Jens Volkmar Schwarzbach

• Prof. Dr. rer. nat.
• Professor at University Hospital Regensburg

Background Electroconvulsive therapy (ECT) is one of the most effective treatments for treatment-resistant depression, yet its precise mechanisms of action remain to be further elucidated. Among other effects, ECT induces an acute inflammatory immune response that might reinforce the expression of neurotrophins such as brain-derived neurotrophic fa...

Resting-state fMRI captures spontaneous neural activity characterized by complex spatiotemporal dynamics. Various metrics, such as local and global brain connectivity and low-frequency amplitude fluctuations, quantify distinct aspects of these dynamics. However, these measures are typically analyzed independently, overlooking their interrelations a...

Spontaneous neural activity observed in resting-state fMRI is characterized by complex spatio-temporal dynamics. Different measures related to local and global brain connectivity and fluctuations in low-frequency amplitudes can quantify individual aspects of these neural dynamics. Even though such measures are derived from the same functional signa...

Background: Deviating emotion perception affects the interpretation of emotional stimuli and is linked to mal adaptive emotion regulation. In adolescents with non-suicidal self-injury (NSSI), it remains unclear whether emotion regulation is altered from the earliest stage of visual emotion perception. The early visual system de composes visual sce...

The intensity of noxious stimuli usually shapes the perception of discomfort or pain. Here, we compare three mechanistic accounts of how cued expectation about stimulus intensity may modulate behavioral reports of discomfort: response gain, input gain or baseline shift. In two behavioral sessions, thirty-nine healthy participants rated a series of...

Recently, the gamma-aminobutyric acid (GABA) system has come into focus for the treatment of anxiety, postpartum depression, and major depressive disorder. Endogenous 3α-reduced steroids such as allopregnanolone are potent positive allosteric modulators of GABAA receptors and have been known for decades. Current industry developments and first appr...

The functional organization of brain networks maintains a delicate equilibrium between segregation and integration where it facilitates local neural communication together with effective global integration of information across network’s components. While numerous whole-brain imaging studies have linked alterations in functional topology to major d...

TSPO ligands are promising alternatives to benzodiazepines in the treatment of anxiety, as they display less pronounced side effects such as sedation, cognitive impairment, tolerance development and abuse potential. In a randomized double-blind repeated-measures study we compare a benzodiazepine (alprazolam) to a TSPO ligand (etifoxine) by assessin...

Background Recent developments suggest that neurosteroids may achieve rapid antidepressant effects. As such, neurosteroidogenesis mediated by the translocator protein 18 kDa (TSPO) might constitute a promising option for the treatment of depression. Therefore, the current clinical trial aims to get the first evidence of whether TPSO ligands promote...

Introduction In contrast to other sensory domains, detection of primary olfactory processes using functional magnetic resonance imaging has proven to be notably challenging with conventional block designs. This difficulty arises from significant habituation and hemodynamic responses in olfactory areas that do not appear to align with extended boxca...

Background Neurosteroids have recently gained in interest as a treatment strategy for affective disorders. Etifoxine is known for its dual mode of action, one of which is to stimulate endogenous neurosteroid synthesis. The gut microbiome has been studied in affective disorders, but it has not been investigated in the context of human etifoxine or n...

The complexity of our actions and thinking is likely reflected in functional brain networks. Independent component analysis (ICA) is a popular data-driven method to compute group differences between such networks. A common way to investigate network differences is based on ICA maps which are generated from study-specific samples. However, this appr...

Introduction There is a need for novel anxiolytics with improved side effect profiles compared to benzodiazepines. A promising candidate with alternative pharmacodynamics is the translocator protein ligand, etifoxine. Methods To get further insight into its mechanisms of action and side effects compared to the benzodiazepine alprazolam, we performe...

There is need for novel fast acting treatment options in affective disorders. 3α-reduced neurosteroids such as allopregnanolone are powerful positive allosteric modulators of GABAA receptors and target also extrasynaptic receptors. Their synthesis is mediated by the translocator protein 18 kDa (TSPO). TSPO ligands not only promote endogenous neuros...

