Reply to “On the stimulation depth of transcranial magnetic stimulation coils” Academic Article uri icon


  • We read with great interest the recent Letter by Deng et al.(2015) following our recent paper (Roth et al., 2014), and we thank them for the opportunity to clarify the issues. In their Letter the authors refer to the values of d½ as defined in their previous review (Deng et al., 2013) for the Magstim figure-8 coil (Magstim P/N 9925, 3190, d½= 1.41) and for the double cone coil (Magstim P/N 9902, d½= 1.98). That review considered some H-coils versions, such as the H2 coil (d½= 2.32) and the HADD coil (d½= 2.43). These values of d½ are significantly higher than the value found for the double cone coil, indicating that the rate of decay of electric field with distance from the double cone coil is significantly faster compared to various versions of H-coils. A more accurate method of field characterization than computer simulation using spherical head model (Deng et al., 2013, 2014) can be obtained using …

publication date

  • January 1, 2015