Thomas F. Münte

YNIMG Journal 2021 Journal Article

Technical Note: Modulation of fMRI brainstem responses by transcutaneous vagus nerve stimulation

• Diba Borgmann
• Lionel Rigoux
• Bojana Kuzmanovic
• Sharmili Edwin Thanarajah
• Thomas F. Münte
• Henning Fenselau
• Marc Tittgemeyer

Our increasing knowledge about gut-brain interaction is revolutionising the understanding of the links between digestion, mood, health, and even decision making in our everyday lives. In support of this interaction, the vagus nerve is a crucial pathway transmitting diverse gut-derived signals to the brain to monitor of metabolic status, digestive processes, or immune control to adapt behavioural and autonomic responses. Hence, neuromodulation methods targeting the vagus nerve are currently explored as a treatment option in a number of clinical disorders, including diabetes, chronic pain, and depression. The non-invasive variant of vagus nerve stimulation (VNS), transcutaneous auricular VNS (taVNS), has been implicated in both acute and long-lasting effects by modulating afferent vagus nerve target areas in the brain. The physiology of neither of those effects is, however, well understood, and evidence for neuronal response upon taVNS in vagal afferent projection regions in the brainstem and its downstream targets remain to be established. Therefore, to examine time-dependent effects of taVNS on brainstem neuronal responses in healthy human subjects, we applied taVNS during task-free fMRI in a single-blinded crossover design. During fMRI data acquisition, we either stimulated the left earlobe (sham), or the target zone of the auricular branch of the vagus nerve in the outer ear (cymba conchae, verum) for several minutes, both followed by a short 'stimulation OFF' period. Time-dependent effects were assessed by averaging the BOLD response for consecutive 1-minute periods in an ROI-based analysis of the brainstem. We found a significant response to acute taVNS stimulation, relative to the control condition, in downstream targets of vagal afferents, including the nucleus of the solitary tract, the substantia nigra, and the subthalamic nucleus. Most of these brainstem regions remarkably showed increased activity in response to taVNS, and these effect sustained during the post-stimulation period. These data demonstrate that taVNS activates key brainstem regions, and highlight the potential of this approach to modulate vagal afferent signalling. Furthermore, we show that carry-over effects need to be considered when interpreting fMRI data in the context of general vagal neurophysiology and its modulation by taVNS.

YNIMG Journal 2020 Journal Article

Effects of hunger, satiety and oral glucose on effective connectivity between hypothalamus and insular cortex

• Arkan Al-Zubaidi
• Sandra Iglesias
• Klaas E. Stephan
• Macià Buades-Rotger
• Marcus Heldmann
• Janis Marc Nolde
• Henriette Kirchner
• Alfred Mertins

The hypothalamus and insular cortex play an essential role in the integration of endocrine and homeostatic signals and their impact on food intake. Resting-state functional connectivity alterations of the hypothalamus, posterior insula (PINS) and anterior insula (AINS) are modulated by metabolic states and caloric intake. Nevertheless, a deeper understanding of how these factors affect the strength of connectivity between hypothalamus, PINS and AINS is missing. This study investigated whether effective (directed) connectivity within this network varies as a function of prandial states (hunger vs. satiety) and energy availability (glucose levels and/or hormonal modulation). To address this question, we measured twenty healthy male participants of normal weight twice: once after 36 ​h of fasting (except water consumption) and once under satiated conditions. During each session, resting-state functional MRI (rs-fMRI) and hormone concentrations were recorded before and after glucose administration. Spectral dynamic causal modeling (spDCM) was used to assess the effective connectivity between the hypothalamus and anterior and posterior insula. Using Bayesian model selection, we observed that the same model was identified as the most likely model for each rs-fMRI recording. Compared to satiety, the hunger condition enhanced the strength of the forward connections from PINS to AINS and reduced the strength of backward connections from AINS to PINS. Furthermore, the strength of connectivity from PINS to AINS was positively related to plasma cortisol levels in the hunger condition, mainly before glucose administration. However, there was no direct relationship between glucose treatment and effective connectivity. Our findings suggest that prandial states modulate connectivity between PINS and AINS and relate to theories of interoception and homeostatic regulation that invoke hierarchical relations between posterior and anterior insula.