Background The development of permanent disability in multiple sclerosis (MS) is highly variable among patients, and the exact mechanisms that contribute to this disability remain unknown. Methods Following the idea that the brain has intrinsic network organization, we investigated changes of functional networks in MS patients to identify possible...

Background Non-suicidal self-injury (NSSI) is a major mental health concern in adolescents worldwide. Dysfunctional emotion regulation is considered a primary contributor to NSSI, but research on alterations in emotion perception contributing to emotion dysregulation is limited. Accurate recognition of emotions in a social context determines how we...

Efficient treatment of stress-related disorders, such as depression, is still a major challenge. The onset of antidepressant drug action is generally quite slow, while the anxiolytic action of benzodiazepines is considerably faster. However, their long-term use is impaired by tolerance development, abuse liability and cognitive impairment. Benzodia...

Representational similarity analysis (RSA) is a popular multivariate analysis technique in cognitive neuroscience that uses functional neuroimaging to investigate the informational content encoded in brain activity. As RSA is increasingly being used to investigate more clinically-geared questions, the focus of such translational studies turns towar...

Schizophrenia is a complex psychiatric disorder that displays an outstanding interindividual variability in clinical manifestation and neurobiological substrates. A better characterization and quantification of this heterogeneity could guide the search for both common abnormalities (linked to lower intersubject variability) and the presence of biol...

An exploration of the neurological and behavioral mechanisms and processes involved in intrusive thinking. On any given day, unintended, recurrent thoughts intrude on our thinking and affect our behavior in ways that can be adaptive. Such thoughts, however, become intrusive and problematic when they are unwanted, become compulsive, or lead to socia...

Fear-generalization is a critical function for survival, in which an organism extracts information from a specific instantiation of a threat (e.g., the western diamondback rattlesnake in my front yard on Sunday) and learns to fear – and accordingly respond to – pertinent higher-order information (e.g., snakes live in my yard). Previous work investi...

Fear-generalization is a critical function for survival, in which an organism extracts information from a specific instantiation of a threat (e.g., the western diamondback rattlesnake in my front yard on Sunday) and learns to fear-and accordingly respond to-pertinent higher-order information (e.g., snakes live in my yard). Previous work investigati...

The complexity of our actions and thinking is likely reflected in functional brain networks. Independent component analysis (ICA) is a popular data-driven method to compute group differences between such networks. To aid interpretation of functional network analyses, Smith and colleagues proposed a template of ten functional networks identified in...

Echo-planar imaging (EPI) is the most common method of functional MRI for acquiring the blood oxygenation level-dependent (BOLD) contrast, allowing the acquisition of an entire brain volume within seconds. However, because imaging protocols are limited by hardware (e.g., fast gradient switching), researchers must compromise between spatial resoluti...

Different individuals respond differently to emotional stimuli in their environment. Therefore, to understand how emotions are represented mentally will ultimately require investigations into individual-level information. Here we tasked participants with freely arranging emotionally charged images on a computer screen according to their subjective...

Echo planar imaging (EPI) is the most common method of functional magnetic resonance imaging for acquiring the blood oxygenation level-dependent (BOLD) contrast. One of the primary benefits of using EPI is that an entire volume of the brain can be acquired on the order of two seconds. However, this speed benefit comes with a cost. Because imaging p...

Resting state fMRI is a tool for studying the functional organization of the human brain. Ongoing brain activity at “rest” is highly dynamic, but procedures such as correlation or independent component analysis treat functional connectivity (FC) as if, theoretically, it is stationary and therefore the fluctuations observed in FC are thought as nois...

Perceptual decision making is the cognitive process wherein the brain classifies stimuli into abstract categories for more efficient downstream processing. A system that, during categorization, can process information regardless of the information’s original sensory modality (i.e., a supramodal system) would have a substantial advantage over a syst...

Background Repetitive transcranial magnetic stimulation (rTMS) has become increasingly popular during the last decades mainly driven by the antidepressant effects of dorsolateral prefrontal cortex stimulation with “butterfly” coils. Only recently, alternative targets such as the dorsomedial prefrontal cortex (dmPFC) have been brought into focus and...

