Biomedical subjects

Jaap Oosterlaan

Publications and source records attributed to Jaap Oosterlaan.

At least 19 recordsLinked to original sources

PubMed2006

Psychophysiological determinants and concomitants of deficient decision making in pathological gamblers.

Psychophysiological responses are considered to be a mediating factor in the development of pathological gambling (PG) and PG has been associated with differential arousal levels during gambling. Yet little is known about the specific psychophysiological responses to wins and losses in PG. This study investigated heart rate (HR) and skin conductance responses (SCRs) during the Iowa Gambling Task (IGT) in an adult PG group (n=46) and a normal control (NC) group (n=47). Anticipatory psychophysiological reactions to disadvantageous and advantageous choices during the IGT and psychophysiological responses to wins and losses were measured. The PG group performed worse than the NC group on the IGT and exhibited lower anticipatory SCRs and HR decreases when pondering choices of disadvantageous card decks during the IGT. The PG group showed a decrease in HR after losses and wins, whereas the NC group showed a decrease in HR after losses, but an increase in HR after wins. Reward and punishment sensitivity as measured by the self-report BIS/BAS scale influenced IGT performance and psychophysiological responses, but in general these effects were similar for the PG group and the NC group. Lower anticipatory psychophysiological responses to disadvantageous choices in PG suggest impaired risk assessment in this group. Absence of a HR increase after wins possibly implies that reward sensitivity is decreased in PG. Because levels of reward and punishment sensitivity were associated with differential anticipatory HR responses to advantageous and disadvantageous decks, it would be advisable to include this taxonomy in studies on psychophysiological responses to rewards and losses.

Adult↗

PubMed2006

ADHD and DCD: a relationship in need of research.

Although the connection between attention deficit hyperactivity disorder (ADHD) and developmental coordination disorder (DCD) has been recognized for several decades, little research has examined the relationship between these two disorders. This paper draws attention to the contribution the cognitive-energetic model (CEM) can make in determining the specific nature of these two disorders. An information processing approach such as the CEM is a useful model to identify specific and overlapping mechanisms that are disrupted in these two disorders. This paper describes the CEM and reviews the research so-far in relation to the model. The CEM has several advantages over other models: First, it predicts which task variables will be independent or may interact, thus enabling the investigator to determine the success/failure of the task manipulation(s) and identify spurious findings. Second, the CEM links energetic factors to task variables and predicts both additive and interactive effects. Third, the CEM enables executive processes such as selective attention, working memory and inhibition to be related to both energetic and lower level processes. Fourth, by employing the CEM in clinical research, taxonomy of deficits can be derived enabling further insight into the nature of the disorders and their specific neuropsychological dysfunction. Suggestions are made for future research into the neuropsychological deficits associated with ADHD and DCD.

Attention Deficit Disorder with Hyperactivity↗

PubMed2006

The relationship of working memory, inhibition, and response variability in child psychopathology.

INTRODUCTION: The aim of this study was to investigate the relationship between working memory and inhibition in children with attention deficit hyperactivity disorder (ADHD), high-functioning autism (HFA), and Tourette syndrome (TS), compared to normally developing children. Furthermore, the contribution of variation in processing speed on working memory and inhibition was investigated in these childhood psychopathologies. METHOD: Four groups of children are reported in this study: 65 children with ADHD, 66 children with HFA, 24 children with TS, and 82 normal control children. All children were in the age range of 6-13 years. RESULTS: The relationship between working memory and inhibition was similar in children with ADHD, HFA, TS, and normally developing children. The relationship between both domains did not alter significantly for any of the groups, when variation in processing speed was taken into account. More symptoms of hyperactivity/impulsivity are related to a poorer inhibitory process and greater response variability. More symptoms of autism are related to a poorer working memory process. CONCLUSION: The current study showed that working memory, inhibition, and response variability, are distinct, but related cognitive domains in children with developmental psychopathologies. Research with experimental manipulations is needed to tackle the exact relationship between these cognitive domains.

Adolescent↗

PubMed2006

Executive functioning in children with an Autism Spectrum Disorder: can we differentiate within the spectrum?

The aim of this study was to investigate whether children with high-functioning autism (HFA), Asperger's syndrome (AS), and pervasive developmental disorder not otherwise specified (PDDNOS) can be differentiated from each other and from normal controls on their neurocognitive executive functioning (EF) profile. Children with HFA and AS showed the most EF deficits. The EF profile of the PDDNOS group was more disturbed that the normal control group, but was less disturbed than the profile of the HFA and AS groups. Little difference was found between the three PDD subtypes with respect to EF. This study supports the view that executive dysfunctioning plays an important role in autism. The usefulness of a distinction between different PDD subtypes was not demonstrated.

