Anya Pedersen

University of Münster, Münster, North Rhine-Westphalia, Germany

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Publications (33)142.19 Total impact

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    ABSTRACT: To identify the brain regions involved in the interpretation of intentional movement by patients with schizophrenia, we investigated the association between cerebral gray matter (GM) volumes and performance on a theory of mind (ToM) task using voxel-based morphometry. Eighteen patients with schizophrenia and thirty healthy controls participated in the study. Participants were given a moving shapes task that employs the interpretation of intentional movement. Verbal descriptions were rated according to intentionality. ToM performance deficits in patients were found to be positively correlated with GM volume reductions in the superior temporal sulcus and medial prefrontal cortex. Our findings confirm that divergent brain regions contribute to mentalizing abilities and that GM volume reductions impact behavioral deficits in patients with schizophrenia.
    Social neuroscience 09/2013; · 3.17 Impact Factor
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    ABSTRACT: The upregulation of glutamatergic excitatory neurotransmission is thought to be partly responsible for the acute withdrawal symptoms and craving experienced by alcohol-dependent patients. Most physiological evidence supporting this hypothesis is based on data from animal studies. Additionally, clinical data show that GABAergic and anti-glutamatergic drugs ameliorate withdrawal symptoms, offering indirect evidence indicative of glutamatergic hyperexcitability in alcohol-dependent subjects. We used proton magnetic resonance spectroscopy to quantify the glutamate levels in healthy control subjects and in alcohol-dependent patients immediately after detoxification. The volumes of interest were located in the nucleus accumbens and the anterior cingulate cortex, which are two brain areas that have important functions in reward circuitry. In addition to glutamate, we quantified the levels of combined glutamate and glutamine, N-acetylaspartate, choline-containing compounds, and creatine. The glutamate levels in the nucleus accumbens were significantly higher in patients than in controls. Craving, which was measured using the Obsessive Compulsive Drinking Scale, correlated positively with levels of combined glutamate and glutamine in the nucleus accumbens and in the anterior cingulate cortex. The levels of all other metabolites were not significantly different between patients and controls. The increased glutamate levels in the nucleus accumbens in alcohol-dependent patients shortly after detoxification confirm the animal data and suggest that striatal glutamatergic dysfunction is related to ethanol withdrawal. The positive correlation between craving and glutamatergic metabolism in both key reward circuitry areas support the hypothesis that the glutamatergic system plays an important role in the later course of alcohol dependence with respect to abstinence and relapse.Neuropsychopharmacology accepted article preview online, 12 February 2013; doi:10.1038/npp.2013.45.
    Neuropsychopharmacology: official publication of the American College of Neuropsychopharmacology 02/2013; · 8.68 Impact Factor
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    ABSTRACT: Objective: Smooth pursuit eye movements are compromised in patients with schizophrenia and their first-degree relatives. Although research has demonstrated that the motor components of smooth pursuit eye movements are intact, motion perception has been shown to be impaired. In particular, studies have consistently revealed deficits in performance on tasks specific to the high-order motion area V5 (middle temporal area, MT) in patients with schizophrenia. In contrast, data from low-level motion detectors in the primary visual cortex (V1) have been inconsistent. Method: To differentiate between low-level and high-level visual motion processing, we applied a temporal-order judgment task for motion events and a motion-defined figure-ground segregation task using patients with schizophrenia and healthy controls. Successful judgments in both tasks rely on the same low-level motion detectors in the V1; however, the first task is further processed in the higher-order motion area MT in the magnocellular (dorsal) pathway, whereas the second task requires subsequent computations in the parvocellular (ventral) pathway in visual area V4 and the inferotemporal cortex (IT). These latter structures are supposed to be intact in schizophrenia. Results: Patients with schizophrenia revealed a significantly impaired temporal resolution on the motion-based temporal-order judgment task but only mild impairment in the motion-based segregation task. Conclusions: These results imply that low-level motion detection in V1 is not, or is only slightly, compromised; furthermore, our data restrain the locus of the well-known deficit in motion detection to areas beyond the primary visual cortex. (PsycINFO Database Record (c) 2013 APA, all rights reserved).
