Rüdiger J . Seitz
Heinrich Heine University Düsseldorf, Neurology, Faculty Member
- 1981 MD, University of Hamburg, Germany 1982-1987 Residency at the Heinrich-Heine-University Düsseldorf, Germ... more1981 MD, University of Hamburg, Germany
1982-1987 Residency at the Heinrich-Heine-University Düsseldorf, Germany
1987-1989 Research Fellowship, PET-Section, Karolinska Hospital, Stockholm, Sweden.
1990 Head, Functional Neuroimaging Laboratory, Department of Neurology, Heinrich-Heine-University Düsseldorf, Germany.
1992 Hugo-Spatz-Award of the German Neurological Society.
1996 Professor of Neurology, Heinrich-Heine-University Düsseldorf,
Germany.
1998 Vice-Chairman, Department of Neurology, University Hospital Düsseldorf, Germany.
2006-2007 Distinguished Fellow, Institute of Advanced Study, LaTrobe University, Bundoora, Victoria, Australia.
2009-2020 Honorary Professorial Fellow, Florey Neuroscience Institutes, Melbourne, Australia.
2012 Head of Neurology, Centre for Neurology and Neuropsychiatry, LVR-Klinikum Düsseldorf, Hospital of the Heinrich-Heine-University Düsseldorf, Germanyedit
ZUSAMMENFASSUNGGlaubensvorgänge sind Ausdruck von Hirnfunktion, die der Entstehung von Glaubensinhalten zugrunde liegen. Glaubensvorgänge beruhen auf der Integration von Wahrnehmungs- und Bewertungsvorgängen und ermöglichen eine implizite... more
ZUSAMMENFASSUNGGlaubensvorgänge sind Ausdruck von Hirnfunktion, die der Entstehung von Glaubensinhalten zugrunde liegen. Glaubensvorgänge beruhen auf der Integration von Wahrnehmungs- und Bewertungsvorgängen und ermöglichen eine implizite Verhaltenssteuerung. Die Integration der Wahrnehmung von Objekten und Ereignissen in der Umgebung mit internen emotionalen Zuständen des Individuums führt zu primären Glaubensinhalten. Glaubensinhalte sind komplexe Repräsentationen von subjektiver Relevanz und spiegeln Wahrscheinlichkeiten wider. Sie werden im Gedächtnis gespeichert und beinhalten den Erfahrungshorizont von Individuen. Konzeptuelle Glaubensinhalte sind sprachabhängig und beruhen auf Narrativen, die durch Riten verstärkt werden können. Glaubensinhalte können zwischen Menschen kommuniziert werden und ermöglichen die Weitergabe von subjektiven Erfahrungen. In diesem Beitrag wird das Entstehen, die Modifikation und die pathologische Ausprägung von Glaubensinhalten beschrieben. Im Ausbl...
Believing has recently been recognized as a fundamental brain function linking a person’s experience with his or her attitude, actions and predictions. In general, believing results from the integration of ambient information with... more
Believing has recently been recognized as a fundamental brain function linking a person’s experience with his or her attitude, actions and predictions. In general, believing results from the integration of ambient information with emotions and can be reinforced or modulated in a probabilistic fashion by new experiences. Although these processes occur in the subliminal realm, humans can become aware of what they believe and express it verbally. We explain how believing is interwoven with memory functions in a multifaceted fashion. Linking the typically rapid and adequate reactions of a subject to what he/she believes is enabled by working memory. Perceptions are stored in episodic memory as beneficial or aversive events, while the corresponding verbal descriptions of what somebody believes are stored in semantic memory. After recall from memory of what someone believes, personally relevant information can be communicated to other people. Thus, memory is essential for maintaining what...
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Despite the long scientific discourse in Western theology and philosophy on religion, spirituality and faith, definitions of what a belief is are still virtually lacking. As events and objects in the complex outside world are transformed... more
Despite the long scientific discourse in Western theology and philosophy on religion, spirituality and faith, definitions of what a belief is are still virtually lacking. As events and objects in the complex outside world are transformed into probabilistic estimates with personal attributes of meaning and value by involvement of the prefrontal cortex, we argue that these probabilistic estimates represent personal beliefs. We present a model for the processes of believing - termed creditions - that is suited to describe the putative components and mental operations underlying secular and non-secular belief formation.
