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7. When fMRI came to Bergen and Norway – as I remember it.

Author

Hugdahl, Kenneth

Subjects
*FUNCTIONAL magnetic resonance imaging, *UNIVERSITY hospitals, *RESEARCH personnel, *MEDICAL research
Abstract

In this personal recollection, I review the beginning of functional magnetic resonance imaging (fMRI) research in Norway, i.e., at the University of Bergen and the Haukeland University Hospital in Bergen. Research with fMRI had already started in Bergen in 1993, and the small group of researchers involved were the first to take up this new method for studies of the brain and brain‐behavior relationships. This article is a recollection of the early years of how the field started and developed in Bergen, Norway over the years, including basic as well as clinical research, and how the research also led to successful innovation and commercialization through the establishment of a MedTech company, NordicNeuroLab (NNL), that has delivered products to more than 2,000 university hospitals worldwide. [ABSTRACT FROM AUTHOR]

Published
2024
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11. GABA, glutamatergic dynamics and BOLD contrast assessed concurrently using functional MRS during a cognitive task.

Author

Craven, Alexander R., Dwyer, Gerard, Ersland, Lars, Kazimierczak, Katarzyna, Noeske, Ralph, Sandøy, Lydia Brunvoll, Johnsen, Erik, and Hugdahl, Kenneth

Subjects
GABA, FUNCTIONAL magnetic resonance imaging, OXYGEN in the blood, CINGULATE cortex, TASK performance
Abstract

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 γ‐aminobutyric acid (GABA), the major excitatory and inhibitory neurotransmitters respectively, are typically measured with MRS sequences separately from fMRI, in the absence of a task. The present study aims to resolve this disconnect, developing acquisition and processing techniques to simultaneously assess GABA, glutamate and glutamine (Glx) and BOLD in relation to a cognitive task, at 3 T. Healthy subjects (N = 81) performed a cognitive task (Eriksen flanker), which was presented visually in a task‐OFF, task‐ON block design, with individual event onset timing jittered with respect to the MRS readout. fMRS data were acquired from the medial anterior cingulate cortex during task performance, using an adapted MEGA‐PRESS implementation incorporating unsuppressed water‐reference signals at a regular interval. These allowed for continuous assessment of BOLD activation, through T2*‐related changes in water linewidth. BOLD‐fMRI data were additionally acquired. A novel linear model was used to extract modelled metabolite spectra associated with discrete functional stimuli, building on well established processing and quantification tools. Behavioural outcomes from the flanker task, and activation patterns from the BOLD‐fMRI sequence, were as expected from the literature. BOLD response assessed through fMRS showed a significant correlation with fMRI, specific to the fMRS‐targeted region of interest; fMRS‐assessed BOLD additionally correlated with lengthening of response time in the incongruent flanker condition. While no significant task‐related changes were observed for GABA+, a significant increase in measured Glx levels (~8.8%) was found between task‐OFF and task‐ON periods. These findings verify the efficacy of our protocol and analysis pipelines for the simultaneous assessment of metabolite dynamics and BOLD. As well as establishing a robust basis for further work using these techniques, we also identify a number of clear directions for further refinement in future studies. [ABSTRACT FROM AUTHOR]

Published
2024
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17. The phenomenology of auditory verbal hallucinations in schizophrenia assessed with the MiniVoiceQuestionnaire (MVQ)

Author

Hugdahl, Kenneth, primary, Hjelmervik, Helene, additional, Weber, Sarah, additional, Sandøy, Lydia Brunvoll, additional, Bless, Josef, additional, Lilleskare, Lin, additional, Craven, Alexander, additional, Hirnstein, Marco, additional, Kazimierczak, Katarzyna, additional, Dwyer, Gerard, additional, Dumitru, Magda L., additional, Sinceviciute, Igne, additional, Ersland, Lars, additional, and Johnsen, Erik, additional

Published
2023
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20. sj-docx-1-jop-10.1177_02698811231168243 – Supplemental material for Signatures of exposure to childhood trauma in young adults in the structure and neurochemistry of the superior temporal gyrus

Author

Hepsomali, Piril, Machon, Sandra, Barker, Holly, Lythgoe, David J, Hugdahl, Kenneth, Gudbrandsen, Maria, and Allen, Paul

Subjects
FOS: Psychology, FOS: Clinical medicine, 170199 Psychology not elsewhere classified, 110319 Psychiatry (incl. Psychotherapy), 111599 Pharmacology and Pharmaceutical Sciences not elsewhere classified, 110904 Neurology and Neuromuscular Diseases
Abstract

Supplemental material, sj-docx-1-jop-10.1177_02698811231168243 for Signatures of exposure to childhood trauma in young adults in the structure and neurochemistry of the superior temporal gyrus by Piril Hepsomali, Sandra Machon, Holly Barker, David J Lythgoe, Kenneth Hugdahl, Maria Gudbrandsen and Paul Allen in Journal of Psychopharmacology