    Neuropsychology 01/2013; 27(1):60-8. · 3.58 Impact Factor
  • Anya Pedersen, Patricia Ohrmann
    Journal of Attention Disorders 11/2012; · 2.16 Impact Factor
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    ABSTRACT: Attempts to identify the central disturbed processes explaining the overt symptoms of juvenile and adult ADHD rely heavily on the concept of deficient error monitoring processes. A number of studies have investigated event-related potentials (ERPs) and behavioral performance in tasks traditionally used to probe the interference control and inhibition of motor responses. The inspection of the error negativity (Ne/ERN) and error positivity (Pe) components evoked in these tasks has produced conflicting results with respect to the nature and extent of an error monitoring deficit in ADHD. A meta-analytic aggregation of these single studies should help develop a reliable appraisal of the evidence for the compromised performance monitoring processes in ADHD. Our meta-analysis was confined to studies of adult and juvenile ADHD participants examined in GoNogo and Flanker task studies that also reported the Ne/ERN and Pe ERP components. Only seven studies were suited for the meta-analysis, but their aggregation nevertheless led to clear results: Ne was attenuated in adult and adolescent ADHD participants for both tasks, and Pe was attenuated only in the GoNogo tasks. The ADHD participants made more errors than the controls in both tasks but responded slower only in the Flanker task. To our knowledge, this meta-analysis is the first to compare electrophysiological and behavioral indices of error monitoring in adult and juvenile ADHD patients and healthy controls. Admittedly, the data available for this comparison were sparse and heterogeneous; nevertheless, this meta-analysis produced salient results that indicate a monitoring deficit as a central feature of the ADHD syndrome.
    International journal of psychophysiology: official journal of the International Organization of Psychophysiology 08/2012; · 3.05 Impact Factor
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    ABSTRACT: The remediation of executive function in patients with schizophrenia is important in rehabilitation because these skills affect the patient's capacity to function in the community. There is evidence that instructional techniques can improve deficits in the Wisconsin Card Sorting Test (WCST) in some schizophrenia patients. We used a standard test/training phase/standard test format of the WCST to classify 36 schizophrenia patients as high-achievers, learners or non-retainers. All healthy controls performed as high-achievers. An event-related fMRI design assessed neural activation patterns during post-training WCST performance. Patients showed a linear trend between set-shifting related activation in the anterior cingulate cortex and learning potential, i.e. increased activation in high-achievers, a trend for increased activation in learners, and no activation in non-retainers compared to controls. In addition, activation in the temporoparietal cortex was highest in patients classified as learners, whereas in non-retainers activation was increased in the inferior frontal gyrus compared to controls and high-achieving patients. These results emphasize the relevance of the ACC's neural integrity in learning set-shifting strategies for patients with schizophrenia. Also, our results support the hypothesis that compensatory neural activation in patients with schizophrenia helps them to catch up with healthy controls on cognitive tasks.
    Brain and Cognition 05/2012; 79(3):245-51. · 2.82 Impact Factor
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    ABSTRACT: Functional imaging studies have used numerous neurocognitive designs to investigate brain activation during theory of mind (ToM) tasks in patients with schizophrenia. The majority of studies asks participants to retrospectively attribute mental states to others. We used a novel animated task to investigate implicit mentalizing online. Because behavioral studies have revealed slower ToM performance reaction times in patients with schizophrenia, we hypothesized that time would influence functional MRI (fMRI) activation patterns also. We applied the "Moving Shapes" paradigm, which involves two interacting triangles, to a functional MRI block design and investigated the neural activation patterns of 15 patients with schizophrenia and 14 healthy controls. We additionally analyzed the first and second halves of each video separately to assess time-related differences. Overall, patients with schizophrenia showed increased activation in the inferior and middle frontal gyri, the superior temporal gyrus, the precuneus and the cerebellum compared with controls during ToM versus non-ToM videos. Most importantly, patients with schizophrenia had predominantly increased activation in ToM-related brain areas during the second half of the ToM paradigm, whereas the activation in areas of the ToM-network in healthy controls occurred during the first half of the presentation. Our results confirm recent findings of significantly stronger neural activations that encompass the fronto-temporo-parietal cerebral areas in patients with schizophrenia compared with controls during ToM tasks. The observation of slower cognitive processing in patients with schizophrenia during mentalizing might explain some of the contradictory imaging findings in these patients and have implications for cognitive remediation.
