HM's declarative memory impairment occurred in which domains?

HM's declarative memory impairment occurred in which domains?

• A. Verbal and Nonverbal
• B. Visual and auditory
• C. Motor and sensory
• D. Short-term and long-term

Answer: (A)

Declarative memory refers to explicit, conscious recall of facts and events, and it relies on the hippocampal system to form new memories across all content. In HM, damage to these structures produced a profound inability to form new declarative memories, and this impairment showed up across both verbal and nonverbal material. He couldn’t learn new facts or remember events, whether the information was presented in words or as nonverbal content like pictures or spatial relationships. This demonstrates that the declarative memory system—the part of memory that the hippocampus supports—operates across modalities, not in a single channel like only language or only vision. In contrast, his ability to learn new motor skills remained intact, illustrating the distinction between declarative (explicit) memory and nondeclarative (procedural) memory.

Declarative memory refers to explicit, conscious recall of facts and events, and it relies on the hippocampal system to form new memories across all content. In HM, damage to these structures produced a profound inability to form new declarative memories, and this impairment showed up across both verbal and nonverbal material. He couldn’t learn new facts or remember events, whether the information was presented in words or as nonverbal content like pictures or spatial relationships. This demonstrates that the declarative memory system—the part of memory that the hippocampus supports—operates across modalities, not in a single channel like only language or only vision. In contrast, his ability to learn new motor skills remained intact, illustrating the distinction between declarative (explicit) memory and nondeclarative (procedural) memory.