{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,11,7]],"date-time":"2026-11-07T08:52:22Z","timestamp":1794041542585,"version":"4.8.0"},"reference-count":45,"publisher":"MIT Press","license":[{"start":{"date-parts":[[2024,11,14]],"date-time":"2024-11-14T00:00:00Z","timestamp":1731542400000},"content-version":"vor","delay-in-days":318,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["direct.mit.edu"],"crossmark-restriction":true},"short-container-title":[],"published-print":{"date-parts":[[2024,12,2]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>Electric field calculations are increasingly used for dose characterization of transcranial electrical stimulation (tES), but existing open-source head models are inaccurate for extracephalic montages that include electrodes placed on the neck or shoulder. We introduce the \u201cErnie Extended\u201d model, an MRI- and CT-derived open-source head model extending to the upper shoulder region. Simulations of extracephalic tES targeting the cerebellum and supplementary motor area show significant differences in electric fields when using Ernie Extended compared to the non-extended Ernie model. Additionally, we propose an electrode layout that complements the electroencephalography 10\u201320 system with extracephalic electrode positions. We demonstrate the use of this layout for optimizing multi-electrode tES montages for cerebellar stimulation, enhancing focality, and reducing off-target stimulation, particularly of the spinal cord. Our results highlight the practical value of the Ernie Extended model for accurately characterizing doses produced by extracephalic tES montages and when targeting more caudal brain regions.<\/jats:p>","DOI":"10.1162\/imag_a_00379","type":"journal-article","created":{"date-parts":[[2024,11,14]],"date-time":"2024-11-14T16:18:43Z","timestamp":1731601123000},"update-policy":"https:\/\/doi.org\/10.1162\/mitpressjournals.corrections.policy","source":"Crossref","is-referenced-by-count":13,"title":["Head and shoulders\u2014The impact of an extended head model on the simulation and optimization of transcranial electric stimulation"],"prefix":"10.1162","volume":"2","author":[{"given":"Sybren","family":"Van Hoornweder","sequence":"first","affiliation":[{"name":"REVAL - Rehabilitation Research Center, Faculty of Rehabilitation Sciences, University of Hasselt, Diepenbeek, Belgium"},{"name":"Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Amager and Hvidovre, Hvidovre, Denmark"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Vittoria","family":"Cappozzo","sequence":"additional","affiliation":[{"name":"Department of Health Technology, Technical University of Denmark, Kgs. Lyngby, Denmark"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Laura","family":"De Herde","sequence":"additional","affiliation":[{"name":"Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Amager and Hvidovre, Hvidovre, Denmark"},{"name":"Department of Health Technology, Technical University of Denmark, Kgs. Lyngby, Denmark"},{"name":"Department of Medicine and Health Technology, Aalborg University, Aalborg, Denmark"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Oula","family":"Puonti","sequence":"additional","affiliation":[{"name":"Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Amager and Hvidovre, Hvidovre, Denmark"},{"name":"Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hartwig R.","family":"Siebner","sequence":"additional","affiliation":[{"name":"Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Amager and Hvidovre, Hvidovre, Denmark"},{"name":"Department of Neurology, Copenhagen University Hospital Bispebjerg, Copenhagen, Denmark"},{"name":"Institute for Clinical Medicine, Faculty of Medical and Health Sciences, University of Copenhagen, Copenhagen, Denmark"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Raf L.J.","family":"Meesen","sequence":"additional","affiliation":[{"name":"REVAL - Rehabilitation Research Center, Faculty of Rehabilitation Sciences, University of Hasselt, Diepenbeek, Belgium"},{"name":"Movement Control and Neuroplasticity Research Group, Department of Movement Sciences, Group Biomedical Sciences, KU