1. Memory Working Memory Long term Memory Implicit Memory
Deficits: HM, Alzheimer’s, Semantic Dementia
Implicit Memory

2. Memory Retrieval Encoding Sensory Memory Short-term Working Memory
Long-term
Memory
(knowledge)
200 ms
‘Vision’
20 secs
Implicit memory

3. Working Memory

4. Short-term memory: Memory for a stimulus that has just been perceived.
Delayed matching-to-sample task: A task that requires the subject to indicate which of several stimuli has just been perceived.
Paired-associate task A task that requires the subject to learn to recognize pairs of stimuli.

6. fMRI study of WM, showing distinct activation to faces and scenes

7. Working Memory & Long-term memory in a single task:
the Free Recall Task
(& serial position function)
Subjects:
- hear items (usually words), then
- they say or write all the items they can remember, in any order.

8. Probability of reporting
1. Monster
2. Camera
3. Tricycle
4. Melon
5. Window
6. Guest
7. Quiet
8. Cherish
9. Waiting
10. Rabbitt
11. Computer
12. Child
13. Chicken
14. Ghost
15. Slave
Serial Position Function
Probability of reporting
the item ?
Turns out that one informative way to break down these data is in terms of how well subjects remember items based on their position in the list they were presented.
………
Position in Original List

9. Primacy Recency Faster presentation rate 30 secs filled delay
Patient HM
Primacy
Recency
Time after time…it has been observed that there are clear effects of serial position on free recall performance.
Subjects are better able to remember items presented at the beginning and at the end of the list…..leading to primacy and recency effects.
So….how can we account for this effect? What might we learn about memory from these patterns of data?
Well, one fairly intuitive hypothesis about the recency effect in particular, is that it is a simple consequence of short term memory. That is, the last items of the list are maintained in short term memory…and so this limited number of items is better remembered…and is readily and quickly retrieved
primacy on the other hand, might be explained by differential amounts of memory rehearsal that different items in the list receive. Remember that the items are presented one at a time…a typical strategy is for subjects to begin repeatingthe words to themselves from the moment the list begins…thus, the first items in the list get more of this rehearsal time than later items. In addition, after the first several items, the number of items will quickly exceed the capacity of subjects rehearsal….thus, primacy may reflect the first items’ reception of more rehearsal time…and better encoding into LTM
Privileged rehearsal
better LTM encoding
STM contribution

10. Types of Knowledge (long-term memory) Declarative Procedural Semantic
Episodic
Memory
Declarative memory: Memory that can be verbally expressed, such as memory for events in a person’s past. Episodic memory: Memory of a collection of perceptions of events organized in time and identified by a particular context
Semantic memory: A memory of facts and general information.
Semantic dementia: Loss of semantic memories caused by progressive degeneration of the neocortex of the lateral temporal lobes.
Nondeclarative memory: Memory whose formation does not depend on the hippocampal formation; a collective term for perceptual, stimulus-response, and motor memory.
2+2, sky is blue
The Eagles won; ‘cook’ was a word in the list
Affected by Amnesia
This distinction emphasizes the kind of information represented (i.e. knowledge reported verbally vs motor skills).

11. Another Possible architecture of:
Long-term Memory Systems
Implicit Memory
Explicit Memory
Motor Skill
Learning
Priming
Semantic
Memory
Episodic
Memory
According to this view, memory can be classified into two basic categories….explicit and implicit. Remember before that we discussed the division between Declarative and Procedural knowledge representations…
This is almost the same distinction being drawn here…except that the emphasis is on the process by which memory is accessed as opposed to the particular type of information being accessed.
So, implicit memory (or knowledge) includes more than just motor skills, as we emphasized earlier…priming can be perceptual or conceptual…classical conditioning involves learned automatic responses (like Pavlov’s dog)…As you can see, similar types of information are accessed in both implicit and explicit memory situations…
Implicit knowledge is not always low-level (muscle or reflex)--people also develop implicit memories for things like puzzles. An amnesic patient working on complex puzzle will show the normal benefits of experience, without any conscious knowledge of their history with the puzzle...
Classical
Conditioning
Instrumental
Learning
2+2, sun is blue
Affected by Amnesia
This emphasizes how information is accessed (conscious vs automatic)