Adolescent↗

PubMed2006

Neurocognitive functions in pathological gambling: a comparison with alcohol dependence, Tourette syndrome and normal controls.

AIMS: Neurocognitive functions in pathological gambling have relevance for the aetiology and treatment of this disorder, yet are poorly understood. This study therefore investigated neurocognitive impairments of executive functions in a group of carefully screened Diagnostic and Statistical Manual version IV (DSM-IV-TR) pathological gamblers. Performance was compared to a group of normal control participants. To study the specificity of these neurocognitive deficits, a substance dependence group (alcohol dependence) and an impulse control disorder group (Tourette syndrome) were included. DESIGN: Cross-sectional study. SETTING: Addiction and general mental health treatment centres. PARTICIPANTS: Forty-nine pathological gamblers, 48 abstinent alcohol-dependent patients, 46 participants with Tourette syndrome and 49 normal control participants. MEASUREMENTS: A comprehensive neuropsychological battery measuring executive functions as well as basic cognitive functions. FINDINGS: Both the pathological gambling and the alcohol dependent groups were characterized by diminished performance on inhibition, time estimation, cognitive flexibility and planning tasks. The Tourette syndrome group showed deficits only on inhibition tasks. Basic cognitive functions were intact in all clinical groups. Comorbid attention deficit hyperactivity disorder, antisocial personality disorder and nicotine dependence influenced the impaired functions of the clinical groups only minimally. CONCLUSIONS: Carefully screened groups of pathological gamblers and alcohol dependents were characterized by diminished executive functioning, suggesting a dysfunction of frontal lobe circuitry in these disorders. The resemblance between the pathological gambling group and the alcohol dependence group suggests a common neurocognitive aetiology for these disorders. Psychosocial treatment of these disorders could benefit from assessing and targeting deficits in executive functions, as they probably influence the course of these disorders negatively.

Adult↗

PubMed2006

Can the Children's Communication Checklist differentiate autism spectrum subtypes?

The study explored whether children with high functioning autism (HFA), Asperger syndrome (AS), and pervasive developmental disorder not otherwise specified (PDD-NOS) can be differentiated on the Children's Communication Checklist (CCC). The study also investigated whether empirically derived autistic subgroups can be identified with a cluster analytic method based on the Autism Diagnostic Interview-Revised. Fifty-seven children with HFA, 47 with AS, 31 with PDD-NOS, and a normal control group of 47 children between 6 and 13 years participated. Children with HFA, AS, and PDD-NOS showed pragmatic communication deficits in comparison to the controls. Little difference was found between the three subtypes with respect to their CCC profile. A three-cluster solution explained the data best. The HFA cluster showed most autism characteristics, followed by the combined HFA + AS cluster, and then the PDD-NOS cluster. The findings support the autism spectrum concept based on severity of symptom impairment rather than distinct categories.

Adolescent↗

PubMed2005

Factor structure and cultural factors of disruptive behaviour disorders symptoms in Italian children.

OBJECTIVE: Poor parent and teacher awareness for attention-deficit/hyperactivity disorder (ADHD) and the scepticism of many clinicians on the prevalence of the disorder, make Italy an interesting environment in which to verify neuropsychological constructs generated in a predominantly Northern American cultural contest. The aim of the study was to verify, by factor confirmatory analysis, the empirical validity of the DSM constructs underlying the diagnostic criteria for developmental disruptive behaviour disorders in Italian school-age children. METHODS: Scores for DSM-IV inattention and hyperactivity/impulsivity, for oppositional defiant disorder (ODD) and for conduct disorder (CD) symptoms in 6-12 years old Italian children were analysed from 1575 parent and 1085 teacher forms of the disruptive behaviour disorders questionnaires collected in four different Italian regions. RESULTS: Reliability indicates high internal consistencies for both parent and teacher rating of inattention, hyperactivity/impulsivity, and oppositionality, but not for conduct problems. In accordance with the literature, a relatively low inter-rater convergent and discriminant validity correlation was observed comparing measures obtained by between parents and teachers. Confirmatory factor analysis of both parent and teacher data showed a better fit for a four-factor model, indicating a factor structure in accordance with the DSM-IV taxonomy. When completed by parents and teachers of clinically assessed ADHD, dyslexic or normal children, the disruptive behavioural disorder questionnaires showed a significant predictive diagnostic value. CONCLUSION: Although an informant variance higher that dimensional (trait) variance was observed, the study provides support for DSM-IV taxonomy for developmental disruptive disorders, showing construct validity of ADHD. ODD and CD could also be distinguished from each other.