Leuven, Leuven, Belgium"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Axel","family":"Thielscher","sequence":"additional","affiliation":[{"name":"Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Amager and Hvidovre, Hvidovre, Denmark"},{"name":"Department of Health Technology, Technical University of Denmark, Kgs. Lyngby, Denmark"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"281","published-online":{"date-parts":[[2024,12,2]]},"reference":[{"issue":"6","key":"2025081119493664200_b1","doi-asserted-by":"crossref","first-page":"1776","DOI":"10.1016\/j.brs.2023.11.018","article-title":"Multi-scale model of axonal and dendritic polarization by transcranial direct current stimulation in realistic head geometry","volume":"16","author":"Aberra","year":"2023","journal-title":"Brain Stimulation"},{"issue":"2","key":"2025081119493664200_b2","doi-asserted-by":"crossref","first-page":"304","DOI":"10.1016\/j.brs.2021.01.018","article-title":"Pinging the brain with transcranial magnetic stimulation reveals cortical reactivity in time and space","volume":"14","author":"Ahn","year":"2021","journal-title":"Brain Stimulation"},{"issue":"5","key":"2025081119493664200_b3","doi-asserted-by":"crossref","first-page":"1221","DOI":"10.1016\/j.brs.2022.08.018","article-title":"A minimum effective dose for (transcranial) alternating current stimulation","volume":"15","author":"Alekseichuk","year":"2022","journal-title":"Brain Stimulation"},{"key":"2025081119493664200_b4","doi-asserted-by":"crossref","DOI":"10.1016\/j.neuroimage.2020.117353","article-title":"Inter-subject variability of skull conductivity and thickness in calibrated realistic head models","volume":"223","author":"Antonakakis","year":"2020","journal-title":"NeuroImage"},{"issue":"2","key":"2025081119493664200_b5","doi-asserted-by":"crossref","first-page":"242","DOI":"10.1016\/j.brs.2016.11.001","article-title":"Long term clinical and neurophysiological effects of cerebellar transcranial direct current stimulation in patients with neurodegenerative ataxia","volume":"10","author":"Benussi","year":"2017","journal-title":"Brain Stimulation"},{"issue":"3","key":"2025081119493664200_b6","doi-asserted-by":"crossref","first-page":"430","DOI":"10.1016\/j.brs.2011.06.001","article-title":"Guidelines for precise and accurate computational models of tDCS","volume":"5","author":"Bikson","year":"2012","journal-title":"Brain Stimulation"},{"issue":"7","key":"2025081119493664200_b7","doi-asserted-by":"crossref","first-page":"1051","DOI":"10.1111\/j.1600-6143.2004.00460.x","article-title":"Porcine endogenous retroviral nucleic acid in peripheral tissues is associated with migration of porcine cells post islet transplant","volume":"4","author":"Binette","year":"2004","journal-title":"American Journal of Transplantation"},{"key":"2025081119493664200_b8","first-page":"5913","article-title":"A computational analysis of the electric field components in transcranial direct current stimulation","volume":"2019","author":"Callejon-Leblic","year":"2019","journal-title":"Annual International Conference of the IEEE Engineering in Medicine and Biology Society"},{"issue":"4","key":"2025081119493664200_b9","doi-asserted-by":"crossref","DOI":"10.1088\/1741-2552\/abeab7","article-title":"A comprehensive analysis of the impact of head model extent on electric field predictions in transcranial current stimulation","volume":"18","author":"Callej\u00f3n-Leblic","year":"2021","journal-title":"Journal of Neural Engineering"},{"issue":"1","key":"2025081119493664200_b10","doi-asserted-by":"crossref","first-page":"20116","DOI":"10.1038\/s41598-022-24618-3","article-title":"Optimized APPS-tDCS electrode position, size, and distance doubles the on-target stimulation magnitude in 3000 electric field models","volume":"12","author":"Caulfield","year":"2022","journal-title":"Scientific Reports"},{"key":"2025081119493664200_b11","doi-asserted-by":"crossref","first-page":"1214959","DOI":"10.3389\/fncir.2023.1214959","article-title":"Template MRI scans reliably approximate individual and group-level tES and TMS electric fields induced in motor and prefrontal circuits","volume":"17","author":"Cho","year":"2023","journal-title":"Frontiers