Harrie C. M. Vorst
University of Amsterdam
Network
Latest external collaboration on country level. Dive into details by clicking on the dots.
Publication
Featured researches published by Harrie C. M. Vorst.
Personality and Individual Differences | 2001
Harrie C. M. Vorst; Bob Bermond
Abstract The aim of this research is to establish the validity and reliability of the Bermond–Vorst Alexithymia Questionnaire (BVAQ). The BVAQ consists of five subscales, each comprising of eight items. The subscales are denoted Emotionalizing, Fantasizing, Identifying, Analyzing, and Verbalizing. The validity of the instruments was investigated by comparing results of psychometric analyses in three language groups. In addition BVAQ scores were correlated, for comparison, with the TAS-20 test scores and with measures of psychological problems. Two studies were carried out. In the first study the BVAQ was administered to a sample of Dutch students ( n =375), a sample of French-speaking Belgian students ( n =175), and a sample of English students ( n =129). Cronbach’s alpha was found to be about the same in the three samples (means of subscales about 0.79; total scales about 0.85). Principal components analyses of the 40 items revealed comparable five-factor solutions in the three samples. The mean total score of UK students differs about 0.29 SD from that of the Dutch and Belgian students. The intercorrelations of subscales were the same in the three samples. However, principal components analyses of the subscale scores of the English subjects revealed a different factor structure compared to that in the other samples. In the second study, the BVAQ and the Dutch version of the TAS-20 were administered to 430 Dutch students. Correlations between (sub)scales of the Dutch BVAQ and (sub)scales of the TAS-20 support the validity of the BVAQ. The validity of the BVAQ is further supported by correlations between BVAQ scores and measurements of psychological problems.
Journal of Sex Research | 2002
Erick Janssen; Harrie C. M. Vorst; Peter R. Finn; John Bancroft
This study involves the development and initial validation of a questionnaire measuring the propensity for sexual inhibition and excitation in men: the Sexual Inhibition & Sexual Excitation Scales (SIS/SES). The underlying theoretical model postulates that sexual response and associated behavior depend on dual control mechanisms, involving excitatory and inhibitory neurophysiological systems. The scales and their discriminant and convergent validity and test‐retest reliability are described. In a sample of 408 sexually functional men (mean age = 22.8 years), factor analyses identified three higher‐level factors: two related to sexual inhibition and one to sexual excitation. Multigroup Confirmatory Factor Analyses revealed that the factor structure provided an acceptable fit to the data obtained in a second (N = 459; mean age = 20.9 years) and third (N = 313; mean age = 46.2 years) sample of men, with similar distributions and relationships with other measures. Theoretical issues and areas for further research, including male sexual dysfunction and risk taking, are discussed.
Journal of Sex Research | 2002
Erick Janssen; Harrie C. M. Vorst; Peter R. Finn; John Bancroft
This study evaluated the predictive value of a newly developed measure of the propensity for sexual inhibition and excitation; the Sexual Inhibition & Sexual Excitation Scales (SIS/SES). Sexual, cardiovascular, and startle responses were measured in a group of 40 sexually functional men during the presentation of threatening and nonthreatening erotic films. Two levels of performance demand were created and two films were combined with a distraction task. Participants were assigned to high and low groups for each of the three SIS/SES scales. As predicted, men with high SES scores showed generally higher sexual responses. High and low SIS1 groups did not differ in their responses. Men with high and low SIS2 scores did not differ in their responses to nonthreatening stimuli; however, low SIS2 men showed greater genital response to the threatening stimuli. The findings provide support for the value of the SIS/SES scales in predicting sexual responses.
