Wilke, Melanie

[["dc.bibliographiccitation.journal","Frontiers in Neuroscience"],["dc.bibliographiccitation.volume","16"],["dc.contributor.affiliation","Steinmann, Iris; 1Department of Cognitive Neurology, University Medical Center Göttingen, Göttingen, Germany"],["dc.contributor.affiliation","Williams, Kathleen A.; 1Department of Cognitive Neurology, University Medical Center Göttingen, Göttingen, Germany"],["dc.contributor.affiliation","Wilke, Melanie; 1Department of Cognitive Neurology, University Medical Center Göttingen, Göttingen, Germany"],["dc.contributor.affiliation","Antal, Andrea; 4Department of Neurology, University Medical Center Göttingen, Göttingen, Germany"],["dc.contributor.author","Steinmann, Iris"],["dc.contributor.author","Williams, Kathleen A."],["dc.contributor.author","Wilke, Melanie"],["dc.contributor.author","Antal, Andrea"],["dc.date.accessioned","2022-07-11T15:00:32Z"],["dc.date.available","2022-07-11T15:00:32Z"],["dc.date.issued","2022-06-27"],["dc.date.updated","2022-07-11T13:34:32Z"],["dc.description.abstract","Non-invasive electrical stimulation methods, such as transcranial alternating current stimulation (tACS), are increasingly used in human neuroscience research and offer potential new avenues to treat neurological and psychiatric disorders. However, their often variable effects have also raised concerns in the scientific and clinical communities. This study aims to investigate the influence of subject-specific factors on the alpha tACS-induced aftereffect on the alpha amplitude (measured with electroencephalography, EEG) as well as on the connectivity strength between nodes of the default mode network (DMN) [measured with functional magnetic resonance imaging (fMRI)]. As subject-specific factors we considered the individual electrical field (EFIELD) strength at target regions in the brain, the frequency mismatch between applied stimulation and individual alpha frequency (IAF) and as a covariate, subject’s changes in mental state, i.e., sleepiness. Eighteen subjects participated in a tACS and a sham session conducted on different days. Each session consisted of three runs (pre/stimulation/). tACS was applied during the second run at each subject’s individual alpha frequency (IAF), applying 1 mA peak-to-peak intensity for 7 min, using an occipital bihemispheric montage. In every run, subjects watched a video designed to increase in-scanner compliance. To investigate the aftereffect of tACS on EEG alpha amplitude and on DMN connectivity strength, EEG data were recorded simultaneously with fMRI data. Self-rated sleepiness was documented using a questionnaire. Conventional statistics (ANOVA) did not show a significant aftereffect of tACS on the alpha amplitude compared to sham stimulation. Including individual EFIELD strengths and self-rated sleepiness scores in a multiple linear regression model, significant tACS-induced aftereffects were observed. However, the subject-wise mismatch between tACS frequency and IAF had no contribution to our model. Neither standard nor extended statistical methods confirmed a tACS-induced aftereffect on DMN functional connectivity. Our results show that it is possible and necessary to disentangle alpha amplitude changes due to intrinsic mechanisms and to external manipulation using tACS on the alpha amplitude that might otherwise be overlooked. Our results suggest that EFIELD is really the most significant factor that explains the alpha amplitude modulation during a tACS session. This knowledge helps to understand the variability of the tACS-induced aftereffects."],["dc.description.sponsorship","Open-Access-Publikationsfonds 2022"],["dc.identifier.doi","10.3389/fnins.2022.870758"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/112460"],["dc.language.iso","en"],["dc.relation.eissn","1662-453X"],["dc.rights","CC BY 4.0"],["dc.rights.uri","http://creativecommons.org/licenses/by/4.0/"],["dc.title","Detection of Transcranial Alternating Current Stimulation Aftereffects Is Improved by Considering the Individual Electric Field Strength and Self-Rated Sleepiness"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.subtype","original_ja"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.journal","Frontiers in Psychology"],["dc.bibliographiccitation.volume","4"],["dc.contributor.author","Boly, Melanie"],["dc.contributor.author","Seth, Anil K."],["dc.contributor.author","Wilke, Melanie"],["dc.contributor.author","Ingmundson, Paul"],["dc.contributor.author","Baars, Bernard"],["dc.contributor.author","Laureys, Steven"],["dc.contributor.author","Edelman, David B."],["dc.contributor.author","Tsuchiya, Naotsugu"],["dc.date.accessioned","2017-09-07T11:43:41Z"],["dc.date.available","2017-09-07T11:43:41Z"],["dc.date.issued","2013"],["dc.description.abstract","This joint article reflects the authors' personal views regarding noteworthy advances in the neuroscience of consciousness in the last 10 years, and suggests what we feel may be promising future directions. It is based on a small conference at the Samoset Resort in Rockport, Maine, USA, in July of 2012, organized by the Mind Science Foundation of San Antonio, Texas. Here, we summarize recent advances in our understanding of subjectivity in humans and other animals, including empirical, applied, technical, and conceptual insights. These include the evidence for the importance of fronto-parietal connectivity and of “top-down” processes, both of which enable information to travel across distant cortical areas effectively, as well as numerous dissociations between consciousness and cognitive functions, such