12. Anatomy of Explicit Memory
Fornix
Posterior
Parahippocampal
cortex
Mammillary body
Hippocampal formation
Mediotemporal Lobe (MTL)

13. Medial temporal lobe (MRI)
Folded shape
stained hippocampus
1. Hippocampus
3. Posterior parahippocampal cortex
4. Amygdala
2. Perirhinal cortex

14. Bird species with good spatial memory have larger hippocampi
Mastering London Topography Changes Hippocampal Structure in Taxi Drivers (humans)
London taxi cab drivers have "the Knowledge" = a detailed memory for every single street in London and how to go from one place to another by the quickest route. Studies show high levels of activation via PET scans for spatial related questions (e.g., What is the shortest route from the Tate Museum to Buckingham Palace?). Further, drivers have larger posterior hippocampi than normal.
Humans with hippocampal damage do poorly on tests of spatial memory   
Bird species with good spatial memory have larger hippocampi

15. fMRI in normal subjects provide convergent evidence for the
Role of hippocampus on episodic memory

16. Relational Memory What did you do at home last Wednesday?
A temporal context (last Wednesday)
A physical context (home)
A set of memory events (turkey, annoying parents, tiredness, watching the game)
A relation between the events and the context (relational memory)

18. Amnesia Bitemporal Lobectomy (patient HM)
- treatment for epileptic seizures
- It caused anterograde amnesia, but normal IQ, digit span, conversation, motor learning
Anterograde amnesia: Amnesia for events that occur after some disturbance to the brain,
Retrograde amnesia: Amnesia for events that preceded some disturbance to the brain,

19. Impaired Long-term Memory Encoding
(chaplin vs. Britney spears;
Old memories ok)
Spared Working memory
(digit span, recall)
Spared Implicit memory
- conceptual
- perceptual
- motor

20. Implicit memory: Conceptual Priming in anterograde amnesia
Study phase: “is this word pleasant or not? “rape”, “love”, “sincere”, …..”
Test phase:
Free Recall: Name the words on the list
Word Stem Completion: Complete “sco_ _ _”
Impaired recall
but normal stem completion
(i.e., as likely as normals to complete stems
with words that were observed earlier).
amnesics also show typical priming effects with brief presentations of words. That is, they are better able to read briefly presented words that they have seen recently. Remember that this effect was explained by a higher baseline level of activation of words that had been seen earlier. This suggests that similar mechanisms are working in amnesic patients.
Recognition requires the subject to remember that the word scorch was presented at a particular time and place (earlier in this experiment).
In contrast, the word stem completion experiment makes no explicit (directly instructed) requirement that the subjects think about any particular instance of “SCO” words…the subjects are free to fill in whatever word comes to mind first.
Normal subjects, after seeing a list of words that they may not have been trying to memorize, will be influenced by that list on a subsequent word-stem completion task.
That is, they will be more likely to complete these partial words with words they’ve seen recently, even if they have no conscious memory of the list items.
We know that amnesic patients are poor at recognizing items they’ve seen before…how will they perform on this word stem completion task? Just like normals!
(Graf, Squire, & Mandler, 1984)

21. Implicit memory:
Perceptual priming

24. Implicit memory motor: sequence learning task

25. implicit memory: rule learning
Tower of Hanoi game
HM cannot remember playing, but solves quickly.
Start Position
Goal 2 (2 moves)
Goal 10 (5 moves)

26. summary Medial Temporal Lobe amnesics So far: single dissociation
Explicit memory: unable to create
Implicit memory: relatively intact
So far: single dissociation
2 possibilities:
Implicit/Explicit 2 independent systems
Implicit simply easier, relies on residual processing of a single, partially damaged system
Double dissociation would support claim of 2 independent systems

27. Compared to MTL amnesics and healthy controls.
Patient MS
29 year old, right handed male
Intractable epilepsy: surgery removed right BA 17,18, part of 19.
Hemianopic (blind in left field)
Compared to MTL amnesics and healthy controls.
Explicit memory task
Shown 24 words, later shown 48 words (24 from 1st phase, 24 new foils): asked to say if words were previously seen.
Amnesics poor, visual lesion patient fine.
Gabrieli et al. (1995)

