Figure 3: Signal localization and reconstruction during and in absence of electric stimulation.
From: In vivo assessment of human brain oscillations during application of transcranial electric currents
Synthetic aperture magnetometry (SAM)-based localization of the generated oscillating dipole signal (5 Hz, 8 nAm) in absence (a) and during electric stimulation with device A (b) and device B (c) within the electrolyte-filled phantom head. Localization of the signal source characterized by the largest signal power changes (maximum in red) was consistent across conditions (a–c). (d) SAM-based reconstruction of the generated dipole signal oscillating at 11 Hz (left) and 23 Hz (right). Field strength of the dipole signal was changed from 3–10 nAm to resemble task-related changes of neuromagnetic oscillatory brain activity typically found in the human brain. Similarity between the generated and reconstructed signal source reflects the fidelity of TESANA. Frequency spectra (e) of recorded activity while the generated dipole signal was oscillating at 11 Hz (left) and 23 Hz (right) indicate a clear and undistorted power peak at the tested frequencies, and no stimulation specific distortions in other frequencies.
