increase in the course of the illness, in contrast with other cognitive dysfunctions. However, whereas perseveration is already present in the early stages of the illness, stereotyped behaviour only manifests itself in the later stages of schizophrenia. Failure of cognitive inhibition may result in an activation of prepotent stereotyped responses captured by the STA.

Adult↗

PubMed2006

Effects of antipsychotic and antidepressant drugs on action monitoring in healthy volunteers.

Humans need to monitor their actions continuously to detect errors as fast as possible and to adjust their performance to prevent future errors. This process of action monitoring can be investigated by measuring the error-related negativity (ERN), an ERP component elicited immediately after an error. In the current study, we investigated action monitoring after administration of the classic antipsychotic haloperidol (2.5 mg), the atypical antipsychotic olanzapine (10 mg), and the antidepressant paroxetine (20 mg), a selective serotonin reuptake inhibitor. Healthy volunteers (N = 14) were administered the three compounds and placebo in a randomized, double-blind, single-dose, four-way cross-over design. All participants performed a speeded two-choice reaction task, while event-related potentials and behavioral measurements were obtained. Both haloperidol and olanzapine significantly reduced ERN amplitudes. After paroxetine, the ERN was not different from placebo. N2 congruency effects were not affected by treatment condition. Only olanzapine demonstrated behavioral effects, namely a slowing of responses, an increase in error rates, and the absence of performance adjustments. The attenuated ERNs after the dopamine antagonist haloperidol are in line with the presumed role of dopamine in action monitoring. Haloperidol is thought to block dopaminergic signaling, thus reducing ERN amplitudes. On the other hand, the effects of olanzapine are mainly caused by its sedative side effects, leading to a decline in motivation and appraisal of errors. Finally, the absence of any effects after paroxetine suggests that serotonin transmission does not play a direct role in regulating mechanisms related to action monitoring.

Adult↗

PubMed2006

The relationship between pre-treatment clinical profile and treatment outcome in an integrated stuttering program.

UNLABELLED: A procedure for subtyping individuals who stutter and its relationship to treatment outcome is explored. Twenty-five adult participants of the Comprehensive Stuttering Program (CSP) were classified according to: (1) stuttering severity and (2) severity of negative emotions and cognitions associated with their speech problem. Speech characteristics (percentage of stuttered syllables, distorted speech score, and the number of correctly produced syllables on a diadochokinesis task) and emotional/cognitive states (emotional reaction, speech satisfaction, and attitudes toward speaking) were assessed before and after treatment, and at a 1- and 2-year follow-up. The results showed that: (a) there was no relationship between stuttering severity and the severity of negative emotions and cognitions, (b) the severe stuttering group had the largest treatment gains but also the highest level of regression, and (c) at post-treatment and both follow-up assessments the differences on measures of emotions between the mild and severe emotional group had disappeared, chiefly due to a large decrease in the latter group's negative emotions and cognitions. Our findings show that, based on treatment gains, specific subgroups can be identified, each requiring different treatment approaches. This underlines the necessity of developing a better understanding of how various dimensions of stuttering relate to treatment outcome. EDUCATIONAL OBJECTIVES: The reader will be able to: (1) describe why stuttering severity and negative emotions and cognitions that are related to stuttering should be investigated separately and (2) describe how treatment outcome relates to subtypes of persons who stutter.

Adolescent↗

PubMed2006

Fragmented visuospatial processing in children with pervasive developmental disorder.

Children diagnosed with Pervasive Developmental Disorder Not Otherwise Specified (PDD-NOS) and Asperger Syndrome (AS) may be characterised by a similar perceptual focus on details as children with autistic disorder (AD). This was tested by analysing their performance in a visuoperceptual task [the Children's Embedded Figure Test (CEFT)] and a graphic reproduction task [the Rey Complex Figure Task (Rey CFT)]. Control groups were children with Tourette Syndrome (TS) and typically developing children. The TS sample performed similarly to the normal control group in both tasks. The CEFT results did not show the expected preference for local processing in children with PDD-NOS. However, the Rey CFT data revealed that the children with this lesser variant of PDD processed visuospatial information in a fragmented way and were deficient in global processing.