Published
2023
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22. Reproducibility in the absence of selective reporting : An illustration from large-scale brain asymmetry research

Author

Kong, Xiang-Zhen, Francks, Clyde, Allen, Nicholas B., Heslenfeld, Dirk, Hester, Robert, Hibar, Derrek Paul, Ho, Beng-Choon, Ho, Tiffany C., Hoekstra, Pieter J., Holst, Ruth J., Hoogman, Martine, Høvik, Marie F., Howells, Fleur M., Ames, David, Hugdahl, Kenneth, Huyser, Chaim, Ingvar, Martin, Ishikawa, Akari, James, Anthony, Jahanshad, Neda, Jernigan, Terry L., Jönsson, Erik G, Kaleda, Vasily, Kelly, Clare, Andreassen, Ole A., Kerich, Michael, Keshavan, Matcheri S., Khadka, Sabin, Kircher, Tilo, Kohls, Gregor, Konrad, Kerstin, Korucuoglu, Ozlem, Krämer, Bernd, Krug, Axel, Kuntsi, Jonna, Vasquez, Alejandro Arias, Kwon, Jun Soo, Lambregts-Rommelse, Nanda, Landén, Mikael, Lázaro, Luisa, Lebedeva, Irina, Lenroot, Rhoshel, Lesch, Klaus-Peter, Li, Qinqin, Lim, Kelvin O., Liu, Jia, Armstrong, Nicola J., Lochner, Christine, London, Edythe D., Lorenzetti, Valentina, Luciano, Michelle, Luijten, Maartje, Lundervold, Astri J., Mackey, Scott, MacMaster, Frank P., Maingault, Sophie, Malpas, Charles B., Asherson, Phil, Malt, Ulrik F., Mataix-Cols, David, Martin-Santos, Rocio, Mayer, Andrew R., McCarthy, Hazel, Medland, Sarah, Metha, Mitul, Mitchell, Philip B., Mueller, Bryon A., Maniega, Susana Muñoz, Bergo, Felipe, Mazoyer, Bernard, McDonald, Colm, McLellan, Quinn, McMahon, Katie L., McPhilemy, Genevieve, Momenan, Reza, Morales, Angelica M., Narayanaswamy, Janardhanan C., Moreira, José Carlos Vasques, Nerland, Stener, Bastin, Mark E., Nestor, Liam, Newman, Erik, Nigg, Joel T., Nordvik, Jan Egil, Novotny, Stephanie, Weiss, Eileen Oberwelland, O'Gorman, Ruth L., Oosterlaan, Jaap, Oranje, Bob, Orr, Catherine, Batalla, Albert, Overs, Bronwyn, Paloyelis, Yannis, Pauli, Paul, Paulus, Martin, Plessen, Kerstin Jessica, Polier, Georg G., Pomarol-Clotet, Edith, Portella, Maria J., Qiu, Jiang, Radua, Joaquim, Bauer, Jochen, Ramos-Quiroga, Josep Antoni, Reddy, Y. C. Janardhan, Reif, Andreas, Roberts, Gloria, Rosa, Pedro, Rubia, Katya, Sacchet, Matthew D., Sachdev, Perminder S., Salvador, Raymond, Schmaal, Lianne, Baune, Bernhard T, Schulte-Rüther, Martin, Schweren, Lizanne, Seitz, Jochen, Serpa, Mauricio Henriques, Shaw, Philip, Shumskaya, Elena, Silk, Timothy J., Simmons, Alan N., Simulionyte, Egle, Sinha, Rajita, Baur-Streubel, Ramona, Sjoerds, Zsuzsika, Smelror, Runar Elle, Soliva, Joan Carlos, Solowij, Nadia, Souza-Duran, Fabio Luisde, Sponheim, Scott R., Stein, Dan J., Stein, Elliot A., Stevens, Michael, Strike, Lachlan T., Biederman, Joseph, Sudre, Gustavo, Sui, Jing, Tamm, Leanne, Temmingh, Hendrik S., Thoma, Robert J., Tomyshev, Alexander, Tronchin, Giulia, Turner, Jessica, Uhlmann, Anne, Erp, Theo G. M., Blaine, Sara K., Heuvel, Odile A., Meer, Dennis, Eijk, Liza, Vance, Alasdair, Veer, Ilya M., Veltman, Dick J., Venkatasubramanian, Ganesan, Vilarroya, Oscar, Vives-Gilabert, Yolanda, Voineskos, Aristotle N, Boedhoe, Premika, Völzke, Henry, Vuletic, Daniella, Walitza, Susanne, Walter, Henrik, Walton, Esther, Wardlaw, Joanna M., Wen, Wei, Westlye, Lars T., Whelan, Christopher D., White, Tonya, Bøen, Erlend, Wiers, Reinout W., Wright, Margaret J., Wittfeld, Katharina, Yang, Tony T., Yasuda, Clarissa L., Yoncheva, Yuliya, Yücel, Murat, Yun, Je-Yeon, Zanetti, Marcus Vinicius, Zhen, Zonglei, Bose, Anushree, Zhu, Xing-xing, Ziegler, Georg C., Zubicaray, Greig I., Zwiers, Marcel, Project, Karolinska Schizophrenia, Glahn, David C., Crivello, Fabrice, Fisher, Simon E., Thompson, Paul M., Bralten, Janita, Farde, Lars, Flyckt, Lena, Engberg, Göran, Erhardt, Sophie, Fatouros-Bergman, Helena, Cervenka, Simon, Schwieler, Lilly, Piehl, Fredrik, Agartz, Ingrid, Collste, Karin, Brandeis, Daniel, Victorsson, Pauliina, Malmqvist, Anna, Hedberg, Mikael, Orhan, Funda, Sellgren, Carl, Brem, Silvia, Mathias, Samuel R., Brodaty, Henry, Yüksel, Dilara, Brooks, Samantha J., Buitelaar, Jan, Bürger, Christian, Bülow, Robin, Calhoun, Vince, Calvo, Anna, Canales-Rodríguez, Erick Jorge, Cannon, Dara M., Guadalupe, Tulio, Caparelli, Elisabeth C., Castellanos, Francisco X., Cendes, Fernando, Chaim-Avancini, Tiffany Moukbel, Chantiluke, Kaylita, Chen, Qun-lin, Chen, Xiayu, Cheng, Yuqi, Christakou, Anastasia, Clark, Vincent P., Abé, Christoph, Coghill, David, Connolly, Colm G., Conzelmann, Annette, Córdova-Palomera, Aldo, Cousijn, Janna, Crow, Tim, Cubillo, Ana, Dannlowski, Udo, Bruttopilo, Sara Ambrosino, Zeeuw, Patrick, Deary, Ian J., Demeter, Damion V., Di Martino, Adriana, Dickie, Erin W, Dietsche, Bruno, Doan, Nhat Trung, Doherty, Colin P., Doyle, Alysa, Durston, Sarah, Earl, Eric, Akudjedu, Theophilus N., Ehrlich, Stefan, Ekman, Carl Johan, Elvsåshagen, Torbjørn, Epstein, Jeffery N., Fair, Damien A., Faraone, Stephen V., Fernández, Guillén, Flint, Claas, Filho, Geraldo Busatto, Förster, Katharina, Aleman, Andre, Fouche, Jean-Paul, Foxe, John J., Frodl, Thomas, Fuentes-Claramonte, Paola, Fullerton, Janice M., Garavan, Hugh, Santos Garcia, Danielle, Gotlib, Ian H., Goudriaan, Anna E., Grabe, Hans Jörgen, Alhusaini, Saud, Groenewold, Nynke A., Grotegerd, Dominik, Gruber, Oliver, Gurholt, Tiril, Haavik, Jan, Hahn, Tim, Hansell, Narelle K., Harris, Mathew A., Hartman, Catharina A., Carmen Valdés Hernández, Maria, Alhusaini, Saud, Del Carmen Valdés Hernández, Maria, Heslenfeld, Dirk, Hester, Robert, Hibar, Derrek Paul, Ho, Beng-Choon, Ho, Tiffany