Shana is a young girl who was in a bus accident a few years ago. Since her accident, Shana is only able to remember people she had met before the accident and instances from her childhood. However, she is unable to remember people she met recently or events that are currently happening in her life. She reads the same newspaper for several days without realizing that she has read it before. The accident has disabled Shana's ability to permanently store new information because she sustained an injury to her _____.