Attention Deficit Disorder with Hyperactivity↗

PubMed2005

Low basal salivary cortisol is associated with teacher-reported symptoms of conduct disorder.

Cortisol has been implicated in psychobiological explanations of antisocial behavior. This study measured basal salivary cortisol in a sample of 25 children (age range 6 to 12 years) selected to vary in levels of antisocial behavior. Regression analyses were used to predict cortisol concentrations from parent- and teacher-reported symptoms. Parent-reported symptoms did not predict basal cortisol. Teacher-reported conduct disorder (CD) symptoms explained 38% of the variance in the cortisol concentrations, with high symptom severity associated with low cortisol. When a distinction was made between aggressive and non-aggressive CD symptoms, aggressive CD symptoms were more clearly related to low cortisol than non-aggressive CD symptoms. In contrast to previous research, no evidence was found for a mediating role of anxiety symptoms in the relationship between CD and cortisol. The results support biologically based models of antisocial behavior in children that involve reduced autonomic activity.

Adolescent↗

PubMed2005

Dopamine receptor D4 (DRD4) gene in Han Chinese children with attention-deficit/hyperactivity disorder (ADHD): increased prevalence of the 2-repeat allele.

There is an increased prevalence of the 7-repeat (7R) allele of the dopamine receptor D4 (DRD4) gene in attention-deficit/hyperactivity disorder (ADHD). However, the population prevalence of the 7R allele varies considerably across ethnicity and is very low in Asians. To test whether this 7R allele/ADHD association still held in a Chinese clinical sample, 32 Han Chinese children with a confirmed ADHD diagnosis and normal IQ who were methylphenidate-responders were genotyped. None of them had a DRD4 7R allele. Instead, we observed a significantly increased prevalence of the 2-repeat (2R) allele in this clinical sample (33%) compared to ethnically-matched controls (20%) (chi(2)(1d.f.) = 5.90, P = 0.015). This approximately 1.65-fold increase of the 2R allele in our probands is close to the observed increase of the 7R allele in European-ancestry ADHD children. Recent genetic studies have indicated that the 2R allele in Asians is likely derived from the 7R allele. Further, available biochemical data indicate that both the 2R and 7R protein have blunted responses to dopamine compared to the 4R protein. Based on these results, we propose that the observed increased prevalence of the 2R allele in our Han Chinese ADHD probands is still consistent with the 7R allele hypothesis of ADHD in European-ancestry children. Recent studies have suggested that any variant from the conserved ancestral 4R allele might potentially alter biochemistry/phenotype. We hypothesize that an increased frequency of any non-4R allele may define the association of the DRD4 gene with ADHD that holds across ethnicity. The present findings, however, obtained with a small ADHD sample size, should be replicated.

Adolescent↗

PubMed2005

Which executive functioning deficits are associated with AD/HD, ODD/CD and comorbid AD/HD+ODD/CD?

This study investigated (1) whether attention deficit/hyperactivity disorder (AD/HD) is associated with executive functioning (EF) deficits while controlling for oppositional defiant disorder/conduct disorder (ODD/CD), (2) whether ODD/CD is associated with EF deficits while controlling for AD/HD, and (3) whether a combination of AD/HD and ODD/CD is associated with EF deficits (and the possibility that there is no association between EF deficits and AD/HD or ODD/CD in isolation). Subjects were 99 children ages 6-12 years. Three putative domains of EF were investigated using well-validated tests: verbal fluency, working memory, and planning. Independent of ODD/CD, AD/HD was associated with deficits in planning and working memory, but not in verbal fluency. Only teacher rated AD/HD, but not parent rated AD/HD, significantly contributed to the prediction of EF task performance. No EF deficits were associated with ODD/CD. The presence of comorbid AD/HD accounts for the EF deficits in children with comorbid AD/HD+ODD/CD. These results suggest that EF deficits are unique to AD/HD and support the model proposed by R. A. Barkley (1997).

Adolescent↗

PubMed2005

Decision making in pathological gambling: a comparison between pathological gamblers, alcohol dependents, persons with Tourette syndrome, and normal controls.