28. Implicit memory: word completion task
Shown/Heard 24 words ‘stick’, later asked to complete 48 stems, 24 could be solved with items from 1st phase (‘sti__’) and 24 unrelated stems (‘sta__’).
Healthy people show priming effect (faster if solution seen previously). This effect is much bigger if words were seen (physical match) rather than heard.
Amensics show normal priming. Shows implicit memory.
MS visual priming is no greater than auditory priming. Therefore, shows no extra benefit for physical match of stem and previously seen word.
Conclusion
Double dissociation
Explicit memory has some distinct processing from implicit memory.
‘Conceptual’ priming intact in MS, perceptual priming damaged

29. Anterograde Amnesia: causes
Fornix
Mammillary body
(Korsakoff Patients)
Hippocampal formation - HM

30. Other causes of amnesia include
Chronic alcoholism (atrophy of mamillary body due to vitamin depletion, thiamin)
Alzheimer’s disease (midtemporal atrophy)
Electroconvulsive therapy
Left frontal stroke (example)
Confabulation: The reporting of memories of events that did not take place without the intention to deceive; seen in people with Korsakoff’s syndrome.

32. Other causes of amnesia include
- Anoxia (CA1 atrophy)
Interestingly, a genetic mutation inactivating NMDA receptors in CA1 leads to:
Lack of Long-term potentiation
Poor spatial memory in the watermaze
Large & unfocused spatial receptive fields

33. Long-term Memory Systems
Implicit Memory
Explicit Memory
Motor Skill
Learning
Priming
Semantic
Memory
Episodic
Memory
Classical
Conditioning
Instrumental
Learning
2+2, sun is blue
Semantic dementia: Loss of semantic memories caused by progressive degeneration of the neocortex of the left lateral temporal lobe.

34. Graham et al. suggest double dissociation:
Early Alzheimer's patients
‘Semantic dementia’ patients
Alzheimers Patient
Hippocampus atrophy
Semantic Dementia
Temporal lobe atophy

35. B: Test stimuli A: Semantic naming task (‘phone’)
Correct answer: ‘phone’.
Memory tested 30 minutes later:
B: Episodic memory task (perceptually identical)
Correct answer: ‘I saw a phone earlier’
C: Episodic memory task (perceptually different)
Correct answer: ‘I saw a phone earlier’.

36. C: Semantic memory
Semantic dementia patients have difficulty naming items.
AD patients are fine at this task.

37. D: Episodic memory AD patients SD patients poor episodic memory.
OK with identical items
Poor with perceptually different (especially if unable to name item in picture naming phase).

38. E: Conclusions Suggests semantic and episodic memory may be separate.
Hippocampal formation: encoding episodic memories
Temporal lobe: storage of semantic memories.
Additional support from Vargha-Khadem (1997), who reports 4 patients with selective hippocampal damage: all show impaired episodic but intact semantic memory.
Note: all sustained hippocampal damage early in life, so does not necessarily generalize to adult brain.

39. Interaction of different brain regions
Lesions in animals and functional imaging suggest network of regions work together to encode memory.

40. Spatial memory Anatomy: Evidence Medial temporal lobe:
Hippocampus
Posterior parahippocampal area
Evidence
Human Neuropsychology HM
London taxi drivers
Animal research

41. Medial temporal lobe (MRI)
Folded shape
stained hippocampus
1. Hippocampus
3. Posterior parahippocampal cortex
4. Amygdala
2. Perirhinal cortex

43. Bird species with good spatial memory have larger hippocampi
Mastering London Topography Changes Hippocampal Structure in Taxi Drivers (humans)
London taxi cab drivers have "the Knowledge" = a detailed memory for every single street in London and how to go from one place to another by the quickest route. Studies show high levels of activation via PET scans for spatial related questions (e.g., What is the shortest route from the Tate Museum to Buckingham Palace?). Further, drivers have larger posterior hippocampi than normal.
Humans with hippocampal damage do poorly on tests of spatial memory   
Bird species with good spatial memory have larger hippocampi

44. Spatial memory: Animal research

45. Spatial memory: Animal research

46. Place fields are stationary over time
Place cell:
A neuron that becomes active when the animal is in a particular location in the environment; most typically found in the hippocampal formation (in dorsal hippoc, which is analogous to human post hippoc)