YNICL Journal 2020 Journal Article

Patients with mutations of the Thyroid hormone beta-receptor show an ADHD-like phenotype for performance monitoring: an electrophysiological study

• Jan Uter
• Marcus Heldmann
• Berenike Rogge
• Martina Obst
• Julia Steinhardt
• Georg Brabant
• Carla Moran
• Krishna Chatterjee

Resistance to thyroid hormone beta (RTHβ) is a syndrome of reduced responsiveness of peripheral tissue to thyroid hormone, caused by mutations in the thyroid hormone receptor beta (THRB). Its cognitive phenotype has been reported to be similar to attention deficit hyperactivity disorder (ADHD). This study used electrophysiological biomarkers of performance monitoring in RTHβ to contribute further evidence on its phenotypical similarity to ADHD. Twenty-one participants with RTHβ aged 18-67 years and 21 matched healthy controls performed a modified flanker task during EEG recording. The RTHβ and control groups were compared on behavioural measures and components of event related potentials (ERPs), i.e. the error related negativity (ERN), the error positivity (Pe) and P3 component. There were no significant group differences with regard to behaviour. RTHβ subjects displayed significantly reduced ERN and Pe amplitudes compared to the controls in the response-locked ERPs. In addition, we observed reduced P3 amplitudes in both congruent and incongruent trials, as well as prolonged P3 latencies in RTHβ subjects in the stimulus-locked ERPs. Our findings reveal alterations in error detection and performance monitoring of RTHβ patients, likely indicating reduced error awareness. The electrophysiological phenotype of RTHß subjects with regard to action monitoring is indistinguishable from ADHD.

YNIMG Journal 2019 Journal Article

Quantifying the individual auditory and visual brain response in 7-month-old infants watching a brief cartoon movie

• Sarah Jessen
• Lorenz Fiedler
• Thomas F. Münte
• Jonas Obleser

Electroencephalography (EEG) continues to be the most popular method to investigate cognitive brain mechanisms in young children and infants. Most infant studies rely on the well-established and easy-to-use event-related brain potential (ERP). As a severe disadvantage, ERP computation requires a large number of repetitions of items from the same stimulus-category, compromising both ERPs’ reliability and their ecological validity in infant research. We here explore a way to investigate infant continuous EEG responses to an ongoing, engaging signal (i. e. , “neural tracking”) by using multivariate temporal response functions (mTRFs), an approach increasingly popular in adult EEG research. N = 52 infants watched a 5-min episode of an age-appropriate cartoon while the EEG signal was recorded. We estimated and validated forward encoding models of auditory-envelope and visual-motion features. We compared individual and group-based (‘generic’) models of the infant brain response to comparison data from N = 28 adults. The generic model yielded clearly defined response functions for both, the auditory and the motion regressor. Importantly, this response profile was present also on an individual level, albeit with lower precision of the estimate but above-chance predictive accuracy for the modelled individual brain responses. In sum, we demonstrate that mTRFs are a feasible way of analyzing continuous EEG responses in infants. We observe robust response estimates both across and within participants from only 5 min of recorded EEG signal. Our results open ways for incorporating more engaging and more ecologically valid stimulus materials when probing cognitive, perceptual, and affective processes in infants and young children.

YNICL Journal 2018 Journal Article

Increased insula-putamen connectivity in X-linked dystonia-parkinsonism

• Anne J. Blood
• Jeff L. Waugh
• Thomas F. Münte
• Marcus Heldmann
• Aloysius Domingo
• Christine Klein
• Hans C. Breiter
• Lillian V. Lee

Preliminary evidence from postmortem studies of X-linked dystonia-parkinsonism (XDP) suggests tissue loss may occur first and/or most severely in the striatal striosome compartment, followed later by cell loss in the matrix compartment. However, little is known about how this relates to pathogenesis and pathophysiology. While MRI cannot visualize these striatal compartments directly in humans, differences in relative gradients of afferent cortical connectivity across compartments (weighted toward paralimbic versus sensorimotor cortex, respectively) can be used to infer potential selective loss in vivo. In the current study we evaluated relative connectivity of paralimbic versus sensorimotor cortex with the caudate and putamen in 17 individuals with XDP and 17 matched controls. Although caudate and putamen volumes were reduced in XDP, there were no significant reductions in either "matrix-weighted", or "striosome-weighted" connectivity. In fact, paralimbic connectivity with the putamen was elevated, rather than reduced, in XDP. This was driven most strongly by elevated putamen connectivity with the anterior insula. There was no relationship of these findings to disease duration or striatal volume, suggesting insula and/or paralimbic connectivity in XDP may develop abnormally and/or increase in the years before symptom onset.

