Background: The recommended psychological treatment of choice for obsessive-compulsive disorder (OCD) is exposure with response prevention (ERP). Although this treatment is quite effective, recovery rates are modest and attrition rate is relatively high. Also, ERP treatment requires amounts of therapist time. A possible way to improve OCD treatment is by taking into account key cognitive processes involved in the development and maintenance of the disorder. The metacognitive model is such an account and pilot findings suggest that the associated metacognitive therapy (MCT) might be an effective treatment for OCD.Methods: In the present study, a randomized controlled trial (RCT) is used to assess the effectiveness of MCT in comparison to ERP in an outpatient clinical sample of patients with OCD.Results: Both MCT and ERP produced significant pre-treatment to post-treatment decreases in obsessive -compulsive, comorbid psychological symptoms and metacognitive beliefs, both with moderate to large within -group effect sizes and high proportions of significant clinical change. Drop-out rates were low and treatment gains were maintained at six-month follow-up. There were no differences in efficacy observed between MCT and ERP treatments. Conclusions: MCT proves to be a promising treatment of OCD.

AbstractExperimental studies applying cognitive bias modification of attention (CBM-A) and interpretation (CBM-I) to reduce aggression have examined the effect of modifying each cognitive bias in isolation. In order to maximise the potential impact on both biases and symptom reduction, we examined whether a combined bias training procedure targeting both attention and interpretation biases (CBM-AI) in combination would be more effective than targeting interpretation bias (CBM-I) alone. University students (17–35 years) were randomly assigned to either a single session of CBM-AI training (n = 40), CBM-I training (n = 40), or a control condition (n = 40). Contrary to our expectations, participants showed an increase in adaptive attention and pro-social interpretation bias in all training conditions. Additionally, in none of the conditions, we found a significant change on self-reported or behavioural aggression. These findings suggest: (1) that the combined training did not have added effect over single interpretation bias training, (2) that training interpretation bias may lead to changes in attention bias, (3) that elements of the control condition unexpectedly, but interestingly, also affected attention and interpretation biases, and (4) single-session CBM procedures do not produce robust effects on self-report or behavioural measures of aggression in unselected samples.

BACKGROUND:Mindfulness has become increasingly popular, and positive outcomes have been reported for mindfulness-based interventions (MBIs) in reducing stress. These findings make room for innovative perspectives on how MBIs could be applied, for instance through mobile health (mHealth).OBJECTIVE:The aim of this study is to investigate whether a nonguided mindfulness mobile app can decrease perceived stress in a nonclinical Dutch population over the course of 8 weeks, with follow-up at 6 months.METHODS:A randomized controlled trial was performed to compare an experimental group that made use of a structured 8-week mHealth mindfulness program and a control group after 8 weeks, with follow-up after 6 months. Participants were recruited via a national television program. The primary outcome measure was perceived stress as measured by the Perceived Stress Scale, secondary outcomes were symptoms of burnout (measured using the visual analog scale [VAS]) and psychological symptoms (measured using the Four-Dimensional Symptom Questionnaire [4DSQ] at follow-up). Outcomes were analyzed using a multilevel regression model.RESULTS:At baseline, 587 respondents were included. Results showed no postintervention differences between groups for the level of perceived stress. With regard to the secondary outcome measures, the VAS for emotional exhaustion and physical exhaustion showed significantly lower scores for the experimental group after 8 weeks (P=.04 and P=.01, respectively), but not at follow-up. There were no differences between groups for psychological symptoms measured using the 4DSQ.CONCLUSIONS:These findings do not support our hypothesis that using the mindfulness app would reduce stress levels. However, our findings related to diminished exhaustion at 8 weeks are encouraging and require further investigation.TRIAL REGISTRATION:ClinicalTrials.gov NCT05246800; https://clinicaltrials.gov/show/NCT05246800.

There is abundant evidence suggesting that attention and interpretation biases are powerful precursors of aggression. However, little is known how these biases may interact with one another in the development and maintenance of aggression. Using cognitive bias modification of interpretation (CBM-I), the present study examined whether training more pro-social or hostile intent attributions would affect attention bias, interpretation bias of facial expressions, aggression and mood. University students (17–48 years) were assigned to either a positive training (n = 40), negative training (n = 40), or control training (n = 40). Results showed that the positive training successfully changed measures of intent attributions in a pro-social direction compared to the control training. The negative training changed measures of intent attributions in a hostile direction but not more so than the control training. We found no generalization of the training effects to relevant other outcomes. Possible explanations underlying these findings are discussed.

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, M-age=19.8) and a convenience community sample (N=186; 66% female, M-age=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.