Multiple sclerosis is a debilitating disorder resulting from scattered lesions in the central nervous system. Because of the high variability of the lesion patterns between patients, it is difficult to relate existing biomarkers to symptoms and their progression. The scattered nature of lesions in multiple sclerosis offers itself to be studied thro...

Humans experience emotions every day. Traditionally, psychology has described emotions through discrete labels (e.g. happy, afraid) or standardized affective dimensions (e.g. valence, arousal), and neuroscience has more recently sought the neurobiological basis of emotions via functional neuroimaging. However, by treating emotions similarly among e...

While prior work has demonstrated that fear-conditioning changes the neural representation of previously neutral stimuli, it remains unknown to what extent this new representation abstracts away from specific fears and which brain areas are involved therein. To investigate this question, we sought commonalities between experimentally-induced fear v...

Many investigations into emotion processing contend that emotions can be reduced to a set of lower dimensions (e.g., valence and arousal). Additionally, emotion dysregulation is associated with numerous psychiatric disorders, whose treatment(s) may require inspiration from personalized medicine. To translate emotion research to the clinical domain,...

Many investigations into emotion processing contend that emotions can be reduced to a set of lower dimensions (e.g., valence and arousal). Additionally, emotion dysregulation is associated with numerous psychiatric disorders, whose treatment(s) may require inspiration from personalized medicine. To translate emotion research to the clinical domain,...

Resting state fMRI has been the primary tool for studying the functional organization of the human brain. However, even at so-called “rest”, ongoing brain activity and its underlying physiological organization is highly dynamic and yet most of the information generated so far comes from group analysis. Here we developed an imaging-based technique c...

Brain representations of visual space are predominantly eye-centered (retinotopic) yet our experience of the world is largely world-centered (spatiotopic). A long-standing question is how the brain creates continuity between these reference frames across successive eye movements (saccades). Here we use fMRI to address whether spatially specific rep...

10 sec at a rate of 3-4 taps per second alternating with a mean rest period of 25 sec (sd = 1.39) repeated for 20 blocks. Data acquisition and processing: Data for one participant was collected at the Stanford NIRS Lab [2,3] with an ETG-4000 Hitachi System. One 4x4 probe covered the motor cortex contralateral to the effector activated. We applied a...

Neuropsychological studies have described patients with a selective impairment of finger identification in association with posterior parietal lesions. However, evidence of the role of these areas in finger gnosis from studies of the healthy human brain is still scarce. Here we used functional magnetic resonance imaging to identify the brain networ...

Right hand finger tapping performed for 10 sec at a rate of 3-4 taps per second alternating with a mean rest period of 25 sec (sd = 1.39) repeated for 20 blocks. Data acquisition and processing: Data for one participant was collected at the Stanford NIRS Lab [2,3] with an ETG-4000 Hitachi System. One 4x4 probe covered the motor cortex contralateral...

Right hand finger tapping performed for 10 sec at a rate of 3-4 taps per second alternating with a mean rest period of 25 sec (sd = 1.39) repeated for 20 blocks. Data acquisition and processing: Data for one participant was collected at the Stanford NIRS Lab [2,3] with an ETG-4000 Hitachi System. One 4x4 probe covered the motor cortex contralateral...

We typically fixate targets such that they are projected onto the fovea for best spatial resolution. Macular degeneration patients often develop fixation strategies such that targets are projected to an intact eccentric part of the retina, called pseudofovea. A longstanding debate concerns which pseudofovea location is optimal for non-foveal vision...

Although the somatosensory homunculus is a classically used description of the way somatosensory inputs are processed in the brain, the actual contributions of primary (SI) and secondary (SII) somatosensory cortices to the spatial coding of touch remain poorly understood. We studied adaptation of the fMRI BOLD response in the somatosensory cortex b...

The effects of transcranial magnetic stimulation (TMS) vary depending on the brain state at the stimulation moment. Four mechanisms have been proposed to underlie these effects: (1) virtual lesion-TMS suppresses neural signals; (2) preferential activation of less active neurons-TMS drives up activity in the stimulated area, but active neurons are s...