YNICL Journal 2017 Journal Article

Cerebellar degeneration affects cortico-cortical connectivity in motor learning networks

• Elinor Tzvi
• Christoph Zimmermann
• Richard Bey
• Thomas F. Münte
• Matthias Nitschke
• Ulrike M. Krämer

The cerebellum plays an important role in motor learning as part of a cortico-striato-cerebellar network. Patients with cerebellar degeneration typically show impairments in different aspects of motor learning, including implicit motor sequence learning. How cerebellar dysfunction affects interactions in this cortico-striato-cerebellar network is poorly understood. The present study investigated the effect of cerebellar degeneration on activity in causal interactions between cortical and subcortical regions involved in motor learning. We found that cerebellar patients showed learning-related increase in activity in two regions known to be involved in learning and memory, namely parahippocampal cortex and cerebellar Crus I. The cerebellar activity increase was observed in non-learners of the patient group whereas learners showed an activity decrease. Dynamic causal modeling analysis revealed that modulation of M1 to cerebellum and putamen to cerebellum connections were significantly more negative for sequence compared to random blocks in controls, replicating our previous results, and did not differ in patients. In addition, a separate analysis revealed a similar effect in connections from SMA and PMC to M1 bilaterally. Again, neural network changes were associated with learning performance in patients. Specifically, learners showed a negative modulation from right SMA to right M1 that was similar to controls, whereas this effect was close to zero in non-learners. These results highlight the role of cerebellum in motor learning and demonstrate the functional role cerebellum plays as part of the cortico-striato-cerebellar network.

YNIMG Journal 2017 Journal Article

Valsalva-induced elevation of intracranial pressure selectively decouples deoxygenated hemoglobin concentration from neuronal activation and functional brain imaging capability

• Martin Knauth
• Marcus Heldmann
• Thomas F. Münte
• Georg Royl

During neuronal activation, neurovascular coupling leads to a local decrease of deoxygenated hemoglobin concentration (deoxy-Hb) and thus forms the basis of many functional brain mapping methods. In animals, an elevated intracranial pressure (ICP) can attenuate or even reverse this deoxy-Hb signaling. To study the effect of an elevated ICP on functional brain imaging in humans, we used different breathing tasks to modify ICP and analyzed the resulting effect on neurovascular coupling in the motor cortex. Functional near-infrared spectroscopy (fNIRS) was performed on 45 subjects during alternating conditions of finger tapping and resting state combined with four different breathing maneuvers (normal breathing (NB), breath holding without Valsalva maneuver (BH), Valsalva maneuver with 15 mm Hg forced expiratory pressure against resistance (V15) and Valsalva maneuver with 35 mm Hg forced expiratory pressure against resistance (V35)) in randomized order. With escalation of breathing tasks the median amplitude of the functional deoxy-Hb decrease during finger tapping became smaller. In contrast, functional oxygenated hemoglobin concentration (oxy-Hb) and total hemoglobin concentration (total-Hb) responses did not show a significant alteration. The functional oxy-Hb map evoked by finger tapping withstood Valsalva challenges while the functional deoxy-Hb map identified the correct motor cortex in normal breathing conditions only and did not reveal a functional contrast during Valsalva maneuvers. In summary, we conclude that during ICP elevation, deoxy-Hb is not a reliable basis for functional brain imaging. This suggests that the validity of BOLD fMRI during increased ICP might be impaired.

YNIMG Journal 2017 Journal Article

Viewing socio-affective stimuli increases connectivity within an extended default mode network

• Martin Göttlich
• Zheng Ye
• Antoni Rodriguez-Fornells
• Thomas F. Münte
• Ulrike M. Krämer

Empathy is an essential ability for prosocial behavior. Previous imaging studies identified a number of brain regions implicated in affective and cognitive aspects of empathy. In this study, we investigated the neural correlates of empathy from a network perspective using graph theory and beta-series correlations. Two independent data sets were acquired using the same paradigm that elicited empathic responses to socio-affective stimuli. One data set was used to define the network nodes and modular structure, the other data set was used to investigate the effects of emotional versus neutral stimuli on network connectivity. Emotional relative to neutral stimuli increased connectivity between 74 nodes belonging to different networks. Most of these nodes belonged to an extended default mode network (eDMN). The other nodes belonged to a cognitive control network or visual networks. Within the eDMN, posterior STG/TPJ regions were identified as provincial hubs. The eDMN also showed stronger connectivity to the cognitive control network encompassing lateral PFC regions. Connector hubs between the two networks were posterior cingulate cortex and ventrolateral PFC. This stresses the advantage of a network approach as regions similarly modulated by task conditions can be dissociated into distinct networks and regions crucial for network integration can be identified.

