Reading from a book each night before bed according to jang encourages the brain to remember the text

which of the following reflects the proper punctuation of the above sentence?

reading from a book each night before bed, “according to jang,” encourages the brain to remember the text.
“reading from a book each night before bed,” according to jang, “encourages the brain to remember the text.” . .
[r]eading from a book each night before bed according to jang encourages the brain to remember the text?
“reading from a book each night before bed (according to jang) encourages the brain to remember the text”.