Roy Eyono
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royeyono.bsky.social
Roy Eyono
@royeyono.bsky.social
PhD Student in NeuroAI @Mila and @McGill
Wouldn't have been possible without you! Thanks Dan!!
March 19, 2026 at 6:25 PM
These findings complement several theories on how SST-subtypes targeting apical dendrites (where error-related signals arrive) are critical in supporting learning.

Potentially, via the normalization of error signals!

e.g. Payeur et al. : nature.com/articles/s41...
March 19, 2026 at 3:27 PM
Hence this led us to believe if the brain uses inhibition for normalization, it must have a dedicated mechanism to normalize learning signals!

tldr;

In the end, we found that centering the gradients via lateral inhibition was enough to recapitulate performance on the task!
March 19, 2026 at 3:27 PM
Upon further inspection, we indeed noticed that despite our high alignment in neural activity, we had poor gradient alignment with layer norm.
March 19, 2026 at 3:27 PM
Why you may ask? It turns out that layer normalization actually implicitly normalizes back-propagated error signals "under the hood" !
March 19, 2026 at 3:27 PM
Surprisingly!

Despite successfully normalizing feedforward neural activity, this didn't reflect in performance. As we were unable to recapitulate layer normalization's performance on the task.
March 19, 2026 at 3:27 PM
With our simple inhibitory loss function on our EI network, we were able to successfully *learn* to layer normalize neural activity!
March 19, 2026 at 3:27 PM
Our network was trained on a robust perceptual invariance task: FashionMNIST with randomized brightness levels during both training and testing. (bounded by epsilon)
March 19, 2026 at 3:27 PM
The brain is believed to recruit inhibitory neurons to perform normalization, but how does it actually help us learn?🤔

To find out, we built an ANN with separate excitatory and inhibitory neurons. And trained the E weights on the task and the I weights to do layer normalization
March 19, 2026 at 3:27 PM
9️⃣
November 24, 2024 at 12:40 AM