as attention, in humans. In addition, we describe the development of mental imagery paradigms, which made it possible to identify covert awareness in non-responsive subjects. Non-human animal consciousness research has also witnessed substantial advances on the specific role of cortical areas and higher order thalamus for consciousness, thanks to important technological enhancements. In addition, much progress has been made in the understanding of non-vertebrate cognition relevant to possible conscious states. Finally, major advances have been made in theories of consciousness, and also in their comparison with the available evidence. Along with reviewing these findings, each author suggests future avenues for research in their field of investigation."],["dc.identifier.doi","10.3389/fpsyg.2013.00625"],["dc.identifier.gro","3151613"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/10704"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/8426"],["dc.language.iso","en"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","public"],["dc.notes.submitter","chake"],["dc.relation.issn","1664-1078"],["dc.rights","CC BY 3.0"],["dc.rights.uri","https://creativecommons.org/licenses/by/3.0"],["dc.title","Consciousness in humans and non-human animals: recent advances and future directions"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dc.type.peerReviewed","no"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","94"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","Human Brain Mapping"],["dc.bibliographiccitation.lastpage","121"],["dc.bibliographiccitation.volume","37"],["dc.contributor.author","Cabral-Calderin, Yuranny"],["dc.contributor.author","Weinrich, Christiane Anne"],["dc.contributor.author","Schmidt-Samoa, Carsten"],["dc.contributor.author","Poland, Eva"],["dc.contributor.author","Dechent, Peter"],["dc.contributor.author","Bähr, Mathias"],["dc.contributor.author","Wilke, Melanie"],["dc.date.accessioned","2017-09-07T11:54:45Z"],["dc.date.available","2017-09-07T11:54:45Z"],["dc.date.issued","2016"],["dc.description.abstract","Transcranial alternating current stimulation (tACS) has emerged as a promising tool for manipulating ongoing brain oscillations. While previous studies demonstrated frequency-specific effects of tACS on diverse cognitive functions, its effect on neural activity remains poorly understood. Here we asked how tACS modulates regional fMRI blood oxygenation level dependent (BOLD) signal as a function of frequency, current strength, and task condition. TACS was applied over the posterior cortex of healthy human subjects while the BOLD signal was measured during rest or task conditions (visual perception, passive video viewing and motor task). TACS was applied in a blockwise manner at different frequencies (10, 16, 60 and 80 Hz). The strongest tACS effects on BOLD activity were observed with stimulation at alpha (10 Hz) and beta (16 Hz) frequency bands, while effects of tACS at the gamma range were rather modest. Specifically, we found that tACS at 16 Hz induced BOLD activity increase in fronto-parietal areas. Overall, tACS effects varied as a function of frequency and task, and were predominantly seen in regions that were not activated by the task. Also, the modulated regions were poorly predicted by current density modeling studies. Taken together, our results suggest that tACS does not necessarily exert its strongest effects in regions below the electrodes and that region specificity might be achieved with tACS due to varying susceptibility of brain regions to entrain to a given frequency. (C) 2015 The Authors. Human Brain Mapping Published by Wiley Periodicals, Inc."],["dc.identifier.doi","10.1002/hbm.23016"],["dc.identifier.fs","618728"],["dc.identifier.gro","3141752"],["dc.identifier.isi","000369150500007"],["dc.identifier.pmid","26503692"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/14044"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/680"],["dc.language.iso","en"],["dc.notes.intern","WoS Import 2017-03-10 / Funder: Hermann and Lilly Schilling Foundation"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","final"],["dc.notes.submitter","PUB_WoS_Import"],["dc.relation.eissn","1097-0193"],["dc.relation.issn","1065-9471"],["dc.rights","CC BY-NC-ND 4.0"],["dc.rights.uri","https://creativecommons.org/licenses/by-nc-nd/4.0"],["dc.title","Transcranial Alternating Current Stimulation Affects the BOLD Signal in a Frequency and Task-dependent Manner"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.subtype","original"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.journal","Frontiers in Physiology"],["dc.bibliographiccitation.volume","11"],["dc.contributor.author","Kottlarz, Inga"],["dc.contributor.author","Berg, Sebastian"],["dc.contributor.author","Toscano-Tejeida, Diana"],["dc.contributor.author","Steinmann, Iris"],["dc.contributor.author","Bähr, Mathias"],["dc.contributor.author","Luther, Stefan"],["dc.contributor.author","Wilke, Melanie"],["dc.contributor.author","Parlitz, Ulrich"],["dc.contributor.author","Schlemmer, Alexander"],["dc.date.accessioned","2021-04-14T08:29:50Z"],["dc.date.available","2021-04-14T08:29:50Z"],["dc.date.issued","2021"],["dc.description.abstract","In this study, ordinal pattern analysis and classical frequency-based EEG analysis methods are used to differentiate between EEGs of different age groups as well as individuals. As characteristic features, functional connectivity as well as single-channel measures in both the time and frequency domain are considered. We compare the separation power of each feature set after