Honestly,I'm looking to start a case study about this for ages but never had enough interest and time to do it.
I don't think a link that wasn't visited by someone is considered dead,I'd say a link visited by a few persons is more valuable and gets more ranking power.
In my opinion,an easy way to start this would be to simply get a fake traffic bot and make it click on your backlinks trough proxies.
If this turns out to be true,would be interesting to see if old spammy backlinks gets activated by traffic.