YNICL Journal 2016 Journal Article

Neurophysiological evidence of impaired self-monitoring in schizotypal personality disorder and its reversal by dopaminergic antagonism

• Mireia Rabella
• Eva Grasa
• Iluminada Corripio
• Sergio Romero
• Miquel Àngel Mañanas
• Rosa Mª. Antonijoan
• Thomas F. Münte
• Víctor Pérez

BACKGROUND: Schizotypal personality disorder (SPD) is a schizophrenia-spectrum disorder characterized by odd or bizarre behavior, strange speech, magical thinking, unusual perceptual experiences, and social anhedonia. Schizophrenia proper has been associated with anomalies in dopaminergic neurotransmission and deficits in neurophysiological markers of self-monitoring, such as low amplitude in cognitive event-related brain potentials (ERPs) like the error-related negativity (ERN), and the error positivity (Pe). These components occur after performance errors, rely on adequate fronto-striatal function, and are sensitive to dopaminergic modulation. Here we postulated that analogous to observations in schizophrenia, SPD individuals would show deficits in self-monitoring, as measured by the ERN and the Pe. We also assessed the capacity of dopaminergic antagonists to reverse these postulated deficits. METHODS: We recorded the electroencephalogram (EEG) from 9 SPD individuals and 12 healthy controls in two separate experimental sessions while they performed the Eriksen Flanker Task, a classical task recruiting behavioral monitoring. Participants received a placebo or 1 mg risperidone according to a double-blind randomized design. RESULTS: After placebo, SPD individuals showed slower reaction times to hits, longer correction times following errors and reduced ERN and Pe amplitudes. While risperidone impaired performance and decreased ERN and Pe in the control group, it led to behavioral improvements and ERN amplitude increases in the SPD individuals. CONCLUSIONS: These results indicate that SPD individuals show deficits in self-monitoring analogous to those in schizophrenia. These deficits can be evidenced by neurophysiological measures, suggest a dopaminergic imbalance, and can be reverted by dopaminergic antagonists.

YNIMG Journal 2016 Journal Article

Reduced alpha-gamma phase amplitude coupling over right parietal cortex is associated with implicit visuomotor sequence learning

• Elinor Tzvi
• Rolf Verleger
• Thomas F. Münte
• Ulrike M. Krämer

Implicit visuomotor sequence learning is important for our daily life, e. g. , when writing or playing an instrument. Previous research identified a network of cortical regions that is relevant for motor sequence learning, namely primary motor cortex, premotor cortex, superior parietal cortex, and subcortical regions, including basal ganglia and cerebellum. Here, we investigated learning-related changes in oscillatory activity (theta, alpha and gamma power) and cross-frequency interactions (theta- and alpha-gamma phase-amplitude coupling) within cortical regions during sensorimotor memory formation. EEG was recorded from a large group of participants (n =73) performing the serial reaction time task (SRTT). Posterior parietal alpha power was larger early-on during sequence learning and smaller in later sessions. Alpha/low-gamma (8–13Hz and 30–48Hz) phase-amplitude coupling (PAC) was significantly smaller during sequence learning over right superior parietal cortex and frontal cortex. During the transition from sequential stimuli to random stimuli, participants made more errors, indicating that they still implicitly attempted to implement the learned motor sequence. At the same time, alpha/low-gamma phase-amplitude coupling was found to be smaller during the transition relative to later random trials. Our results show that learning and implementing a learned motor sequence reduces alpha/low-gamma PAC over parietal and frontal cortex. Fronto-parietal alpha/low-gamma PAC might be relevant for visuomotor mapping which becomes less relevant once the motor sequence has been encoded.