C., Hoekstra, Pieter J., van Holst, Ruth J., Hoogman, Martine, Høvik, Marie F., Allen, Nicholas B., Howells, Fleur M., Hugdahl, Kenneth, Huyser, Chaim, Ingvar, Martin, Ishikawa, Akari, James, Anthony, Jahanshad, Neda, Jernigan, Terry L., Jönsson, Erik G., Kaleda, Vasily, Ames, David, Kelly, Clare, Kerich, Michael, Keshavan, Matcheri S., Khadka, Sabin, Kircher, Tilo, Kohls, Gregor, Konrad, Kerstin, Korucuoglu, Ozlem, Krämer, Bernd, Krug, Axel, Andreassen, Ole A., Kuntsi, Jonna, Kwon, Jun Soo, Lambregts-Rommelse, Nanda, Landén, Mikael, Lázaro, Luisa, Lebedeva, Irina, Lenroot, Rhoshel, Lesch, Klaus-Peter, Li, Qinqin, Lim, Kelvin O., Vasquez, Alejandro Arias, Liu, Jia, Lochner, Christine, London, Edythe D., Lorenzetti, Valentina, Luciano, Michelle, Luijten, Maartje, Lundervold, Astri J., Mackey, Scott, MacMaster, Frank P., Maingault, Sophie, Armstrong, Nicola J., Malpas, Charles B., Malt, Ulrik F., Mataix-Cols, David, Martin-Santos, Rocio, Mayer, Andrew R., McCarthy, Hazel, Medland, Sarah, Metha, Mitul, Mitchell, Philip B., Mueller, Bryon A., Asherson, Phil, Maniega, Susana Muñoz, Mazoyer, Bernard, McDonald, Colm, McLellan, Quinn, McMahon, Katie L., McPhilemy, Genevieve, Momenan, Reza, Morales, Angelica M., Narayanaswamy, Janardhanan C., Moreira, José Carlos Vasques, Bergo, Felipe, Nerland, Stener, Nestor, Liam, Newman, Erik, Nigg, Joel T., Nordvik, Jan Egil, Novotny, Stephanie, Weiss, Eileen Oberwelland, O'Gorman, Ruth L., Oosterlaan, Jaap, Oranje, Bob, Bastin, Mark E., Orr, Catherine, Overs, Bronwyn, Paloyelis, Yannis, Pauli, Paul, Paulus, Martin, Plessen, Kerstin Jessica, von Polier, Georg G., Pomarol-Clotet, Edith, Portella, Maria J., Qiu, Jiang, Batalla, Albert, Radua, Joaquim, Ramos-Quiroga, Josep Antoni, Reddy, Y. C. Janardhan, Reif, Andreas, Roberts, Gloria, Rosa, Pedro, Rubia, Katya, Sacchet, Matthew D., Sachdev, Perminder S., Salvador, Raymond, Bauer, Jochen, Schmaal, Lianne, Schulte-Rüther, Martin, Schweren, Lizanne, Seitz, Jochen, Serpa, Mauricio Henriques, Shaw, Philip, Shumskaya, Elena, Silk, Timothy J., Simmons, Alan N., Simulionyte, Egle, Baune, Bernhard T., Sinha, Rajita, Sjoerds, Zsuzsika, Smelror, Runar Elle, Soliva, Joan Carlos, Solowij, Nadia, Souza-Duran, Fabio Luisde, Sponheim, Scott R., Stein, Dan J., Stein, Elliot A., Stevens, Michael, Baur-Streubel, Ramona, Strike, Lachlan T., Sudre, Gustavo, Sui, Jing, Tamm, Leanne, Temmingh, Hendrik S., Thoma, Robert J., Tomyshev, Alexander, Tronchin, Giulia, Turner, Jessica, Uhlmann, Anne, Biederman, Joseph, van Erp, Theo G. M., van den Heuvel, Odile A., van der Meer, Dennis, van Eijk, Liza, Vance, Alasdair, Veer, Ilya M., Veltman, Dick J., Venkatasubramanian, Ganesan, Vilarroya, Oscar, Vives-Gilabert, Yolanda, Blaine, Sara K., Voineskos, Aristotle N., Völzke, Henry, Vuletic, Daniella, Walitza, Susanne, Walter, Henrik, Walton, Esther, Wardlaw, Joanna M., Wen, Wei, Westlye, Lars T., Whelan, Christopher D., Boedhoe, Premika, White, Tonya, Wiers, Reinout W., Wright, Margaret J., Wittfeld, Katharina, Yang, Tony T., Yasuda, Clarissa L., Yoncheva, Yuliya, Yücel, Murat, Yun, Je-Yeon, Zanetti, Marcus Vinicius, Bøen, Erlend, Zhen, Zonglei, Zhu, Xing-Xing, Ziegler, Georg C., de Zubicaray, Greig I., Zwiers, Marcel, Project, Karolinska Schizophrenia, Glahn, David C., Crivello, Fabrice, Fisher, Simon E., Thompson, Paul M., Bose, Anushree, Francks, Clyde, Farde, Lars, Flyckt, Lena, Engberg, Göran, Erhardt, Sophie, Fatouros-Bergman, Helena, Cervenka, Simon, Schwieler, Lilly, Piehl, Fredrik, Agartz, Ingrid, Bralten, Janita, Collste, Karin, Victorsson, Pauliina, Malmqvist, Anna, Hedberg, Mikael, Orhan, Funda, Sellgren, Carl, Brandeis, Daniel, Kong, Xiang-Zhen, Brem, Silvia, Brodaty, Henry, Yüksel, Dilara, Brooks, Samantha J., Buitelaar, Jan, Bürger, Christian, Bülow, Robin, Calhoun, Vince, Calvo, Anna, Canales-Rodríguez, Erick Jorge, Mathias, Samuel R., Cannon, Dara M., Caparelli, Elisabeth C., Castellanos, Francisco X., Cendes, Fernando, Chaim-Avancini, Tiffany Moukbel, Chantiluke, Kaylita, Chen, Qun-Lin, Chen, Xiayu, Cheng, Yuqi, Christakou, Anastasia, Guadalupe, Tulio, Clark, Vincent P., Coghill, David, Connolly, Colm G., Conzelmann, Annette, Córdova-Palomera, Aldo, Cousijn, Janna, Crow, Tim, Cubillo, Ana, Dannlowski, Udo, de Bruttopilo, Sara Ambrosino, Abé, Christoph, de Zeeuw, Patrick, Deary, Ian J., Demeter, Damion V., Di Martino, Adriana, Dickie, Erin W., Dietsche, Bruno, Doan, Nhat Trung, Doherty, Colin P., Doyle, Alysa, Durston, Sarah, Earl, Eric, Ehrlich, Stefan, Ekman, Carl Johan, Elvsåshagen, Torbjørn, Epstein, Jeffery N., Fair, Damien A., Faraone, Stephen V., Fernández, Guillén, Flint, Claas, Filho, Geraldo Busatto, Akudjedu, Theophilus N., Förster, Katharina, Fouche, Jean-Paul, Foxe, John J., Frodl, Thomas, Fuentes-Claramonte, Paola, Fullerton, Janice M., Garavan, Hugh, do Santos Garcia, Danielle, Gotlib, Ian H., Goudriaan, Anna E., Aleman, Andre, Grabe, Hans Jörgen, Groenewold, Nynke A., Grotegerd, Dominik, Gruber, Oliver, Gurholt, Tiril, Haavik, Jan, Hahn, Tim, Hansell, Narelle K., Harris, Mathew A., Hartman, Catharina A., Ontwikkelingspsychologie (Psychologie, FMG), Adult Psychiatry, APH - Mental Health, ANS - Compulsivity, Impulsivity & Attention, Child and Adolescent Psychiatry & Psychosocial Care, Child Psychiatry, ANS - Cellular & Molecular Mechanisms, Laboratory Genetic Metabolic Diseases, Paediatrics, General Paediatrics, ARD - Amsterdam Reproduction and Development, Paediatric Pulmonology, Graduate School, and APH - Digital Health

