What are these pronouns refer to?

What are these pronouns refer to?

The passage below is from ‘the Blank Slate’ by Steven Pinker.

http://evolbiol.ru/blankslate/blankslate.htm


And of course the visual system itself must be put into perspective, because it is just one part of the brain. The visual system dominates some half-dozen of the more than fifty major areas of the cortex ?that can be distinguished by ?their anatomy and connections. Many of ?the others underlie other functions such as language, reasoning, planning, and social skills. Though no one knows to what extent ?they are genetically prepared for ?their computational roles, there are hints that the genetic influence is substantial.

In this passage I want to know what all of the underlined pronouns refer to.
I have my answers.

Can you check them out for me?

?that : the more than fifty major areas (of the cortex)
?their : the more than fifty major areas (of the cortex)
?the others : the other areas (except some half-dozen areas)
?they : 'Many of the others' or 'the more than fifty major areas of the cortex'
?their : 'Many of the others' or 'the more than fifty major areas of the cortex'

In #4 and #5, I cannot decide between the two options.

Regards.