Dive summary: 

• Social media service LivesOn has developed a way to use artificial intelligence to mimic a person's Twitter activity so that they may maintain a social media presence even after they are deceased. 
• The service, being developed by Queen Mary University of London, has not launched yet, but already has thousands of potential users signed up online. 
• The theory of interaction postmortem is an example of how we have already expanded our sense of self into our online identities; people are already interacting with our social media identities when we are not present. 

From the article: 

"As cyborg anthropologist Amber Case argued in a 2010 TED Talk, while other technology enhanced our physical abilities, online social networks have allowed for the 'extension of the mental self,' and endowed us each with a 'second self' that's always up to hang out with someone online. 'Whether you like it or not,' Case explained, ''you're starting to show up online, and people are interacting with your second self when you're not there.'"