The posterior superior temporal sulcus (pSTS) is active when observing biological motion. We investigated the functional connections of the pSTS node within the action observation network by measuring the after-effect of focal repetitive transcranial magnetic stimulation (rTMS) with whole-brain functional magnetic resonance imaging (fMRI). Particip...

The effects of transcranial magnetic stimulation (TMS) can vary radically according to the state in which the brain is at the moment of stimulation. Two possible mechanisms by which single magnetic stimuli produce different effects according to the initial activation state of targeted neurons have been proposed: (i) TMS suppresses neural signals an...

Neuropsychological evidence has highlighted the role of the anterior temporal lobes in the processing of conceptual knowledge. That putative role is only beginning to be investigated with fMRI as methodological advances are able to compensate for well-known susceptibility artifacts that affect the quality of the BOLD signal. In this article, we des...

The cognitive neurosciences combine behavioral experiments with acquiring physiological data from different modalities, such as electroencephalography, magnetoencephalography, transcranial magnetic stimulation, and functional magnetic resonance imaging, all of which require excellent timing. A simple framework is proposed in which uni- and multimod...

In normal vision, shifts of attention and gaze are tightly coupled. Here we ask if this coupling affects performance also when central vision is not available. To this aim, we trained normal-sighted participants to perform a visual search task while vision was restricted to a gaze-contingent viewing window ("forced field location") either in the le...

A transcranial magnetic stimulation (TMS) adaptation paradigm was used to investigate the neural representation of observed motor behavior in the inferior parietal lobule (IPL), ventral premotor cortex (PMv), and in the cortex around the superior temporal sulcus (STS). Participants were shown adapting movies of a hand or a foot acting on different...

We present an experiment designed to test whether experienced regret and rejoicing evoked in a risk choice have an impact on subsequent intertemporal choice. We found that regret and rejoicing experienced prior to an intertemporal choice influenced considerably the way people relate to future: when regret was experienced participants preferred not...

Tool use depends on processes represented in distinct regions of left parietal cortex. We studied the role of visual experience in shaping neural specificity for tools in parietal cortex by using functional magnetic resonance imaging with sighted, late-blind, and congenitally blind participants. Using a region-of-interest approach in which tool-spe...

Distinct regions within the ventral visual pathway show neural specialization for nonliving and living stimuli (e.g., tools, houses versus animals, faces). The causes of these category preferences are widely debated. Using functional magnetic resonance imaging, we find that the same regions of the ventral stream that show category preferences for n...

Recent psychophysics studies suggest that the behavioral impact of a visual stimulus and its conscious visual recognition underlie two functionally dissociated neuronal processes. Previous TMS studies have demonstrated that certain features of a visual stimulus can still be processed despite TMS-induced disruption of perception. Here, we tested whe...

Forcing normal-sighted participants to use a distinct parafoveal retinal location for reading, we studied which part of the visual field is best suited to take over functions of the fovea during early stages of macular degeneration (MD). A region to the right of fixation lead to best reading performance and most natural gaze behavior, whereas readi...

Because our brain cannot process all visual information that enters it, we usually pay attention to only a specific aspect of our visual world. Selective visual attention modulates brain activation in cortical areas corresponding to the attended spatial location. However, visual attention has also been associated with the modulation of activation i...

Theoretical and empirical body of research have exposed the powerful role of experiencing regret in guiding choice behavior. In this paper, we examined the impact of experienced regret and rejoicing induced by feedback provided on a risk decision prior to a two-period intertemporal choice. To our knowledge, this is the first attempt to bring togeth...

Written language comprehension at the word and the sentence level was analysed by the combination of spatial and temporal analysis of functional magnetic resonance imaging (fMRI). Spatial analysis was performed via general linear modelling (GLM). Concerning the temporal analysis, local differences in neurovascular coupling may confound a direct com...

