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Werner Strik

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10 papers

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YNIMG Journal 2025 Journal Article

7 tesla multiscale entropy analysis reveals increased resting-state complexity in key regions for fear and anxiety in spider-fearful individuals

Matthias Grieder
Niklaus Denier
Kay Jann
Werner Strik
Leila M. Soravia
Kristina Adorjan
Marcel Meyer
Elisabeth Jehli

Resting-state functional connectivity is limited in assessing the temporal dynamics of brain networks and, due to an insufficient signal-to-noise ratio, in detecting subtle changes at 3T MRI. Nonetheless, measures of complexity, which capitalize on temporal dynamics, have revealed alterations for some affective disorders at this field strength. Anxiety disorders have received only scant attention in this regard, despite indications of altered functional brain architecture in spider-fearful participants (SP). To address this gap, we probed resting-state complexity using 7T MRI, comparing 28 adults with SP with 45 healthy controls (HC). We computed multiscale entropy (MSE) on ten scales (1 - 0.1 Hz) for brain regions of the fear and anxiety networks in HC and SP. The MSE scales interacted with group (HC, SP) and brain area, revealing MSE increments in limbic regions in SP (versus HC). Whilst most MSE changes related to SP ranged between 1 and 0.33 Hz, the MSE of the bed nucleus of the stria terminalis (BNST), a nucleus involved in anxiety and the hormonal system, exhibited increases on all scales bar two for SP (i.e., for 0.5 - 0.125, and 0.1 Hz). MSE was also positively associated with SP severity (but not trait anxiety) in the BNST. Altogether, 7T fMRI detected elevated MSE in SP, indicating excessive intra-regional processing in brain regions key to fear and anxiety. The most pronounced effects were found in the BNST, corroborating its central role in the anxiety circuit.

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YNICL Journal 2020 Journal Article

Subclinical paranoid beliefs and enhanced neural response during processing of unattractive faces

Stephan Furger
Antje Stahnke
Francilia Zengaffinen
Andrea Federspiel
Yosuke Morishima
Martina Papmeyer
Roland Wiest
Thomas Dierks

The perception of faces and consequent social inferences are fundamental for interpersonal communication. While facial expression is important for interindividual communication, constitutional and acquired features are crucial for basic emotions of attraction or repulsion. An emotional bias in face processing has been shown in schizophrenia, but the neurobiological mechanisms are unclear. Studies on the interaction between face processing and the emotional state of healthy individuals may help to elucidate the pathogenesis of the paranoid syndrome in psychosis. This study addressed facial attractiveness and paranoid ideas in a non-clinical population. Using functional magnetic resonance imaging (fMRI), we investigated neural activation patterns of 99 healthy subjects during the passive perception of a dynamic presentation of faces with different attractiveness. We found that the perceived attractiveness of faces was linked to the activity of face processing and limbic regions including the fusiform gyrus, amygdala, and prefrontal areas. Paranoid beliefs interacted with perceived attractiveness in these regions resulting in a higher response range and increased activation after the presentation of unattractive faces. However, no behavioral interactions between reported subjective attractiveness and paranoid beliefs were found. The results showed that increased activation of limbic brain regions is linked to paranoid beliefs. Since similar correlations were found in clinical populations with paranoid syndromes, we suggest a dimension of emotional dysregulation ranging from subclinical paranoid beliefs to paranoid schizophrenia.

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YNICL Journal 2019 Journal Article

Increased structural connectivity of the medial forebrain bundle in schizophrenia spectrum disorders is associated with delusions of paranoid threat and grandiosity

Tobias Bracht
Petra V. Viher
Katharina Stegmayer
Werner Strik
Andrea Federspiel
Roland Wiest
Sebastian Walther