Journal of Sex Research | 2008
Deanna Carpenter; Erick Janssen; Cynthia A. Graham; Harrie C. M. Vorst; Jelte M. Wicherts
The Sexual Inhibition/Sexual Excitation Scales (SIS/SES) assess individual propensities to become sexually aroused and to inhibit arousal. Prior analyses of mens SIS/SES data (Janssen, Vorst, Finn, & Bancroft, 2002a) yielded one excitation factor (SES) and two inhibitory factors (SIS1/Threat of Performance Failure and SIS2/Threat of Performance Consequences). The current study utilized a dataset of 2,045 undergraduates (1,067 women and 978 men) to examine the psychometric properties of womens SIS/SES scores. Women scored higher on sexual inhibition and lower on sexual excitation compared with men. The convergent/discriminant validity of womens SIS/SES scores globally resembled mens, but showed stronger associations with other sexuality − related measures and less pronounced relationships with measures of general behavioral approach/avoidance. The test–retest reliability of mens and womens SIS/SES scores were similar, but individual items exhibited differential relevance to mens and womens arousal. An exploratory factor analysis of womens scores was utilized to further examine shared and unshared themes.
Cognitive Neuropsychiatry | 2006
Bob Bermond; Harrie C. M. Vorst; Peter Paul Moormann
Introduction. We examine the cognitive neuroscience of the five components of the alexithymia syndrome, and propose a classification of alexithymia types based on psychobiological traits. Method. Literature review. Results. The following neural structures have been shown to be prominent in emotional function: right and left hemisphere, corpus callosum, anterior commissure, anterior cingulate, prefrontal cortex, amygdala, and insular cortex. The specific relevance of these structures to alexithymia is discussed. Conclusions. The following conclusions and/or propositions are presented: The right hemisphere produces a global, nonverbal overview of emotional information; the left hemisphere seems dedicated to analysing emotions and higher explicit emotional cognitions. Both orbitoprefrontal cortices are important in affective aspects of alexithymia, while right temporal cortex is involved in cognitive aspects. Two subparts of anterior cingulate fulfil functions in the affective and cognitive dimensions of alexithymia. The amygdalae are involved in both cognitive and affective aspects. All structures mentioned can modulate one another. The role of interhemispheric information transfer via the corpus callosum and the anterior commissure is also discussed. The evidence that that cognitive processing of emotional information inhibits affective processing of such information is discussed in terms of its implications for a theory of alexithymia subtypes.
Psychotherapy and Psychosomatics | 1999
Bob Bermond; Harrie C. M. Vorst; A.J.J.M. Vingerhoets; Welmoet Gerritsen
Background: This article describes the construction and validation of the Amsterdam Alexithymia Scale (AAS) and explores some of the nomological net of alexithymia. Methods: Four correlational studies are presented. The internal structure of the AAS is explored by factor analyses on items. Correlations of the AAS with sex and (Guilford) intellectual abilities are established. Mean scores of three different professional groups are compared. Correlations between the AAS and several clinical and personality scales are determined. Students served as subjects in all studies (347<n<559). Results: The 20-item AAS has a stable 5-factor structure, covering 5 defining features of alexithymia: difficulties in, respectively, experiencing emotions, fantasizing, analyzing emotions, differentiating between emotions and verbalizing emotions. The AAS showed to be reliable. The AAS scores were independent of verbal and nonverbal IQ. As expected, the AAS scores turned out to be significantly lower in a group of dramatic art students and significantly higher in a group of math and artificial intelligence students, when compared to psychology students. The AAS scores correlated negatively with extroversion, positively with social inadequacy and not with neuroticism. Finally, correlations between the AAS and the Adjective Check List scores indicated that alexithymia is associated with, respectively, a neglect of own needs and impulses, a reduced capability to understand social situations and a tendency to stick to rules rigidly, to flee into social isolation, to be submissive, to avoid commitment and to experiences of lack of personal meaning in life. Conclusion: The AAS is the first instrument measuring the 5 defining features of alexithymia reliably and validly.
