Why is the default setting for BATCH_SIZE 1? I changed it and got an error after that

[loki-keroro]

I use the default batchsize=1 and program to run, but once I change it to 4, I get the following error:

***/layer/function.py", line 33, in forward
return self.scale * x * x.pow(2).sum(dim).clamp(min=1e-12).rsqrt().expand_as(x)
RuntimeError: The expanded size of the tensor (512) must match the existing size (4) at non-singleton dimension 1. Target sizes: [4, 512, 51, 51]. Tensor sizes: [4, 51, 51]

i don't know the reason