in Neural Circuits"},{"issue":"3","key":"2025081119493664200_b12","doi-asserted-by":"crossref","first-page":"169","DOI":"10.1016\/j.brs.2010.11.001","article-title":"Individualized model predicts brain current flow during transcranial direct-current stimulation treatment in responsive stroke patient","volume":"4","author":"Datta","year":"2011","journal-title":"Brain Stimulation"},{"issue":"4","key":"2025081119493664200_b13","doi-asserted-by":"crossref","first-page":"485","DOI":"10.1007\/s12311-012-0436-9","article-title":"Modulating human procedural learning by cerebellar transcranial direct current stimulation","volume":"12","author":"Ferrucci","year":"2013","journal-title":"Cerebellum"},{"issue":"20","key":"2025081119493664200_b14","doi-asserted-by":"crossref","first-page":"11050","DOI":"10.1073\/pnas.200033797","article-title":"Measuring the thickness of the human cerebral cortex from magnetic resonance images","volume":"97","author":"Fischl","year":"2000","journal-title":"Proceedings of the National Academy of Sciences"},{"issue":"16","key":"2025081119493664200_b15","doi-asserted-by":"crossref","first-page":"4863","DOI":"10.1088\/0031-9155\/54\/16\/002","article-title":"Electrical conductivity of tissue at frequencies below 1 MHz","volume":"54","author":"Gabriel","year":"2009","journal-title":"Physics in Medicine and Biology"},{"issue":"8","key":"2025081119493664200_b16","doi-asserted-by":"crossref","first-page":"2137","DOI":"10.1088\/0031-9155\/57\/8\/2137","article-title":"Evaluation of local electric fields generated by transcranial direct current stimulation with an extracephalic reference electrode based on realistic 3D body modeling","volume":"57","author":"Im","year":"2012","journal-title":"Physics in Medicine and Biology"},{"issue":"2","key":"2025081119493664200_b17","doi-asserted-by":"crossref","first-page":"825","DOI":"10.1006\/nimg.2002.1132","article-title":"Improved optimization for the robust and accurate linear registration and motion correction of brain images","volume":"17","author":"Jenkinson","year":"2002","journal-title":"NeuroImage"},{"issue":"2","key":"2025081119493664200_b18","doi-asserted-by":"crossref","first-page":"143","DOI":"10.1016\/S1361-8415(01)00036-6","article-title":"A global optimisation method for robust affine registration of brain images","volume":"5","author":"Jenkinson","year":"2001","journal-title":"Medical Image Analysis"},{"issue":"1","key":"2025081119493664200_b19","doi-asserted-by":"crossref","first-page":"196","DOI":"10.1109\/TMI.2009.2035616","article-title":"elastix: A toolbox for intensity-based medical image registration","volume":"29","author":"Klein","year":"2010","journal-title":"IEEE Transactions on Medical Imaging"},{"issue":"2","key":"2025081119493664200_b20","doi-asserted-by":"crossref","first-page":"260","DOI":"10.1016\/j.brs.2014.11.003","article-title":"Montage matters: The influence of transcranial alternating current stimulation on human physiological tremor","volume":"8","author":"Mehta","year":"2015","journal-title":"Brain Stimulation"},{"issue":"3","key":"2025081119493664200_b21","doi-asserted-by":"crossref","first-page":"272","DOI":"10.1007\/s00776-012-0208-x","article-title":"A feasibility study for evaluation of mechanical properties of articular cartilage with a two-electrode electrical impedance method","volume":"17","author":"Morita","year":"2012","journal-title":"Journal of Orthopaedic Science"},{"key":"2025081119493664200_b22","doi-asserted-by":"crossref","first-page":"587","DOI":"10.1016\/j.neuroimage.2018.03.001","article-title":"Automatic skull segmentation from MR images for realistic volume conductor models of the head: Assessment of the state-of-the-art","volume":"174","author":"Nielsen","year":"2018","journal-title":"NeuroImage"},{"issue":"Pt 3","key":"2025081119493664200_b23","doi-asserted-by":"crossref","first-page":"633","DOI":"10.1111\/j.1469-7793.2000.t01-1-00633.x","article-title":"Excitability changes induced in the human motor cortex by weak transcranial direct current stimulation","volume":"3","author":"Nitsche","year":"2000","journal-title":"The Journal of