Answer: retrieval failure
Explanation: Retrieval failure is the difficulty encountered when trying to recall a piece of information from long-term memory without the correct cues or triggers. In the case of Gerald, the title of the song was already in his memory but he could not recall it until someone mentioned the songwriter's name. For Gerald, the name was the retrieval cue or trigger for him to access his memory for the title of the song.
Retrieval cues or triggers are the other information or situation which occur at the time an information is stored. There are a wide range of retrieval clues and they may be locations, smell, sound, a name etc. Such information, while still stored in the memory may not be accessible in the absence of such cues.