    Schizophrenia Research 03/2012; 137(1-3):224-9. · 4.59 Impact Factor
  • European Psychiatry 01/2012; 27:1. · 3.29 Impact Factor
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    ABSTRACT: Objective: Adult Diagnostic and Statistical Manual of Mental Disorders (4th ed.; DSM-IV) and retrospective childhood Wender-Utah ADHD criteria are implemented in self-report measures to assess adult ADHD and its required onset in childhood. Yet their dimensional structure and relationship to adult ADHD depressivity is still at debate. Therefore, both aspects were investigated, applying two respective German instruments (ADHD-Self-Report [ADHD-SR] and Wender Utah Rating Scale-German [WURS-G]) to two student samples. Method: ADHD-SR and WURS-G dimensions were identified by nonlinear confirmatory factor analyses, and their interrelations and relationship with adult depressivity were identified by structural equation modeling. Results: Adult ADHD-SR symptoms were organized into inattention, hyperactivity, and impulsivity, and WURS-G symptoms were organized into inattention/hyperactivity, affect lability, depressivity, and conduct problems. Yet only the first two WURS factors directly affected adult ADHD facets, though childhood depressivity influenced them indirectly via adult depressivity. Conclusion: Only criteria of the first two WURS factors can be considered valid childhood ADHD indicators. Thus, only they should be used as an aid in the retrospective assessment of ADHD symptoms. (J. of Att. Dis. 2011; XX(X) 1-XX).
    Journal of Attention Disorders 11/2011; · 2.16 Impact Factor
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    ABSTRACT: Theory of mind (ToM) functioning develops during certain phases of childhood. Factors such as language development and educational style seem to influence its development. Some studies that have focused on transcultural aspects of ToM development have found differences between Asian and Western cultures. To date, however, little is known about transcultural differences in neural activation patterns as they relate to ToM functioning. EXPERIMENTAL METHODS: The aim of our study was to observe ToM functioning and differences in brain activation patterns, as assessed by functional magnetic resonance imaging (fMRI). This study included a sample of 18 healthy Japanese and 15 healthy Caucasian subjects living in Japan. We presented a ToM task depicting geometrical shapes moving in social patterns. We also administered questionnaires to examine empathy abilities and cultural background factors. Behavioral data showed no significant group differences in the subjects' post-scan descriptions of the movies. The imaging results displayed stronger activation in the medial prefrontal cortex (MPFC) in the Caucasian sample during the presentation of ToM videos. Furthermore, the task-associated activation of the MPFC was positively correlated with autistic and alexithymic features in the Japanese sample. In summary, our results showed evidence of culturally dependent sociobehavioral trait patterns, which suggests that they have an impact on brain activation patterns during information processing involving ToM.
    Social neuroscience 09/2011; 6(5-6):615-26. · 3.17 Impact Factor
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    ABSTRACT: Animal studies have suggested neuropeptide S (NPS) and its receptor (NPSR) to be involved in the pathogenesis of anxiety-related behavior. In this study, a multilevel approach was applied to further elucidate the role of NPS in the etiology of human anxiety. The functional NPSR A/T (Asn¹⁰⁷Ile) variant (rs324981) was investigated for association with (1) panic disorder with and without agoraphobia in two large, independent case-control studies, (2) dimensional anxiety traits, (3) autonomic arousal level during a behavioral avoidance test and (4) brain activation correlates of anxiety-related emotional processing in panic disorder. The more active NPSR rs324981 T allele was found to be associated with panic disorder in the female subgroup of patients in both samples as well as in a meta-analytic approach. The T risk allele was further related to elevated anxiety sensitivity, increased heart rate and higher symptom reports during a behavioral avoidance test as well as decreased activity in the dorsolateral prefrontal, lateral orbitofrontal and anterior cingulate cortex during processing of fearful faces in patients with panic disorder. The present results provide converging evidence for a female-dominant role of NPSR gene variation in panic disorder potentially through heightened autonomic arousal and distorted processing of anxiety-relevant emotional stimuli.
    Molecular Psychiatry 09/2011; 16(9):938-48. · 15.15 Impact Factor
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    ABSTRACT: Several studies have shown that female and male subjects process emotions differently. As women appear to be especially sensitive and responsive to negative and threatening stimuli, gender-specific emotional processing might be an important factor contributing to the increased likelihood of women compared to men to develop anxiety disorders, e.g. panic disorder (PD). In this study, gender-specific neural activation during facial emotion processing was investigated in 20 PD patients (12 women, 8 men) by functional magnetic resonance imaging. Overall, significantly stronger activation, encompassing the amygdala, prefrontal, temporal, and occipital cortical areas, basal ganglia, and thalamus, was observed in women than in men during the processing of angry, fearful, or neutral but not happy facial expressions. Additionally, functional connectivity between the amygdala and prefrontal cortical areas and thalamus during the processing of angry facial expressions was significantly stronger in women than in men. These results emphasize gender as an important variable in neural activation patterns of emotional processing and may help to further elucidate the biological substrate of gender-specific susceptibility for PD.
