The behavioral effects of Transcranial Magnetic Stimulation (TMS) are often nonlinear; factors such as stimulation intensity and brain state can modulate the impact of TMS on observable behavior in qualitatively different manner. Here we propose a theoretical framework to account for these effects. In this model, there are distinct intensity ranges for facilitatory and suppressive effects of TMS – low intensities facilitate neural activity and behavior whereas high intensities induce suppression. The key feature of the model is that these ranges are shifted by changes in neural excitability: consequently, a TMS intensity, which normally induces suppression, can have a facilitatory effect if the stimulated neurons are being inhibited by ongoing task-related processes or preconditioning. For example, adaptation reduces excitability of adapted neurons; the outcome is that TMS intensities which inhibit non-adapted neurons induce a facilitation on adapted neural representations, leading to reversal of adaptation effects. In conventional “virtual lesion” paradigms, similar effects occur because neurons not involved in task-related processes are inhibited by the ongoing task. The resulting reduction in excitability can turn high intensity “inhibitory” TMS to low intensity “facilitatory” TMS for these neurons, and as task-related neuronal representations are in the inhibitory range, the outcome is a reduction in signal-to-noise ratio and behavioral impairment.

(2017). Common framework for “virtual lesion” and state-dependent TMS: The facilitatory/suppressive range model of online TMS effects on behavior [journal article - articolo]. In BRAIN AND COGNITION. Retrieved from http://hdl.handle.net/10446/229012

Common framework for “virtual lesion” and state-dependent TMS: The facilitatory/suppressive range model of online TMS effects on behavior

Cattaneo, Zaira
2017-01-01

Abstract

The behavioral effects of Transcranial Magnetic Stimulation (TMS) are often nonlinear; factors such as stimulation intensity and brain state can modulate the impact of TMS on observable behavior in qualitatively different manner. Here we propose a theoretical framework to account for these effects. In this model, there are distinct intensity ranges for facilitatory and suppressive effects of TMS – low intensities facilitate neural activity and behavior whereas high intensities induce suppression. The key feature of the model is that these ranges are shifted by changes in neural excitability: consequently, a TMS intensity, which normally induces suppression, can have a facilitatory effect if the stimulated neurons are being inhibited by ongoing task-related processes or preconditioning. For example, adaptation reduces excitability of adapted neurons; the outcome is that TMS intensities which inhibit non-adapted neurons induce a facilitation on adapted neural representations, leading to reversal of adaptation effects. In conventional “virtual lesion” paradigms, similar effects occur because neurons not involved in task-related processes are inhibited by the ongoing task. The resulting reduction in excitability can turn high intensity “inhibitory” TMS to low intensity “facilitatory” TMS for these neurons, and as task-related neuronal representations are in the inhibitory range, the outcome is a reduction in signal-to-noise ratio and behavioral impairment.
articolo
2017
Silvanto, Juha; Cattaneo, Zaira
(2017). Common framework for “virtual lesion” and state-dependent TMS: The facilitatory/suppressive range model of online TMS effects on behavior [journal article - articolo]. In BRAIN AND COGNITION. Retrieved from http://hdl.handle.net/10446/229012
File allegato/i alla scheda:
File Dimensione del file Formato  
BC_Silvanto & Cattaneo_Intensity_2017.pdf

accesso aperto

Versione: publisher's version - versione editoriale
Licenza: Creative commons
Dimensione del file 455.14 kB
Formato Adobe PDF
455.14 kB Adobe PDF Visualizza/Apri
Pubblicazioni consigliate

Aisberg ©2008 Servizi bibliotecari, Università degli studi di Bergamo | Terms of use/Condizioni di utilizzo

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10446/229012
Citazioni
  • Scopus 83
  • ???jsp.display-item.citation.isi??? 78
social impact