Asperger Syndrome↗

PubMed2006

Movement planning deficits in schizophrenia: failure to inhibit automatic response tendencies.

INTRODUCTION: Explicit planning deficits have been reported frequently in patients with schizophrenia. This study addressed the question whether these patients would already encounter difficulties in a more "implicit" process of planning an optimal sequence of movements in simple actions. METHODS: Twenty patients with schizophrenia and 20 controls participated in the study. The motor tasks consisted of copying simple line drawings in which the planning of a movement sequence was taxed along various dimensions. In the first task the number of line elements varied between one and two, and the two-line figures differed with respect to the ease with which the so-called graphic production rules could be applied. In the second task the spatial position of the drawing varied between an easy centre position and a somewhat more difficult corner location. In the third task, subjects were asked to start copying either at a preferred or at a less preferred starting point. RESULTS: The results showed that the patients did not encounter planning difficulties while copying the one- or two-segment patterns. However, the variations in the spatial conditions and starting point did affect the patients' performance more than that of the controls. Whereas the patients with higher negative symptom scores tended to be slower when they were forced to start drawing at a particular point, the patients predominantly exhibiting features of disorganisation proved to be faster in this condition. CONCLUSIONS: The findings suggest a fairly intact initiation of simple movement sequences in patients with schizophrenia, but difficulties in inhibiting automatic response tendencies. It is concluded that this inhibition failure may play an important role in the planning difficulties these patients experience.

Adult↗

PubMed2006

Decision-making deficits in alcohol-dependent patients with and without comorbid personality disorder.

BACKGROUND: Impairments in decision making are a consistent finding in substance use disorder (SUD) populations. However, decision-making deficits are not specific for SUDs and are also reported in the context of other psychiatric disorders such as antisocial and borderline personality disorders (PDs). Given the frequent comorbidity between SUD and cluster B PD, it might be questioned whether the decision-making impairments typically reported in SUD populations reflect the addictive disorder, the cluster B PD, or a combination of the 2. METHODS: In the current study, we compare the decision-making performance of non-substance-abusing controls (n=53) on the Iowa Gambling Task (IGT) with the decision-making performance of 3 abstinent alcohol-dependent samples, i.e., alcoholic patients without any PD (n=38), alcoholic patients with a cluster A or C PD (n=19), and alcoholic patients with a cluster B PD (n=23). RESULTS: Overall, all 3 alcohol-dependent subsamples performed inferior compared with controls. Between alcoholic subsamples, the alcoholic patients with a cluster A or C PD had the highest IGT score, followed by the alcoholic patients without a PD, while the cluster B alcoholic patients were the most impaired. CONCLUSION: These findings suggest that impairments in decision making underlie both alcohol dependence and cluster B PD, and alcoholic patients with a comorbid cluster B PD are particularly impaired in their decision making. These deficits may underlie the severe problems that characterize cluster B alcoholic patients specifically in inappropriate behaviors (e.g., poly substance abuse, legal, and professional dysfunction).

Adult↗

PubMed2005

Neural correlates of impulsive responding in borderline personality disorder: ERP evidence for reduced action monitoring.

Patients with borderline personality disorder (BPD) are characterized by marked impulsive behaviour. The impulsive response style of patients with BPD may be associated with diminished action monitoring, which can be investigated by measuring the error-related negativity (ERN). The ERN is an ERP component generated in the anterior cingulate cortex (ACC) following erroneous responses. Behavioural and ERP measurements were obtained during performance on a speeded two-choice reaction task in a group of patients with BPD (N=12) and in a group of age-matched controls (N=12). The ERP results showed that ERN amplitudes were reduced for patients with BPD, as were the P300 amplitudes after late feedback. The behavioural results confirmed a more impulsive response style for the BPD group, reflected in larger RT differences between correct and incorrect responses and in an increase in erroneous responses to the easy congruent stimuli. Additionally, analyses on post-error congruency effects demonstrated that controls adjusted their behaviour following errors, but patients with BPD did not. The attenuated ERNs indicate reduced action monitoring in patients with BPD. This suggests that the ACC, or the action-monitoring network it is part of, is not functioning optimally. Due to this reduced action monitoring, patients with BPD do not learn from their errors as well as controls. Consequently, they do not adjust their behaviour when necessary and thus maintain their impulsive response style.

