Reaction - defined

In 2000 I wrote, published and claimed copyright on this concept (bolding added now):

Detection of and reaction to stimulus

The first sub-quality of speed can be said to be the ability to detect and react to stimulus. This is usually the first action in a chain of speed responses.

I was conducting research and I came upon the following exercise in a publication copyright claimed by another 'author' at a subsequent date (bolding added):

Reaction time:

The ability to detect and react to a stimulus. This usually the first action in a series of speed responses.

And I said to myself: “That looks familiar!” So I cross-referenced it and I said to myself: “Wow! No wonder that looked familiar!”

Published in the absence of credits or references to the origin or permission to use from the original author (myself), and that the 'author' claimed copyright....