> For the complete documentation index, see [llms.txt](https://ethereum-model-of-the-world.gitbook.io/ethereum.model.of.the.world/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://ethereum-model-of-the-world.gitbook.io/ethereum.model.of.the.world/neuromodulation/overview.md).

# Overview

Neuromodulation is **medically** defined as "[*the alteration of nerve activity through targeted delivery of a stimulus, such as electrical stimulation or chemical agents, to specific neurological sites in the body.*](https://en.wikipedia.org/wiki/Neuromodulation_\(medicine\))"

There are invasive and non-invasive types of Neuromodulation; the latter fall into the category of Non-Invasive Brain Stimulation (NIBS). There are several forms of NIBS:

* Transcranial Magnetic Stimulation ([TMS](https://en.wikipedia.org/wiki/Transcranial_magnetic_stimulation))
* Transcranial Direct Current Stimulation ([tDCS](https://neuromodec.com/what-is-transcranial-direct-current-stimulation-tdcs/))
* Transcranial Alternating Current Stimulation ([tACS](https://neuromodec.com/what-is-transcranial-alternating-current-stimulation-tacs/))
* Transcranial Random Noise Stimulation ([tRNS](https://en.wikipedia.org/wiki/Transcranial_random_noise_stimulation))
* Transcutaneous Electrical Nerve Stimulation ([TENS](https://neuromodec.com/what-is-transcutaneous-electrical-nerve-stimulation-tens/))
* Transcutaneous Auricular Vagus Nerve Stimulation ([taVNS](https://neuromodec.com/what-is-vagus-nerve-stimulation-vns/))