One is data, the other is a function. I'm not sure how we could possibly measure memory directly. The only thing we can measure is some form of interaction with it, which means we are measuring the interaction itself.
Our best understanding of memory (AFAIK) is that it is constructed just-in-time by the process of recall. So does the distinction matter? How much of memory is tied to comprehension? Having a word for something is one method of comprehension, but there are others. What happens when the word is provided later?
We know that human behavior tends to be driven by narrative. I would be interested to see a similar study where unique expressions are isolated. Do people with a particular/specific way of talking about something do it differently?