Subjects
P‐hacking, Datasets as Topic, Publication bias, 0302 clinical medicine, 130 000 Cognitive Neurology & Memory, Statistics, team science, Brain asymmetry, Multicenter Studies as Topic, Cervell, Research Articles, Cerebral Cortex, Radiological and Ultrasound Technology, P-hacking, 05 social sciences, Brain, Cerebral cortex, Middle Aged, Magnetic Resonance Imaging, Discoveries in science, Escorça cerebral, Neurology, Biaix de publicació, Anatomy, Psychology, Research Article, Neuroinformatics, Adult, Adolescent, Neuroimaging, Descobriments científics, 050105 experimental psychology, Statistical power, 03 medical and health sciences, Young Adult, Magnetic resonance imaging, Imatges per ressonància magnètica, multisite collaboration, Humans, 0501 psychology and cognitive sciences, Radiology, Nuclear Medicine and imaging, ddc:610, reproducibility, Aged, publication bias, Reproducibility, Neurodevelopmental disorders Donders Center for Medical Neuroscience [Radboudumc 7], Perspective (graphical), Reproducibility of Results, Brain Cortical Thickness, Research data, Sample size determination, Dades de recerca, Neurology (clinical), Scale (map), Developmental Psychopathology, 030217 neurology & neurosurgery
Abstract

