Reality as a Shared hallucination

After watching the TED talk by Dr. Anil Seth below:

Meditate on the following questions in TOK JOURNAL form:

1. What are implications of “reality as a shared hallucination”?
   1. For knowledge acquisition?
   2. For Truth?
   3. For Shared Knowledge?
   4. For Perception?

As an aside, my favorite quote from the talk, “When we agree about hallucinations, we call that reality.”