In many cases delusions in schizophrenia spectrum disorders (SSD) are driven by strong emotions such as feelings of paranoia or grandiosity. We refer to these extreme emotional experiences as psychotic affectivity. We hypothesized that increased structural connectivity of the supero-lateral medial forebrain bundle (slMFB), a major tract of the reward system, is associated with delusional psychotic affectivity. Forty-six patients with SSD and 44 healthy controls (HC) underwent diffusion weighted magnetic resonance imaging (DW-MRI)-scans. The slMFB and a comparison tract (corticospinal tract) were reconstructed using diffusion tensor imaging (DTI)-based tractography. Fractional anisotropy (FA) was sampled across the tracts. We used a mixed-model analyses of variance controlling for age and gender to compare FA of bilateral slMFB between SSD-patients and HC. Correlations of FA of bilateral slMFB and the PANSS-positive item delusions were calculated. In addition, FA was compared between three clinically homogeneous SSD-subgroups in terms of psychotic affectivity (severe, mild and no PA, sPA, mPA, nPA) and HC. FA of the slMFB did not differ between all SSD-patients and HC. In SSD-patients there was a positive correlation between delusions and FA in bilateral slMFB. Likewise, SSD-subgroups of psychotic affectivity and HC differed significantly in FA of the slMFB. Results were driven by higher FA in the right slMFB in sPA as compared to nPA and to HC. There was no significant effect for the comparison tract. In conclusion, increased structural connectivity of the slMFB may underlie delusional experiences of paranoia and grandiosity in SSD.

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YNICL Journal 2018 Journal Article

The cortical signature of impaired gesturing: Findings from schizophrenia

Petra Verena Viher
Katharina Stegmayer
Marek Kubicki
Sarina Karmacharya
Amanda Ellis Lyall
Andrea Federspiel
Tim Vanbellingen
Stephan Bohlhalter

Schizophrenia is characterized by deficits in gesturing that is important for nonverbal communication. Research in healthy participants and brain-damaged patients revealed a left-lateralized fronto-parieto-temporal network underlying gesture performance. First evidence from structural imaging studies in schizophrenia corroborates these results. However, as of yet, it is unclear if cortical thickness abnormalities contribute to impairments in gesture performance. We hypothesized that patients with deficits in gesture production show cortical thinning in 12 regions of interest (ROIs) of a gesture network relevant for gesture performance and recognition. Forty patients with schizophrenia and 41 healthy controls performed hand and finger gestures as either imitation or pantomime. Group differences in cortical thickness between patients with deficits, patients without deficits, and controls were explored using a multivariate analysis of covariance. In addition, the relationship between gesture recognition and cortical thickness was investigated. Patients with deficits in gesture production had reduced cortical thickness in eight ROIs, including the pars opercularis of the inferior frontal gyrus, the superior and inferior parietal lobes, and the superior and middle temporal gyri. Gesture recognition correlated with cortical thickness in fewer, but mainly the same, ROIs within the patient sample. In conclusion, our results show that impaired gesture production and recognition in schizophrenia is associated with cortical thinning in distinct areas of the gesture network.

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YNICL Journal 2016 Journal Article

Cerebral white matter structure is associated with DSM-5 schizophrenia symptom dimensions

Petra V. Viher
Katharina Stegmayer
Stéphanie Giezendanner
Andrea Federspiel
Stephan Bohlhalter
Tim Vanbellingen
Roland Wiest
Werner Strik

Diffusion tensor imaging (DTI) studies have provided evidence of widespread white matter (WM) abnormalities in schizophrenia. Although these abnormalities appear clinically significant, the relationship to specific clinical symptoms is limited and heterogeneous. This study examined the association between WM microstructure and the severity of the five main DSM-5 schizophrenia symptom dimensions. DTI was measured in forty patients with schizophrenia spectrum disorders. Using Tract-Based Spatial Statistics controlling for age, gender and antipsychotic dosage, our analyses revealed significant negative relationships between WM microstructure and two DSM-5 symptom dimensions: Whereas abnormal psychomotor behavior was particularly related to WM of motor tracts, negative symptoms were associated with WM microstructure of the prefrontal and right temporal lobes. However, we found no associations between WM microstructure and delusions, hallucinations or disorganized speech. These data highlight the relevance of characteristic WM disconnectivity patterns as markers for negative symptoms and abnormal psychomotor behavior in schizophrenia and provide evidence for relevant associations between brain structure and aberrant behavior.