The problem of poor reproducibility of scientific findings has received much attention over recent years, in a variety of fields including psychology and neuroscience. The problem has been partly attributed to publication bias and unwanted practices such as p‐hacking. Low statistical power in individual studies is also understood to be an important factor. In a recent multisite collaborative study, we mapped brain anatomical left–right asymmetries for regional measures of surface area and cortical thickness, in 99 MRI datasets from around the world, for a total of over 17,000 participants. In the present study, we revisited these hemispheric effects from the perspective of reproducibility. Within each dataset, we considered that an effect had been reproduced when it matched the meta‐analytic effect from the 98 other datasets, in terms of effect direction and significance threshold. In this sense, the results within each dataset were viewed as coming from separate studies in an “ideal publishing environment,” that is, free from selective reporting and p hacking. We found an average reproducibility rate of 63.2% (SD = 22.9%, min = 22.2%, max = 97.0%). As expected, reproducibility was higher for larger effects and in larger datasets. Reproducibility was not obviously related to the age of participants, scanner field strength, FreeSurfer software version, cortical regional measurement reliability, or regional size. These findings constitute an empirical illustration of reproducibility in the absence of publication bias or p hacking, when assessing realistic biological effects in heterogeneous neuroscience data, and given typically‐used sample sizes., Region‐wise effect sizes and reproducibility rates of hemispheric asymmetry effects. In general, effects with higher effect sizes showed higher reproducibility, given the same conditions (e.g., sample size and data heterogeneity).