We used event-related functional magnetic resonance imaging (erfMRI) to investigate the neural basis of biological and syntactic gender integration during pronoun processing in German sentences about persons or things. German allows for separating both processes experimentally. Overall, syntactic processing activated areas adjacent to Broca's area...

Our visual world can be thought of as organised in a hierarchical manner. Studies on hierarchical letter stimuli (a large letter composed of smaller letters) suggest that processing of a visual scene is global to local, a phenomenon known as the global-precedence effect. Elaborating on this global-to-local hypothesis we tested whether global interf...

Neurophysiological studies in monkeys show that multiple stimuli presented within the receptive field of a neuron are not processed independently but rather act in a mutually suppressive way. Recently, such suppressive interactions have also been reported in human neuroimaging studies. This is seen as evidence that stimuli compete for neural repres...

Recent advances in the study of visual cognition and consciousness have dealt primarily with steady-state properties of visual processing, with little attention to its dynamic aspects. The First Half Second brings together for the first time the latest research on the dynamics of conscious and unconscious processing of visual information, examining...

Early components of visual evoked potentials (VEP) in EEG seem to be unaffected by target visibility in visual masking studies. Bridgeman's reanalysis of Jeffreys and Musselwhite's (1986) data suggests that a later visual component in the VEP, around 250 ms reflects the perceptual effect of masking. We challenge this view on the ground that tempora...

Using event-related functional magnetic resonance imaging, we studied the activation correlating with the awareness of stereoscopic depth using a bistable slanted surface (slant rivalry). Bistability resulted from incongruence between two slant-defining cues: binocular disparity and monocular perspective. The stimulus was perceived as alternating b...

The blood oxygen level dependent (BOLD) response, as measured with fMRI, offers good spatial resolution compared to other non-invasive neuroimaging methods. The use of a spin echo technique rather than the conventional gradient echo technique may further improve the resolution by refocusing static dephasing effects around the larger vessels, so sen...

If attending to a target in a rapid stream of visual stimuli within the next 400 ms or so, a second target in the stream is frequently not detected by an observer. This so-called attentional blink can provide a comparison of neural signals elicited by identical stimuli that, in one condition, reach conscious awareness and, in the other, fail to be...

Visual attention is a mechanism by which observers select relevant or important information from the current visual array. Previous investigations have focused primarily on the ability to select a region of space for further visual analysis. These studies have revealed a distributed frontoparietal circuit that is responsible for the control of spat...

The findings reported in this paper show that perceptual measures based on conscious reports do not suffice to determine whether some information is or is not available to the visual system at large. Instead, motor and perceptual effects can be become perfectly dissociated. This indicates that relevant stimulus attributes are fully processed up to...

Allocating attention to a spatial location in the visual field is associated with an increase in the cortical response evoked by a stimulus at that location, compared to when the same stimulus is unattended. We used event-related functional magnetic resonance imaging to investigate attentional modulation of the cortical response to a stimulus probe...

Visual stimuli may remain invisible but nevertheless produce strong and reliable effects on subsequent actions. How well features of a masked prime are perceived depends crucially on its physical parameters and those of the mask. We manipulated the visibility of masked stimuli and contrasted it with their influence on the speed of motor actions, co...

Moving dots can evoke a percept of the spatial structure of a three-dimensional object in the absence of other visual cues. This phenomenon, called structure from motion (SFM), suggests that the motion flowfield represented in the dorsal stream can form the basis of object recognition performed in the ventral stream. SFM processing is likely to con...

Observers viewing a complex visual scene selectively attend to relevant locations or objects and ignore irrelevant ones. Selective attention to an object enhances its neural representation in extrastriate cortex, compared with those of unattended objects, via top-down attentional control signals. The posterior parietal cortex is centrally involved...

We dealt with the challenge of cognitive brain state prediction as proposed by the Pittsburgh Brain Activity Interpretation Competition (PBAIC) 2007. The problem was decomposed in many subsequent steps: pre-processing, feature selection, learning model selection, model training, and post-processing. We investigated the steps combining unsupervised...

Braunschweig, Techn. University, Diss., 1999. Computerdatei im Fernzugriff.