recognition and memorisation

The downside of Shereshevsky's flawless memory was that the details often got in the way of understanding. For instance, Shereshevsky had great trouble recognising faces. Most of us store in memory the general features of the faces we remember, and when we see someone we know, we identify the person by matching the face we're looking at to a face in that limited catalog. But Shereshevsky's memory housed a great many versions of every face he had ever seen. To Shereshevsky, each time a face changed its expression or was seen in a different lighting, it was a new face, and he remembered them all. So any given person had not one face but dozens, and when Shereshevsky encountered someone he knew, matching that person's face to the faces stored in his memory meant performing a search of a vast inventory of images to try to find an exact equivalent to what he was seeing.

Shereshevsky has similar problems with language. If you spoke to him, though he could always play back your exact words, he had trouble understanding your point. The comparison with language is apt, because this is another trees-and-forest problem.

Subliminal - Leonard Mlodinow (Page 64)

Language acquisition involves grouping impressions under categories via selective forgetting. In other words, there is a trade off between recognition ability and memorisation capacity.

Conjecture: Late talker toddlers should in general exhibit greater memorisation capacity and less recognition ability as adolescents.