# Clarification on Depth Weighting and dSPM in MNE

**URL:** <https://mne.discourse.group/t/clarification-on-depth-weighting-and-dspm-in-mne/11090>\
**Category:** Support & Discussions\
**Tags:** source-localization\
**Created:** [April 11, 2025, 11:05am UTC](https://mne.discourse.group/t/clarification-on-depth-weighting-and-dspm-in-mne/11090 "2025-04-11T11:05:46Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![dasdiptyajit](https://yyz2.discourse-cdn.com/free1/user_avatar/mne.discourse.group/dasdiptyajit/32/4796_2.png) [@dasdiptyajit](https://mne.discourse.group/u/dasdiptyajit)\
**Post date:** [April 11, 2025, 11:05am UTC](https://mne.discourse.group/t/clarification-on-depth-weighting-and-dspm-in-mne/11090/1 "2025-04-11T11:05:46Z")

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Hello MNE users,

I have a question regarding the processing flow for inverse solvers in MNE-python, particularly in relation to depth weighting, wMNE, and dSPM.

From my understanding:

1. **Inverse Operator and Depth Weighting** : When creating the inverse operator, MNE applies a depth weighting (default is 0.8 for MEG). This depth weighting scales the leadfield matrix to adjust for the bias toward superficial sources, particularly helping to emphasize deeper sources.
2. **wMNE Calculation** : Once the inverse operator is created (with depth weighting), **wMNE** is computed. As I understand it, wMNE involves normalizing the source estimates, including noise and depth-weighting corrections (from the inverse operator).
3. **Foundation of dSPM** : Then, the **dSPM** (dynamic Statistical Parametric Mapping) is computed, which further normalizes the wMNE results by dividing by a noise estimate. This noise estimate is often derived from the **noise covariance matrix** , which can be computed from baseline recordings or other noise sources.

Therefore, with depth weighting factor of 0.8 in inverse operator - dSPM solution is build upon wMNE? with Is this understanding correct?

Thanks for your help!  
Dip

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<div class="post-metadata">

**Author:** ![dasdiptyajit](https://yyz2.discourse-cdn.com/free1/user_avatar/mne.discourse.group/dasdiptyajit/32/4796_2.png) [@dasdiptyajit](https://mne.discourse.group/u/dasdiptyajit)\
**Post date:** [April 11, 2025, 11:06am UTC](https://mne.discourse.group/t/clarification-on-depth-weighting-and-dspm-in-mne/11090/2 "2025-04-11T11:06:25Z")

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Hi @richard I can use some help. Thank you 🙂