Have I paraphrased a sentence without changing the meaning? [closed]

This is what I read:

"Neuroimaging of frequent internet users shows twice as much activity in the prefrontal cortex as sporadic Internet users during online tasks."

And this is how I paraphrased:

"Neuroimaging of frequent internet users shows activity in the prefrontal cortex twice as much as sporadic Internet users during online tasks."

And,

"Activity in the prefrontal cortex through neuroimaging of frequent internet users is twice as much as sporadic Internet users during online tasks."

Have I rephrased the sentence I read with the meaning unchanged? If so, which sounds easier to understand?

"[Activity in the prefrontal cortex through neuroimaging of frequent internet users] is [twice as much as sporadic Internet users during online tasks."]

Now of course you didn't mean to compare Activity with sporadic internet users, did you?

"Neuroimaging of frequent internet users shows activity in the prefrontal cortex twice as much as sporadic Internet users during online tasks."

Normally, the reason why you paraphrase a sentence is to cut out the verbiage and trim it to make it more readable.

This version— which is worded at around twenty words (which is the exact same number of words in the original version)— doesn't do any such thing. In fact, it is somewhat clunky.

"Neuroimaging of frequent internet users shows twice as much activity in the prefrontal cortex as sporadic Internet users during online tasks."

This is the sentence you would want to write. It conveys the intended information neatly.