YNIMG Journal 2016 Journal Article

Structural neuroplasticity in expert pianists depends on the age of musical training onset

• Lucía Vaquero
• Karl Hartmann
• Pablo Ripollés
• Nuria Rojo
• Joanna Sierpowska
• Clément François
• Estela Càmara
• Floris Tijmen van Vugt

In the last decade, several studies have investigated the neuroplastic changes induced by long-term musical training. Here we investigated structural brain differences in expert pianists compared to non-musician controls, as well as the effect of the age of onset (AoO) of piano playing. Differences with non-musicians and the effect of sensitive periods in musicians have been studied previously, but importantly, this is the first time in which the age of onset of music-training was assessed in a group of musicians playing the same instrument, while controlling for the amount of practice. We recruited a homogeneous group of expert pianists who differed in their AoO but not in their lifetime or present amount of training, and compared them to an age-matched group of non-musicians. A subset of the pianists also completed a scale-playing task in order to control for performance skill level differences. Voxel-based morphometry analysis was used to examine gray-matter differences at the whole-brain level. Pianists showed greater gray matter (GM) volume in bilateral putamen (extending also to hippocampus and amygdala), right thalamus, bilateral lingual gyri and left superior temporal gyrus, but a GM volume shrinkage in the right supramarginal, right superior temporal and right postcentral gyri, when compared to non-musician controls. These results reveal a complex pattern of plastic effects due to sustained musical training: a network involved in reinforcement learning showed increased GM volume, while areas related to sensorimotor control, auditory processing and score-reading presented a reduction in the volume of GM. Behaviorally, early-onset pianists showed higher temporal precision in their piano performance than late-onset pianists, especially in the left hand. Furthermore, early onset of piano playing was associated with smaller GM volume in the right putamen and better piano performance (mainly in the left hand). Our results, therefore, reveal for the first time in a single large dataset of healthy pianists the link between onset of musical practice, behavioral performance, and putaminal gray matter structure. In summary, skill-related plastic adaptations may include decreases and increases in GM volume, dependent on an optimization of the system caused by an early start of musical training. We believe our findings enrich the plasticity discourse and shed light on the neural basis of expert skill acquisition.

YNIMG Journal 2015 Journal Article

Microstructure of the superior longitudinal fasciculus predicts stimulation-induced interference with on-line motor control

• Borja Rodríguez-Herreros
• Julià L. Amengual
• Ane Gurtubay-Antolín
• Lars Richter
• Philipp Jauer
• Christian Erdmann
• Achim Schweikard
• Joan López-Moliner

A cortical visuomotor network, comprising the medial intraparietal sulcus (mIPS) and the dorsal premotor area (PMd), encodes the sensorimotor transformations required for the on-line control of reaching movements. How information is transmitted between these two regions and which pathways are involved, are less clear. Here, we use a multimodal approach combining repetitive transcranial magnetic stimulation (rTMS) and diffusion tensor imaging (DTI) to investigate whether structural connectivity in the ‘reaching’ circuit is associated to variations in the ability to control and update a movement. We induced a transient disruption of the neural processes underlying on-line motor adjustments by applying 1Hz rTMS over the mIPS. After the stimulation protocol, participants globally showed a reduction of the number of corrective trajectories during a reaching task that included unexpected visual perturbations. A voxel-based analysis revealed that participants exhibiting higher fractional anisotropy (FA) in the second branch of the superior longitudinal fasciculus (SLF II) suffered less rTMS-induced behavioral impact. These results indicate that the microstructural features of the white matter bundles within the parieto-frontal ‘reaching’ circuit play a prominent role when action reprogramming is interfered. Moreover, our study suggests that the structural alignment and cohesion of the white matter tracts might be used as a predictor to characterize the extent of motor impairments.

YNIMG Journal 2015 Journal Article

Multiple brain networks underpinning word learning from fluent speech revealed by independent component analysis

• Diana López-Barroso
• Pablo Ripollés
• Josep Marco-Pallarés
• Bahram Mohammadi
• Thomas F. Münte
• Anne-Catherine Bachoud-Lévi
• Antoni Rodriguez-Fornells
• Ruth de Diego-Balaguer

Although neuroimaging studies using standard subtraction-based analysis from functional magnetic resonance imaging (fMRI) have suggested that frontal and temporal regions are involved in word learning from fluent speech, the possible contribution of different brain networks during this type of learning is still largely unknown. Indeed, univariate fMRI analyses cannot identify the full extent of distributed networks that are engaged by a complex task such as word learning. Here we used Independent Component Analysis (ICA) to characterize the different brain networks subserving word learning from an artificial language speech stream. Results were replicated in a second cohort of participants with a different linguistic background. Four spatially independent networks were associated with the task in both cohorts: (i) a dorsal Auditory-Premotor network; (ii) a dorsal Sensory-Motor network; (iii) a dorsal Fronto-Parietal network; and (iv) a ventral Fronto-Temporal network. The level of engagement of these networks varied through the learning period with only the dorsal Auditory-Premotor network being engaged across all blocks. In addition, the connectivity strength of this network in the second block of the learning phase correlated with the individual variability in word learning performance. These findings suggest that: (i) word learning relies on segregated connectivity patterns involving dorsal and ventral networks; and (ii) specifically, the dorsal auditory-premotor network connectivity strength is directly correlated with word learning performance.

