Blar i Department of Biological and Medical Psychology på forfatter "Ersland, Lars"
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Big GABA II: Water-referenced edited MR spectroscopy at 25 research sites
Mikkelsen, Mark; Rimbault, Daniel L.; Barker, Peter B.; Bhattacharyya, Pallab K.; Brix, Maiken Kirkegaard; Buur, Pieter F.; Cecil, Kim M.; Chan, Kimberly L.; Chen, David Y.-T.; Craven, Alexander R.; Cuypers, Koen; Dacko, Michael; Duncan, Niall W.; Dydak, Ulrike; Edmondson, David A.; Ende, Gabriele; Ersland, Lars; Forbes, Megan A.; Gao, Fei; Greenhouse, Ian; Harris, Ashley D.; He, Naying; Heba, Stefanie; Hoggard, Nigel; Hsu, Tun-Wei; Jansen, Jacobus F.A.; Kangarlu, Alayar; Lange, Thomas; Lebel, R. Marc; Li, Yan; Lin, Chien-Yuan E.; Liou, Jy-Kang; Lirng, Jiing-Feng; Liu, Feng; Long, Joanna R.; Ma, Ruoyun; Maes, Celine; Moreno-Ortega, Marta; Murray, Scott O.; Noah, Sean; Noeske, Ralph; Noseworthy, Michael D.; Oeltzschner, Georg; Porges, Eric C.; Prisciandaro, James J.; Puts, Nicolaas A.J.; Roberts, Timothy P.L.; Sack, Markus; Sailasuta, Napapon; Saleh, Muhammad G.; Schallmo, Michael-Paul; Simard, Nicholas; Stoffers, Diederick; Swinnen, Stephan P.; Tegenthoff, Martin; Truong, Peter; Wang, Guangbin; Wilkinson, Iain D.; Wittsack, Hans-Jörg; Woods, Adam J.; Xu, Hongmin; Yan, Fuhua; Zhang, Chencheng; Zipunnikov, Vadim; Zöllner, Helge J.; Edden, Richard A.E. (Peer reviewed; Journal article, 2019)Accurate and reliable quantification of brain metabolites measured in vivo using 1H magnetic resonance spectroscopy (MRS) is a topic of continued interest. Aside from differences in the basic approach to quantification, ... -
Combined fMRI Region- and Network-Analysis Reveal New Insights of Top-Down Modulation of Bottom-Up Processes in Auditory Laterality
Kazimierczak, Katarzyna; Craven, Alexander R.; Ersland, Lars; Specht, Karsten; Dumitru, Magda L.; Sandøy, Lydia B.; Hugdahl, Kenneth (Journal article; Peer reviewed, 2022)Dichotic listening along with the right-ear advantage (REA) has been a standard method of investigating auditory laterality ever since it was first introduced into neuropsychology in the early 1960s. Beginning in the 1980s, ... -
Comparison of Multivendor Single-Voxel MR Spectroscopy Data Acquired in Healthy Brain at 26 Sites
Považan, Michal; Mikkelsen, Mark; Berrington, Adam; Bhattacharyya, Pallab K.; Brix, Maiken Kirkegaard; Buur, Pieter F.; Cecil, Kim M.; Chan, Kimberly L.; Chen, David Y.T.; Craven, Alexander R.; Cuypers, Koen; Dacko, Michael; Duncan, Niall W.; Dydak, Ulrike; Edmondson, David A.; Ende, Gabriele; Ersland, Lars; Forbes, Megan A.; Gao, Fei; Ian, Greenhouse; Harris, Ashley D.; He, Naying; Heba, Stefanie; Hoggard, Nigel; Hsu, Tun-Wei; Jansen, Jacobus F. A.; Kangarlu, Alayar; Lange, Thomas; Lebel, R. Marc; Li, Yan; Lin, Chien-Yuan E.; Liou, Jy-Kang; Lirng, Jiing-Feng; Liu, Feng; Long, Joanna R.; Ma, Ruoyun; Maes, Celine; Moreno-Ortega, Marta; Murray, Scott O.; Noah, Sean; Noeske, Ralph; Noseworthy, Michael D.; Oeltzschner, Georg; Porges, Eric C.; Prisciandaro, James J.; Puts, Nicolaas A. J.; Roberts, Timothy P. L.; Sack, Markus; Sailasuta, Napapon; Saleh, Muhammad G.; Schallmo, Michael-Paul; Simard, Nicholas; Stoffers, Diederick; Swinnen, Stephan P.; Tegenthoff, Martin; Truong, Peter; Wang, Guangbin; Wilkinson, Iain D.; Wittsack, Hans-Jörg; Woods, Adam J.; Xu, Hongmin; Yan, Fuhua; Zhang, Chencheng; Zipunnikov, Vadim; Zöllner, Helge J.; Edden, Richard A.E.; Barker, Peter B. (Journal article; Peer reviewed, 2020)Background: The hardware and software differences between MR vendors and individual sites influence the quantification of MR spectroscopy data. An analysis of a large data set may help to better understand sources of the ... -
Comparison of seven modelling algorithms for γ-aminobutyric acid–edited proton magnetic resonance spectroscopy
Craven, Alexander R.; Bhattacharyya, Pallab K.; Clarke, William T.; Dydak, Ulrike; Edden, Richard A.E.; Ersland, Lars; Mandal, Pravat K.; Mikkelsen, Mark; Murdoch, James B.; Near, Jamie; Rideaux, Reuben; Shukla, Deepika; Wang, Min; Wilson, Martin; Zöllner, Helge J.; Hugdahl, Kenneth Jan; Oeltzschner, Georg (Journal article; Peer reviewed, 2022)Edited MRS sequences are widely used for studying γ-aminobutyric acid (GABA) in the human brain. Several algorithms are available for modelling these data, deriving metabolite concentration estimates through peak fitting ... -
