Background Previous studies have used network models to investigate how PTSD symptoms associate with each other. However, analyses examining the degree to which these networks are stable over time... Show moreBackground Previous studies have used network models to investigate how PTSD symptoms associate with each other. However, analyses examining the degree to which these networks are stable over time, which are critical to identifying symptoms that may contribute to the chronicity of this disorder, are scarce. In the current study, we evaluated the temporal stability of DSM-5 PTSD symptom networks over a three-year period in a nationally representative sample of trauma-exposed U.S. military veterans. Methods Data were analyzed from 611 trauma-exposed U.S. military veterans who participated in the National Health and Resilience in Veterans Study (NHRVS). We estimated regularized partial correlation networks of DSM-5 PTSD symptoms at baseline (Time 1) and at three-year follow-up (Time 2), and examined their temporal stability. Results Evaluation of the network structure of PTSD symptoms at Time 1 and Time 2 using a formal network comparison indicated that the Time 1 network did not differ significantly from the Time 2 network with regard to network structure (p = 0.12) or global strength (sum of all absolute associations, i.e. connectivity; p = 0.25). Centrality estimates of both networks (r = 0.86) and adjacency matrices (r = 0.69) were highly correlated. In both networks, avoidance, intrusive, and negative cognition and mood symptoms were among the more central nodes. Limitations This study is limited by the use of a self-report instrument to assess PTSD symptoms and recruitment of a relatively homogeneous sample of predominantly older, Caucasian veterans. Conclusion Results of this study demonstrate the three-year stability of DSM-5 PTSD symptom network structure in a nationally representative sample of trauma-exposed U.S. military veterans. They further suggest that trauma-related avoidance, intrusive, and dysphoric symptoms may contribute to the chronicity of PTSD symptoms in this population. Show less
In-course assessment, such as midterms, quizzes or presentations, is often an integral part of higher education courses. These so-called intermediate assessments influence students’ final grades.... Show moreIn-course assessment, such as midterms, quizzes or presentations, is often an integral part of higher education courses. These so-called intermediate assessments influence students’ final grades. The current review investigates which characteristics of intermediate assessment relate to these grades. In total, 88 articles were reviewed that examined the relationship between intermediate assessment and student grades. Four main characteristics were identified: the use of feedback, whether the assessment is mandatory, who is the assessor, and the reward students get for participating. Results indicate that corrective feedback leads to the most positive results, but elaborate feedback may benefit lower achieving groups. No difference in results was found for mandatory versus voluntary intermediate assessments. Peer assessment seemed to be beneficial, and rewarding students with course credit improves grades more than other rewards. Three scenarios are presented on how teachers can combine the different characteristics to optimise their intermediate assessment. Show less
When misfortune befalls another, humans may feel distress, leading to a motivation to escape. When such misfortune is perceived as justified, however, it may be experienced as rewarding and lead to... Show moreWhen misfortune befalls another, humans may feel distress, leading to a motivation to escape. When such misfortune is perceived as justified, however, it may be experienced as rewarding and lead to motivation to witness the misfortune. We explored when in human ontogeny such a motivation emerges and whether the motivation is shared by chimpanzees. Chimpanzees and four- to six-year-old children learned through direct interaction that an agent was either prosocial or antisocial and later saw each agent’s punishment. They were given the option to invest physical effort (chimpanzees) or monetary units (children) to continue watching. Chimpanzees and six-year-olds showed a preference for watching punishment of the antisocial agent. An additional control experiment in chimpanzees suggests that these results cannot be attributed to more generic factors such as scene coherence or informational value seeking. This indicates that both six-year-olds and chimpanzees have a motivation to watch deserved punishment enacted. Show less
