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Dive into the research topics where Marike Polak is active.

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Featured researches published by Marike Polak.


Addictive Behaviors | 2014

Rash Impulsiveness and Reward Sensitivity as predictors of treatment outcome in male substance dependent patients

Michiel Boog; Anna E. Goudriaan; Ben J.M. van de Wetering; Marike Polak; Hilda Deuss; Ingmar H.A. Franken

Recent theories hypothesize that the impulsivity observed in addictive behaviors is a two-factor construct, consisting of Rash Impulsiveness and Reward Sensitivity. There is some evidence for this distinction, but it is unknown what the clinical relevance of this distinction is. The present study examines the predictive value of the two-factor model regarding drop-out from treatment and relapse into substance use in a clinical population of male substance dependent patients. Both behavioral and self-report measures of Rash Impulsiveness and Reward Sensitivity were measured during treatment while substance use relapse was measured after 90days. Results indicate that treatment drop-out could be predicted by a behavioral index of Reward Sensitivity (Card Playing Task); self-reported Rash Impulsiveness only approached significance as predictor drop-out. In contrast, relapse could not be predicted in the present study. These findings might have implications for the early identification and treatment of patients at risk of treatment drop-out.


Computational Statistics & Data Analysis | 2009

Two types of single-peaked data: Correspondence analysis as an alternative to principal component analysis

Marike Polak; Willem J. Heiser; Mark de Rooij

It has been argued that principal component analysis (PCA) is not appropriate for analyzing data conforming to single-peaked response models, also referred to as unfolding models. An overview of these findings is given, which relates them to the distinction between two types of unfolding models; namely, models that are either a quadratic function of the person-to-item distances or an exponential function of these distances. This distinction is easy to recognize empirically because the inter-item correlation matrix for the two types of data typically shows different patterns. Furthermore, for both types of unfolding models, correspondence analysis (CA), which is a rival method for dimensionality reduction, outperforms PCA in terms of representation of both person and item locations, especially for the exponential unfolding model. Finally, it is shown that undoubled CA outperforms doubled CA for both types of unfolding models. It is argued that performing CA on the raw data matrix is an unconventional, but meaningful approach to scaling items and persons on an underlying unfolding scale. A real data example on personality assessment is given, which shows that for this type of data (undoubled) CA is to be preferred over PCA.


Ultrasound in Obstetrics & Gynecology | 2018

Frequency of submicroscopic chromosomal aberrations in pregnancies without increased risk for structural chromosomal aberrations: systematic review and meta‐analysis

Malgorzata I. Srebniak; Marieke Joosten; Maarten F. C. M. Knapen; L. R. Arends; Marike Polak; S. Van Veen; A. T. J. I. Go; D. Van Opstal

To establish, based on a systematic literature review, the frequency of pathogenic submicroscopic chromosomal aberrations in fetuses that are not at increased risk for unbalanced structural chromosomal aberrations, with the aim of determining whether high‐resolution testing for submicroscopic aberrations is beneficial in a general pregnant population.


Human Mutation | 2017

The influence of SNP-based chromosomal microarray and NIPT on the diagnostic yield in 10,000 fetuses with and without fetal ultrasound anomalies

Malgorzata I. Srebniak; Maarten F. C. M. Knapen; Marike Polak; Marieke Joosten; Karin E. M. Diderich; Lutgarde C. P. Govaerts; Marjan Boter; Joan N.R. Kromosoeto; Daniella A.C.M. van Hassel; Gido Huijbregts; Wilfred van IJcken; Roger Heydanus; Anneke Dijkman; Toon Toolenaar; Femke de Vries; Jeroen Knijnenburg; A. T. J. I. Go; Robert-Jan H. Galjaard; Diane Van Opstal

Prenatal diagnostics has been impacted by technological changes in the past decade, which have affected the diagnostic yield. The aim of this study was to evaluate the impact of SNP array and noninvasive prenatal testing (NIPT) on the diagnostic yield and the number of invasive tests in our center. The frequency of pathogenic fetal unbalanced chromosome aberrations was studied in 10,005 cases referred for prenatal testing in 2009–2015. Chromosomal SNP microarray analysis replaced karyotyping in all invasively tested pregnancies and since 2014 a choice between NIPT and diagnostic testing with microarray was offered to women with an increased risk for common aneuploidy. The introduction of microarray led to an additional yield of submicroscopic pathogenic chromosome aberrations: 3.6% in fetuses with ultrasound anomalies and 1.9% in fetuses without ultrasound anomalies. The introduction of NIPT led to a decrease of invasive tests and of diagnostic yield. Moreover, a diagnostic delay in about 1:350 cases was observed. Since 20%–33% of pathogenic fetal chromosome aberrations are different from the common aneuploidies and triploidy, whole‐genome analysis should be offered after invasive sampling. Because NIPT (as a second screening) has led to a decreased diagnostic yield, it should be accompanied by an appropriate pretest counseling.


