There are basically two kinds of amnesia: one is an inability to remember things that happened before the surgery or brain injury (called retrograde amnesia), the other is an inability to form new memories (called anterograde amnesia). Both forms are present in patients with damage to the temporal lobe. (LeDoux, Joseph. Synaptic Self, How Our Brains Become Who We Are. p 105-107. NY: Penguin Books, 2002.)