Published
2022

23. Modular-Level Functional Connectome Alterations in Individuals with Hallucinations Across the Psychosis Continuum

Author

Schutte, Maya J.L., Voppel, Alban, Collin, Guusje, Abramovic, Lucija, Boks, Marco P.M., Cahn, Wiepke, Van Haren, Neeltje E.M., Hugdahl, Kenneth, Koops, Sanne, Mandl, Rencrossed C.W., Sommer, Iris E.C., Schutte, Maya J.L., Voppel, Alban, Collin, Guusje, Abramovic, Lucija, Boks, Marco P.M., Cahn, Wiepke, Van Haren, Neeltje E.M., Hugdahl, Kenneth, Koops, Sanne, Mandl, Rencrossed C.W., and Sommer, Iris E.C.

Abstract

Functional connectome alterations, including modular network organization, have been related to the experience of hallucinations. It remains to be determined whether individuals with hallucinations across the psychosis continuum exhibit similar alterations in modular brain network organization. This study assessed functional connectivity matrices of 465 individuals with and without hallucinations, including patients with schizophrenia and bipolar disorder, nonclinical individuals with hallucinations, and healthy controls. Modular brain network organization was examined at different scales of network resolution, including (1) global modularity measured as Qmax and Normalised Mutual Information (NMI) scores, and (2) within-and between-module connectivity. Global modular organization was not significantly altered across groups. However, alterations in within-and between-module connectivity were observed for higher-order cognitive (e.g., central-executive salience, memory, default mode), and sensory modules in patients with schizophrenia and nonclinical individuals with hallucinations relative to controls. Dissimilar patterns of altered within-and between-module connectivity were found bipolar disorder patients with hallucinations relative to controls, including the visual, default mode, and memory network, while connectivity patterns between visual, salience, and cognitive control modules were unaltered. Bipolar disorder patients without hallucinations did not show significant alterations relative to controls. This study provides evidence for alterations in the modular organization of the functional connectome in individuals prone to hallucinations, with schizophrenia patients and nonclinical individuals showing similar alterations in sensory and higher-order cognitive modules. Other higher-order cognitive modules were found to relate to hallucinations in bipolar disorder patients, suggesting differential neural mechanisms may underlie hallucinations across the psyc

Published
2022

24. NO EVIDENCE FOR CHANGES IN PREFRONTAL AND TEMPORO-PARIETAL AREAS BY TDCS TREATMENT OF AUDITORY HALLUCINATIONS

Author

Hirnstein, Marco, Marquardt, Lynn, Kusztrits, Isabella, SynnoveThomassen, Anne, R.Craven, Alexander, Johnsen, Erik, AndreasKroken, Rune, Weber, Sarah, Dwyer, Gerard, Korbmacher, Max, Specht, Karsten, Hugdahl, Kenneth, Hirnstein, Marco, Marquardt, Lynn, Kusztrits, Isabella, SynnoveThomassen, Anne, R.Craven, Alexander, Johnsen, Erik, AndreasKroken, Rune, Weber, Sarah, Dwyer, Gerard, Korbmacher, Max, Specht, Karsten, and Hugdahl, Kenneth

Published
2022

25. Modular-Level Functional Connectome Alterations in Individuals With Hallucinations Across the Psychosis Continuum

Author

Onderzoeksgroep 2, Psychiatrie_Medisch, Brain, Onderzoek, Onderzoeksgroep 1, Schutte, Maya J L, Voppel, Alban, Collin, Guusje, Abramovic, Lucija, Boks, Marco P M, Cahn, Wiepke, van Haren, Neeltje E M, Hugdahl, Kenneth, Koops, Sanne, Mandl, René C W, Sommer, Iris E C, Onderzoeksgroep 2, Psychiatrie_Medisch, Brain, Onderzoek, Onderzoeksgroep 1, Schutte, Maya J L, Voppel, Alban, Collin, Guusje, Abramovic, Lucija, Boks, Marco P M, Cahn, Wiepke, van Haren, Neeltje E M, Hugdahl, Kenneth, Koops, Sanne, Mandl, René C W, and Sommer, Iris E C

Published
2022

26. Neural Activation in the Ventromedial Prefrontal Cortex Precedes Conscious Experience of Being in or out of a Transient Hallucinatory State.

Author

Hugdahl, Kenneth, Craven, Alexander R, Johnsen, Erik, Ersland, Lars, Stoyanov, Drozdstoy, Kandilarova, Sevdalina, Sandøy, Lydia Brunvoll, Kroken, Rune A, Løberg, Else-Marie, and Sommer, Iris E C

Subjects
HALLUCINATIONS, PREFRONTAL cortex, EVOKED potentials (Electrophysiology), LARGE-scale brain networks, SCHIZOPHRENIA, AUDITORY perception, TRANSCRANIAL magnetic stimulation, MAGNETIC resonance imaging, WORD deafness, COMPARATIVE studies, RESEARCH funding, TIME series analysis, NEURORADIOLOGY
Abstract

