if they are working on the basis we have 5 senses - combine them all together - taste/smell, sight/sound etc would work about that number. It is late and I can't do the sums but it sounds about right to me!!
The didn't list all of them but balance was mentioned, so too was hunger (you know when you are hungry - but what tells you you are?). Another was being able to tell where parts of your body are when you have your eyes shut!! EG Stephen Fry shut his eyes and waved his arm around in front of him - he KNEW where his hand was even though he couldn't see it and wasn't touching it with his other hand.
I found it to be very interesting reading. Actually I found it so thought provoking that it's content (especially the "boss in the chair, surrounded by messengers" analogy) often pops into my mind during random activities.