What are memory beads?

What evidence is there for animals having semantic memory? (Semantic memory is memory of facts about the world, not the "meaning" of symbols.)

• Animals obviously have procedural or implicit memory.  But the other major type of memory is http://en.wikipedia.org/wiki/Memory#Declarative_memory. This covers episodic memory, one sub-type of declarative memory. (The evidence is that animals do have episodic memory.)  However, the other major sub-type of declarative memory is http://en.wikipedia.org/wiki/Semantic_memory.  So the question is what evidence is there that any other animals have semantic memory beside humans. In other words when did semantic memory evolve in the tree of life?   The episodic and semantic memory I am talking about is (from Wikipedia): ---- http://en.wikipedia.org/wiki/Episodic_memory, a part of http://en.wikipedia.org/wiki/Autobiographical_memory, consists of the recollection of events in the life of a person. These can be memories that happened to the person directly or just memories of events that happened around them. ..... [these have the place and time when the event happened encoded in them] http://en.wikipedia.org/wiki/Semantic_memory consists of all explicit memory that is not autobiographical. Examples of semantic memory is knowledge of historical events and figures; the ability to recognize friends and acquaintances; and information learned in school, such as specialized vocabularies and reading, writing and mathematics. [these are facts about the world without memory of the place and time they were learned.] ---- So, Semantic memory is like "Paris is the capital of France". It is something that can be learned in one presentation - just like episodic memory is remembering something that happens only once. I suspect it is hard to demonstrate since humans usually use language to demonstrate semantic memory. Is there a non-language way for an animal to learn a "fact" in one exposure that would not be classified as a type of episodic memory.  Episodic memory is memory of the time and place where a significant event happened.

• Answer:

  There is quite a lot of evidence, particularly with primates like Koko the gorilla and Kanzi the Bonobo. Both of whom have learned sign language and are thus demonstrating an ability to learn concepts - which is what we use semantic memory for. Semantic memory in animals is also pretty evident to any pet owner.  Dogs and cats can learn concepts and names for those concepts.  It doesn't take too long for a dog to learn to associate the sound of a name with each of the people or other animals that live in the house.  If you say your spouse's name, the dog knows who you are referencing. There is actually more debate about the extent of episodic memory in animals than there is about semantic memory.  The debate frames around whether or not the animal has enough awareness of self and time to construct episodic memories that describe the animal as having experienced an event at a particular time.  For example, my grandmother's wiener dog has a deep hatred for UPS delivery men - not any one particular UPS delivery man, but anyone that pulls up in that brown truck or wears those brown clothes.  Yet the dog is generally oblivious to the arrival of a Fedex delivery person or the mailman.  It is assumed the dog had a negative experience with a UPS delivery man.  That shows the dog has semantic capabilities to mentally create the concept of UPS delivery man and to associate that semantic concept with some negative sensation such as fear or pain or bloody rage.  It doesn't necessarily prove the dog stored that event as an episodic memory.  It may have stored it as purely semantic. A lot of the understanding of these types of long term memory comes from the work of Endel Tulving.  Tulving believes that episodic memory evolved from semantic memory.  Therefore semantic memory is a prerequisite for episodic memory. Tulving does not believe that animals have episodic memory.  He believes they do have semantic memory. I am neither a psychologist nor cognitive neuroscientist like Tulving, but my experience growing up around animals makes it hard for me to believe they don't have some degree of episodic memory capability.  I've known dogs with a good sense of time - if they get used to an owner coming home at a particular time, they will go to the door at that time to greet them - even if the individual is running late and is nowhere near the home.  That doesn't mean they can distinguish between an event that happened a month ago versus a year ago, but it might be enough to qualify for rudimentary episodic capability.