layer normalization

In the paper + the video https://www.youtube.com/watch?v=F7wd4wQyPd8 you mention using layer normalization

> To prevent this, FF normalizes the length of the hidden vector before using
> it as input to the next layer (Ba et al., 2016b; Carandini and Heeger, 2013) This removes all of the
> information that was used to determine the goodness in the first hidden layer and forces the next
> hidden layer to use information in the relative activities of the neurons in the first hidden layer. These
> relative activities are unaffected by the layer-normalization

However I did not notice layer norm in your implementation. I see that you used per layer training where each layer does not use previous layers outputs which probably achieves similar outcome?, why did you decide to use that instead of layer normalization? or was the reason for not using layernorm that you only have 1 hidden layer?