Please go watch these 2 lectures after class

1. Please go watch these 2 lectures after class 2008 HHMI lecture by Eric Kandel and Tom Jessell This week http://media.hhmi.org/hl/08Lect1.html More history about early works on mapping the brain function Next week http://media.hhmi.org/hl/08Lect4.html

2. Where is the seat of the soul? • Socrates (469-399 BC) • “… brain may be the originating power of the perceptions of hearing and sight and smell, and memory and opinion may come from them…” • Aristotle (384-322 BC) • cardiocentric view of mental function • function of the brain is to cool the heart

3. Origins of the study of learning and memory The study of learning is closely related to the beginning of experimental psychology (~1900) Hermann Ebbinghaus The 1st psychologist study memory scientifically. Used introspection to study forgetting in himself list of 12-16 consonant-vowel-consonant nonsense syllabus (Ex:KEG, MIW). On Memory:  An Investigation in Experimental Psychology in 1885. 

4. Several modern disciplines study of learning and memory • Psychology • classification of learning and memory • Physiology/Anatomy • Which part of brain is important for learning and memory • Molecular Biology • Molecular mechanism of learning and memory

6. Patient HM Most famous case reported by Scoville & Milner (1957) HM: bilateral medial temporal lobe lesion for status epilepticus in 1953

7. The medial temporal lobe and memory storage

8. Importance of hippocampus in long-term memory formation: case of H.M.

9. Amnesia: severe memory loss Amnesia: Partial or total loss of memory, usually resulting from shock, psychological disturbance, brain injury, or illness. 1. Retrograde amnesia: cannot recall events that occurred prior to the brain trauma. 2. Anterograde amnesia: cannot recall events that occurs after the brain trauma.

10. H.M. showed normal motor learning and long term memory

11. H.M. perform well in priming • Subjects were presented with common words • asked to recall the words (free recall) • given the first three letters of a word (priming)

12. Evidence of postmorbid acquisition of semantic knowledge

13. H.M.‘s specific memory deficit • IQ and personality unchanged • Normal learning and short-term memory • Normal long-term memory for facts before operation • Loss of information acquired just before the operation • Unable to transfer new short-term memory into new long-term memory (explicit memory) • Normal procedural (motor) memory

14. What we learn from H.M.’s case • We have two types of memory: Short term and long term. • The hippocampus is not involved in the formation of short term memory and retrieval of long-term memories. • The hippocampus is not involved in 'procedural memories‘. • The hippocampus is not be involved in personality, IQ and other cognitive functions. • The hippocampus is involved in transferring short term explicitmemory to long term memory.

15. The anatomical organization of the hippocampus

16. pyramidal cell layer Hippocampus anatomy sub CA=CornuAmmonis DG=dentate gyrus Sub=subiculum EC= Entorhinal Cortex granular cell layer hilus

17. The input and output pathways of the hippocampal formation

18. Right hippocampus - spatial memories

19. London Taxi Drivers : Structural MRI & Neuropsychological Analysis Bus drivers were not found such correlation

20. Memory • Types of memory: • short-term (working)memory • temporary • limited capacity • needs rehearsal • long-term memory • 'permanent' • greater capacity • no continual rehearsal needed

21. Current view of explicative memory CPU Hard disk RAM

22. Short-term memory • Works like RAM memory in computers; provides a working space. • A limited capacity for 7±2 independent information. • Last only few seconds to minutes • Vulnerable to interruption or interference • The information held in short-term memory may be: • recently processed sensory input • items recently retrieved from long-term memory

23. Ways to move information to long term memory 1. Senses and emotions 2. Repetition and Rehearsal 3. Organization Principles

24. Senses and emotions Where were you on the following day? 0-9-3-5-1-5-7-3-7-6 September 01, 2004 September 11, 2001 September 21, 1999

25. Repetition and Rehearsal Effortful learning usually requires rehearsal or conscious repetition. Ebbinghaus studied rehearsal by using nonsense syllables: TUV YOF GEK XOZ

26. Organization Principles Acronyms are another way of chunking information to remember it. abuse Ab = away, from HOMES = Huron, Ontario, Michigan,Erie, Superior

27. Long-term memory • Long-term memory store containing the accumulated knowledge base • Characteristics • Duration: Hours to years • Capacity: Huge - possibly limitless Hippocampal system would mediate the initial steps of long-term storage. It would then slowly transfer information into the neocortical storage system.

