Final answer:
H.M.'s inability to form new memories after hippocampus removal is an example of anterograde amnesia, where new episodic and semantic memories cannot be formed, yet procedural memories remain intact.
Step-by-step explanation:
H.M. could not remember things that happened after surgery to remove his hippocampus. This is an example of anterograde amnesia.
Anterograde amnesia is a condition following brain trauma, such as head injury or surgery, where the individual cannot form new memories. This suggests damage to brain structures, like the hippocampus, results in an inability to transfer information from short-term to long-term memory, impairing the consolidation process. H.M.'s case is a profound example, demonstrating the inability to form new episodic and semantic memories while retaining the capacity for new procedural memories.
Although he could learn new skills, such as solving a puzzle, H.M. would not recall having encountered the puzzle before, despite showing improvement in performance. This indicates that procedural memory is dependent on brain areas separate from those involved in the consolidation of episodic or semantic memories.