Physiology"},{"issue":"9","key":"2025081119493664200_b24","doi-asserted-by":"crossref","first-page":"2488","DOI":"10.1109\/TBME.2014.2322774","article-title":"Comparison of cephalic and extracephalic montages for transcranial direct current stimulation\u2014A numerical study","volume":"61","author":"Noetscher","year":"2014","journal-title":"IEEE Transactions on Bio-Medical Engineering"},{"key":"2025081119493664200_b25","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1162\/imag_a_00106","article-title":"Electric-field-based dosing for TMS","volume":"2","author":"Numssen","year":"2024","journal-title":"Imaging Neuroscience"},{"key":"2025081119493664200_b26","doi-asserted-by":"crossref","first-page":"118654","DOI":"10.1016\/j.neuroimage.2021.118654","article-title":"Efficient high-resolution TMS mapping of the human motor cortex by nonlinear regression","volume":"245","author":"Numssen","year":"2021","journal-title":"NeuroImage"},{"key":"2025081119493664200_b27","doi-asserted-by":"crossref","first-page":"140","DOI":"10.1016\/j.neuroimage.2015.01.033","article-title":"Determinants of the electric field during transcranial direct current stimulation","volume":"109","author":"Opitz","year":"2015","journal-title":"NeuroImage"},{"key":"2025081119493664200_b28","doi-asserted-by":"crossref","first-page":"560","DOI":"10.1016\/j.neuroimage.2018.07.027","article-title":"On the importance of precise electrode placement for targeted transcranial electric stimulation","volume":"181","author":"Opitz","year":"2018","journal-title":"NeuroImage"},{"key":"2025081119493664200_b29","first-page":"237","article-title":"Computational model of cerebellar transcranial direct current stimulation","volume":"2013","author":"Parazzini","year":"2013","journal-title":"Annual International Conference of the IEEE Engineering in Medicine and Biology Society"},{"issue":"3","key":"2025081119493664200_b30","doi-asserted-by":"crossref","first-page":"577","DOI":"10.1016\/j.clinph.2013.09.039","article-title":"Modelling the electric field and the current density generated by cerebellar transcranial DC stimulation in humans","volume":"125","author":"Parazzini","year":"2014","journal-title":"Clinical Neurophysiology"},{"key":"2025081119493664200_b31","doi-asserted-by":"crossref","first-page":"117044","DOI":"10.1016\/j.neuroimage.2020.117044","article-title":"Accurate and robust whole-head segmentation from magnetic resonance images for individualized head modeling","volume":"219","author":"Puonti","year":"2020","journal-title":"NeuroImage"},{"issue":"3","key":"2025081119493664200_b32","doi-asserted-by":"crossref","first-page":"441","DOI":"10.1109\/TNSRE.2014.2308997","article-title":"Simulating transcranial direct current stimulation with a detailed anisotropic human head model","volume":"22","author":"Rampersad","year":"2014","journal-title":"IEEE Transactions on Neural Systems and Rehabilitation Engineering"},{"key":"2025081119493664200_b33","doi-asserted-by":"crossref","first-page":"288","DOI":"10.1016\/j.neuroscience.2021.03.008","article-title":"Differential behavioral and neural effects of regional cerebellar tDCS","volume":"462","author":"Rice","year":"2021","journal-title":"Neuroscience"},{"issue":"1","key":"2025081119493664200_b34","doi-asserted-by":"crossref","DOI":"10.1088\/1741-2552\/abca15","article-title":"Optimizing the electric field strength in multiple targets for multichannel transcranial electric stimulation","volume":"18","author":"Saturnino","year":"2021","journal-title":"Journal of Neural Engineering"},{"key":"2025081119493664200_b35","doi-asserted-by":"crossref","first-page":"116183","DOI":"10.1016\/j.neuroimage.2019.116183","article-title":"Accessibility of cortical regions to focal TES: Dependence on spatial position, safety, and practical constraints","volume":"203","author":"Saturnino","year":"2019","journal-title":"NeuroImage"},{"key":"2025081119493664200_b36","doi-asserted-by":"crossref","first-page":"821","DOI":"10.1016\/j.neuroimage.2018.12.053","article-title":"A principled approach to conductivity uncertainty analysis in electric field calculations","volume":"188","author":"Saturnino","year":"2019","journal-title":"NeuroImage"},{"key":"2025081119493664200_b37","doi-asserted-by":"crossref","first-page":"50","DOI":"10.3389\/fninf.2013.00050","article-title":"Fast