PM case memory implies what dissociation?

• A. Musical memory is identical to semantic memory
• B. Musical memory can be preserved despite severe memory impairment
• C. Semantic memory governs musical memory completely
• D. There is no dissociation

Answer: (B)

The main idea here is that memory is organized into distinct systems that can be affected differently by brain damage. The PM case shows that a person can have severe impairments in many memory abilities, yet still retain musical memory. This demonstrates a dissociation between musical memory and other memory systems, meaning music memory can function independently when other memory declines. That’s why the best interpretation is that musical memory can be preserved despite severe memory impairment. It wouldn’t fit to say musical memory is identical to semantic memory, or that semantic memory governs musical memory completely, or that there is no dissociation.