Researcher and author Dan Schacter has defined seven ways in which memory fails human beings: transience, absent-mindedness, blocking, misattribution, suggestibility, bias, and persistence. (LeDoux, Joseph. Synaptic Self, How Our Brains Become Who We Are. p 123-133. NY: Penguin Books, 2002.)

A form of Explicit memory, semantic memories are about facts (and within the capacity of many animals). Refer to Explicit Memory for additional information. (LeDoux, Joseph.Synaptic Self, How Our Brains Become Who We Are. p 108-109, 192. NY: Penguin Books, 2002.)