# Running speed Neuropixels data missing

**URL:** <https://community.brain-map.org/t/running-speed-neuropixels-data-missing/1260>\
**Category:** Technical\
**Created:** [August 29, 2021, 11:55am UTC](https://community.brain-map.org/t/running-speed-neuropixels-data-missing/1260 "2021-08-29T11:55:27Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![jpduf](https://avatars.discourse-cdn.com/v4/letter/j/71c47a/32.png) [@jpduf](https://community.brain-map.org/u/jpduf)\
**Post date:** [August 29, 2021, 11:55am UTC](https://community.brain-map.org/t/running-speed-neuropixels-data-missing/1260/1 "2021-08-29T11:55:27Z")

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Hello,

I was wondering about the running\_speed data in the Neuropixels sessions - in the whitepaper they are said to be recorded at 60Hz, however in the NWB data there seems to be every third entry missing in the sessions I checked (for example 786091066 or 719161530). I’m trying to do some simple preliminary analysis of running speed vs firing rate for some neurons and so wanted to ask if this was a known issue with the data?

Thanks for the help!

Best,

Jean-Philippe Dufour

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**Author:** ![joshs](https://yyz1.discourse-cdn.com/flex027/user_avatar/community.brain-map.org/joshs/32/8_2.png) [@joshs](https://community.brain-map.org/u/joshs)\
**Post date:** [August 29, 2021, 7:01pm UTC](https://community.brain-map.org/t/running-speed-neuropixels-data-missing/1260/2 "2021-08-29T19:01:34Z")

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Yes, this is a known issue. There was a problem with the rotational sensors on the ephys rig running wheels that caused them to skip every second or third sample. For our running speed analysis, we typically select intervals of 30 ms or higher (so there is at least one valid sample), and compute the average speed within that interval.