Final answer:
James' difficulty with memory could be from encoding failure, proactive or retroactive interference, or storage decay as described by Ebbinghaus' forgetting curve. Using mnemonic devices, rehearsals, and adequate sleep are strategies to improve memory retention.
Step-by-step explanation:
James may have experienced difficulties in remembering what he studied for a few reasons. One potential contributor is encoding failure, which implies that the information was never properly stored in memory due to a lack of focus or ineffective study methods. Additionally, there could have been interference, particularly proactive (where old information hinders the recall of new information) or retroactive interference (where new information affects the recall of older information). Moreover, storage decay outlined by Hermann Ebbinghaus in his forgetting curve, suggests that memory fades over time especially without periodic review; thus, information can be lost if not reinforced. Effective strategies, such as using mnemonic devices, rehearsal, self-referencing, and ensuring adequate sleep, can combat these issues and enhance memory retention.