# Amplitude of sensor level average

**URL:** <https://mne.discourse.group/t/amplitude-of-sensor-level-average/614>\
**Category:** Mailing List Archive (read-only)\
**Tags:** list-archive\
**Created:** [September 9, 2013, 4:41pm UTC](https://mne.discourse.group/t/amplitude-of-sensor-level-average/614 "2013-09-09T16:41:02Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![system](https://global.discourse-cdn.com/free1/uploads/mne/original/1X/85cc6bd2b69cb698a166dc6d880fb550510d0144.jpeg) [@system](https://mne.discourse.group/u/system)\
**Post date:** [September 9, 2013, 4:41pm UTC](https://mne.discourse.group/t/amplitude-of-sensor-level-average/614/1 "2013-09-09T16:41:02Z")

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Hi,

I have looked in the manual, cookbook and discussion archives but can't find out how to measure the amplitude of an evoked average in mne\_browse\_raw. I know the latency comes up when you select a time point of interest, however I am unsure of how to measure the amplitude of the peak of the response, if it is indeed possible.

Any help would be greatly appreciated.

Thanks  
Lauren

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**Author:** ![system](https://global.discourse-cdn.com/free1/uploads/mne/original/1X/85cc6bd2b69cb698a166dc6d880fb550510d0144.jpeg) [@system](https://mne.discourse.group/u/system)\
**Post date:** [September 15, 2013, 7:57pm UTC](https://mne.discourse.group/t/amplitude-of-sensor-level-average/614/2 "2013-09-15T19:57:15Z")

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Dear Lauren,

I don't think you can do this with mne\_browse\_raw.  
I'd give a try to mne\_analyze but I personally do this with mne-python  
or matlab.

Best,  
Alex

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**Author:** ![system](https://global.discourse-cdn.com/free1/uploads/mne/original/1X/85cc6bd2b69cb698a166dc6d880fb550510d0144.jpeg) [@system](https://mne.discourse.group/u/system)\
**Post date:** [September 15, 2013, 8:08pm UTC](https://mne.discourse.group/t/amplitude-of-sensor-level-average/614/3 "2013-09-15T20:08:57Z")

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You cannot measure the amplitude with mne\_browse\_raw. It is easy to do in either Matlab or Python, just a SMOP. It can be challenging to find a definition of a peak which can be turned into automatic detection, though.

However, it is possible to measure amplitudes from raw data in mne\_browse\_raw. How about turning the ERF/ERP file into a short raw file in Matlab or Python and then measuring amplitudes from this file with mne\_browse\_raw?

- Matti

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**Author:** ![system](https://global.discourse-cdn.com/free1/uploads/mne/original/1X/85cc6bd2b69cb698a166dc6d880fb550510d0144.jpeg) [@system](https://mne.discourse.group/u/system)\
**Post date:** [September 16, 2013, 2:32pm UTC](https://mne.discourse.group/t/amplitude-of-sensor-level-average/614/4 "2013-09-16T14:32:27Z")

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Hi both,

Thanks for your suggestions, I will let you know how I get on.

Cheers  
Lauren

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**Author:** ![system](https://global.discourse-cdn.com/free1/uploads/mne/original/1X/85cc6bd2b69cb698a166dc6d880fb550510d0144.jpeg) [@system](https://mne.discourse.group/u/system)\
**Post date:** [December 14, 2013, 7:35pm UTC](https://mne.discourse.group/t/amplitude-of-sensor-level-average/614/5 "2013-12-14T19:35:29Z")

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Dear Lauren,

for your interest, we just added simple peak finding methods in  
MNE-Python for evoked and stc objects.

[https://github.com/mne-tools/mne-python/pull/984#issuecomment-30583928](https://github.com/mne-tools/mne-python/pull/984#issuecomment-30583928)

Those allow you to get the channel name or the vertex ID associated  
with the maximum response as well as the latency, either in seconds or  
as time index pointing at the related position in the times vector.

Here two examples.

[https://github.com/mne-tools/mne-python/blob/c8633989fc3429d7dc1a4635fe05d09848a99e43/examples/inverse/plot\_compute\_mne\_inverse.py#L57](https://github.com/mne-tools/mne-python/blob/c8633989fc3429d7dc1a4635fe05d09848a99e43/examples/inverse/plot_compute_mne_inverse.py#L57)

[https://github.com/mne-tools/mne-python/blob/c8633989fc3429d7dc1a4635fe05d09848a99e43/examples/plot\_from\_raw\_to\_epochs\_to\_evoked.py#L59](https://github.com/mne-tools/mne-python/blob/c8633989fc3429d7dc1a4635fe05d09848a99e43/examples/plot_from_raw_to_epochs_to_evoked.py#L59)

For evoked data with a clear peak this is expected to work reliably.  
For single trial data it might take more sophisticated handling.  
However, with the new functions you can specify tmin and tmax  
paramters as well as handle the sign (only consider negative / positve  
or absolute signals).

Best,  
Denis