# Differences in z-score values for the same donor, same probe and same region

**URL:** <https://community.brain-map.org/t/differences-in-z-score-values-for-the-same-donor-same-probe-and-same-region/2691>\
**Category:** General\
**Created:** [November 4, 2023, 5:55pm UTC](https://community.brain-map.org/t/differences-in-z-score-values-for-the-same-donor-same-probe-and-same-region/2691 "2023-11-04T17:55:10Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![Sdh](https://avatars.discourse-cdn.com/v4/letter/s/e9c0ed/32.png) [@Sdh](https://community.brain-map.org/u/Sdh)\
**Post date:** [November 4, 2023, 5:55pm UTC](https://community.brain-map.org/t/differences-in-z-score-values-for-the-same-donor-same-probe-and-same-region/2691/1 "2023-11-04T17:55:10Z")

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I tried looking for z-scores values on Allen brain atlas (on the six healthy brain donors). Does anyone know why z-score values are different when you look at them on the two screen shots?  
These values are for the same donor, same region, same gene and same probe. On the upper screen shot z-score is 0,55 and on the other one below is 0,79.  
Thank you

 ![image](https://canada1.discourse-cdn.com/flex027/uploads/brainobservatory/original/1X/b539a2653fa70f5a6e2ce80304dc31db015afb2b.jpeg)

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**Author:** ![Changkyu\_Lee](https://yyz1.discourse-cdn.com/flex027/user_avatar/community.brain-map.org/changkyu_lee/32/1454_2.png) [@Changkyu\_Lee](https://community.brain-map.org/u/Changkyu_Lee)\
**Post date:** [November 10, 2023, 12:55am UTC](https://community.brain-map.org/t/differences-in-z-score-values-for-the-same-donor-same-probe-and-same-region/2691/2 "2023-11-10T00:55:58Z")

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“Good eye: these point to different data normalizations. Please use the most recent versions in the Download page for your work.” Thanks!

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**Author:** ![Sdh](https://avatars.discourse-cdn.com/v4/letter/s/e9c0ed/32.png) [@Sdh](https://community.brain-map.org/u/Sdh)\
**Post date:** [November 10, 2023, 10:04am UTC](https://community.brain-map.org/t/differences-in-z-score-values-for-the-same-donor-same-probe-and-same-region/2691/3 "2023-11-10T10:04:06Z")

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Thank you for your reply.  
Does this mean that the correct z-score values are the ones we get when we click on download? If so, in which of the two screen shots should we click on download?  
Thank you

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**Author:** ![jeremyinseattle](https://yyz1.discourse-cdn.com/flex027/user_avatar/community.brain-map.org/jeremyinseattle/32/50_2.png) [@jeremyinseattle](https://community.brain-map.org/u/jeremyinseattle)\
**Post date:** [November 13, 2023, 12:56pm UTC](https://community.brain-map.org/t/differences-in-z-score-values-for-the-same-donor-same-probe-and-same-region/2691/4 "2023-11-13T12:56:51Z")

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The correct intensity values are the ones you get from the [download page](https://human.brain-map.org/static/download). I _think_ these will match what is in the download page from the heatmap (when you have the color map set to log2 intensity… see image below), but it you could confirm to be safe. In this case the z-score downloaded from the heatmap would be correct.  
 ![image](https://canada1.discourse-cdn.com/flex027/uploads/brainobservatory/original/1X/868296ff6cace2b4640e088d3b0cdea51f79c64c.png)