# What is the unit for the source estimates returned by apply\_inverse\_epochs function for EEG data?

**URL:** <https://mne.discourse.group/t/what-is-the-unit-for-the-source-estimates-returned-by-apply-inverse-epochs-function-for-eeg-data/3829>\
**Category:** Support & Discussions\
**Tags:** source-localization, eeg, epochs\
**Created:** [October 18, 2021, 2:52am UTC](https://mne.discourse.group/t/what-is-the-unit-for-the-source-estimates-returned-by-apply-inverse-epochs-function-for-eeg-data/3829 "2021-10-18T02:52:37Z")\
**Posts on this page:** 1\
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**Author:** ![richard](https://yyz2.discourse-cdn.com/free1/user_avatar/mne.discourse.group/richard/32/15_2.png) [@richard](https://mne.discourse.group/u/richard)\
**Post date:** [October 18, 2021, 6:49am UTC](https://mne.discourse.group/t/what-is-the-unit-for-the-source-estimates-returned-by-apply-inverse-epochs-function-for-eeg-data/3829/2 "2021-10-18T06:49:09Z")

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Hello @dahaiyu and welcome to the forum!

The dSPM and sLORETA algorithms produce source estimates in unit-less values (based on F-statistics).

On the other hand, the MNE and eLORETA algorithms return the electrical current in Ampere meters (that’s why the numbers are so tiny!).

It is therefore totally alright to label the y-axis in your above figure as “dSPM value”.

Hope that helps!

Richard

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