    Depression and Anxiety 11/2010; 27(11):1034-43. · 4.61 Impact Factor
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    ABSTRACT: Although there is considerable evidence that patients with schizophrenia have impaired executive functions, the neural mechanisms underlying these deficits are unclear. Generation and selection is one of the basic mechanisms of executive functioning. We investigated the neural correlates of this mechanism by means of functional magnetic resonance imaging (fMRI) in patients with schizophrenia and healthy controls. We used the Wisconsin Card Sorting Test (WCST) in an event-related fMRI study to analyze neural activation patterns during the distinct components of the WCST in 36 patients with schizophrenia and 28 controls. We focused our analyses on the process of set-shifting. After participants received negative feedback, they had to generate and decide on a new sorting rule. A widespread activation pattern encompassing the inferior and middle frontal gyrus, parietal, temporal and occipital cortices, anterior cingulate cortex (ACC), supplementary motor area, insula, caudate, thalamus and brainstem was observed in patients with schizophrenia after negative versus positive feedback, whereas in healthy controls, significant activation clusters were more confined to the cortical areas. Significantly increased activation in the rostral ACC after negative feedback and in the dorsal ACC during matching after negative feedback were observed in schizophrenia patients compared with controls. Controls showed activation in the bilateral dorsolateral prefrontal cortex (Brodmann area 46), whereas schizophrenia patients showed activation in the right dorsolateral prefrontal cortex only. All patients were taking neuroleptic medication, which has an impact on cognitive function as well as on dopaminergic and serotonergic prefrontal metabolism. Our data suggest that, in patients with schizophrenia, set-shifting is associated with increased activation in the rostral and dorsal ACC, reflecting higher emotional and cognitive demands, respectively.
    Journal of psychiatry & neuroscience: JPN 09/2010; 35(5):321-9. · 6.24 Impact Factor
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    ABSTRACT: Schizophrenia patients show abnormalities in the processing of facial emotion. The amygdala is a central part of a brain network that is involved in the perception of facial emotions. Previous functional neuroimaging studies on the perception of facial emotion in schizophrenia have focused almost exclusively on controlled processing. In the present study, we investigated the automatic responsivity of the amygdala to emotional faces in schizophrenia and its relationship to clinical symptomatology by applying an affective priming task. 3-T fMRI was utilized to examine amygdala responses to sad and happy faces masked by neutral faces in 12 schizophrenia patients and 12 healthy controls. The Positive and Negative Syndrome Scale (PANSS) was administered to assess current symptomatology. Schizophrenia patients exhibited greater automatic amygdala responses to sad and happy faces relative to controls. Amygdala responses to masked sad and happy expressions were positively correlated with the negative subscale of the PANSS. Schizophrenia patients appear to be characterized by amygdalar hyperresponsiveness to negative and positive facial expressions on an automatic processing level. Heightened automatic amygdala responsivity could be involved in the development and maintenance of negative symptoms in schizophrenia.
    Psychiatry Research 06/2010; 182(3):200-6. · 2.68 Impact Factor
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    ABSTRACT: There is substantial evidence for Theory of Mind (ToM) deficits in patients with schizophrenia. Many psychotic symptoms may best be understood in light of an impaired capacity to infer one's own and other persons' mental states and to relate those to executing behavior. The aim of our study was to investigate ToM abilities in first-episode schizophrenia patients and to analyze them in relation to neuropsychological and psychopathological functioning. A modified Moving Shapes paradigm was used to assess ToM abilities in 23 first-episode patients with schizophrenia and 23 matched healthy controls. Participants had to describe animated triangles which moved (1) randomly, (2) goal-directed, or (3) in complex, socially interactive ways (ToM video sequences). Neuropsychological functioning, psychopathology, autistic and alexithymic features as well as empathetic abilities were correlated with ToM performance. Compared to healthy controls, first-episode schizophrenia patients gave more incorrect descriptions and used less ToM-related vocabulary when responding to socially complex ToM video sequences. No group differences were revealed for videos with random movements. ToM abilities correlated significantly with positive symptoms, reasoning, verbal memory performance and verbal IQ, but not with empathetic abilities or autistic and alexithymic features. When controlling for reasoning, verbal memory performance and verbal IQ, the correctness of video descriptions was still significantly worse in schizophrenia patients. The results of our study in first-episode schizophrenia patients underline recent findings on ToM deficits in the early course of schizophrenia. Only a moderate influence of neurocognitive deficits on ToM performance was observed. Impairment in ToM abilities seems to be predominantly independent of clinical state, alexithymia and empathy.
