Abnormal Parietal Function in Conversion Paresis

The etiology of medically unexplained symptoms such as conversion disorder is poorly understood. This is partly because the interpretation of neuroimaging results in conversion paresis has been complicated by the use of different control groups, tasks and statistical comparisons. The present study includes these different aspects in a single data set. In our study we included both normal controls and feigners to control for conversion paresis. We studied both movement execution and imagery, and we contrasted both within-group and between-group activation. Moreover, to reveal hemisphere-specific effects that have not been reported before, we performed these analyses using both flipped and unflipped data. This approach resulted in the identification of abnormal parietal activation which was specific for conversion paresis patients. Patients also showed reduced activity in the prefrontal cortex, supramarginal gyrus and precuneus, including hemisphere-specific activation that is lateralized in the same hemisphere, regardless of right- or left-sided paresis. We propose that these regions are candidates for an interface between psychological mechanisms and disturbed higher-order motor control. Our study presents an integrative neurophysiological view of the mechanisms that contribute to the etiology of this puzzling psychological disorder, which can be further investigated with other types of conversion symptoms

Working mechanisms of virtual reality based cbt for paranoia:A randomized controlled trial examining cognitive biases, schematic beliefs and safety behavior

Background: Recently, the efficacy of a novel virtual reality based cognitive behavior therapy (VR-CBT) for paranoia was demonstrated. Cognitive biases, cognitive limitations, negative schematic beliefs and safety behavior have been associated with paranoid ideations and delusions. It is unknown whether VR-CBT affects these associated factors, and how changes in these factors relate to changes in paranoid ideation. Methods: In this multi-center randomized controlled trial patients with a psychotic disorder and paranoia were randomized to VR-CBT (n = 58) or treatment as usual (TAU; n = 58). VR-CBT consisted of maximally sixteen 60-minute individual therapy sessions. Paranoia, safety behavior, schematic beliefs, cognitive biases and limitations were assessed at baseline, post-treatment (at three months) and follow-up (at six months). Mixed model analyses were conducted to study treatment effects. Mediation analyses were performed to explore putative working mechanisms by which VR-CBT reduced paranoia. Results: VR-CBT, but not TAU, led to reductions in jumping to conclusions, attention for threat bias and social cognition problems. Schematic beliefs remained unaffected. The effect of VR-CBT on paranoia was mediated by reductions in safety behavior and social cognition problems. Discussion: VR-CBT affects multiple mechanisms that are associated with paranoid ideation. Although maintaining factors of paranoia are likely to influence each other, targeting safety behavior and social cognitive problems seems effective in breaking the vicious circle of paranoia

Functional (psychogenic) movement disorders associated with normal scores in psychological questionnaires:A case control study

AbstractObjectiveFunctional movement disorders (FMDs) fall within the broader category called functional neurological symptom disorder (FNSD). New DSM-5 criteria for FNSD no longer require the presence of a ‘psychological conflict’ suggesting that some patients with FMD may not have obvious psychological comorbidity. We studied patients with FMD in comparison to patients with a neurological movement disorder (MD) and healthy controls (HC) to identify whether there is a subgroup of patients with FMD who have normal psychological test scores.MethodsWe assessed self-rated measures of depression/anxiety (SCL-90), dissociation and personality disorder (PDQ-4) in patients attending neurological clinics and healthy controls. The proportion of patients scoring within normal ranges was determined, and the levels of somatic and psychological symptoms were compared between the three groups.ResultsAmong the FMD group, 39% (20/51) scored within the normal range for all measures compared to 38% (13/34) of MD subjects and 89% (47/53) of healthy controls. There were no differences in overall scores in the SCL-90 and PDQ-4 between FMD and MD patients. FMD patients also did not differ from controls on a self-rated measure of personality pathology.ConclusionOur data show that a substantial proportion of patients with FMD score within the normal range in psychological questionnaires, lending some support to the new DSM-5 criteria

Correction to: Spontaneous discontinuation of distressing auditory verbal hallucinations in a school-based sample of adolescents:A longitudinal study

In the Original Publication Table 2 was incorrectly published. The correct table is given below

Virtual reality based cognitive behavioral therapy for paranoia:Effects on mental states and the dynamics among them

Background: Negative affective processes may contribute to maintenance of paranoia in patients with psychosis, and vice versa. Successful treatment may break these pathological symptom networks. This study examined whether treatment with virtual reality based cognitive behavioral therapy (VR-CBT) for paranoia influences momentary affective states, and whether VR-CBT changes the adverse interplay between affective states and paranoia. Methods: Patients with a psychotic disorder (n = 91) were randomized to 16-session VR-CBT or treatment as usual (TAU). With the experience sampling method (structured diary technique) mental states were assessed for 6–10 days at baseline, posttreatment and 6-month follow-up. Multilevel analysis were performed to establish treatment effects and time-lagged associations between mental states, that were visualized with networks of mental states. Results: Average levels of paranoia (feeling suspicious [b = −032., p = .04], disliked [b = −49., p < .01] and hurt [b = −0.52, p < .01]) and negative affect (anxious [b = −0.37, p = .01], down [b = −0.33, p = .04] and insecure [b = −0.17, p = .03) improved more after VR-CBT than TAU, but positive affect did not. Baseline mental state networks had few significant connections, with most stable connections being autocorrelations of mental states. The interplay between affective states and paranoia did not change in response to treatment. A trend reduction in average intranode connections (autocorrelations) was found after VR-CBT (b = −0.07, p = .08), indicating that mental states reinforce themselves less after treatment. Conclusions: VR-CBT reduced paranoid symptoms and lowered levels of negative affect in daily life, but did not affect the extent to which mental states influenced each other. Findings do suggest that as a result of treatment mental states regain flexibility