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Therapy of brain infarction has been advanced profoundly in recent years. This was due to improved diagnosis based on magnetic resonance imaging and on systemic thrombolysis performed in dedicated units. Acute stroke therapy should be... more
Therapy of brain infarction has been advanced profoundly in recent years. This was due to improved diagnosis based on magnetic resonance imaging and on systemic thrombolysis performed in dedicated units. Acute stroke therapy should be supplemented with neurophysiologically based rehabilitation to provide an optimal degree of functional restoration. Training strategies aiming at voluntary initiation of action have been shown to be particularly effective. The cerebral mechanisms underlying functional recovery can be studied in the patients with functional neuroimaging and transcranial magnetic stimulation. The open literature provides evidence suggesting that even the elderly can benefit from acute stroke therapy and rehabilitation.
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The brain may reorganize to optimize stroke recovery. Yet relatively little is known about neural correlates of training-facilitated recovery, particularly after loss of body sensations. Our aim was to characterize changes in brain... more
The brain may reorganize to optimize stroke recovery. Yet relatively little is known about neural correlates of training-facilitated recovery, particularly after loss of body sensations. Our aim was to characterize changes in brain activation following clinically effective touch discrimination training in stroke patients with somatosensory loss after lesions of primary/secondary somatosensory cortices or thalamic/capsular somatosensory regions using functional magnetic resonance imaging (fMRI). Eleven stroke patients with somatosensory loss, 7 with lesions involving primary (S1) and/or secondary (S2) somatosensory cortex (4 male, 58.7 ± 13.3 years) and 4 with lesions primarily involving somatosensory thalamus and/or capsular/white matter regions (2 male, 58 ± 8.6 years) were studied. Clinical and MRI testing occurred at 6 months poststroke (preintervention), and following 15 sessions of clinically effective touch discrimination training (postintervention). Improved touch discriminat...
Research Interests: Psychology, Cognitive Science, Magnetic Resonance Imaging, Medicine, Physical Medicine and Rehabilitation, and 15 moreMovement disorders, Stroke, Humans, Functional Magnetic Resonance Imaging, Female, Male, Clinical Sciences, Somatosensory Cortex, Aged, Middle Aged, Precuneus, Oxygen, Neurosciences, Case Control Studies, and Somatosensory system
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Stroke patients can recover upon intravenous thrombolysis but remain impaired in lacking recanalization. We sought to investigate the clinical effect of systemic thrombolysis with an intravenous bolus of 20 mg recombinant tissue... more
Stroke patients can recover upon intravenous thrombolysis but remain impaired in lacking recanalization. We sought to investigate the clinical effect of systemic thrombolysis with an intravenous bolus of 20 mg recombinant tissue plasminogen activator (rtPA) and an infusion of body-weight adjusted tirofiban for 48 hours in acute stroke. This prospective, open label study, included 192 patients (68±13 years, 50% males) treated between 1 January 2005 and 31 December 2007. The neurological deficit was assessed with the National Institutes of Health stroke scale (NIHSS). Follow-up was performed using a telephone interview of modified Rankin Scale (mRS) and Barthel index. The site of cerebral artery occlusion was determined by computed tomography or magnetic resonance angiography. Data were analyzed by descriptive statistics and multiple regression analyses. Eighty-one percent of the patients had an infarct in the middle cerebral artery (MCA) territory and were severely affected with a me...
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Background and Purpose —Diffusion-weighted imaging (DWI) and perfusion-weighted imaging (PWI) have been used increasingly in recent years to evaluate acute stroke in the emergency setting. In the present study, we compared DWI and PWI... more
Background and Purpose —Diffusion-weighted imaging (DWI) and perfusion-weighted imaging (PWI) have been used increasingly in recent years to evaluate acute stroke in the emergency setting. In the present study, we compared DWI and PWI findings in acute stroke patients with and without severe extracranial internal carotid artery (ICA) disease. Methods —Twenty-seven patients with nonlacunar ischemic stroke were selected for this analysis. DWI, PWI, and conventional MRI were performed in all patients within 24 hours of symptom onset and after 1 week. To exclude patients with partial or complete reperfusion, we included only patients with a PWI deficit larger than the DWI lesion. Severe ICA disease (>70% stenosis) was present unilaterally in 9 and bilaterally in 2 patients. Acute DWI lesion volume, the size of the acute PWI/DWI mismatch, and final infarct size (on T2-weighted images) were determined. Results —The PWI/DWI mismatch was significantly larger in patients with severe ICA d...