Journal of Personality and Social Psychology | 2011
Iris A. M. Smits; Conor V. Dolan; Harrie C. M. Vorst; Jelte M. Wicherts; Marieke E. Timmerman
The notion of personality traits implies a certain degree of stability in the life span of an individual. But what about generational effects? Are there generational changes in the distribution or structure of personality traits? This article examines cohort changes on the Big Five personality factors Extraversion, Agreeableness, Conscientiousness, Neuroticism, and Openness to Experience, among first-year psychology students in The Netherlands, ages 18 to 25 years, between 1982 and 2007. Because measurement invariance of a personality test is essential for a sound interpretation of cohort differences in personality, we first assessed measurement invariance with respect to cohort for males and females separately on the Big Five personality factors, as measured by the Dutch instrument Five Personality Factors Test. Results identified 11 (females) and 2 (males) biased items with respect to cohort, out of a total of 70 items. Analyzing the unbiased items, results indicated small linear increases over time in Extraversion, Agreeableness, and Conscientiousness and small linear decreases over time in Neuroticism. No clear patterns were found on the Openness to Experience factor. Secondary analyses on students from 1971 to 2007 of females and males of different ages together revealed linear trends comparable to those in the main analyses among young adults between 1982 onward. The results imply that the broad sociocultural context may affect personality factors.
International Journal of Psychophysiology | 2010
Bob Bermond; Dick J. Bierman; Minke A. Cladder; Peter Paul Moormann; Harrie C. M. Vorst
OBJECTIVE The literature regarding research into alexithymia and sympathetic responses is far from consistent. An explanation might be on the way subjects are classified. Generally, subjects are diagnosed as either alexithymic or non-alexithymic on the basis of questionnaires focusing on the cognitive aspects of alexithymia. However, alexithymia, as originally defined, concerns both emotion-affective and emotion-cognitive deficits. The aim of the present paper is to study the importance of the affective and cognitive alexithymia components in the regulation of sympathetic responses. METHODS Subjects, who scored extremely (either high or low) on both the cognitive and the affective components of alexithymia, were shown neutral and emotional pictures, while their GSR was measured. RESULTS The affective alexithymia component, not the cognitive component, turned out to be an important factor in the regulation of GSR peak amplitude. The results further indicate a significant interaction of type of emotional deficit (cognitive by affective) on GSR latency times. Finally, suggestive evidence indicated that baselines values, defined by the levels during the second preceding the stimulus, are related to the cognitive component of alexithymia, in the sense that higher emotion-cognitive capacities result in higher baseline values. CONCLUSIONS We cautiously conclude that the classification of alexithymics on the basis of both the affective and cognitive components, rather than on the basis of the cognitive component only, might provide more consistent research results, and thus lead to a better understanding of emotional physiological responses in alexithymic subjects.
Applied Psychological Measurement | 2007
A. Michiel Hol; Harrie C. M. Vorst; Gideon J. Mellenbergh
In a randomized experiment (n = 515), a computerized and a computerized adaptive test (CAT) are compared. The item pool consists of 24 polytomous motivation items. Although items are carefully selected, calibration data show that Samejimas graded response model did not fit the data optimally. A simulation study is done to assess possible consequences of model misfit. CAT efficiency was studied by a systematic comparison of the CAT with two types of conventional fixed length short forms, which are created to be good CAT competitors. Results showed no essential administration mode effects. Efficiency analyses show that CAT outperformed the short forms in almost all aspects when results are aggregated along the latent trait scale. The real and the simulated data results are very similar, which indicate that the real data results are not affected by model misfit.
Human Relations | 1978
Johan Hoogstraten; Harrie C. M. Vorst
Three laboratory experiments were done to study the effects of cohesion on task fulfillment and to explore the influence of task fulfillment on the initial level of cohesion. Within four-person groups of freshmen psychology students, cohesion was manipulated successfully by a triple procedure. The level of cohesion was ascertained directly after the induction treatment and again after task fulfillment. Group and individual ability tasks were used in the first and second experiment, while individual learning tasks were used in the third experiment. The hypothesis that cohesion facilitates task performance was partly supported for both individual and group tasks. All eight comparisons of the means favoured the high-cohesion condition; only four of the differences, however, were statistically significant. Performing a group task tended to raise cohesion, whereas individual task performance lowered liking for the group. There were no indications that the findings were a function of a pretest effect of the cohesion questionnaire or the experimenters awareness of the research hypotheses. The facilitating influence of cohesion on task fulfillment was considered a consequence of heightened drive level of group members.