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YNIMG Journal 2015 Journal Article

Rivalry of homeostatic and sensory-evoked emotions: Dehydration attenuates olfactory disgust and its neural correlates

Lea Meier
Hergen Friedrich
Andrea Federspiel
Kay Jann
Yosuke Morishima
Basile Nicolas Landis
Roland Wiest
Werner Strik

Neural correlates have been described for emotions evoked by states of homeostatic imbalance (e. g. thirst, hunger, and breathlessness) and for emotions induced by external sensory stimulation (such as fear and disgust). However, the neurobiological mechanisms of their interaction, when they are experienced simultaneously, are still unknown. We investigated the interaction on the neurobiological and the perceptional level using subjective ratings, serum parameters, and functional magnetic resonance imaging (fMRI) in a situation of emotional rivalry, when both a homeostatic and a sensory-evoked emotion were experienced at the same time. Twenty highly dehydrated male subjects rated a disgusting odor as significantly less repulsive when they were thirsty. On the neurobiological level, we found that this reduction in subjective disgust during thirst was accompanied by a significantly reduced neural activity in the insular cortex, a brain area known to be considerably involved in processing of disgust. Furthermore, during the experience of disgust in the satiated condition, we observed a significant functional connectivity between brain areas responding to the disgusting odor, which was absent during the stimulation in the thirsty condition. These results suggest interference of conflicting emotions: an acute homeostatic imbalance can attenuate the experience of another emotion evoked by the sensory perception of a potentially harmful external agent. This finding offers novel insights with regard to the behavioral relevance of biologically different types of emotions, indicating that some types of emotions are more imperative for behavior than others. As a general principle, this modulatory effect during the conflict of homeostatic and sensory-evoked emotions may function to safeguard survival.

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YNIMG Journal 2014 Journal Article

Magnetic resonance spectroscopy investigations of functionally defined language areas in schizophrenia patients with and without auditory hallucinations

Philipp Homan
Peter Vermathen
Claudia Van Swam
Andrea Federspiel
Chris Boesch
Werner Strik
Thomas Dierks
Daniela Hubl

Background Cerebral dysfunction occurring in mental disorders can show metabolic disturbances which are limited to circumscribed brain areas. Auditory hallucinations have been shown to be related to defined cortical areas linked to specific language functions. Here, we investigated if the study of metabolic changes in auditory hallucinations requires a functional rather than an anatomical definition of their location and size to allow a reliable investigation by magnetic resonance spectroscopy (MRS). Methods Schizophrenia patients with (AH; n=12) and without hallucinations (NH; n=8) and healthy controls (HC; n=11) underwent a verbal fluency task in functional MRI (fMRI) to functionally define Broca's and Wernicke's areas. Left and right Heschl's gyri were defined anatomically. Results The mean distances in native space between the fMRI-defined regions and a corresponding anatomically defined area were 12. 4±6. 1mm (range: 2. 7–36. 1mm) for Broca's area and 16. 8±6. 2mm (range: 4. 5–26. 4mm) for Wernicke's area, respectively. Hence, the spatial variance was of similar extent as the size of the investigated regions. Splitting the investigations into a single voxel examination in the frontal brain and a spectroscopic imaging part for the more homogeneous field areas led to good spectral quality for almost all spectra. In Broca's area, there was a significant group effect (p=0. 03) with lower levels of N-acetyl-aspartate (NAA) in NH compared to HC (p=0. 02). There were positive associations of NAA levels in the left Heschl's gyrus with total (p=0. 03) and negative (p=0. 006) PANSS scores. In Broca's area, there was a negative association of myo-inositol levels with total PANSS scores (p=0. 008). Conclusion This study supports the neurodegenerative hypothesis of schizophrenia only in a frontal region whereas the results obtained from temporal regions are in contrast to the majority of previous studies. Future research should test the hypothesis raised by this study that a functional definition of language regions is needed if neurochemical imbalances are expected to be restricted to functional foci.

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YNICL Journal 2014 Journal Article

Ventral striatum gray matter density reduction in patients with schizophrenia and psychotic emotional dysregulation

Katharina Stegmayer
Helge Horn
Andrea Federspiel
Nadja Razavi
Tobias Bracht
Karin Laimböck
Werner Strik
Thomas Dierks