Adult↗

PubMed2005

Neural dynamics of error processing in medial frontal cortex.

Adaptive behavior requires an organism to evaluate the outcome of its actions, such that future behavior can be adjusted accordingly and the appropriate response selected. During associative learning, the time at which such evaluative information is available changes as learning progresses, from the delivery of performance feedback early in learning to the execution of the response itself during learned performance. Here, we report a learning-dependent shift in the timing of activation in the rostral cingulate zone of the anterior cingulate cortex from external error feedback to internal error detection. This pattern of activity is seen only in the anterior cingulate, not in the pre-supplementary motor area. The dynamics of these reciprocal changes are consistent with the claim that the rostral cingulate zone is involved in response selection on the basis of the expected outcome of an action. Specifically, these data illustrate how the anterior cingulate receives evaluative information, indicating that an action has not produced the desired result.

Adaptation, Psychological↗

PubMed2005

Muscular co-contraction covaries with task load to control the flow of motion in fine motor tasks.

This study focuses on the relationship between movement-time fluctuations in fine motor tasks and changing levels of muscular co-contraction. Based on a recent neuromotor noise theory, we expected that increased task stress would increase muscular co-contraction and prolong movement times. Ten right-handed adults performed a graphic task, which elicited local movement-time prolongations. In half the trials, a distracting sound was presented as an external stressor. Besides pen-tip kinematics, two estimates of muscular co-contraction were obtained from the surface EMG measurements of eight arm and hand muscles. The results confirm the presumed co-variation of movement time and co-contraction. We conclude that muscular co-contraction forms a strategic means to adapt the flow of motion to central information processing demands.

Acoustic Stimulation↗

PubMed2005

Fast psychomotor functioning in anorexia nervosa: effect of weight restoration.

In a previous study young seriously underweight anorexia nervosa (AN) patients in the early phase of treatment were found to react faster in psychomotor tasks. To further understand this finding we studied the impact of weight restoration on the performance of AN patients in drawing and copying tasks. A group of 17 female AN patients, aged 14 to 25, was compared with 17 healthy controls, matched for sex, age and educational level. Patients were tested when severely underweight and after weight restoration. Control subjects were also tested twice. Using computerized recording and analysis of writing and drawing behavior, reaction times and drawing times were derived, while cognitive and motor demands were manipulated. Overall, AN patients showed shorter reaction times in copying tasks and shorter drawing time in the drawing task than normal controls, and this pattern persisted after weight restoration. No significant group (AN vs. controls) by session (test vs. retest) effect emerged. The finding of a consistent pattern of shorter reaction and drawing times in AN patients before and after weight restoration is compatible with a personality characteristic of perfectionism and overachievement in AN patients.

Adult↗

PubMed2004

Differentiation of cognitive and motor aspects in a digit symbol substitution test in Anorexia nervosa patients, before and after weight restoration.

BACKGROUND: In a previous study, using computerized analysis of fine motor behaviour, seriously underweight anorexia nervosa patients in the early phase of treatment were found to have shorter reaction times, but not movement times, in experimental drawing and copying tasks. These differences persisted with weight restoration. SAMPLING AND METHODS: Using computerized analysis of writing and drawing behaviour during the performance of a Digit Symbol Substitution Test, 15 anorexia nervosa patients were compared with 15 normal controls, matched for age, sex and educational level. Patients were retested after weight restoration, as were controls after a similar interval. RESULTS: Patients turned out to be superior in the cognitive, but not in the motor aspects of the Digit Symbol Substitution Test. These differences persisted after weight restoration. A practice effect, due to repeated testing, was found in both groups, which turned out to be cognitive in nature. CONCLUSIONS: The findings show that this new technique can add to the interpretation of classic neuropsychological tests. The results are compatible with previous findings of intact or even superior functioning in anorexia nervosa patients on neuropsychological tasks requiring considerable cognitive effort.

Adolescent↗