An unconscious memory of skills, known as muscle memory
Declarative memories
Episodic and semantic memories
Non-declarative memories
Procedural memories
Episodic memories
Stored with a reference to time and place
Can be recalled consciously
Autobiographical
Easy to forget
Semantic memories
Not stored with a reference to time and place
Can be recalled consciously
Not autobiographical
More resistant to forgetting
Strength affected by depth of processing
Procedural memories
Not stored with a reference to time and place
Recalled unconsciously
Not autobiographical
Very resistant to forgetting
Strength affected by amount of practice
Damage to the hippocampus can cause episodic amnesia but leave semantic abilities largely unaffected
Clive Wearing had retrograde amnesia for episodic memories but could still recall semantic facts and perform procedural skills
Amnesiac patients can improve on procedural skills through training, without retaining episodic or semantic memories of the training
There are reasons to argue the types of long-term memory may not be as clearly separated, such as the connection between procedural and semantic memory in language production