INTRODUCTION: Substantial heterogeneity remains across studies investigating changes in gray matter in schizophrenia. Differences in methodology, heterogeneous symptom patterns and symptom trajectories may contribute to inconsistent findings. To address this problem, we recently proposed to group patients by symptom dimensions, which map on the language, the limbic and the motor systems. The aim of the present study was to investigate whether patients with prevalent symptoms of emotional dysregulation would show structural neuronal abnormalities in the limbic system. METHOD: 43 right-handed medicated patients with schizophrenia were assessed with the Bern Psychopathology Scale (BPS). The patients and a control group of 34 healthy individuals underwent structural imaging at a 3T MRI scanner. Whole brain voxel-based morphometry (VBM) was compared between patient subgroups with different severity of emotional dysregulation. Group comparisons (comparison between patients with severe emotional dysregulation, patients with mild emotional dysregulation, patients with no emotional dysregulation and healthy controls) were performed using a one way ANOVA and ANCOVA respectively. RESULTS: Patients with severe emotional dysregulation had significantly decreased gray matter density in a large cluster including the right ventral striatum and the head of the caudate compared to patients without emotional dysregulation. Comparing patients with severe emotional dysregulation and healthy controls, several clusters of significant decreased GM density were detected in patients, including the right ventral striatum, head of the caudate, left hippocampus, bilateral thalamus, dorsolateral prefrontal and orbitofrontal cortex. The significant effect in the ventral striatum was lost when patients with and without emotional dysregulation were pooled and compared with controls. DISCUSSION: Decreased gray matter density in a large cluster including the right ventral striatum was associated with severe symptoms of emotional dysregulation in patients with schizophrenia. The ventral striatum is an important part of the limbic system, and was indicated to be involved in the generation of incentive salience and psychotic symptoms. Only patients with severe emotional dysregulation had decreased gray matter in several brain structures associated with emotion and reward processing compared to healthy controls. The results support the hypothesis that grouping patients according to specific clinical symptoms matched to the limbic system allows identifying patient subgroups with structural abnormalities in the limbic network.

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YNIMG Journal 2008 Journal Article

The early context effect reflects activity in the temporo-prefrontal semantic system: Evidence from electrical neuroimaging of abstract and concrete word reading

Miranka Wirth
Helge Horn
Thomas Koenig
Annick Razafimandimby
Maria Stein
Thomas Mueller
Andrea Federspiel
Beat Meier

Spatial and temporal characteristics of lexico-semantic retrieval are frequently examined with semantic context (i. e. , priming) paradigms. These paradigms measure context (i. e. , priming) effects in word processing evoked by semantically related context. Besides the well-known attention-dependent N400 context effect (>250 ms), recent studies demonstrate early automatic context effects in the P1–N1 time period (<200 ms). However, in visual word presentation the semantic origin of these early effects remains debated. This study examined spatio-temporal activation dynamics of the early context effect as well as the modulation of the effect by differences in structure and accessibility of verbal semantics existent in abstract and concrete words. The early context effect was measured in visually displayed words that followed semantically related single-word context. Spatial and temporal aspects of the effect were analyzed by applying topographic and source analyses on the word-triggered Event Related Potentials. The early context effect was enhanced in abstract compared to concrete words as indicated by a difference in the occurrence of P1–N1 transition map and a corresponding topographic dissimilarity (116–140 ms). This concreteness-dependent modulation demonstrates the sensitivity of the early context effect to structural differences in verbal semantics. Furthermore, the topographic difference was explained by enhanced activation in the left inferior prefrontal cortex for related compared to unrelated words in addition to temporo-parietal generators recruited in both conditions. The result suggests automatic feedforward processing of context-related information in temporo-prefrontal brain regions critical to semantic analysis. Taken together our findings show that the early context effect reflects activation processes in verbal semantic memory.

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YNIMG Journal 2004 Journal Article

Dissociation between overt and unconscious face processing in fusiform face area

Christoph Lehmann
Thomas Mueller
Andrea Federspiel
Daniela Hubl
Gerhard Schroth
Oswald Huber
Werner Strik
Thomas Dierks

The precise role of the fusiform face area (FFA) in face processing remains controversial. In this study, we investigated to what degree FFA activation reflects additional functions beyond face perception. Seven volunteers underwent rapid event-related functional magnetic resonance imaging while they performed a face-encoding and a face-recognition task. During face encoding, activity in the FFA for individual faces predicted whether the individual face was subsequently remembered or forgotten. However, during face recognition, no difference in FFA activity between consciously remembered and forgotten faces was observed, but the activity of FFA differentiated if a face had been seen previously or not. This demonstrated a dissociation between overt recognition and unconscious discrimination of stimuli, suggesting that physiological processes of face recognition can take place, even if not all of its operations are made available to consciousness.

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