parallel image registration on CPU and GPU for diagnostic classification of Alzheimer\u2019s disease","volume":"7","author":"Shamonin","year":"2013","journal-title":"Frontiers in Neuroinformatics"},{"issue":"5","key":"2025081119493664200_b38","doi-asserted-by":"crossref","first-page":"1028","DOI":"10.1038\/s41386-020-00928-w","article-title":"Efficacy and safety of transcranial direct current stimulation as an add-on treatment for obsessive-compulsive disorder: A randomized, sham-controlled trial","volume":"46","author":"Silva","year":"2021","journal-title":"Neuropsychopharmacology"},{"key":"2025081119493664200_b39","first-page":"222","article-title":"Field modeling for transcranial magnetic stimulation: A useful tool to understand the physiological effects of TMS?","volume":"2015","author":"Thielscher","year":"2015","journal-title":"Annual International Conference of the IEEE Engineering in Medicine and Biology Society"},{"issue":"1","key":"2025081119493664200_b40","doi-asserted-by":"crossref","first-page":"234","DOI":"10.1016\/j.neuroimage.2010.07.061","article-title":"Impact of the gyral geometry on the electric field induced by transcranial magnetic stimulation","volume":"54","author":"Thielscher","year":"2011","journal-title":"NeuroImage"},{"key":"2025081119493664200_b41","doi-asserted-by":"crossref","first-page":"199","DOI":"10.3389\/fnhum.2016.00199","article-title":"tDCS of the cerebellum: Where do we stand in 2016? Technical issues and critical review of the literature","volume":"10","author":"van Dun","year":"2016","journal-title":"Frontiers in Human Neuroscience"},{"issue":"5","key":"2025081119493664200_b42","doi-asserted-by":"crossref","first-page":"056045","DOI":"10.1088\/1741-2552\/ac9a78","article-title":"Addressing transcranial electrical stimulation variability through prospective individualized dosing of electric field strength in 300 participants across two samples: The 2-SPED approach","volume":"19","author":"Van Hoornweder","year":"2022","journal-title":"Journal of Neural Engineering"},{"key":"2025081119493664200_b43","doi-asserted-by":"crossref","first-page":"120379","DOI":"10.1016\/j.neuroimage.2023.120379","article-title":"Outcome measures for electric field modeling in tES and TMS: A systematic review and large-scale modeling study","volume":"281","author":"Van Hoornweder","year":"2023","journal-title":"NeuroImage"},{"issue":"9","key":"2025081119493664200_b44","doi-asserted-by":"crossref","first-page":"1586","DOI":"10.1109\/TBME.2004.827925","article-title":"Three-dimensional head model simulation of transcranial magnetic stimulation","volume":"51","author":"Wagner","year":"2004","journal-title":"IEEE Transactions on Biomedical Engineering"},{"issue":"3","key":"2025081119493664200_b45","doi-asserted-by":"crossref","first-page":"1116","DOI":"10.1016\/j.neuroimage.2006.01.015","article-title":"User-guided 3D active contour segmentation of anatomical structures: Significantly improved efficiency and reliability","volume":"31","author":"Yushkevich","year":"2006","journal-title":"NeuroImage"}],"container-title":["Imaging Neuroscience"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/direct.mit.edu\/imag\/article-pdf\/doi\/10.1162\/imag_a_00379\/2482306\/imag_a_00379.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/direct.mit.edu\/imag\/article-pdf\/doi\/10.1162\/imag_a_00379\/2482306\/imag_a_00379.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,8,11]],"date-time":"2025-08-11T23:49:47Z","timestamp":1754956187000},"score":1,"resource":{"primary":{"URL":"https:\/\/direct.mit.edu\/imag\/article\/doi\/10.1162\/imag_a_00379\/125235\/Head-and-shoulders-The-impact-of-an-extended-head"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024]]},"references-count":45,"URL":"https:\/\/doi.org\/10.1162\/imag_a_00379","relation":{"has-preprint":[{"id-type":"doi","id":"10.1101\/2024.08.29.610251","asserted-by":"object"}]},"ISSN":["2837-6056"],"issn-type":[{"value":"2837-6056","type":"electronic"}],"subject":[],"published-other":{"date-parts":[[2024]]},"published":{"date-parts":[[2024]]},"article-number":"imag-2-00379"}}