Journal of Behavior Therapy and Experimental Psychiatry | 2012

Covariation bias for food-related control is associated with eating disorders symptoms in normal adolescents

Birgit Mayer; Peter Muris; Nancy Kramer Freher; Janne Stout; Marike Polak

BACKGROUND AND OBJECTIVES Covariation bias refers to the phenomenon of overestimating the contingency between certain stimuli and negative outcomes, which is considered as a heuristic playing a role in the maintenance of certain types of psychopathology. In the present study, covariation bias was investigated within the context of eating pathology. METHODS In a sample of 148 adolescents (101 girls, 47 boys; mean age 15.3 years), a priori and a posteriori contingencies were measured between words referring to control and loss of control over eating behavior, on the one hand, and fear, disgust, positive and neutral outcomes, on the other hand. RESULTS Results indicated that all adolescents displayed an a priori covariation bias reflecting an overestimation of the contingency of words referring to loss of control over eating behavior and fear- and disgust-relevant outcomes, while words referring to control over eating behavior were more often associated with positive and neutral outcomes. This bias was unrelated to level of eating disorder symptoms. In the case of a posteriori contingency estimates no overall bias could be observed, but some evidence was found indicating that girls with higher levels of eating disorder symptoms displayed a stronger covariation bias. CONCLUSION These findings provide further support for the notion that covariation bias is involved in eating pathology, and also demonstrate that this type of cognitive distortion is already present in adolescents.


Psychotherapy Research | 2010

The developmental profile: Validation of a theory-driven instrument for personality assessment

Marike Polak; Henricus L. Van; Joanneke Overeem-Seldenrijk; Willem J. Heiser; Robert E. Abraham

Abstract The Developmental Profile is an instrument for personality assessment. It covers both maladaptive and adaptive characteristics. The current study examined its internal consistency and construct validity in a Dutch sample of 763 participants from various clinical and nonclinical settings. The internal consistency reliability estimates were good for the clusters of levels (adaptive, neurotic, and primitive), although not for all separate levels. Confirmatory factor analysis showed an overall good fit, with the exception of the level of primary narcissism. Furthermore, empirical evidence was found for the interpretation of a patients Developmental Profile according to increasing levels of aggregation, with as a highest level a single maladaptivity–adaptivity scale score. This scale significantly distinguished among different patient groups.


Multivariate Behavioral Research | 2012

A Model-Free Diagnostic for Single-Peakedness of Item Responses Using Ordered Conditional Means

Marike Polak; Mark de Rooij; Willem J. Heiser

In this article we propose a model-free diagnostic for single-peakedness (unimodality) of item responses. Presuming a unidimensional unfolding scale and a given item ordering, we approximate item response functions of all items based on ordered conditional means (OCM). The proposed OCM methodology is based on Thurstone & Chaves (1929) criterion of irrelevance, which is a graphical, exploratory method for evaluating the “relevance” of dichotomous attitude items. We generalized this criterion to graded response items and quantified the relevance by fitting a unimodal smoother. The resulting goodness-of-fit was used to determine item fit and aggregated scale fit. Based on a simulation procedure, cutoff values were proposed for the measures of item fit. These cutoff values showed high power rates and acceptable Type I error rates. We present 2 applications of the OCM method. First, we apply the OCM method to personality data from the Developmental Profile; second, we analyze attitude data collected by Roberts and Laughlin (1996) concerning opinions of capital punishment.


Mindfulness | 2018

Mindfulness, Interpretation Bias, and Levels of Anxiety and Depression: Two Mediation Studies

Birgit Mayer; Marike Polak; Danielle Remmerswaal

In two studies, a possible mediation effect was tested of cognitive interpretation bias in the relation between respectively dispositional mindfulness and acceptance, on the one hand, and symptoms of depression and anxiety, on the other hand. An undergraduate student sample (N = 133; 86% female, Mage = 19.8) and a convenience community sample (N = 186; 66% female, Mage = 36.5) were examined by means of an online questionnaire measuring dispositional mindfulness (FFMQ-SF; Study 1) and acceptance (AAQ-II; Study 2), anxiety (STAI-trait) and depressive (BDI-II) symptoms, and interpretation bias (with the interpretation bias task, IBT). Considering both studies, results showed consistently the expected relations of larger mindfulness skills going together with a smaller cognitive interpretation bias and lower levels of depression and anxiety symptoms. More interestingly, it was found that interpretation bias served as a mediator in the relations between respectively dispositional mindfulness and acceptance, and symptoms of depression and anxiety. With these findings, some more insight in the working mechanisms of mindfulness-based treatments on internalizing psychopathology has been obtained.