Research Interests: Magnetic Resonance Imaging, Diffusion MRI, Emergency Medical Services, Humans, Female, and 15 moreMale, Brain Ischemia, Ischemic Stroke, Clinical Sciences, Aged, Adult, Lesion, Infarct Size, Internal Carotid Artery, Cerebral Infarction, Carotid Stenosis, Carotid Artery Stenosis, Magnetic resonance image, Acute Disease, and Cardiovascular medicine and haematology
Background and Purpose— A major challenge to effective treatment after stroke is the restoration of neuronal function. In recent years, cell-based therapies for stroke have been explored in experimental animal models, and the results have... more
Background and Purpose— A major challenge to effective treatment after stroke is the restoration of neuronal function. In recent years, cell-based therapies for stroke have been explored in experimental animal models, and the results have suggested behavioral improvements. However, the anatomic targets of a cell-based stroke therapy and the relationship of cell grafts to post stroke reorganization are poorly understood, which results in difficulties defining strategies for neuronal substitution. Given that stroke causes a variety of secondary changes at locations beyond the infarct lesion, overcoming these difficulties is even more important. Summary of Review We describe which brain structures and cell types are candidates for substitution and how new neuronal functionality could be implemented in a damaged brain by capitalizing on current concepts of post stroke plasticity.
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Background. Studies of stroke patients using functional imaging and transcranial magnetic stimulation (TMS) of the primary motor cortex (M1) demonstrated increased recruitment and abnormally decreased short interval cortical inhibition... more
Background. Studies of stroke patients using functional imaging and transcranial magnetic stimulation (TMS) of the primary motor cortex (M1) demonstrated increased recruitment and abnormally decreased short interval cortical inhibition (SICI) of the M1 contralateral to the lesioned hemisphere (contralesional M1) within the first month after infarction of the M1 or its corticospinal projections. Objective. The authors sought to identify mechanisms underlying decreased SICI of the contralesional M1. Methods. In patients within 6 weeks of their first ever infarction of the M1 or its corticospinal projections, SICI in the M1 of the lesioned and nonlesioned hemisphere was studied using paired-pulse TMS. Interhemispheric inhibition (IHI) was measured by applying TMS to the M1 of the lesioned hemisphere and a second pulse to the homotopic M1 of the nonlesioned hemisphere and vice versa with the patient at rest. The results were compared to M1 stimulation of age-matched healthy controls. Re...
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Research Interests: Cognitive Science, Neurology, Skeletal muscle biology, Magnetic Resonance Imaging, Dysarthria, and 15 moreCausality, Medicine, Humans, Brainstem, Clinical Sciences, Quadriplegia, Disease Progression, Hypoglossal Nerve, Neurosciences, Extremities, Functional Laterality, Hemiparesis, Infarction, Muscle spasticity, and Vertebrobasilar insufficiency
Regional cerebral glucose metabolism (rCMRGlc) and dopamine D2 receptor binding were measured in a 31-year-old, severely affected, untreated patient with Wilson's disease of 3 years'... more
Regional cerebral glucose metabolism (rCMRGlc) and dopamine D2 receptor binding were measured in a 31-year-old, severely affected, untreated patient with Wilson's disease of 3 years' duration using positron emission tomography and 18F-deoxyglucose and 18F-methylspiperone ([18F]MSP), respectively. There was a severe reduction of striatal and extrastriatal rCMRGlc as well as of striatal [18F]MSP accumulation rate. After 1 year of treatment with D-penicillamine, striatal and extrastriatal rCMRGlc and striatal [18F]MSP accumulation rate reached almost normal levels. It is hypothesized that recovery of motor functions due to copper trapping therapy was associated with an increase in basal ganglia activity and a re-expression or upregulation of dopamine D2 receptors.
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The computerized brain atlas programme (CBA) provides a powerful tool for the anatomical analysis of functional images obtained with positron emission tomography (PET). With a repertoire of simple transformations, the data base of the CBA... more
The computerized brain atlas programme (CBA) provides a powerful tool for the anatomical analysis of functional images obtained with positron emission tomography (PET). With a repertoire of simple transformations, the data base of the CBA is first adapted to the anatomy of the subject's brain represented as a set of magnetic resonance (MR) or computed tomography (CT) images. After this, it is possible to spatially standardize (reformat) any set of tomographic images related to the subject, PET images, as well as CT and MR images, by applying the inverse atlas transformations. From these reformatted images, statistical images, such as average images and associated error images corresponding to different groups of subjects, may be produced. In all these images, anatomical structures can be localized using the atlas data base and the functional values can be evaluated quantitatively. The purpose of this study was to determine the spatial and quantitative accuracy and precision of t...