YNICL Journal 2014 Journal Article

Altered resting-state functional connectivity in patients with chronic bilateral vestibular failure

• Martin Göttlich
• Nico M. Jandl
• Jann F. Wojak
• Andreas Sprenger
• Janina von der Gablentz
• Thomas F. Münte
• Ulrike M. Krämer
• Christoph Helmchen

Patients with bilateral vestibular failure (BVF) suffer from gait unsteadiness, oscillopsia and impaired spatial orientation. Brain imaging studies applying caloric irrigation to patients with BVF have shown altered neural activity of cortical visual-vestibular interaction: decreased bilateral neural activity in the posterior insula and parietal operculum and decreased deactivations in the visual cortex. It is unknown how this affects functional connectivity in the resting brain and how changes in connectivity are related to vestibular impairment. We applied a novel data driven approach based on graph theory to investigate altered whole-brain resting-state functional connectivity in BVF patients (n= 22) compared to age- and gender-matched healthy controls (n= 25) using resting-state fMRI. Changes in functional connectivity were related to subjective (vestibular scores) and objective functional parameters of vestibular impairment, specifically, the adaptive changes during active (self-guided) and passive (investigator driven) head impulse test (HIT) which reflects the integrity of the vestibulo-ocular reflex (VOR). BVF patients showed lower bilateral connectivity in the posterior insula and parietal operculum but higher connectivity in the posterior cerebellum compared to controls. Seed-based analysis revealed stronger connectivity from the right posterior insula to the precuneus, anterior insula, anterior cingulate cortex and the middle frontal gyrus. Excitingly, functional connectivity in the supramarginal gyrus (SMG) of the inferior parietal lobe and posterior cerebellum correlated with the increase of VOR gain during active as compared to passive HIT, i.e., the larger the adaptive VOR changes the larger was the increase in regional functional connectivity. Using whole brain resting-state connectivity analysis in BVF patients we show that enduring bilateral deficient or missing vestibular input leads to changes in resting-state connectivity of the brain. These changes in the resting brain are robust and task-independent as they were found in the absence of sensory stimulation and without a region-related a priori hypothesis. Therefore they may indicate a fundamental disease-related change in the resting brain. They may account for the patients' persistent deficits in visuo-spatial attention, spatial orientation and unsteadiness. The relation of increasing connectivity in the inferior parietal lobe, specifically SMG, to improvement of VOR during active head movements reflects cortical plasticity in BVF and may play a clinical role in vestibular rehabilitation.

YNIMG Journal 2014 Journal Article

Delineating the cortico-striatal-cerebellar network in implicit motor sequence learning

• Elinor Tzvi
• Thomas F. Münte
• Ulrike M. Krämer

Theoretical models and experimental evidence suggest that cortico-striatal-cerebellar networks play a crucial role in mediating motor sequence learning. However, how these different regions interact in order to mediate learning is less clear. In the present fMRI study, we used dynamic causal modeling to investigate effective connectivity within the cortico-striatal-cerebellar network while subjects performed a serial reaction time task. Using Bayesian model selection and family wise inference, we show that the cortico-cerebellar loop had higher model evidence than the cortico-striatal loop during motor learning. We observed significant negative modulatory effects on the connections from M1 to cerebellum bilaterally during learning. The results suggest that M1 causes the observed decrease in activity in the cerebellum as learning progresses. The current study stresses the significant role that the cerebellum plays in motor learning as previously suggested by fMRI studies in healthy subjects as well as behavioral studies in patients with cerebellar dysfunction. These results provide important insight into the neural mechanisms underlying motor learning.