Cognitive theories propose that aggression is associated with specific patterns of attention to social cues, and suggest that cognitive biases in attention and interpretation are interrelated, The current study tested whether these attention patterns can be altered using a single session of a novel gaze-contingent cognitive bias modification paradigm (CBM-A) and assessed the impact of this on interpretation bias, aggressive behavior and mood. University students (18–31 years) were randomly assigned to either a single session of positive training ( n = 40) aimed at increasing attention to pro-social cues, or negative training ( n = 40) aimed at increasing attention to negative cues. Results showed that the positive training indeed resulted in an increase in pro-social attention bias, while the negative training seemed not to have an effect on attention to negative cues. Both groups did not differ on their interpretations, mood levels, self-reported aggression and behavioral aggression. Findings suggest that this novel gaze-contingent CBM-A paradigm can indeed alter biased gaze processes, but may not impact interpretations, aggression and mood. The current study was conducted in a non-clinical sample, further research with a clinical aggressive sample, such as forensic patients is necessary to further explore these issues.

Microchips that operate with light instead of electronics have become a vision that has been a key driver of semiconductor and nano research during the past years. The consequent drive to replace electronic components by photonic devices has reached a level where today’s communication and computation speed limit, as well as their energy consumption appears antiqued. The data capacity of fiber technology has evolved even faster than the downscaling of microchips and provides huge potential especially for short haul and chip-level interconnects in the near future. In contrast, the increasingly problematic of heat dissipation in electronic microchips and rising costs per bit make it very difficult to enhance speed and computing power simply by following constant field scaling. However, the inefficiency of silicon light sources and the incompatibility of the majority of optically active gain materials for the far advanced silicon technology has hindered the integration of efficient light sources on microchips. Offering a solution to this challenge, semiconductor nanowires can be monolithically integrated directly on silicon whilst maintaining the exceptional optical properties of crystalline direct bandgap semiconductors. Furthermore, the optical cavity formed by the unique nanowire geometry, in combination with the nanowire gain material constitutes all the required components for a nano-scale laser. Integrated on silicon, such coherent on-chip light sources could represent a major step towards the realization of chip-level optical interconnects or even photonic computers that, in the next decade, might not only remain a vision. However, the deleterious impact of non-radiative surface recombinations on the optical properties of III-V semiconductors has inhibited the demonstration of nanowire lasers that operate in the technologically important near infrared spectral range. Furthermore, in previous studies, nanowires typically had to be removed from their growth substrate to enable lasing, negating the huge technological advantage of monolithic integration and rendering their integration impractical. Besides their strong potential for future applications, nanowire lasers constitute a unique system that provide entirely new insights into fundamental gain dynamics at the ultimate downscaling limit of photonic lasers. Although, lasing operation of nanowires has been demonstrated from a broad range of material systems, coherent light-matter interactions within nanowire lasers have not received significant attraction. This thesis demonstrates how GaAs based nanowires are carefully designed to achieve lasing operation in the near infrared spectral range. The presented results demonstrate the first observation of room temperature lasing from GaAs nanowire lasers subject to pulsed optical excitation. Experiments using continuous optical pumping demonstrate continuous wave operation and show spectral linewidths below 200meV. Investigations of the gain and photon dynamics of the nanowire lasers reveal a novel mechanism that allows long-term mutual phase locking of picosecond pulse pairs and potential operation at modulation frequencies >200GHz. Finally, a novel nanowire laser geometry that allows the monolithic integration of nanowire lasers onto silicon microchips is introduced, successfully demonstrated in experiments and has been submitted as patent application. The exceptional properties of GaAs nanowire lasers combined with their unique ability for monolithic integration onto silicon provide nanowire lasers with the potential to impact a broad range of integrated optoelectronic technologies and could be a step along the road toward the vision of photonic microchips.

The ability to generate phase-stabilized trains of ultrafast laser pulses by mode-locking underpins photonics research in fields, such as precision metrology and spectroscopy. However, the complexity of conventional mode-locked laser systems has hindered their realization at the nanoscale. Here we demonstrate that GaAs-AlGaAs nanowire lasers are capable of emitting pairs of phase-locked picosecond laser pulses with a repetition frequency up to 200 GHz when subject to incoherent pulsed optical excitation. By probing the two-pulse interference spectra, we show that pulse pairs remain mutually coherent over timescales extending to 30 ps, much longer than the emitted laser pulse duration (≤3 ps). Simulations performed by solving the optical Bloch equations produce good quantitative agreement with experiments, revealing how the phase information is stored in the gain medium close to transparency. Our results open the way to phase locking of nanowires integrated onto photonic circuits, optical injection locking and applications, such as on-chip Ramsey comb spectroscopy.