Research Interests: Computer Science, Computed Tomography, Nuclear medicine, Positron Emission Tomography, Medicine, and 15 moreBrain Mapping, Brain, Humans, PET imaging, Functional Imaging, Male, Magnetic Resonance, Dislocations, Clinical Sciences, Cerebral, Adult, Mr Imaging, Neurosciences, Magnetic resonance image, and Cardiovascular medicine and haematology
The computerized individually adjustable brain atlas (CBA) has been further developed. The atlas was primarily designed for anatomical localization and quantitative evaluation of data in positron emission tomography (PET), but may also be... more
The computerized individually adjustable brain atlas (CBA) has been further developed. The atlas was primarily designed for anatomical localization and quantitative evaluation of data in positron emission tomography (PET), but may also be employed for other neuroimaging modalities, such as transmission computed tomography (CT) and magnetic resonance imaging (MRI). The atlas is based on anatomical information obtained from digitized cryosectioned brains. Using spatially standardized and then averaged MRI images, we demonstrate the high localization accuracy and precision of the brain atlas. This is a prerequisite for obtaining accuracy when using the atlas in the localization and the quantitative evaluation of PET data. The specification and the selection of region of interests (ROIs) by the CBA are presented and discussed.
Research Interests: Neuroscience, Computer Science, Neurology, Neuroimaging, Magnetic Resonance Imaging, and 15 moreMedicine, Anatomy, Atlas, Brain, Neurovascular, Humans, Brain Circulation, Data Display, Accuracy, Clinical Sciences, Cerebral Blood Flow, Nuclear Magnetic Resonance Imaging, Neurosciences, Magnetic resonance image, and Cardiovascular medicine and haematology
Research Interests: Cognitive Science, Magnetic Resonance Imaging, Medicine, Brain Mapping, Brain, and 15 moreHumans, Kinematics, Female, Functional Imaging, Male, Arm, Hemispheric Asymmetry, Human Brain, Adult, Brain Physiology, Human Brain Mapping, J, Electrooculography, Functional Laterality, and Functional Specialization
A shift is emerging in the way in which we view post-stroke recovery. This shift, supported by evidence from neuroimaging studies, encourages us to look beyond the lesion and to identify viable brain networks with capacity for plasticity.... more
A shift is emerging in the way in which we view post-stroke recovery. This shift, supported by evidence from neuroimaging studies, encourages us to look beyond the lesion and to identify viable brain networks with capacity for plasticity. In this article, the authors review current advances in neuroimaging techniques and the new insights that they have contributed. The ability to quantify salvageable tissue, evidence of changes in remote networks, changes of functional and structural connectivity, and alterations in cortical thickness are reviewed in the context of their impact on post-stroke recovery. The value of monitoring spared structural connections and functional connectivity of brain networks within and across hemispheres is highlighted.
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Research Interests: Magnetic Resonance Imaging, Medicine, Clinical Decision Making, Humans, Female, and 15 moreMale, Clinical Sciences, Aged, Adult, Carotid Endarterectomy, Conservation Management, Cerebral Ischemia, Carotid Artery, Internal Carotid Artery, Carotid Artery Disease, Magnetic resonance angiography, Diagnostic Criteria, Acute Disease, Cardiovascular medicine and haematology, and Carotid artery diseases
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Research Interests: Neuroscience, Psychology, Magnetic Resonance Imaging, Medicine, Catheterization, and 15 moreBrain Mapping, Humans, Cerebral Cortex, Sensation, Functional Magnetic Resonance Imaging, Functional Imaging, Clinical Sciences, Middle Aged, Adult, Esophagus, Limbic System, Insular Cortex, Annals, Neurosciences, and Somatosensory system
Research Interests: Electrophysiology, Magnetic Resonance Imaging, Medicine, Brain, Humans, and 15 moreCorpus Callosum, Discrimination Learning, Female, Male, Magnetics, Adult, Hand, Lesion, Kinematic Analysis, Brain Neoplasms, Biomechanical Phenomena, Functional Laterality, bimanual interaction, Medical and Health Sciences, and Electric stimulation
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Research Interests: Cognitive Science, Cognition, Magnetic Resonance Imaging, Positron Emission Tomography, Medicine, and 15 moreInformation Processing, Memory, Problem Solving, Brain Mapping, Humans, Movement, Functional Imaging, Parietal Cortex, Cluster Analysis, Medical Physiology, Center of Gravity, Meta Analysis, Parietal Lobe, Eye Movement, and Neurosciences
Skilled action is the end-product of learning processes that can improve several aspects of motor control such as strategic movement organisation, perceptual–motor associations, or muscle commands for basic components of sequentially... more
Skilled action is the end-product of learning processes that can improve several aspects of motor control such as strategic movement organisation, perceptual–motor associations, or muscle commands for basic components of sequentially evolving, complex movements. Experimental studies in healthy participants using functional imaging and transcranial magnetic stimulation have identified separable processes that form cortical motor representations and that assist this formation of representations. These processes capitalise on use-dependent plasticity and changes in cortical excitability before and after practice. In terms of neural circuits, motor learning manifests measurably via structures that support transient phenomena, such as attentive error monitoring, or through continued activation of brain structures that support control processes still adapting. Specifically, movement guidance engages the dorsal premotor and parietal cortex along the intraparietal sulcus in addition to the ...