The fact that tyrosine increases dopamine availability that, in turn, may enhance cognitive performance has led to numerous studies on healthy young participants taking tyrosine as a food... Show moreThe fact that tyrosine increases dopamine availability that, in turn, may enhance cognitive performance has led to numerous studies on healthy young participants taking tyrosine as a food supplement. As a result of this dietary intervention, participants show performance increases in working memory and executive functions. However, the potential association between habitual dietary tyrosine intake and cognitive performance has not been investigated to date. The present study aims at clarifying the association of episodic memory (EM), working memory (WM) and fluid intelligence (Gf), and tyrosine intake in younger and older adults. To this end, we acquired habitual tyrosine intake (food frequency questionnaire) from 1724 participants of the Berlin Aging Study II (1383 older adults, 341 younger adults) and modelled its relations to cognitive performance assessed in a broad battery of cognitive tasks using structural equation modeling. We observed a significant association between tyrosine intake and the latent factor capturing WM, Gf, and EM in the younger and the older sample. Due to partial strong factorial invariance between age groups for a confirmatory factor analysis on cognitive performance, we were able to compare the relationship between tyrosine and cognition between age groups and found no difference. Above and beyond previous studies on tyrosine food supplementation the present result extend this to a cross-sectional association between habitual tyrosine intake levels in daily nutrition and cognitive performance (WM, Gf, and EM). This corroborates nutritional recommendations that are thus far derived from single-dose administration studies. Show less
Background It was recently demonstrated that a significant number of patients with common skin diseases across Europe are clinically depressed and anxious. Studies have shown that physicians not... Show moreBackground It was recently demonstrated that a significant number of patients with common skin diseases across Europe are clinically depressed and anxious. Studies have shown that physicians not trained as psychiatrists underdiagnose depression. This has not been explored among dermatologists. Objectives To estimate the concordance between clinical assessment of depression and anxiety by a dermatologist and assessment with the Hospital Anxiety and Depression Scale (HADS). Methods The study was an observational cross‐sectional multicentre study of prevalent cases of skin diseases in 13 countries in Europe. Consecutive patients were recruited in outpatient clinics and filled in questionnaires prior to clinical examination by a dermatologist who reported any diagnosis of skin disease and signs of mood disorders.ResultsAnalysis of the 3635 consultations showed that the agreement between dermatologist and HADS was poor to fair (lower than 0·4) for all diagnosis categories. The true‐positive rate (represented by the percentage of dermatologists recognizing signs of depression or anxiety in patients with depression or anxiety as defined by a HADS value ≥ 11) was 44·0% for depression and 35·6% for anxiety. The true negative rate (represented by the percentage of dermatologists not detecting signs of depression or anxiety in non‐depressed or non‐anxious patients defined by HADS‐value < 11) was 88.8% for depression and 85.7% for anxiety.ConclusionsDermatologists in Europe tend to underestimate mood disorders. The results suggest that further training for dermatologists to improve their skills in diagnosing depression and anxiety might be appropriate. When present, the psychological suffering of patients with dermatological conditions needs to be addressed. Show less
Klaassens, B.L.; Gerven, J.M.A. van; Klaassen, E.S.; Grond, J. van der; Rombouts, S.A.R.B. 2017
Aging is accompanied by changes in neurotransmission. To advance our understanding of how aging modifies specific neural circuitries, we examined serotonergic and cholinergic stimulation with... Show moreAging is accompanied by changes in neurotransmission. To advance our understanding of how aging modifies specific neural circuitries, we examined serotonergic and cholinergic stimulation with resting state functional magnetic resonance imaging (RS-fMRI) in young and older adults. The instant response to the selective serotonin reuptake inhibitor citalopram (30 mg) and the acetylcholinesterase inhibitor galantamine (8 mg) was measured in 12 young and 17 older volunteers during a randomized, double blind, placebo-controlled, crossover study. A powerful dataset consisting of 522 RS-fMRI scans was obtained by acquiring multiple scans per subject before and after drug administration. Group × treatment interaction effects on voxelwise connectivity with ten functional networks were investigated (p < .05, FWE-corrected) using a non-parametric multivariate analysis technique with cerebrospinal fluid, white matter, heart rate and baseline measurements as covariates. Both groups showed a decrease in sensorimotor network connectivity after citalopram administration. The comparable findings after citalopram intake are possibly due to relatively similar serotonergic systems in the young and older subjects. Galantamine altered connectivity between the occipital visual network and regions that are implicated in learning and memory in the young subjects. The lack of a cholinergic response in the elderly might relate to the well-known association between cognitive and cholinergic deterioration at older age. Show less