48. Contextual information Spatial alternation task (left, right, left)
Copyright © Allyn & Bacon 2007

49. SPARE SLIDES

50. From Patterson, 2007, NatNeuroRev

51. From Patterson, 2007, NatNeuroRev

52. From Patterson, 2007, NatNeuroRev

53. From Patterson, 2007, NatNeuroRev

54. Copyright © Allyn & Bacon 2007

55. Copyright © Allyn & Bacon 2007

56. Copyright © Allyn & Bacon 2007

57. Delayed non-match to sample
Familiarity vs. explicit memory

58. Long-term Memory Systems
Implicit Memory
Explicit Memory
Motor Skill
Learning
Priming
Semantic
Memory
Episodic
Memory
Classical
Conditioning
Instrumental
Learning
Chapter 13: Single cell recording

59. Perceptual learning: Learning to recognize a particular stimulus.
Motor learning: Learning to make a new response.

60. Instrumental learning
Instrumental learning (also called operant conditioning): A learning procedure whereby the effects of a particular behavior in a particular situation increase (reinforce) or decrease (punish) the probability of the behavior;.
Neural Circuits Involved in Reinforcement (as in drug addiction lecture)
Medial forebrain bundle (MFB): A fiber bundle that runs in a rostral-caudal direction through the basal forebrain and lateral hypothalamus; electrical stimulation of these axons is reinforcing
Ventral tegmental area (VTA): A group of dopaminergic neurons in the ventral midbrain whose axons form the mesolimbic and mesocortical system; plays a critical role in reinforcement
Nucleus accumbens: A nucleus of the basal forebrain near the septum; receives dopamine-secreting terminal buttons from neurons of the ventral tegmental area and is thought to be involved in reinforcement and attention.

61. Classical Conditioning (associative Learning)
Hebb rule: The hypothesis proposed by Donald Hebb that the cellular basis of learning involves strengthening of a synapse that is repeatedly active when the postsynaptic neuron fires.
Long-term potentiation: A long-term increase in the excitability of a neuron to a particular synaptic input caused by repeated high-frequency activity of that input
Population EPSP: An evoked potential that represents the EPSPs of a population of neurons.
When a presynaptic and post-synaptic neuron are activated at the same time, the synapse between these cells is strengthened, hence “cells that fire together, wire together”.
What is the bases of such learning?
Synaptic plasticity: “cells that fire together, wire together” (Donald Hebb)
Long-term potentiation: Following increased input there is a long-term
increase in the excitability of the neuron that receives such input

62. Long-term potentiation in the rat hippocampus
Hippocampal formation: A forebrain structure of the temporal lobe, constituting an important part of the limbic system; includes the hippocampus proper (Ammon’s horn), dentate gyrus, and subiculum. Entorhinal cortex: A region of the limbic cortex that provides the major source of input to the hippocampal formation.
Granule cell: A small, granular cell; those found in the dentate gyrus send axons to the field CA3 of the hippocampus. Dentate gyrus: Part of the hippocampal formation; receives inputs from the entorhinal cortex and projects to the CA3 field of the hippocampus.
Perforant path: The system of axons that travel from cells in the entorhinal cortex to the dentate gyrus of the hippocampal formation.
Field CA3: Part of the hippocampus; receives inputs from the dentate gyrus and projects to field CA3.
Pyramidal cell: A category of large neurons with a pyramidal shape; found in the cerebral cortex and Ammon’s horn of the hippocampal formation.
Field CA1: Part of the hippocampus; receives inputs from field CA3 and projects out of the hippocampal formation via the subiculum.

64. Learning and Synaptic Plasticity (Role of NMDA Receptors): Associative long-term potentiation: A long-term potentiation in which concurrent stimulation of weak and strong synapses to a given neuron strengthens the weak one. NMDA receptor: A specialized ionotropic glutamate receptor that controls a calcium channel that is normally blocked by Mg2 ions; involved in long-term potentiation.
AP5: 2-Amino-5-phosphonopentanoate; a drug that blocks NMDA receptors. AMPA receptor: An ionotropic glutamate receptor that controls a sodium channel; when it’s open, it produces EPSPs

65. biopsych4e-fig jpg

68. biopsych4e-fig jpg

69. biopsych4e-fig jpg

70. biopsych4e-fig jpg