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Research Interests: Psychology, Neurology, Psycholinguistics, Attention, Electroencephalography, and 15 moreLanguage, Positron Emission Tomography, Medicine, Language Production, Language Comprehension, Brain Mapping, Humans, Discrimination Learning, Comprehension, Noun Phrase, Neurons, Frontal Lobe, Psychomotor Performance, Psychology and Cognitive Sciences, and Medical and Health Sciences
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Research Interests: Engineering, Nonparametric Statistics, Magnetic Resonance Imaging, Humans, Diffusion, and 15 moreFemale, Male, Perfusion, Brain Ischemia, Aged, Middle Aged, Adult, Magnetic, Cerebral Ischemia, Blood Flow Velocity, Contrast Media, Cerebral Infarction, Magnetic resonance angiography, Diffusion magnetic resonance imaging, and Medical and Health Sciences
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Research Interests: Intelligence, Cognition, Science, Positron Emission Tomography, Multidisciplinary, and 15 moreBrain Mapping, Humans, Frontal Cortex, Clinical Sciences, Middle Aged, Optometry and Ophthalmology, Single Photon Emission Computed Tomography, Adult, Public health systems and services research, Cognitive Function, General Intelligence, Intelligence tests, Nuclear Magnetic Resonance Imaging, Frontal Lobe, and Psychomotor Performance
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Research Interests: Psychology, Neurology, Psycholinguistics, Attention, Electroencephalography, and 15 moreLanguage, Positron Emission Tomography, Medicine, Language Production, Language Comprehension, Brain Mapping, Humans, Discrimination Learning, Comprehension, Noun Phrase, Neurons, Frontal Lobe, Psychomotor Performance, Psychology and Cognitive Sciences, and Medical and Health Sciences
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The objective of this study was to evaluate the clinical aspects of mirror therapy (MT) interventions after stroke, phantom limb pain and complex regional pain syndrome. A systematic literature search of the Cochrane Database of... more
The objective of this study was to evaluate the clinical aspects of mirror therapy (MT) interventions after stroke, phantom limb pain and complex regional pain syndrome. A systematic literature search of the Cochrane Database of controlled trials, PubMed/MEDLINE, CINAHL, EMBASE, PsycINFO, PEDro, RehabTrials and Rehadat, was made by two investigators independently (A.S.R. and M.J.). No restrictions were made regarding study design and type or localization of stroke, complex regional pain syndrome and amputation. Only studies that had MT given as a long-term treatment were included. Two authors (A.S.R. and S.M.B.) independently assessed studies for eligibility and risk of bias by using the Amsterdam-Maastricht Consensus List. Ten randomized trials, seven patient series and four single-case studies were included. The studies were heterogeneous regarding design, size, conditions studied and outcome measures. Methodological quality varied; only a few studies were of high quality. Important clinical aspects, such as assessment of possible side effects, were only insufficiently addressed. For stroke there is a moderate quality of evidence that MT as an additional intervention improves recovery of arm function, and a low quality of evidence regarding lower limb function and pain after stroke. The quality of evidence in patients with complex regional pain syndrome and phantom limb pain is also low. Firm conclusions could not be drawn. Little is known about which patients are likely to benefit most from MT, and how MT should preferably be applied. Future studies with clear descriptions of intervention protocols should focus on standardized outcome measures and systematically register adverse effects.