    Schizophrenia Research 06/2010; 119(1-3):115-23. · 4.59 Impact Factor
  • European Neuropsychopharmacology - EUR NEUROPSYCHOPHARMACOL. 01/2010; 20.
  • European Neuropsychopharmacology. 01/2010; 20:S530.
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    ABSTRACT: The traumatic loss of an unborn child by induced termination of pregnancy because of fetal malformation is a major life event that causes intense maternal grief. Increasing evidence supports the hypothesis that the same neural structures involved in the experience of physical pain are involved in the experience of social pain and loss. To investigate neural activation patterns related to acute grief, the authors conducted a functional MRI study of 12 post-termination women and 12 noninduced women who delivered a healthy child. Brain activation was measured while participants viewed pictures of happy baby, happy adult, and neutral adult faces. Relative to comparison women, post-termination women showed greater activation in the middle and posterior cingulate gyrus, the inferior frontal gyrus, the middle temporal gyrus, the thalamus, and the brainstem in response to viewing happy baby faces. Functional connectivity between the cingulate gyrus and the thalamus during the processing of happy baby faces was significantly stronger in post-termination women. Overall, acute grief after the loss of an unborn child was closely related to the activation of the physical pain network encompassing the cingulate gyrus, the inferior frontal gyrus, the thalamus, and the brainstem. To the authors' knowledge, the stronger functional thalamocingulate connectivity in post-termination women is the first in vivo demonstration of an involvement of the neural maternal attachment network in grief after the loss of an unborn child.
    American Journal of Psychiatry 11/2009; 166(12):1402-10. · 14.72 Impact Factor
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    ABSTRACT: In acute depression a high prevalence of deficits in learning and memory performance has been reported. Still, it is unclear whether these cognitive deficits are present after remission of clinical symptoms of depression. The present study compared 20 inpatients recently remitted from severe major depressive disorder (MDD) with 20 healthy matched control participants on two sequence learning tasks: a modified serial reaction-time task (SRT) for implicit learning, which is sensitive to subcortical and frontal impairments, and a serial generation task (SGT) for explicit learning. As compared with performance in healthy controls, implicit and explicit learning were not impaired in recently remitted inpatients with depression. Intentional acquisition of new information was related to the severity of depressive symptoms as patients with higher scores on Beck's Depression Inventory (BDI) showed poorer explicit learning. In contrast to findings in acute depression, our results suggest a normal degree of learning in remitted depression; these findings are consistent with unimpaired fronto-striatal functioning. However, although not statistically significant, patients remitted from melancholic MDD revealed poorer implicit learning performance compared with patients remitted from non--melancholic MDD. Longitudinal studies in patients with melancholic vs. non-melancholic MDD are needed to investigate the course of cognitive functioning during the recovery from MDD.
    Psychiatry Research 09/2009; 169(1):1-6. · 2.68 Impact Factor
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    ABSTRACT: Dynamic testing has increasingly been recognized as a measure of neurocognitive modifiability. For instance, executive function deficits as measured by the Wisconsin Card Sorting Test (WCST) can be ameliorated in a subgroup of schizophrenic patients by integrating instructions and feedback into the testing procedure. In the first study reported herein, we investigated the relation between learning typology on the WCST and chronicity in 60 first-episode patients and 44 patients with chronic schizophrenia. We found that nonretainer categorization of WCST performance is not related to chronic schizophrenia. In the second study, we investigated the relationship between learning potential on the WCST and cerebral metabolism, assessed by single-voxel proton magnetic resonance spectroscopy of the dorsolateral prefrontal cortex (DLPFC) and the anterior cingulate cortex (ACC), in 43 schizophrenic patients and 37 matched healthy control subjects. The level of N-acetylaspartate (NAA), a marker of neuronal integrity, in the DLPFC correlated with performance on the dynamic WCST in healthy subjects. In schizophrenic patients, a significant correlation was observed between NAA in the ACC and learning potential (cf. Ohrmann et al., 2008). These data suggest the involvement of different neuronal networks in learning among schizophrenic patients as compared to healthy controls.
    Journal of Cognitive Education and Psychology. 01/2009; 8(1):81-90.