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, especially their underlying neuronal architecture. Neuroimaging methods have been used to identify brain areas and networks that are activated during hallucinations. A characteristic feature of AVHs is, however, that they fluctuate over time, with varying frequencies of starts and stops. An unanswered question is, therefore, what neuronal events co-occur with the initiation and inhibition of an AVH episode. Study Design We investigated brain activation with fMRI in 66 individuals who experienced multiple AVH-episodes while in the scanner. We extracted time-series fMRI-data and monitored changes second-by-second from 10 s before to 15 s after participants indicated the start and stop of an episode, respectively, by pressing a hand-held response-button. Study Results We found a region in the ventromedial prefrontal cortex (VMPFC) which showed a significant increase in activation initiated a few seconds before participants indicated the start of an episode, and a corresponding decrease in activation initiated a few seconds before the end of an episode. Conclusions The consistent increase and decrease in activation in this area in advance of the consciously experienced presence or absence of the "voice" imply that this region may act as a switch in turning episodes on and off. The activation is unlikely to be confounded by motor responses. The findings could have clinical implications for brain stimulation treatments, like transcranial magnetic stimulation. [ABSTRACT FROM AUTHOR]

Published
2023
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27. Neural Activation in the Ventromedial Prefrontal Cortex Precedes Conscious Experience of Being in or Out of a Transient Hallucinatory State

Author

Hugdahl, Kenneth, primary, Craven, Alexander R, additional, Johnsen, Erik, additional, Ersland, Lars, additional, Stoyanov, Drozdstoy, additional, Kandilarova, Sevdalina, additional, Brunvoll Sandøy, Lydia, additional, Kroken, Rune A, additional, Løberg, Else-Marie, additional, and Sommer, Iris E, additional

Published
2022
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28. Comparison of seven modelling algorithms for GABA-edited (1)H-MRS: Evaluation of data from 20 sites, with: FSL-MRS, Gannet, jMRUI (AMARES, QUEST), LCModel, Osprey and Tarquin

Author

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, and Oeltzschner, Georg

Subjects
Magnetic Resonance Spectroscopy, Proton Magnetic Resonance Spectroscopy, Brain, Humans, Reproducibility of Results, Article, Algorithms, gamma-Aminobutyric Acid
Abstract

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 or a linear combination of basis spectra. The present study compares seven such algorithms, using data obtained in a large multisite study. GABA-edited (GABA+, TE = 68 ms MEGA-PRESS) data from 222 subjects at 20 sites were processed via a standardised pipeline, before modelling with FSL-MRS, Gannet, AMARES, QUEST, LCModel, Osprey and Tarquin, using standardised vendor-specific basis sets (for GE, Philips and Siemens) where appropriate. After referencing metabolite estimates (to water or creatine), systematic differences in scale were observed between datasets acquired on different vendors' hardware, presenting across algorithms. Scale differences across algorithms were also observed. Using the correlation between metabolite estimates and voxel tissue fraction as a benchmark, most algorithms were found to be similarly effective in detecting differences in GABA+. An interclass correlation across all algorithms showed single-rater consistency for GABA+ estimates of around 0.38, indicating moderate agreement. Upon inclusion of a basis set component explicitly modelling the macromolecule signal underlying the observed 3.0 ppm GABA peaks, single-rater consistency improved to 0.44. Correlation between discrete pairs of algorithms varied, and was concerningly weak in some cases. Our findings highlight the need for consensus on appropriate modelling parameters across different algorithms, and for detailed reporting of the parameters adopted in individual studies to ensure reproducibility and meaningful comparison of outcomes between different studies.

Published
2022

29. Comparison of seven modelling algorithms for γ‐aminobutyric acid–edited proton magnetic resonance spectroscopy

Author

Craven, Alexander R., primary, Bhattacharyya, Pallab K., additional, Clarke, William T., additional, Dydak, Ulrike, additional, Edden, Richard A. E., additional, Ersland, Lars, additional, Mandal, Pravat K., additional, Mikkelsen, Mark, additional, Murdoch, James B., additional, Near, Jamie, additional, Rideaux, Reuben, additional, Shukla, Deepika, additional, Wang, Min, additional, Wilson, Martin, additional, Zöllner, Helge J., additional, Hugdahl, Kenneth, additional, and Oeltzschner, Georg, additional

Published
2022
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32. Negative valence of hallucinatory voices as predictor of cortical glutamatergic metabolite levels in schizophrenia patients

Author

Hjelmervik, Helene, primary, Craven, Alexander R., additional, Johnsen, Erik, additional, Kompus, Kristiina, additional, Bless, Josef J., additional, Sinkeviciute, Igne, additional, Kroken, Rune A., additional, Løberg, Else‐Marie, additional, Ersland, Lars, additional, Grüner, Renate, additional, Sommer, Iris E., additional, and Hugdahl, Kenneth, additional

Published
2021
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33. Comparison of seven modelling algorithms for GABA-edited 1H-MRS

Author

Craven, Alexander R., primary, Bhattacharyya, Pallab K., additional, Clarke, William T., additional, Dydak, Ulrike, additional, Edden, Richard A. E., additional, Ersland, Lars, additional, Mandal, Pravat K., additional, Mikkelsen, Mark, additional, Murdoch, James B., additional, Near, Jamie, additional, Rideaux, Reuben, additional, Shukla, Deepika, additional, Wang, Min, additional, Wilson, Martin, additional, Zöllner, Helge, additional, Hugdahl, Kenneth, additional, and Oeltzschner, Georg, additional

Published
2021
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35. Brain pathology and cognitive scores prior to onset of late-life depression.