Research Interests: Rehabilitation, Visual perception, Magnetic Resonance Imaging, Transcranial Magnetic Stimulation, Treatment Outcome, and 12 moreEvidence, Medicine, Stroke, Humans, Phantom limb, Scientific, Intervention, Therapy, Clinical Sciences, Publication, Recovery of Function, and Randomized Controlled Trials as Topic
The vascularization of 50 tumors of the central nervous system (CNS) including 17 meningiomas, 25 neuroectodermal tumors, i.e., astrocytomas, oligodendrogliomas, mixed gliomas, glioblastomas, medulloblastomas, seven metastatic carcinomas,... more
The vascularization of 50 tumors of the central nervous system (CNS) including 17 meningiomas, 25 neuroectodermal tumors, i.e., astrocytomas, oligodendrogliomas, mixed gliomas, glioblastomas, medulloblastomas, seven metastatic carcinomas, and one malignant hemangioendothelioma were investigated using biotinylated Ulex europaeus type I lectin (UEA I) in an indirect avidinbiotin-peroxidase procedure. The cytochemical staining pattern of UEA I on paraffin sections was compared with that of biotinylated Dolichos biflorus lectin (DBA), and with the immunocytochemical staining of factor VIII related antigen (F VIII/RAG) by polyclonal antisera using the PAP technique. UEA I visualized the endothelia of blood vessels with equal intensity, sensitivity, and reliability in normal brain and in tumor tissue with neovascularization. While large, medium, and small vessels were equally well demonstrated by UEA I and antibodies against FVIII/RAG, capillaries and endothelial sprouts were stained more consistently and intensely by UEA I. No reliable cytochemical staining could be obtained by DBA regardless of tissue or cell type investigated. It is concluded that UEA I is a highly useful cytochemical marker for the identification of vascular endothelia in paraffin sections of human brain tumors.
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Universal positive correlations between different cognitive tests motivate the concept of general intelligence or Spearman'sg. Here the neural basis for g is investigated by means of positron emission tomography. Spatial, verbal,... more
Universal positive correlations between different cognitive tests motivate the concept of general intelligence or Spearman'sg. Here the neural basis for g is investigated by means of positron emission tomography. Spatial, verbal, and perceptuo-motor tasks ...
Research Interests: Intelligence, Cognition, Science, Positron Emission Tomography, Multidisciplinary, and 15 moreBrain Mapping, Humans, Frontal Cortex, Clinical Sciences, Middle Aged, Optometry and Ophthalmology, Single Photon Emission Computed Tomography, Adult, Public health systems and services research, Cognitive Function, General Intelligence, Intelligence tests, Nuclear Magnetic Resonance Imaging, Frontal Lobe, and Psychomotor Performance
The factors determining recovery from hemiparetic stroke are manifold. We studied spontaneous arm movement activity in the acute phase after stroke as a predictor of recovery. Included in this prospective study were 25 patients... more
The factors determining recovery from hemiparetic stroke are manifold. We studied spontaneous arm movement activity in the acute phase after stroke as a predictor of recovery. Included in this prospective study were 25 patients (63 ± 10 years; 9 women, 16 men) with acute middle cerebral artery stroke and 7 control patients without neurological disease (61 ± 14 years; 3 women, 4 men). Movement activity was
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We studied the cerebral activations related to restitution of hand function in five patients with first hemiplegic subcortical stroke due to ischaemic infarction in the area of the basal ganglia or thalamus. In two subjects, involvement... more
We studied the cerebral activations related to restitution of hand function in five patients with first hemiplegic subcortical stroke due to ischaemic infarction in the area of the basal ganglia or thalamus. In two subjects, involvement of the cortico-spinal tract was demonstrated by magnetic evoked potentials. The subjects were requested to discriminate rectangular parallelepipeda of identical mass with their affected hands. Regional cerebral blood flow (rCBF) was measured with PET after intravenous bolus injection of [15O]butanol, at rest and during task execution. Evaluation of the rCBF changes was based on pixel-by-pixel t statistics of spatially standardized and averaged PET images and on a statistical distribution analysis of regions of interest in the individual subjects. For anatomical localization of the significant rCBF changes, a computerized brain atlas (Greitz et al. J Comput Assist Tomogr 1991; 15: 26-38) and a matching procedure that directly aligns individual PET and high resolution magnetic resonance images were used. The rCBF at rest and the task-induced rCBF changes varied from subject to subject, as did the residual neurological deficits at the time of PET scanning. In all subjects there were large activation areas in the motor and the sensory hand area contralateral to the affected hand. Poor performance of the task was correlated with a low rCBF in the contralateral sensorimotor cortex at rest and a bilateral activation of the primary sensorimotor cortex during task performance. The premotor cortex, ipsilateral and anterior cerebellum, contralateral to the affected hand, were also significantly activated. Further activations were observed in the contralateral premotor cortex, supplementary motor area and bilaterally in the posterior cingulate cortex, but were less consistent among the subjects. Our data suggest that recovery from hemiplegic stroke is associated with a marked reorganization of the cerebral activation patterns, including common and subject-specific activation sites. With respect to task-specific information processing a lower discrimination rate of objects compared with controls was associated with diminished activations in parietal lobe.
