Distinguish anterograde amnesia from retrograde amnesia with a classic case (H.M.).

Distinguish anterograde amnesia from retrograde amnesia with a classic case (H.M.).

• A. Anterograde: impairment in forming new memories after the incident; retrograde: loss of memories before the incident; H.M. could not form new declarative memories but could learn new motor skills.
• B. Anterograde: preservation of new memories; retrograde: loss of old memories.
• C. Anterograde: ability to form new declarative memories; retrograde: no memory loss.
• D. Anterograde and retrograde both spared.

Answer: (A)

The main idea here is how memory can be disrupted in different ways, as shown by H.M.: anterograde amnesia means trouble forming new memories after the brain injury, while retrograde amnesia means losing memories from the period before the injury. In H.M.’s case, the surgery damaged the hippocampus, leading to a severe inability to form new declarative memories (facts and events) after the operation. Yet he could still learn new motor skills, a sign that procedural memory—learning through doing—relies on other brain areas and can remain intact. Retrograde memory loss refers to memories from before the incident; in H.M., some retrograde gaps did occur for memories close to the time of surgery, but the decisive pattern is the strong anterograde impairment paired with preserved procedural learning. So the best description is that new memory formation is impaired while old memories prior to the incident can be lost, and declarative memory is affected whereas procedural memory can still be acquired.

The main idea here is how memory can be disrupted in different ways, as shown by H.M.: anterograde amnesia means trouble forming new memories after the brain injury, while retrograde amnesia means losing memories from the period before the injury. In H.M.’s case, the surgery damaged the hippocampus, leading to a severe inability to form new declarative memories (facts and events) after the operation. Yet he could still learn new motor skills, a sign that procedural memory—learning through doing—relies on other brain areas and can remain intact. Retrograde memory loss refers to memories from before the incident; in H.M., some retrograde gaps did occur for memories close to the time of surgery, but the decisive pattern is the strong anterograde impairment paired with preserved procedural learning. So the best description is that new memory formation is impaired while old memories prior to the incident can be lost, and declarative memory is affected whereas procedural memory can still be acquired.