YNIMG Journal 2013 Journal Article

Rapid event-related near-infrared spectroscopy detects age-related qualitative changes in the neural correlates of response inhibition

• Urs Heilbronner
• Thomas F. Münte

Near-infrared spectroscopy (NIRS) is a promising neuroimaging tool for the study of human cognition. Here, we show that event-related NIRS is able to detect age-related differences in the neural processing in a simple visual Go/NoGo task using a relatively fast (stimulus onset asynchrony approx. 1. 4s) event-related design together with a model-based analysis approach. Subjects were healthy young (<30years) and elderly (>60years) adults. Behaviorally, old adults were slower but more accurate than young adults. The event-related analysis approach of NIRS data allowed us to contrast activation of successfully inhibited NoGo stimuli with that of correctly answered Go stimuli. Both age-groups showed frontal activation differences between these events in oxy- (HbO; increase) and deoxyhemoglobin (HbR; decrease). Between age groups, differences in HbR were found in right dorsolateral frontal (old>young), right temporal/postcentral/precentral and left precentral/inferior frontal (young>old) channels. These differences are in line with age-associated activation changes in inhibition detected with functional magnetic resonance imaging. The present study successfully separated the neural correlates of response inhibition from errors of commission/omission and provides data from multiple simultaneously recorded optodes. Furthermore, these results demonstrate the feasibility of using NIRS to investigate neural processes related to aging and dementia, in particular in patients for which other neuroimaging techniques are contraindicated. In the future, functional phenotyping of successful aging in respect to executive performance may be feasible.

YNIMG Journal 2012 Journal Article

Magneto- and electroencephalographic manifestations of reward anticipation and delivery

• Nuria Doñamayor
• M. Ariel Schoenfeld
• Thomas F. Münte

The monetary incentive delay task was used to characterize reward anticipation and delivery with concurrently acquired evoked magnetic fields, EEG potentials and EEG/MEG oscillatory responses, obtaining a precise portrayal of their spatiotemporal evolution. In the anticipation phase, differential activity was most prominent over midline electrodes and parieto-occipital sensors. Differences between non-reward- and reward-predicting cues were localized in the cuneus and later in the dorsal PCC, suggesting a modulation by potential reward information during early visual processing, followed by a coarse emotional evaluation of the cues. Oscillatory analysis revealed increased theta power after non-reward cues over fronto-central sites. In the beta range, power decreased with the magnitude of the potential reward and increased with reaction time, probably reflecting the influence of the striatal response to potential reward on the sensorimotor cortex. At reward delivery, negative prediction errors led to a larger mediofrontal negativity. The spatiotemporal evolution of reward processing was modulated by prediction error: whereas differences were located in PCC and putamen in the prediction error comparison, in the case of expected outcomes they were located in PCC, ACC and parahippocampal gyrus. In the oscillatory realm, theta power was largest following rewards and, in the case of non-rewards, was largest when these were unexpected. Higher beta activity following rewards was also observed in both modalities, but MEG additionally showed a significant power decrease for this condition over parieto-occipital sensors. Our results show how visual, limbic and striatal structures are involved in the different stages of reward anticipation and delivery, and how theta and beta oscillations have a prominent role in the processing of these stimuli.

YNIMG Journal 2012 Journal Article

Rearranging the world: Neural network supporting the processing of temporal connectives

• Zheng Ye
• Marta Kutas
• Marie St. George
• Martin I. Sereno
• Feng Ling
• Thomas F. Münte

Temporal connectives (before/after) give us the freedom to describe a sequence of events in different orders. Studies have suggested that ‘before-initiating’ sentences, in which events are expressed in an order inconsistent with their actual order of occurrence, might need additional computation(s) during comprehension. The results of independent component analysis suggest that these computations are supported by a neural network connecting the bilateral caudate nucleus with the right middle frontal gyrus, left precentral gyrus, bilateral parietal lobule and inferior temporal gyrus. Among those regions, the caudate nucleus and the left middle frontal gyrus showed greater activations for ‘before’ than ‘after’ sentences. The functional network observed in this study may support sequence learning and processing in a general sense.

YNIMG Journal 2010 Journal Article

Neural differences in the mapping of verb and noun concepts onto novel words

• Anna Mestres-Missé
• Antoni Rodriguez-Fornells
• Thomas F. Münte

A dissociation between noun and verb processing has been found in brain damaged patients leading to the proposal that different word classes are supported by different neural representations. This notion is supported by the facts that children acquire nouns faster and adults usually perform better for nouns than verbs in a range of tasks. In the present study, we simulated word learning in a variant of the human simulation paradigm that provided only linguistic context information and required young healthy adults to map noun or verb meanings to novel words. The mapping of a meaning associated with a new-noun and a new-verb recruited different brain regions as revealed by functional magnetic resonance imaging. While new-nouns showed greater activation in the left fusiform gyrus, larger activation was observed for new-verbs in the left posterior middle temporal gyrus and left inferior frontal gyrus (opercular part). Furthermore, the activation in several regions of the brain (for example the bilateral hippocampus and bilateral putamen) was positively correlated with the efficiency of new-noun but not new-verb learning. The present results suggest that the same brain regions that have previously been associated with the representation of meaning of nouns and verbs are also associated with the mapping of such meanings to novel words, a process needed in second language learning.