Comparison of seven modelling algorithms for γ-aminobutyric acid–edited proton magnetic resonance spectroscopy
Craven, Alexander R.; Bhattacharyya, Pallab K.; Clarke, William T.; Dydak, Ulrike; Edden, Richard A.E.; Ersland, Lars; Mandal, Pravat K.; Mikkelsen, Mark; Murdoch, James B.; Near, Jamie; Rideaux, Reuben; Shukla, Deepika; Wang, Min; Wilson, Martin; Zöllner, Helge J.; Hugdahl, Kenneth; Oeltzschner, Georg (Journal article; Peer reviewed, 2022)Edited MRS sequences are widely used for studying γ-aminobutyric acid (GABA) in the human brain. Several algorithms are available for modelling these data, deriving metabolite concentration estimates through peak fitting ... -
Default-mode network functional connectivity is closely related to metabolic activity
Passow, Susanne; Specht, Karsten; Adamsen, Tom Christian; Biermann, Martin; Brekke, Njål; Craven, Alexander R.; Ersland, Lars; Grüner, Renate; Kleven-Madsen, Nina; Kvernenes, Ole Heine; Schwarzlmüller, Thomas; Olesen, Rasmus Aamand; Hugdahl, Kenneth (Peer reviewed; Journal article, 2015-06)Over the last decade, the brain's default-mode network (DMN) and its function has attracted a lot of attention in the field of neuroscience. However, the exact underlying mechanisms of DMN functional connectivity, or more ... -
Dynamic up- and down-regulation of thedefault (DMN) and extrinsic (EMN) modenetworks during alternating task-on and task-offperiods
Hugdahl, Kenneth; Kazimierczak, Katarzyna Anna; Beresniewicz, Justyna; Kompus, Kristiina; Westerhausen, René; Ersland, Lars; Grüner, Renate; Specht, Karsten (Peer reviewed; Journal article, 2019)Using fMRI, Hugdahl et al. (2015) reported the existence of a general-domain cortical network during active task-processing which was non-specific to the cognitive task being processed. They labelled this network the ... -
fMRI fluctuations within the language network are correlated with severity of hallucinatory symptoms in schizophrenia
Spironelli, Chiara; Marino, Marco; Mantini, Dante; Montalti, Riccardo; Craven, Alexander R.; Ersland, Lars; Angrilli, Alessandro; Hugdahl, Kenneth Jan (Journal article; Peer reviewed, 2023)Although schizophrenia (SZ) represents a complex multiform psychiatric disorder, one of its most striking symptoms are auditory verbal hallucinations (AVH). While the neurophysiological origin of this pervasive symptom has ... -
Frequency drift in MR spectroscopy at 3T
Hui, Steve C.N.; Mikkelsen, Mark; Zöllner, Helge J.; Craig-Craven, Alexander Richard; Ersland, Lars; Edden, Richard A.E. (Journal article; Peer reviewed, 2021)Purpose Heating of gradient coils and passive shim components is a common cause of instability in the B0 field, especially when gradient intensive sequences are used. The aim of the study was to set a benchmark for typical ... -
GABA, glutamatergic dynamics and BOLD contrast assessed concurrently using functional MRS during a cognitive task
Craven, Alexander R.; Dwyer, Gerard Eric; Ersland, Lars; Kazimierczak, Katarzyna Anna; Noeske, Ralph; Sandøy, Lydia Brunvoll; Johnsen, Erik; Hugdahl, Kenneth Jan (Journal article; Peer reviewed, 2023)A recurring issue in functional neuroimaging is how to link task-driven haemodynamic blood oxygen level dependent functional MRI (BOLD-fMRI) responses to underlying neurochemistry at the synaptic level. Glutamate and ... -
Glutamate- and GABA-Modulated Connectivity in Auditory Hallucinations—A Combined Resting State fMRI and MR Spectroscopy Study
Weber, Sarah; Hjelmervik, Helene; Craven, Alexander R.; Johnsen, Erik; Kroken, Rune Andreas; Løberg, Else-Marie; Ersland, Lars; Kompus, Kristiina; Hugdahl, Kenneth (Journal article; Peer reviewed, 2021)Background: Auditory verbal hallucinations (AVH) have been linked to aberrant interhemispheric connectivity between the left and the right superior temporal gyrus (STG), labeled the interhemispheric miscommunication theory. ... -
Intra-Regional Glu-GABA vs Inter-Regional Glu-Glu Imbalance: A 1H-MRS Study of the Neurochemistry of Auditory Verbal Hallucinations in Schizophrenia.