28. Forms of long-term memory Implicit Explicit

29. Memory can be classified as implicate or explicit on the basis of how information is stored and recalled

30. Explicit versus Implicit Memory Explicit(or declarative) memory – recalled by a deliberate, conscious effort. - semanticmemory (facts) - episodicmemory (events) Implicit memory( nondeclarative) – a memory that is recalled unconsciously. Stored in perceptual, motor and emotional circuits. - procedural memory (swimming, biking) - associative learning (conditioning) - nonassociative learning - priming

31. Semantic vs. episodic memory Episodic Memory refers to memories for particular events that have been experienced. Semantic Memory refers to knowledge such as vocabularies, concepts, numbers or facts.

32. Selective lesions in the posterior parietal cortex produce selective defects in semantic knowledge damage to the posterior parietal cortex damage to the occipital lobes associative agnosia apperceptiveagnosia

33. Explicit knowledge involves four distinct processes Encoding: process of newly learned information. Consolidation: make new information more stable for long-term storage. Synthesis of new proteins is required. Storage: the mechanism and sites to retain memory over time. Retrieval: recall and use of the stored information. The more association, the stronger memory Retrieval of information is most effective when it occurs in the same cues.

35. Implicit memory Implicit memory( nondeclarative) – a memory that is recalled unconsciously. Stored in perceptual, motor and emotional circuits. - procedural memory (swimming, biking) - associative learning (conditioning) - nonassociative learning - priming Builds up slowly, through repetition over many trials, and is expressed primarily in performance, not in words. Does not depend on conscious processes.

36. Learning of implicit memory • Non-associative learning:learns about the properties of a single stimulus • Habituation • Sensitization • Associative learning: learns about the relationship between two stimuli or between a stimulus and a behavior • Classical conditioning (Pavlovian conditioning) • Operant conditioning (Instrumental conditioning)

37. NonassociativeLearning Habituation : decrease in response to a repeated stimulus not accompanied by changes in other stimuli Sensitisation: an increase in response to a moderate stimuli as a result of a previous exposure to a strong stimulus 如入鮑魚之肆，久而不聞其臭 一朝被蛇咬，十年怕草繩

38. Operant conditioning Classical conditioning Associative Learning learning a relationship between a behavior and the consequences learning a relationship between two stimuli

39. Classical conditioning (US) • US → UR • CS+ US → UR • CS → CR（salivation） (CS) (UR) (CR)

40. Classical Conditioning • Unconditionedstimulus(US): unrelated to the response that eventually will be learned. • Conditioned stimulus (CS): neutral response • During conditioning, the CS and US are paired over many trials • Test of learning: Does the CS alone produce a response? CS-US paired CR TRIALS UR

41. Pavlov’s view of the physiology of learning Pavlov believed that conditioning strengthened connections between the CS center and US center in the brain.

42. Contest vs. cued fear conditioning • CS= something neutral (tone, light) • US= aversive stimulus (loud noise, shock )

43. The formation of classical conditioned response depend on the correlation between CS and US

44. Extinction and spontaneous recovery Re-train Training Extinction 1 Tone-Shock Pairings 10 Tone-Shock Pairings 10 Tone only Training Extinction Re-train

45. Importance of hippocampus in contextual fear conditioning test Remote training Freezing 10 Tone-Shock Pairings

46. Importance of hippocampus in contextual fear conditioning test 50 days later Remote Training Recent Training 10 light-Shock Pairings

47. Importance of hippocampus in contextual fear conditioning test 50 days later With in 24 hr Remote Training Recent Training Lesion Electrolytic Dorsal Hippocampus Lesion

48. Importance of hippocampus in contextual fear conditioning test 50 days later next day 10 day recovery C 100 75 50 25 0 Remote Recent (first six min) Remote Training Recent Training Sham or Hippocampus Lesion SHAM Remote Recent % freezing Next day DH

49. Operant Behavior • Associative learning process between a stimulus and a response. • The term operant comes from the verb to operate and refers to behavior that operates on the environment to produce a consequence. • Not automatic • Operant conditioning as a process, has evolved over species history and is based on genetic endowment.

50. Operant learning • The mouse is “operating” on its environment by pressing the lever in the box and receiving a food reward. • Voluntary and goal directed • Controlled by its consequences • Strengthened if rewarded or punished