Author

Almdahl, Ina S., Agartz, Ingrid, Hugdahl, Kenneth, Korsnes, Maria S., and Alzheimer’s Disease Neuroimaging Initiative

Subjects
BRAIN diseases, MENTAL depression, OLDER people, WHITE matter (Nerve tissue), ALZHEIMER'S disease, BRAIN metabolism, PROTEINS, RESEARCH, HIPPOCAMPUS (Brain), RESEARCH methodology, COGNITION, MAGNETIC resonance imaging, EVALUATION research, COMPARATIVE studies, RESEARCH funding, PEPTIDES
Abstract

Objectives: Understanding the biological changes that occur prior to onset of late-life depression (LLD) is key to its prevention. To investigate potential predictors of LLD, we assessed cognitive scores and neurodegenerative and vascular biomarkers in healthy older adults who later developed depression.Methods: Longitudinal data from the Alzheimer's Disease Neuroimaging Initiative of 241 cognitively unimpaired and non-depressed older adults aged 56-90 at baseline with at least 4 years of follow-up were included. Participants were classified based on whether they developed an incident depression (n = 96) or not (n = 145). Cognitive measures of memory, executive functioning, and language, and biomarkers proposed to be related to LLD: hippocampal volume, white matter hyperintensity volume (WMH), and cortical and cerebrospinal fluid (CSF) amyloid beta levels, were compared between the incident depression and the never-depressed groups at four time points: at baseline, the visit prior to onset, at onset, and after the onset of depression.Results: In the incident depression group, there was a mild decline in cognitive scores from baseline to the visit before depression onset compared with the never-depressed group. The cognitive differences between the groups became more marked after depression onset. Baseline cortical amyloid burden, CSF amyloid beta levels, and WMH were significant predictors of incident depression. Compared to the non-depressed group, hippocampal volume was not reduced before onset, but was reduced following depression.Conclusions: Amyloid pathology and WMH can predict future development of LLD in cognitively unimpaired individuals and may be involved in precipitating vulnerability for depression in older adults. [ABSTRACT FROM AUTHOR]

Published
2022
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37. Linewidth-related bias in modelled concentration estimates from GABA-edited 1 H-MRS.

Author

Craven AR, Bell TK, Ersland L, Harris AD, Hugdahl K, and Oeltzschner G

Abstract

J-difference-edited MRS is widely used to study GABA in the human brain. Editing for low-concentration target molecules (such as GABA) typically exhibits lower signal-to-noise ratio (SNR) than conventional non-edited MRS, varying with acquisition region, volume and duration. Moreover, spectral lineshape may be influenced by age-, pathology-, or brain-region-specific effects of metabolite T 2 , or by task-related blood-oxygen level dependent (BOLD) changes in functional MRS contexts. Differences in both SNR and lineshape may have systematic effects on concentration estimates derived from spectral modelling. The present study characterises the impact of lineshape and SNR on GABA+ estimates from different modelling algorithms: FSL-MRS, Gannet, LCModel, Osprey, spant and Tarquin. Publicly available multi-site GABA-edited data (222 healthy subjects from 20 sites; conventional MEGA-PRESS editing; TE = 68 ms) were pre-processed with a standardised pipeline, then filtered to apply controlled levels of Lorentzian and Gaussian linebroadening and SNR reduction. Increased Lorentzian linewidth was associated with a 2-5% decrease in GABA+ estimates per Hz, observed consistently (albeit to varying degrees) across datasets and most algorithms. Weaker, often opposing effects were observed for Gaussian linebroadening. Variations are likely caused by differing baseline parametrization and lineshape constraints between models. Effects of linewidth on other metabolites (e.g., Glx and tCr) varied, suggesting that a linewidth confound may persist after scaling to an internal reference. These findings indicate a potentially significant confound for studies where linewidth may differ systematically between groups or experimental conditions, e.g. due to T 2 differences between brain regions, age, or pathology, or varying T 2 * due to BOLD-related changes. We conclude that linewidth effects need to be rigorously considered during experimental design and data processing, for example by incorporating linewidth into statistical analysis of modelling outcomes or development of appropriate lineshape matching algorithms., Competing Interests: Declaration of Interest The authors declare no conflicting interests.

Published
2024
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