Comparing the performance of beamformer algorithms in estimating orientations of neural sources
Yvonne Buschermöhle,
Malte B. Höltershinken,
Tim Erdbrügger,
Jan-Ole Radecke,
Andreas Sprenger,
Till R. Schneider,
Rebekka Lencer,
Joachim Gross,
Carsten H. Wolters
Affiliations
Yvonne Buschermöhle
Institute for Biomagnetism and Biosignalanalysis, University of Münster, 48149 Münster, Germany; Otto Creutzfeldt Center for Cognitive and Behavioral Neuroscience, University of Münster, 48149 Münster, Germany; Corresponding author
Malte B. Höltershinken
Institute for Biomagnetism and Biosignalanalysis, University of Münster, 48149 Münster, Germany; Institute for Analysis and Numerics, University of Münster, 48149 Münster, Germany
Tim Erdbrügger
Institute for Biomagnetism and Biosignalanalysis, University of Münster, 48149 Münster, Germany; Institute for Analysis and Numerics, University of Münster, 48149 Münster, Germany
Jan-Ole Radecke
Department of Psychiatry and Psychotherapy, University of Lübeck, 23562 Lübeck, Germany; Center of Brain, Behavior and Metabolism, University of Lübeck, 23562 Lübeck, Germany
Andreas Sprenger
Center of Brain, Behavior and Metabolism, University of Lübeck, 23562 Lübeck, Germany; Department of Neurology, University of Lübeck, 23562 Lübeck, Germany; Institute of Psychology II, University of Lübeck, 23562 Lübeck, Germany
Till R. Schneider
Department of Neurophysiology and Pathophysiology, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
Rebekka Lencer
Otto Creutzfeldt Center for Cognitive and Behavioral Neuroscience, University of Münster, 48149 Münster, Germany; Department of Psychiatry and Psychotherapy, University of Lübeck, 23562 Lübeck, Germany; Center of Brain, Behavior and Metabolism, University of Lübeck, 23562 Lübeck, Germany; Institute of Translational Psychiatry, University of Münster, 48149 Münster, Germany
Joachim Gross
Institute for Biomagnetism and Biosignalanalysis, University of Münster, 48149 Münster, Germany; Otto Creutzfeldt Center for Cognitive and Behavioral Neuroscience, University of Münster, 48149 Münster, Germany
Carsten H. Wolters
Institute for Biomagnetism and Biosignalanalysis, University of Münster, 48149 Münster, Germany; Otto Creutzfeldt Center for Cognitive and Behavioral Neuroscience, University of Münster, 48149 Münster, Germany
Summary: The efficacy of transcranial electric stimulation (tES) to effectively modulate neuronal activity depends critically on the spatial orientation of the targeted neuronal population. Therefore, precise estimation of target orientation is of utmost importance. Different beamforming algorithms provide orientation estimates; however, a systematic analysis of their performance is still lacking. For fixed brain locations, EEG and MEG data from sources with randomized orientations were simulated. The orientation was then estimated (1) with an EEG and (2) with a combined EEG-MEG approach. Three commonly used beamformer algorithms were evaluated with respect to their abilities to estimate the correct orientation: Unit-Gain (UG), Unit-Noise-Gain (UNG), and Array-Gain (AG) beamformer. Performance depends on the signal-to-noise ratios for the modalities and on the chosen beamformer. Overall, the UNG and AG beamformers appear as the most reliable. With increasing noise, the UG estimate converges to a vector determined by the leadfield, thus leading to insufficient orientation estimates.
