Final answer:
The most researched area of long-term memory is episodic memory, focusing on information about personal experiences and notable events. Studies of patient H.M. have contributed significantly to this understanding. Semantic memory and implicit memory have also been studied, but episodic memory remains a primary focus.
Step-by-step explanation:
When considering the organization in long-term memory, the area that has been most researched is episodic memory. Episodic memory is a type of declarative memory that contains information about events we have personally experienced, such as the details of a past birthday celebration. Research in this area has been extensive, partly due to the pioneering work of psychologists like Endel Tulving in the 1970s.
The investigation into episodic memory has also been supported by case studies such as patient H.M., who demonstrated the role of the hippocampus in the consolidation of short-term to long-term memories, especially episodic ones. On the other hand, semantic memory—our knowledge about words, concepts, and language-based information—has been researched as well, although perhaps not to the same extent as episodic memory. Implicit memory, which includes procedural memory and is not part of our consciousness, and procedural memory in particular—skills and tasks learned through repetition—also significant but perhaps less so in comparison to episodic memory according to the body of research.