Episodic memory in nonhumans: what, and where, is when?

Area of Science:

• Cognitive Neuroscience
• Comparative Psychology
• Animal Behavior

Background:

• Episodic memory involves recalling personal past events with a sense of presence.
• Investigating episodic memory in nonhuman animals presents significant methodological challenges.
• Current operationalizations (e.g., memory for when/where, event order, self-behavior) lack cross-species generalizability and fail to capture human episodic memory nuances.

Purpose of the Study:

• To address the challenges in studying episodic memory in nonhuman animals.
• To propose criteria for demonstrating episodic memory in nonhuman subjects.
• To advance the comparative study of memory systems across species.

Main Methods:

• Review of current operationalizations of episodic memory in nonhuman research.
• Identification of key criteria for establishing episodic memory in nonhumans.
• Discussion of the distinction between episodic, semantic, short-term, and working memory.

Main Results:

• Existing methods for studying nonhuman episodic memory are limited and not universally applicable.
• Progress in understanding nonhuman episodic memory is evident compared to five years ago.
• Three key areas require further research to establish cross-species correspondence.

Conclusions:

• Demonstrating episodic memory in nonhumans requires evidence of long-term memory representation.
• Putative episodic memories in animals must be explicit and accessible to introspection.
• It is crucial to differentiate nonhuman episodic memory from semantic memory (general knowledge).