There is a difference between “low level” and “human specific”. Faces are highly complex geometrically, while numbers, such as 8, are simple. Animals sure can recognise simple shapes (https://docsmith.co/2007/01/can-animals-recognize-shapes/), but they cannot endow them with abstract meanings, such as "number 8". The person in the article lost the basic ability of recognising very simple shapes while still being able to recognise more complex shapes, like faces, and to operate with abstract concepts.