European Journal of Human Genetics | 2018

Offering a choice between NIPT and invasive PND in prenatal genetic counseling: the impact of clinician characteristics on patients’ test uptake

Sanne L. van der Steen; Diewertje Houtman; Iris M. Bakkeren; Robert-Jan H. Galjaard; Marike Polak; Jan J. Busschbach; Aad Tibben; Sam Riedijk

Testing options for pregnant women at increased risk of common aneuploidies are non-invasive prenatal testing (NIPT) and invasive prenatal diagnosis (PND). Clinicians are challenged to comprehensively discuss the complex information in a patient-centered and non-directive manner, to allow for patients’ informed decision-making. This study explored the information-centeredness, patient-centeredness, and level of non-directivity of different clinicians and examined group differences between their patients. First, semi-structured interviews with four senior obstetricians and one senior nurse were held regarding their information provision, their adaptation of a patient-centered attitude, and their practice of non-directivity. Interviews were transcribed verbatim and rated by four independent researchers. Secondly, 181 pregnant women were included in the study, of whom 82% opted for NIPT and 18% chose PND. Between clinicians, we assessed the distribution of choice ratios, patients’ impression of clinicians’ test preferences, and patients’ knowledge scores. The results indicate that clinicians do not differ in their information-centeredness, but do differ in their patient-centeredness and their level of non-directivity. Significant differences in patients’ NIPT/PND ratios were observed between clinicians, with the largest difference being 35 vs. 4% opting for invasive PND. Between 9 and 22% of the patients had an impression of their clinician’s preference and chose in accordance with this preference. Patients’ overall knowledge scores did not differ across clinicians. In conclusion, the differences in NIPT/PND ratios between clinicians indicate that clinicians’ differing counseling approaches affect the choices their patients make. The interviews indicate a possible framing effect which may unintentionally steer the decision-making process.


Ultrasound in Obstetrics & Gynecology | 2017

P16.05: The influence of chromosomal microarray and NIPT on the diagnostic yield in 6,811 high-risk pregnancies without ultrasound anomalies

Malgorzata I. Srebniak; Maarten F. C. M. Knapen; Marike Polak; Marieke Joosten; Karin E. M. Diderich; Lutgarde C. P. Govaerts; W.F. Ijcken; R. Heydanus; Anneke Dijkman; Toon Toolenaar; F. A. T. de Vries; Jeroen Knijnenburg; A. T. J. I. Go; Robert Jan H. Galjaard; D. Van Opstal

Methods: On 3rd June 2016 Embase and PubMed databases were systematically searched for all relevant articles on prevalence of pathogenic submicroscopic CNVs in fetuses tested due to advanced maternal age or parental anxiety. Relevant full text articles were analysed and based on the extracted data the prevalence of submicroscopic CNVs was calculated. Results: Meta-analysis was conducted in a pooled cohort of 10,614 fetuses based on the 10 largest studies (N > 300) of a total of 19 relevant studies. In 0.84%, 95%CI [0.55%, 1.30%] of fetuses a submicroscopic pathogenic aberration was detected prenatally. The onset/penetrance of the submicroscopic findings was studied in 10,314 fetuses out of 8 papers that presented aberrant cases with all necessary details. The prevalence of early onset syndromic disorders due to a submicroscopic aberration was calculated to be 1:270, based on 0.37%, 95%CI [0.27%, 0.52%] cases where aberrations were specified. Conclusions: This systematic review shows that a significant proportion of fetuses in a general pregnant population carry a submicroscopic pathogenic CNV. Based on these figures all women should be informed on their individual risk for all pathogenic chromosome aberrations and not only for common trisomies.

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A. T. J. I. Go

Erasmus University Rotterdam

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D. Van Opstal

Erasmus University Rotterdam

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Marieke Joosten

Erasmus University Rotterdam

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L. R. Arends

Erasmus University Rotterdam

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S. Van Veen

Erasmus University Rotterdam

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Birgit Mayer

Erasmus University Rotterdam

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