Decision making deficits play an important role in the definition of pathological gambling (PG). However, only few empirical studies are available regarding decision making processes in PG. This study therefore compares decision making processes in PG and normal controls in detail using three decision making tasks examining general performance levels on these tasks as well as feedback processing using reaction time analyses. To investigate the specificity of decision making deficits in PG, a substance dependence group (alcohol dependence; AD) and an impulse control disordered group (Tourette syndrome; TS) were included. The PG group (n = 48), AD group (n = 46), TS group (n = 47), and a normal control (NC) group (n = 49) were administered (1) the Iowa Gambling Task (IGT), an ecologically valid gambling task; (2) the Card Playing Task, a task measuring perseveration for reward; and (3) a Go/No-Go discrimination task, a task measuring reward and response cost sensitivity. The PG group showed a diminished performance on all tasks and deficient feedback processing as compared to the NC group on the IGT and the Card Playing Task. In general, performance measures were not associated with levels of comorbidity or with self-reported motivational measures. For the larger part, deficiencies in decision making processes in the PG group were also present in the AD group, but not in the TS group. Subgroup analyses revealed larger decision making deficits in pathological slot machine gamblers than in pathological casino gamblers. Deficits in decision making and feedback processing in PG should be addressed in treatment and incorporated more explicitly in theoretical models of PG.

Adult↗

PubMed2005

Telling good from bad news: ADHD differentially affects processing of positive and negative feedback during guessing.

Neuroimaging studies on ADHD suggest abnormalities in brain regions associated with decision-making and reward processing such as the anterior cingulate cortex (ACC) and orbitofrontal cortex. Recently, event-related potential (ERP) studies demonstrated that the ACC is involved in processing feedback signals during guessing and gambling. The resulting negative deflection, the 'feedback-related negativity' (FRN) has been interpreted as reflecting an error in reward prediction. In the present study, ERPs elicited by positive and negative feedback were recorded in children with ADHD and normal controls during guessing. 'Correct' and 'incorrect' guesses resulted in respectively monetary gains and losses. The FRN amplitude to losses was more pronounced in the ADHD group than in normal controls. Positive and negative feedback differentially affected long latency components in the ERP waveforms of normal controls, but not ADHD children. These later deflections might be related to further emotional or strategic processing. The present findings suggest an enhanced sensitivity to unfavourable outcomes in children with ADHD, probably due to abnormalities in mesolimbic reward circuits. In addition, further processing, such as affective evaluation and the assessment of future consequences of the feedback signal seems to be altered in ADHD. These results may further help understanding the neural basis of decision-making deficits in ADHD.

Attention Deficit Disorder with Hyperactivity↗

PubMed2005

Executive functioning in adult ADHD: a meta-analytic review.

BACKGROUND: Several theoretical explanations of ADHD in children have focused on executive functioning as the main explanatory neuropsychological domain for the disorder. In order to establish if these theoretical accounts are supported by research data for adults with ADHD, we compared neuropsychological executive functioning and non-executive functioning between adults with ADHD and normal controls in a meta-analytic design. METHOD: We compared 13 studies that (1) included at least one executive functioning measure, (2) compared the performance of an adult ADHD group with that of an adult normal control group, (3) provided sufficient information for calculation of effect sizes, and (4) used DSM-III-R or DSM-IV criteria to diagnose ADHD. RESULTS: We found medium effect sizes both in executive functioning areas [verbal fluency (d= 0-62), inhibition (d = 0-64 and d = 0.89), and set shifting (d = 0.65)] and in non-executive functioning domains [consistency of response (d = 0.57), word reading (d = 0.60) and color naming (d = 0.62)]. CONCLUSIONS: Neuropsychological difficulties in adult ADHD may not be confined to executive functioning. The field is in urgent need of better-designed executive functioning tests, methodological improvements, and direct comparisons with multiple clinical groups to answer questions of specificity.

Attention Deficit Disorder with Hyperactivity↗

PubMed2005

Executive functioning in children with autism and Tourette syndrome.

The main aims of this study were to investigate if children with high-functioning autism (HFA) and children with Tourette syndrome (TS) can be differentiated in their executive functioning (EF) profile compared to normal controls (NCs) and compared to each other and to investigate whether children with HFA or children with TS and a comorbid group of children with both disorders are distinct conditions in terms of EF, Four groups of children participated in this study: HFA, TS, comorbid HFA + TS, and a NC group. All children were in the age range of 6 to 13 years. The groups were compared on five major domains of EF: inhibition, visual working memory, planning, cognitive flexibility, and verbal fluency. Children with HFA scored lower than NC children on all the EFs measured. Children with TS and NC children showed the same EF profile. The HFA group scored lower than the TS group for inhibition of a prepotent response and cognitive flexibility. Children with HFA performed poorer than children with comorbid HFA + TS on all functions, with the exception of inhibiting an ongoing response, interference control, and verbal fluency. Children with TS and children with comorbid HFA + TS could not be differentiated from one another in terms of EF. This study indicates that EF deficits are highly characteristic of children with HFA in comparison to children with TS and NC. The results suggest that for the comparison between HFA and TS groups, it is important to take into account comorbidity. A reevaluation of the EF hypothesis in children with TS is suggested.