Spontaneous discontinuation of distressing auditory verbal hallucinations in a school-based sample of adolescents:a longitudinal study

Auditory verbal hallucinations (AVH) can be transiently present in both clinical and healthy adolescent populations. It is not yet fully understood why AVH discontinue in some adolescents and persist in others. The aim of this explorative study is to investigate predictors of spontaneous discontinuation of distressing AVH in a school-based sample of adolescents. 1841 adolescents (mean age 12.4 years, 58% female) completed self-report questionnaires at baseline. The current study included 123 adolescents (7%; 63% female) who reported at least mild distressing AVH at baseline and completed follow-up measurements. LASSO analyses were used to uncover predictors of spontaneous discontinuation of distressing AVH. During follow-up, 43 adolescents (35%) reported having experienced distressing AVH during the last 12 months, while 80 adolescents did not. Spontaneous discontinuation of distressing AVH was predicted by never having used cannabis, parents not being divorced in the past year, never having been scared by seeing a deceased body, less prosocial behaviour, school grade repetition, having the feeling that others have it in for you, having anxiety when meeting new people, having lived through events exactly as if they happened before and having the feeling as if parts of the body have changed. No associations between spontaneous discontinuation of distressing AVH and age or ethnicity were found. Distressing AVH in non-clinical adolescents are mostly transient. Discontinuation was predicted up to a certain extent. However, several predictors were difficult to interpret and do not provide leads for preventive measures, except for discouraging cannabis use.</p

Executive Functioning in Daily Life in Parkinson's Disease: Initiative, Planning and Multi-Task Performance

Impairments in executive functioning are frequently observed in Parkinson's disease (PD). However, executive functioning needed in daily life is difficult to measure. Considering this difficulty the Cognitive Effort Test (CET) was recently developed. In this multi-task test the goals are specified but participants are free in their approach. This study applies the CET in PD patients and investigates whether initiative, planning and multi-tasking are associated with aspects of executive functions and psychomotor speed. Thirty-six PD patients with a mild to moderate disease severity and thirty-four healthy participants were included in this study. PD patients planned and demonstrated more sequential task execution, which was associated with a decreased psychomotor speed. Furthermore, patients with a moderate PD planned to execute fewer tasks at the same time than patients with a mild PD. No differences were found between these groups for multi-tasking. In conclusion, PD patients planned and executed the tasks of the CET sequentially rather than in parallel presumably reflecting a compensation strategy for a decreased psychomotor speed. Furthermore, patients with moderate PD appeared to take their impairments into consideration when planning how to engage the tasks of the test. This compensation could not be detected in patients with mild PD

Attentional Window Set by Expected Relevance of Environmental Signals

The existence of an attentional window—a limited region in visual space at which attention is directed—has been invoked to explain why sudden visual onsets may or may not capture overt or covert attention. Here, we test the hypothesis that observers voluntarily control the size of this attentional window to regulate whether or not environmental signals can capture attention. We have used a novel approach to test this: participants eye-movements were tracked while they performed a search task that required dynamic gaze-shifts. During the search task, abrupt onsets were presented that cued the target positions at different levels of congruency. The participant knew these levels. We determined oculomotor capture efficiency for onsets that appeared at different viewing eccentricities. From these, we could derive the participant's attentional window size as a function of onset congruency. We find that the window was small during the presentation of low-congruency onsets, but increased monotonically in size with an increase in the expected congruency of the onsets. This indicates that the attentional window is under voluntary control and is set according to the expected relevance of environmental signals for the observer's momentary behavioral goals. Moreover, our approach provides a new and exciting method to directly measure the size of the attentional window

Effects of Visual Priming on Taste-Odor Interaction

Little is known about the influence of visual characteristics other than colour on flavor perception, and the complex interactions between more than two sensory modalities. This study focused on the effects of recognizability of visual (texture) information on flavor perception of odorized sweet beverages

Measuring executive functioning in schizophrenia: clinical implications

De laatste jaren worden in de psychiatrische diagnostiek steeds vaker neuropsychologische tests toegepast. Bij onder andere schizofrenie zijn cognitieve tekorten vastgesteld en de individuele patiënt wordt dan ook steeds vaker cognitief onderzocht. Neuropsychologische tests zijn oorspronkelijk ontwikkeld bij neurologische patiënten met structurele laesies. Nu deze methoden toegepast worden op patiënten waarbij functionele (dat wil zeggen neurochemische en fysiologische) afwijkingen in het brein op de voorgrond staan, wordt belangrijk te onderzoeken of de klassieke neuropsychologische test ook hier bruikbaar is, en zo ja, of de tests op dezelfde wijze geïnterpreteerd kan worden. In dit proefschrift wordt deze vraag met name wat betreft het gebied van de executieve functies (planning en regulatie) onderzocht. De aard van de cognitieve functiestoornissen bij schizofrenie en het meten van de tekorten in de executieve functies staan hierin centraal. Bij het testen van de executieve functies is het belangrijk om na te gaan of de tests bij schizofrenie hetzelfde meten als bij neurologische patiëntengroepen. Ook de relatie met de problemen in het sociaal functioneren komt aan bod: is het sociaal functioneren te voorspellen met bestaande cognitieve tests? Zie: Samenvatting.