nonlinear dimensionality reduction using t-distributed stochastic neighbor embedding and demonstrate that ordinal pattern-based measures yield results comparable to frequency-based measures applied to preprocessed data, and outperform them if applied to raw data. Our analysis yields no significant differences in performance between single-channel features and functional connectivity features regarding the question of age group separation."],["dc.identifier.doi","10.3389/fphys.2020.614565"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/82999"],["dc.language.iso","en"],["dc.notes.intern","DOI Import GROB-399"],["dc.publisher","Frontiers Media S.A."],["dc.relation.eissn","1664-042X"],["dc.rights","http://creativecommons.org/licenses/by/4.0/"],["dc.title","Extracting Robust Biomarkers From Multichannel EEG Time Series Using Nonlinear Dimensionality Reduction Applied to Ordinal Pattern Statistics and Spectral Quantities"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","7590"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","Scientific Reports"],["dc.bibliographiccitation.volume","9"],["dc.contributor.author","Poland, E."],["dc.contributor.author","Donner, T. H."],["dc.contributor.author","Müller, K. -M."],["dc.contributor.author","Leopold, D. A."],["dc.contributor.author","Wilke, M."],["dc.date.accessioned","2019-07-09T11:51:40Z"],["dc.date.available","2019-07-09T11:51:40Z"],["dc.date.issued","2019"],["dc.description.abstract","Spiking activity exhibits a large degree of variability across identical trials, which has been shown to be significantly reduced by stimulus onset in a wide range of cortical areas. Whether similar dynamics apply to the thalamus and in particular to the pulvinar is largely unknown. Here, we examined electrophysiological recordings from two adult rhesus macaques performing a perceptual task and comparatively investigated trial-to-trial variability in higher-order thalamus (ventral and dorsal pulvinar), the lateral geniculate nucleus (LGN) and visual cortex (area V4) prior to and following the presentation of a visual stimulus. We found spiking variability during stable fixation prior to stimulus onset to be considerably lower in both pulvinar and the LGN as compared to area V4. In contrast to the prominent variability reduction in V4 upon stimulus onset, variability in the thalamic nuclei was largely unaffected by visual stimulation. There was a small but significant variability decrease in the dorsal pulvinar, but not in the ventral portion of the pulvinar, which is closely connected to visual cortices and would thus have been expected to reflect cortical response properties. This dissociation did not stem from differences in response strength or mean firing rates and indicates fundamental differences in variability quenching between thalamus and cortex."],["dc.identifier.doi","10.1038/s41598-019-43934-9"],["dc.identifier.pmid","31110242"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/16166"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/59985"],["dc.language.iso","en"],["dc.notes.intern","Merged from goescholar"],["dc.rights","CC BY 4.0"],["dc.rights.uri","https://creativecommons.org/licenses/by/4.0"],["dc.subject.ddc","610"],["dc.title","Thalamus exhibits less sensory variability quenching than cortex"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","102076"],["dc.bibliographiccitation.journal","NeuroImage: Clinical"],["dc.bibliographiccitation.volume","25"],["dc.contributor.author","Miloserdov, Kristina"],["dc.contributor.author","Schmidt-Samoa, Carsten"],["dc.contributor.author","Williams, Kathleen"],["dc.contributor.author","Weinrich, Christiane Anne"],["dc.contributor.author","Kagan, Igor"],["dc.contributor.author","Bürk, Katrin"],["dc.contributor.author","Trenkwalder, Claudia"],["dc.contributor.author","Bähr, Mathias"],["dc.contributor.author","Wilke, Melanie"],["dc.date.accessioned","2020-12-10T15:20:31Z"],["dc.date.available","2020-12-10T15:20:31Z"],["dc.date.issued","2020"],["dc.identifier.doi","10.1016/j.nicl.2019.102076"],["dc.identifier.issn","2213-1582"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/16784"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/72695"],["dc.language.iso","en"],["dc.notes.intern","DOI Import GROB-354"],["dc.notes.intern","Merged from goescholar"],["dc.rights","CC BY-NC-ND 4.0"],["dc.rights.uri","https://creativecommons.org/licenses/by-nc-nd/4.0"],["dc.title","Aberrant functional connectivity of resting state networks related to misperceptions and intra-individual variability in Parkinson‘s disease"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","101898"],["dc.bibliographiccitation.journal","NeuroImage: Clinical"],["dc.bibliographiccitation.volume","23"],["dc.contributor.author","Paschke, Kerstin"],["dc.contributor.author","Bähr, Mathias"],["dc.contributor.author","Wüstenberg, Torsten"],["dc.contributor.author","Wilke, Melanie"],["dc.date.accessioned","2019-07-30T07:47:17Z"],["dc.date.available","2019-07-30T07:47:17Z"],["dc.date.issued","2019"],["dc.identifier.doi","10.1016/j.nicl.2019.101898"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/16804"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/62177"],["dc.language.iso","en"],["dc.notes.intern","Merged from goescholar"],["dc.relation.issn","2213-1582"],["dc.rights","CC BY-NC-ND 4.0"],["dc.rights.uri","https://creativecommons.org/licenses/by-nc-nd/4.0"],["dc.title","Trunk rotation and handedness modulate cortical activation in neglect-associated regions during temporal order judgments"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]