The present study examined the relationship between worry and threat-related confirmation bias in children. Forty non-clinical children aged 10–12 years completed the child version of the Penn State Worry Questionnaire as a cognitive index of anxiety proneness, and then were administered a modified version of the Wason Selection Task to assess verifying and falsifying reasoning strategies in response to conditional danger rules. Results demonstrated that children with high levels of worry displayed a stronger tendency towards verification and a weaker inclination towards falsification than children with low levels of worry. This finding indicates that confirmation bias occurs in individuals with a general vulnerability to anxiety, and fits well with current theoretical models in which cognitive distortions are viewed as risk factors predisposing to the development of fear and anxiety problems.

This study examined behavioral inhibition and overprotective parenting as correlates and predictors of anxiety disorder symptoms in preschoolers with a multi-cultural background (N=168). Parents of 3- to 6-year-old children completed a set of questionnaires twice, 12 months apart. Parents were also interviewed with the Anxiety Disorders Interview Schedule for DSM-IV at the 12-month point to assess the clinical severity of children's anxiety symptoms. Behavioral inhibition consistently emerged as a significant concurrent correlate of anxiety symptoms and this was particularly true for social anxiety symptoms. Overprotective parenting also emerged as a significant correlate of anxiety, but only in the case of non-social anxiety symptoms and mainly in non-native Dutch children. Prospective analyses revealed that behavioral inhibition was a significant predictor of social anxiety symptoms, while overprotective parenting did not explain significant variance in the development of children's anxiety over time. The support for an interactive effect of behavioral inhibition and overprotective parenting was unconvincing. Finally, it was found that children who exhibited stable high levels of behavioral inhibition throughout the study ran the greatest risk for developing an anxiety disorder.

This study examined parent-offspring communication of disgust-related information and its effects on children's feelings of disgust and fear towards an animal. Mothers were instructed to provide information about a novel animal to their children (N=60) by studying in secrecy either disgusting or neutral attributes that were allegedly characteristic of this animal. First, mothers were instructed to do this in a nonverbal way; then they were also allowed to use verbal utterances. Results indicated that nonverbal communication of disgust by the mothers failed to produce any effects on offspring's subjective evaluations of the animal. However, verbal information transmission did have a differential impact on children's feelings of disgust and fear. That is, children to whom mothers had verbally communicated about a set of disgusting specimens not only displayed higher levels of disgust (Cohen's d=1.02) but also exhibited higher levels of fear (Cohen's d=.62) towards the novel animal as compared to children to whom mothers had verbally communicated about neutral specimens. The effect on fear was mainly due to the fact that children after the verbal neutral information exhibited a clear decline in fear, whereas children to whom mothers had provided verbal disgust information maintained a similar level of fear towards the animal. The implications of these results for the familial transmission of disgust and fear will be discussed.

The Behavioral Inhibition Questionnaire-Short Form (BIQ-SF) is a 14-item parent-rating scale for assessing an inhibited, anxiety-prone temperament in preschool children. This study examined the psychometric properties of the BIQ-SF scores in a multi-ethnic community population of Dutch boys and girls aged 2.5-6 years (total N = 2,343, from which various subsamples were derived). Results revealed that the factor structure of the BIQ-SF was as hypothesized: a model with six correlated factors representing children's inhibited behaviors in various social and non-social contexts provided a good fit for the data. The internal consistency of the BIQ-SF was generally satisfactory and scores on the scale were found to be fairly stable over a time period of up to 2 years. Parent-teacher agreement was acceptable, and relations between the BIQ-SF and observations of an inhibited temperament were moderate. Finally, BIQ-SF scores were positively associated with measures of anxiety and internalizing symptoms, whereas no significant links were found with externalizing symptoms. Altogether, these results provide support for the reliability and validity of the BIQ-SF as an economical method for assessing behavioral inhibition and anxiety proneness in young children.

The present study examined the psychometric properties of the Disgust Emotion Scale for Children (DES-C). Principal components analysis of the DES-C data revealed five factors reflecting disgust toward (a) rotting foods, (b) injection and blood, (c) odors, (d) mutilation and death, and (e) animals, which were largely in keeping with the intended subscales. The DES-C showed good reliability, excellent convergent validity (as established by correlations with an alternative self-report index of disgust), fairly good predictive validity (as assessed by correlations with measures of fear/anxiety and a behavioral index of disgust), and acceptable parent-child agreement (in particular with the mothers). Importantly, the DES-C proved to perform better on some psychometric indicators than an age-downward version of the Disgust Scale. These findings indicate that the DES-C should be regarded as the preferred scale for measuring disgust sensitivity and its role in the etiology and maintenance of anxiety problems in children.

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. (c) 2012 Elsevier Ltd. All rights reserved.