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We have developed, validated, and employed a technique of retrospective spatial alignment and integrated display of positron emission tomographic (PET) and high-resolution magnetic resonance (MR) brain images. The method was designed to... more
We have developed, validated, and employed a technique of retrospective spatial alignment and integrated display of positron emission tomographic (PET) and high-resolution magnetic resonance (MR) brain images. The method was designed to improve the anatomical evaluation of functional images obtained from single subjects. In the first computational step, alignment of PET and MR data sets is achieved by iteratively matching in three orthogonal views the outermost scalp contours derived from front-to-back projections of each data set. This procedure avoids true three-dimensional modeling, runs without user interaction, and tolerates missing parts of the head circumference in the image volume, as usually the case with PET. Thereafter, high-resolution MR sections corresponding to the PET slices are reconstructed from the spatially transformed MR data. In a phantom study of this method, PET/MR alignment of the phantom's surface was accurate with average residual misfits of 2.17 to 2.32 mm as determined in three orthogonal planes. In-plane alignment of the phantom's insertion holes was accurate with an average residual misfit of 2.30 mm. In vivo application in six subjects allowed the individual anatomical localization of regional CBF (rCBF) responses obtained during unilateral manual exploration. In each subject, the maxima of the rCBF activations in the hand area were precisely allocated to gray matter in the anterior or posterior wall of the central sulcus. The configuration of the rCBF responses closely followed the gyral structures. The technique provided a better topographical understanding of rCBF changes in subtraction images of PET activation studies. It opens the perspective for studies of structural–functional relationships in individual subjects.
Research Interests: Image Processing, Brain Imaging, Magnetic Resonance Imaging, Positron Emission Tomography, Brain, and 15 moreHumans, Functional Imaging, Structural equation models, Magnetic Resonance, Clinical Sciences, High Resolution, Cerebral, Single Photon Emission Computed Tomography, Three Dimensional, User Interaction, Neurosciences, Gray Matter, Motor activity, Magnetic resonance image, and Cardiovascular medicine and haematology
Research Interests: Psychology, Cognitive Science, Motion perception, Brain Mapping, Right Hemisphere Functions, and 17 moreHumans, Lateralization, Human Motion, Action Recognition, Female, Mirror Neuron System, Male, Mirror Neuron, Biological Motion, Somatosensory, Somatosensory Cortex, Visual Representation, Adult, Inferior frontal gyrus, Hemispheric Specialization, Visual Fields, and Neurosciences
The human propensity to believe is one of the most fascinating phenomena of mankind. Since antiquity, philosophers have spent time and energy trying to understand how and why humans are touched and influenced by their beliefs.... more
The human propensity to believe is one of the most fascinating phenomena of mankind. Since antiquity, philosophers have spent time and energy trying to understand how and why humans are touched and influenced by their beliefs. Nevertheless “belief” remains a strange phenomenon; it is both wanted and unwanted. Knowledge-based societies as well as either secular or strict religious worldviews can cast belief in a very negative light. Also, from a scientific point of view belief can be considered overly complex and heavily interwoven with religion. This chapter argues against the underestimation of the relevance of belief. It highlights the predominant use of the noun “belief” as one of the basic problems in both everyday speech and scientific research. But an understanding of belief that reduces it to only a noun is not sufficient. Beliefs are expressions and results of activities. This means that believing does not exist only as a noun, but also as a verb. We are active when we do wh...