Studies show that reading, often improves memory.
The house that got a new roof, recently was sold.
Studies show that reading often, improves memory.
The house that got a new roof recently, was sold.
Studies show that reading often, improves memory.
The house that got a new roof recently, was sold.
Thank you for posting this.
I recall from my high-school grammar class that commas can be used to indicate places where a person would naturally pause.
If one reads your example sentences aloud, one notices that the placement of the comma not only changes the meaning but also changes the cadence of the speech.
There might be examples where a comma is used to indicate a pause other than those containing squinting adverbs.