1. Memory: An Introduction
Andrea Mejia
Spring 2017

2. Goals for Lecture The Legacy of H.M. Defining Memory Loss
Subtypes of Memory

3. Henry Molaison (i.e., H.M.) Pre-operation
Uncontrollable Seizures in both temporal lobes
 Removed via neurosurgery
Post-surgery (H + A +)
Controllable seizures
Unable to form new memories

4. Defining Memory: Memory Loss
Amnesia
Severe memory impairment
Usually due to injury or disease
Retrograde amnesia
Loss of memories formed prior to an event
Accidents  disruption of memory consolidation
Anterograde amnesia
Inability to form new memories
(i.e., H.M.)

5. Defining Memory Short-term memory Long-term Memory
Temporary information storage
Long-term Memory
If short-term memory is rehearsed
Extremely large (limitless?) capacity

6. Subtypes of LTM LTM Declarative Episodic Semantic Nondeclarative
(Procedural)
Skill learning
Priming
Conditioning

7. LTM: Declarative vs. Nondeclarative
Declarative memory
Memory that can be stated or described
Capital of France
Nondeclarative (procedural) memory
Memory about perceptual / motor procedures
Demonstrated via performance (not conscious recollection)
Riding a bicycle

8. Declarative: Episodic vs. Semantic
Detailed autobiographical memory
10th birthday party
Semantic
Generalized declarative memory
Facts and information acquired through learning
Capital of France
Declarative memories are conscious and verbal

9. Nondeclarative: Skill learning vs. Priming vs. Conditioning
Learning how to perform a task by repeating the process
May include:
Sensorimotor skills (mirror tracing)
Perceptual skills (priming)
Cognitive skills (rules and strategies)
Memories you learn by doing, not transferable by language

10. Nondeclarative: Skill learning vs. Priming vs. Conditioning
Change in how you process a stimulus (e.g., word, picture) because you’ve seen it (or something similar) previously
Does not require declarative memory of the stimulus
Intact in H.M.

11. Nondeclarative: Skill learning vs. Priming vs. Conditioning
Involves relationships between events
Associative learning
Classical conditioning
Association is formed between two previously unrelated stimuli
Pavlov’s dogs
Operant conditioning
Association is formed between behavior and consequence(s)
Skinner box

12. Neuroanatomy of Memory

13. Declarative: Formation of Memories
Medial temporal lobes (especially hippocampus)
Damage: More severe impairments when both temporal lobes removed
Do you think hippocampus is responsible for Nondeclarative memories? What type of surgery did HM have again? What memory complaints did he display?

14. Nondeclarative: Skill learning
Different areas of the brain
Example:
Basal ganglia, motor cortex, cerebellum – motor skills
Cerebellum – classical conditioning
???? – operant conditioning
No specific brain region identified
Because so many aspects of behavior involved?

15. How are memories formed?
Iconic memories
Briefest memories (a few seconds)
From the senses  vision, hearing, smell, touch
Short-term memories
Slightly longer than iconic memories (~ 30 seconds)
E.g., rehearsing a phone number
Subtype: Working memory
Manipulate info for immediate use
E.g., reverse a phone number in your head

16. How are memories formed?
Encoding -- Raw info (sensory channels) transformed into STM
Consolidation -- STM transformed into LTM
Retrieval -- Stored info brought out of LTM for use
**Emotionally arousing experiences are remembered best

17. STM vs. LTM Hippocampal involvement
Consolidation of declarative STMs into LTMs
Takes years (i.e. HM had retrograde amnesia for two years)
Not involved in STM “encoding” or retrieval

18. LTM: Remembering and Forgetting
No “upper limit”
Forgetting is natural
Beneficial to forget some things
Filter out unimportant info, free up cognitive resources
Memory interference
Proactive interference  Previously learned info interferes with learning of new info
Retroactive interference  Newly learned info interferes with previously learned info