Adolescent↗

PubMed2005

Delta plots in the study of individual differences: new tools reveal response inhibition deficits in AD/Hd that are eliminated by methylphenidate treatment.

The authors highlight the utility of distribution-analytical techniques in the study of individual differences and clinical disorders. Cognitive deficits associated with attention-deficit/hyperactivity disorder (AD/HD) were examined by using delta-plot analyses of performance data (reaction time and accuracy) obtained through the use of a prototypical conflict task, the Eriksen flanker task. In 20 children with AD/HD (compared with matched control participants), overall performance measures indicated a marginal performance deficit. Delta-plot analyses indicated that performance deficits associated with AD/HD involve response inhibition but not automatic response activation. In a within-subjects titration study, the response inhibition deficit was eliminated by methylphenidate treatment, but these effects were highly dose specific. The beneficial effect of methylphenidate was clarified further after correcting for inter-individual variation in sensitivity to medicine dosage.

Attention↗

PubMed2005

Does methylphenidate improve inhibition and other cognitive abilities in adults with childhood-onset ADHD?

We examined the effect of methylphenidate (Mph) on inhibition and several other cognitive abilities in 43 adults with Attention Deficit Hyperactivity Disorder (ADHD) by use of Conners' Continuous Performance Test (CPT) and the Change Task (ChT), an extension of the Stop Signal Test (SST). In a double blind, cross-over, placebo controlled study with Mph, tests were administered during the third week of individually titrated treatment with Mph (maximum dose 1 mg / kg / day) and during the third week of treatment with placebo. We established large medication effects for commission errors, standard error of mean reaction time, and attentiveness on the CPT, as well as moderate medication effects for mean reaction time on the CPT and response re-engagement speed on the ChT. For Stop Signal Reaction Time (SSRT) on the ChT, we also established large effects of Mph, but only in a group of participants who showed slow SSRTs on placebo. Mph indeed ameliorates inhibition, which is the core problem of ADHD, and certain other cognitive abilities in adults with ADHD.

Adult↗

PubMed2005

Motivational effects on motor timing in attention-deficit/hyperactivity disorder.

OBJECTIVE: This study was designed to clarify whether poor performance of children with attention-deficit/hyperactivity disorder (ADHD) on motor timing tasks reflects a true deficit in the temporal organization of motor output or is due to a lack of intrinsic motivation. METHOD: Eighteen children with ADHD (age 8-12) were compared with 18 age- and gender-matched normal controls with respect to timing precision, timing variability, and the frequency of extreme under- and overestimations during a 1-second interval production task. Monetary reward, response cost, and no reward were implemented to manipulate motivation. RESULTS: Children with ADHD produced significantly more inaccurate and more variable time intervals and exhibited a larger number of extreme over- and underestimations than control children. Although all children performed significantly better when monetary incentives were applied, group differences were not eliminated. CONCLUSIONS: In this study, no evidence was found for a motivational deficit as an explanation for impaired performance on a time production task in ADHD. Rather, results provide clear support for a generic motor timing deficit, probably due to a dysfunctional frontostriatocerebellar network involved in temporal aspects of motor preparation.

Adolescent↗

PubMed2005

Towards an understanding of unique and shared pathways in the psychopathophysiology of ADHD.

Most attention deficit hyperactivity disorder (ADHD) research has compared cases with unaffected controls. This has led to many associations, but uncertainties about their specificity to ADHD in contrast with other disorders. We present a selective review of research, comparing ADHD with other disorders in neuropsychological, neurobiological and genetic correlates. So far, a specific pathophysiological pathway has not been identified. ADHD is probably not specifically associated with executive function deficits. It is possible, but not yet established, that ADHD symptoms may be more specifically associated with motivational abnormalities, motor organization and time perception. Recent findings indicating common genetic liabilities of ADHD and other conditions raise questions about diagnostic boundaries. In future research, the delineation of the pathophysiological mechanisms of ADHD needs to match cognitive, imaging and genetic techniques to the challenge of defining more homogenous clinical groups; multi-site collaborative projects are needed.

Attention Deficit Disorder with Hyperactivity↗