Hjelmervik, Helene; Craven, Alexander R.; Sinkeviciute, Igne; Johnsen, Erik; Kompus, Kristiina; Bless, Josef Johann; Kroken, Rune Andreas; Løberg, Else-Marie; Ersland, Lars; Gruner, Eli Renate; Hugdahl, Kenneth (Peer reviewed; Journal article, 2019-10-18)Glutamate (Glu), gamma amino-butyric acid (GABA), and excitatory/inhibitory (E/I) imbalance have inconsistently been implicated in the etiology of schizophrenia. Elevated Glu levels in language regions have been suggested ... -
Multi-vendor standardized sequence for edited magnetic resonance spectroscopy
Saleh, Muhammad G.; Rimbault, Daniel; Mikkelsen, Mark; Oeltzschner, Georg; Wang, Anna M; Jiang, Dengrong; Alhamud, Ali; Near, Jamie; Schär, Michael; Noeske, Ralph; Murdoch, James B; Ersland, Lars; Craven, Alexander R.; Dwyer, Gerard Eric; Grüner, Renate; Pan, Li; Ahn, Sinyeob; Edden, Richard A.E. (Peer reviewed; Journal article, 2019)Spectral editing allows direct measurement of low-concentration metabolites, such as GABA, glutathione (GSH) and lactate (Lac), relevant for understanding brain (patho)physiology. The most widely used spectral editing ... -
Negative valence of hallucinatory voices as predictor of cortical glutamatergic metabolite levels in schizophrenia patients
Hjelmervik, Helene; Craven, Alexander R.; Johnsen, Erik; Kompus, Kristiina; Bless, Josef Johann; Sinkeviciute, Igne; Kroken, Rune Andreas; Løberg, Else-Marie; Ersland, Lars; Grüner, Eli Renate; Sommer, Iris E.; Hugdahl, Kenneth Jan (Journal article; Peer reviewed, 2021)Objectives Negative emotional valence of auditory verbal hallucinations (AVHs) in schizophrenia can be a source of distress and is considered a strong predictor of illness severity. Previous studies have found glutamate ... -
Neural activation in the ventromedial prefrontal cortex precedes conscious experience of being in or out of a transient hallucinatory state
Hugdahl, Kenneth; Craven, Alexander R.; Johnsen, Erik; Ersland, Lars; Stoyanov, Drozdstoy; Kandilarova, Sevdalina; Sandøy, Lydia Brunvoll; Kroken, Rune A.; Løberg, Else-Marie; Sommer, Iris E. (Journal article; Peer reviewed, 2022)Background and Hypotheses Auditory verbal hallucinations (AVHs) is not only a common symptom in schizophrenia but also observed in individuals in the general population. Despite extensive research, AVHs are poorly understood, ... -
No Effects of Anodal tDCS on Local GABA and Glx Levels in the Left Posterior Superior Temporal Gyrus
Dwyer, Gerard Eric; Craven, Alexander R.; Hirnstein, Marco; Kompus, Kristiina; Assmus, Jörg; Ersland, Lars; Hugdahl, Kenneth; Grüner, Renate (Peer reviewed; Journal article, 2019-01-08)A number of studies investigating the biological effects of transcranial direct current stimulation (tDCS) using magnetic resonance spectroscopy (MRS) have found that it may affect local levels of γ-aminobutyric acid (GABA), ... -
Similarities and differences between intermittent and continuous resting-state fMRI
Beresniewicz, Justyna; Riemer, Frank; Kazimierczak, Katarzyna Anna; Ersland, Lars; Craven, Alexander R.; Hugdahl, Kenneth Jan; Grüner, Renate (Journal article; Peer reviewed, 2023)Introduction: Functional Magnetic Resonance Imaging (fMRI) block-design experiments typically include active ON-blocks with presentation of cognitive tasks which are contrasted with OFF- blocks with no tasks presented. ... -
Simultaneous Measurement of the BOLD Effect and Metabolic Changes in Response to Visual Stimulation Using the MEGA-PRESS Sequence at 3 T
Dwyer, Gerard Eric; Craven, Alexander R.; Beresniewicz, Justyna; Kazimierczak, Katarzyna Anna; Ersland, Lars; Hugdahl, Kenneth Jan; Grüner, Eli Renate (Journal article; Peer reviewed, 2021)The blood oxygen level dependent (BOLD) effect that provides the contrast in functional magnetic resonance imaging (fMRI) has been demonstrated to affect the linewidth of spectral peaks as measured with magnetic resonance ...