We examined conservative ideological shift among adolescents by assessing the effect of different types of threat on the self-reported political orientation of 183 New York City high school... Show moreWe examined conservative ideological shift among adolescents by assessing the effect of different types of threat on the self-reported political orientation of 183 New York City high school students and investigated the mediating role of system justification. Participants read one of three newspaper passages: (1) a system-related passage that described flaws in the American social, economic, and political system; (2) a self-related passage that described the deleterious health effects of cell phone use; or (3) a control passage that described house plant cultivation. Participants then completed measures of system justification and political orientation. As hypothesized, a threat to the system (but not the self) increased self-reported conservatism indirectly through its effect on system justification. This suggests that when the overarching social system is threatened, adolescents may be drawn to conservative ideology and that this is attributable, at least in part, to a heightened desire to defend and bolster the societal status quo. Show less
Kant, A. van der; Huijbregts, S.C.J.; Levelt, C.C.; Biro, S. 2017
Both social perception and temperament in young infants have been related to social functioning later in life. Previous functional Near-Infrared Spectroscopy (fNIRS) data (Lloyd-Fox et al., 2009)... Show moreBoth social perception and temperament in young infants have been related to social functioning later in life. Previous functional Near-Infrared Spectroscopy (fNIRS) data (Lloyd-Fox et al., 2009) showed larger blood-oxygenation changes for social compared to non-social stimuli in the posterior temporal cortex of five-month-old infants. We sought to replicate and extend these findings by using fNIRS to study the neural basis of social perception in relation to infant temperament (Negative Affect) in 37 five-to-eight-month-old infants.Infants watched short videos displaying either hand and facial movements of female actors (social dynamic condition) or moving toys and machinery (non-social dynamic condition), while fNIRS data were collected over temporal brain regions. Negative Affect was measured using the Infant Behavior Questionnaire.Results showed significantly larger blood-oxygenation changes in the right posterior-temporal region in the social compared to the non-social condition. Furthermore, this differential activation was smaller in infants showing higher Negative Affect.Our results replicate those of Lloyd-Fox et al. and confirmed that five-to-eight-month-old infants show cortical specialization for social perception. Furthermore, the decreased cortical sensitivity to social stimuli in infants showing high Negative Affect may be an early biomarker for later difficulties in social interaction. Show less
Hout, M.A. van den; Dis, E.A.M. van; Woudenberg, C. van; Groep, I.H. van de 2017
Van den Hout and Kindt (2003a) developed a Virtual Gas Stove Checking paradigm. They demonstrated that repeated checking resulted in lower confidence and reduced the vividness and detail of... Show moreVan den Hout and Kindt (2003a) developed a Virtual Gas Stove Checking paradigm. They demonstrated that repeated checking resulted in lower confidence and reduced the vividness and detail of recollections. Over the past decades, many experiments have used (an adaptation of) this experimental paradigm to study phenomena related to obsessive compulsive disorders (OCD). The first aim of the present study was to conduct a meta-analysis of experiments (k = 28; N = 1662) on the repeated checking paradigm. Repeated checking was found to have large effects on decreases in memory confidence, vividness and detail. Unexpectedly, repeated checking also produced small reductions in memory accuracy. The second aim of the present study was to develop an improved version of the checking paradigm in which 1) stimuli presentations were fully balanced; and 2) the checking latency was comparable across stimuli in order to 3) assess actual checking behavior. The improved version (Virtual checking task 2.0) replicated earlier findings on meta-memory. Show less
