I think "cannot" is a bit too strong a claim. The brain literally invents faces when it interprets the signals from our eyes. Are you saying that it can't make

I think "cannot" is a bit too strong a claim. The brain literally invents faces when it interprets the signals from our eyes. Are you saying that it can't make up signals that don't exist? I don't see any reason to assume that it couldn't. I think it is reasonable to expect that the brain will dream up faces based on what it has seen before, but it's not like you've never seen anything other than faces.