What is the meaning and grammatical structure of bold part? Is there any easier paraphrase?
The vast majority of F5 mirror neurons shows a marked similarity between the action effective when observed and the action effective when executed.
Stamenov, M., & Gallese, V. (Eds.). (2002). Mirror neurons and the evolution of brain and language (Vol. 42). John Benjamins Publishing.
It is a little odd, but I think the intention here is a reduced relative clause. That is you should understand this to mean
...the action that was effective when observed and the action that was effective when executed.
Get rid of the word "effective" and it immediately becomes easier to understand.
The phrase "action effective" appears to be technical jargon or a term of art that is presumed to be understood by a reader well-versed in experimental neuroscience. The action effective is either what the monkey does or what it watches another monkey do. For ordinary mortals it's just the action.
The vast majority of F5 mirror neurons shows a marked similarity between the action effective when observed and the action effective when executed.
If we understand the meaning of the difficult words or phrases, then we would be able to fully grasp the meaning of the extract.
I. Action effective.
The original text appears to be from a scientific or academic context, where precise language is crucial. In such cases, the original phrase "action effective" might be preferred for its technical accuracy.
Action effective" is a phrase used to describe the effectiveness of an action, but it's not a commonly used expression in everyday language.
II. "F5 Mirror neurons": Why are they named so?
Mirror neurons are called F5 mirror neurons because they were first discovered in the F5 area of the premotor cortex of macaque monkeys in the early 1990s. Italian researchers Giacomo Rizzolatti and colleagues noticed that a group of neurons in this area would fire when a monkey performed an action, and also when it observed the same action being performed by another animal. For example, a neuron that fired when the monkey grasped a peanut would also fire when the experimenter grasped a peanut.
From the above the phrase "the action effective when observed and the action effective when executed" is clear.
III. Action effective= noun + adjective explanation.
For easy understanding, you can paraphrase as following:
Is there any easier paraphrase?
The vast majority of F5 mirror neurons show a marked similarity between the effectiveness of an action when observed and when executed."-
"Most F5 mirror neurons respond similarly when an action is observed or performed.".
Ref. Google
