| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
INNOVATIVE METHODOLOGY
Department for Clinical Neurophysiology, Georg-August-University, Goettingen, Germany
Submitted 15 December 2006; accepted in final form 21 January 2007
Transcranial DC stimulation (tDCS) induces stimulation polarity-dependent neuroplastic excitability shifts in the human brain. Because it accomplishes long-lasting effects and its application is simple, it is used increasingly. However, one drawback is its low focality, caused by 1) the large stimulation electrode and 2) the functionally effective reference electrode, which is also situated on the scalp. We aimed to increase the focality of tDCS, which might improve the interpretation of the functional effects of stimulation because it will restrict its effects to more clearly defined cortical areas. Moreover, it will avoid unwanted reversed effects of tDCS under the reference electrode, which is of special importance in clinical settings, when a homogeneous shift of cortical excitability is needed. Because current density (current strength/electrode size) determines the efficacy of tDCS, increased focality should be accomplished by 1) reducing stimulation electrode size, but keeping current density constant; or 2) increasing reference electrode size under constant current strength. We tested these hypotheses for motor cortex tDCS. The results show that reducing the size of the motor cortex DC-stimulation electrode focalized the respective tDCS-induced excitability changes. Increasing the size of the frontopolar reference electrode rendered stimulation over this cortex functionally inefficient, but did not compromise the tDCS-generated motor cortical excitability shifts. Thus tDCS-generated modulations of cortical excitability can be focused by reducing the size of the stimulation electrode and by increasing the size of the reference electrode. For future applications of tDCS, such paradigms may help to achieve more selective tDCS effects.
This article has been cited by other articles:
|
|
 |
|
  T. O. Bergmann, S. Groppa, M. Seeger, M. Molle, L. Marshall, and H. R. Siebner Acute Changes in Motor Cortical Excitability During Slow Oscillatory and Constant Anodal Transcranial Direct Current Stimulation J Neurophysiol, October 1, 2009; 102(4): 2303 - 2311. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. A. Dockery, R. Hueckel-Weng, N. Birbaumer, and C. Plewnia Enhancement of Planning Ability by Transcranial Direct Current Stimulation J. Neurosci., June 3, 2009; 29(22): 7271 - 7277. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. A. Karim, M. Schneider, M. Lotze, R. Veit, P. Sauseng, C. Braun, and N. Birbaumer The Truth about Lying: Inhibition of the Anterior Prefrontal Cortex Improves Deceptive Behavior Cereb Cortex, May 14, 2009; (2009) bhp090v1. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. Knoch, M. A. Nitsche, U. Fischbacher, C. Eisenegger, A. Pascual-Leone, and E. Fehr Studying the Neurobiology of Social Interaction with Transcranial Direct Current Stimulation--The Example of Punishing Unfairness Cereb Cortex, September 1, 2008; 18(9): 1987 - 1990. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Fecteau, D. Knoch, F. Fregni, N. Sultani, P. Boggio, and A. Pascual-Leone Diminishing Risk-Taking Behavior by Modulating Activity in the Prefrontal Cortex: A Direct Current Stimulation Study J. Neurosci., November 14, 2007; 27(46): 12500 - 12505. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Fecteau, A. Pascual-Leone, D. H. Zald, P. Liguori, H. Theoret, P. S. Boggio, and F. Fregni Activation of Prefrontal Cortex by Transcranial Direct Current Stimulation Reduces Appetite for Risk during Ambiguous Decision Making J. Neurosci., June 6, 2007; 27(23): 6212 - 6218. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