YNIMG Journal 2010 Journal Article

Neurophysiological markers of novelty processing are modulated by COMT and DRD4 genotypes

• Josep Marco-Pallarés
• Wido Nager
• Ulrike M. Krämer
• Toni Cunillera
• Estela Càmara
• David Cucurell
• Rebecca Schüle
• Ludger Schöls

Humans are faced with the dilemma to maintain a stable cognitive set on the one hand and to be able to redirect and switch attention to novel stimuli of potential importance. The dopaminergic system has been implicated in the balance between these two antagonistic constraints and in particular in novelty processing. Here we studied the impact of two polymorphisms affecting dopaminergic functioning (COMT Val108/158Met and DRD4 SNP −521) on neurophysiological correlates of novelty processing. Recording event-related potentials (ERPs) and oscillatory activity in a modified oddball task that featured infrequent but task-irrelevant novel sounds in addition to frequent standard and rare target tones, we examined participants homozygous for the Met or Val variant of COMT as well as homozygous for the C or T variant of DRD4. We found effects mainly on the P3a component to novel stimuli. A greater P3a amplitude was found for the COMT-ValVal group relative to MetMet. There was a tendency for DRD4-TT participants to show greater P3a amplitude and shorter P3a latency. Finally, DRD4-TT and COMT-ValVal participants showed the greatest increase of theta-power to novel stimuli. By contrast, the P3b component to target stimuli showed little influence of the studied polymorphism. Individual differences in dopaminergic genes explain part of the interindividual variance in the neural correlates of novelty but not target processing.

YNIMG Journal 2007 Journal Article

Tit-for-tat: The neural basis of reactive aggression

• Ulrike M. Krämer
• Henk Jansma
• Claus Tempelmann
• Thomas F. Münte

Aggressive behavior is a basic form of human social interaction, yet little is known about its neural substrates. We used a laboratory task to investigate the neural correlates of reactive aggression using functional magnetic resonance imaging. The task is disguised as a reaction-time competition between the subject and two opponents and entitles the winner to punish the loser. It seeks to elicit aggression by provocation of the subject. As each single trial in this task is separated into a decision phase, during which the severity of the prospective punishment of the opponent is set, and an outcome phase, during which the actual punishment is applied or received, the paradigm enables us to analyze the neural events during each of these phases. Specific neural responses in areas related to negative affect, cognitive control and reward processing provide additional information about the cognitive, emotional and motivational processes underlying reactive aggressive behavior and afford us with the possibility to test and expand theories on aggression such as the General Aggression Model.

YNIMG Journal 2006 Journal Article

Juicy fruit and creepy crawlies: An electrophysiological study of the implicit Go/NoGo association task

• Jane F. Banfield
• Arie H. van der Lugt
• Thomas F. Münte

The Go/NoGo association task (GNAT) has been used in behavioral studies to measure the strength of association between different category groups and two poles of an evaluative dimension. However, reaction time data do not provide information about the neural time course of such associative information. We investigated event-related brain potentials (ERPs) elicited when participants were required to respond (Go) or withhold a response (NoGo) according to task instructions. Task instructions paired words from one of two taxonomic categories (fruit/bugs) with either pole of an evaluative dimension (good/bad). Within a given run, Go responses were assigned to one of the categories and one evaluative dimension. ERPs showed an increased negativity over frontal sites to NoGo as compared to Go responses. Moreover, NoGo minus Go difference waves showed that the N200 effect was delayed in trials within incongruent blocks (e. g. , “Press if a bug word or a good word”) as compared to trials within congruent blocks (e. g. , “Press if a bug word or a bad word”). These results suggest that such associative attitude information is available at a very early stage of processing, less than 250 ms after seeing a fruit or a bug word. This finding is further discussed with respect to alternative explanations of the behavioral effect.

YNIMG Journal 2001 Journal Article

Conceptual and semantic information access during tacit picture naming estimated by event related potentials

• Bernadette M. Schmitt
• Antoni Rodriguez-Fornells
• Thomas F. Münte